Fossil

    }
    if {$found} {
        define FOSSIL_ENABLE_SSL
        define-append EXTRA_CFLAGS $cflags
        define-append EXTRA_LDFLAGS $ldflags
        define-append LIBS -lssl -lcrypto
        msg-result "HTTP support enabled"







    } else {
        user-error "OpenSSL not found. Consider --with-openssl=none to disable HTTPS support"
    }
}

if {[opt-bool lineedit]} {
    # Need readline-compatible line editing

    }
    if {$found} {
        define FOSSIL_ENABLE_SSL
        define-append EXTRA_CFLAGS $cflags
        define-append EXTRA_LDFLAGS $ldflags
        define-append LIBS -lssl -lcrypto
        msg-result "HTTP support enabled"

        # Silence OpenSSL deprecation warnings on Mac OS X 10.7.
        if {[string match *-darwin* [get-define host]]} {
            if {[cctest -cflags {-Wdeprecated-declarations}]} {
                define-append EXTRA_CFLAGS -Wdeprecated-declarations
            }
        }
    } else {
        user-error "OpenSSL not found. Consider --with-openssl=none to disable HTTPS support"
    }
}

if {[opt-bool lineedit]} {
    # Need readline-compatible line editing

#!/bin/sh
# Copyright (c) 2006-2011 WorkWare Systems http://www.workware.net.au/
# All rights reserved
# vim:se syntax=tcl:
# \
dir=`dirname "$0"`; exec `"$dir/find-tclsh" || echo false` "$0" "$@"

set autosetup(version) 0.6.2

# Can be set to 1 to debug early-init problems
set autosetup(debug) 0

##################################################################
................................................................................
	exit 0
}

# @opt-bool option ...
#
# Check each of the named, boolean options and return 1 if any of them have
# been set by the user.
# 
proc opt-bool {args} {
	option-check-names {*}$args
	opt_bool ::useropts {*}$args
}

# @opt-val option-list ?default=""?
#
................................................................................
# There will be one entry in the list for each option given by the user, including if the
# same option was used multiple times.
# If only a single value is required, use something like:
#
## lindex [opt-val $names] end
#
# If no options were set, $default is returned (exactly, not as a list).
# 
proc opt-val {names {default ""}} {
	option-check-names {*}$names
	join [opt_val ::useropts $names $default]
}

proc option-check-names {args} {
	foreach o $args {
................................................................................
#
# Undocumented options are also supported by omitting the "=> description.
# These options are not displayed with --help and can be useful for internal options or as aliases.
#
# For example, --disable-lfs is an alias for --disable=largefile:
#
## lfs=1 largefile=1 => "Disable large file support"
# 
proc options {optlist} {
	# Allow options as a list or args
	options-add $optlist "Local Options:"

	if {$::autosetup(showhelp)} {
		options-show
		exit 0
................................................................................
		exec-with-stderr sh $::autosetup(dir)/config.sub $alias
	} else {
		return $alias
	}
}

# @define name ?value=1?
# 
# Defines the named variable to the given value.
# These (name, value) pairs represent the results of the configuration check
# and are available to be checked, modified and substituted.
#
proc define {name {value 1}} {
	set ::define($name) $value
	#dputs "$name <= $value"
................................................................................
proc quote-argv {argv} {
	set args {}
	foreach arg $argv {
		lappend args [quote-if-needed $arg]
	}
	join $args
}































# @find-executable name
#
# Searches the path for an executable with the given name.
# Note that the name may include some parameters, e.g. "cc -mbig-endian",
# in which case the parameters are ignored.
# Returns 1 if found, or 0 if not.
................................................................................
# Copyright (c) 2006 WorkWare Systems http://www.workware.net.au/
# All rights reserved

# Simple getopt module

# Parse everything out of the argv list which looks like an option
# Knows about --enable-thing and --disable-thing as alternatives for --thing=0 or --thing=1

proc getopt {argvname} {
	upvar $argvname argv


	for {set i 0} {$i < [llength $argv]} {incr i} {
		set arg [lindex $argv $i]

		#dputs arg=$arg

		if {$arg eq "--"} {
			# End of options
			incr i

			break
		}

		if {[regexp {^--([^=][^=]+)=(.*)$} $arg -> name value]} {
			lappend opts($name) $value
		} elseif {[regexp {^--(enable-|disable-)?([^=]*)$} $arg -> prefix name]} {
			if {$prefix eq "disable-"} {
				set value 0
			} else {
				set value 1
			}
			lappend opts($name) $value
		} else {
			break
		}
	}

	#puts "getopt: argv=[join $argv] => [join [lrange $argv $i end]]"
	#parray opts

	set argv [lrange $argv $i end]

	return [array get opts]
}

proc opt_val {optarrayname options {default {}}} {
	upvar $optarrayname opts

................................................................................
			user-notice "Warning: Initialising from the development version of autosetup"

			writefile configure "#!/bin/sh\nWRAPPER=\"\$0\" exec $::autosetup(dir)/autosetup \"\$@\"\n"
		} else {
			writefile configure \
{#!/bin/sh
dir="`dirname "$0"`/autosetup"
WRAPPER="$0" exec `"$dir/find-tclsh" || echo false` "$dir/autosetup" "$@"
}
		}
		catch {exec chmod 755 configure}
	}
	if {![file exists auto.def]} {
		puts "I don't see auto.def, so I will create a default one."
		writefile auto.def {# Initial auto.def created by 'autosetup --init'
................................................................................

use cc

# Add any user options here
options {
}

make-autoconf-h config.h
make-template Makefile.in
}
	}
	if {![file exists Makefile.in]} {
		puts "Note: I don't see Makefile.in. You will probably need to create one."
	}

................................................................................
	# (Assume that Tcl does this for us)
	proc getenv {name args} {
		string map {\\ /} [env $name {*}$args]
	}
	# Jim uses system() for exec under mingw, so
	# we need to fetch the output ourselves
	proc exec-with-stderr {args} {
			set tmpfile /tmp/autosetup.[format %05x [rand 10000]].tmp
			set rc [catch [list exec {*}$args >$tmpfile 2>&1] result]
			set result [readfile $tmpfile]
			file delete $tmpfile
			return -code $rc $result
	}
} else {
	# Jim on unix is simple

#!/bin/sh
# Copyright (c) 2006-2011 WorkWare Systems http://www.workware.net.au/
# All rights reserved
# vim:se syntax=tcl:
# \
dir=`dirname "$0"`; exec "`$dir/find-tclsh`" "$0" "$@"

set autosetup(version) 0.6.2

# Can be set to 1 to debug early-init problems
set autosetup(debug) 0

##################################################################
................................................................................
	exit 0
}

# @opt-bool option ...
#
# Check each of the named, boolean options and return 1 if any of them have
# been set by the user.
#
proc opt-bool {args} {
	option-check-names {*}$args
	opt_bool ::useropts {*}$args
}

# @opt-val option-list ?default=""?
#
................................................................................
# There will be one entry in the list for each option given by the user, including if the
# same option was used multiple times.
# If only a single value is required, use something like:
#
## lindex [opt-val $names] end
#
# If no options were set, $default is returned (exactly, not as a list).
#
proc opt-val {names {default ""}} {
	option-check-names {*}$names
	join [opt_val ::useropts $names $default]
}

proc option-check-names {args} {
	foreach o $args {
................................................................................
#
# Undocumented options are also supported by omitting the "=> description.
# These options are not displayed with --help and can be useful for internal options or as aliases.
#
# For example, --disable-lfs is an alias for --disable=largefile:
#
## lfs=1 largefile=1 => "Disable large file support"
#
proc options {optlist} {
	# Allow options as a list or args
	options-add $optlist "Local Options:"

	if {$::autosetup(showhelp)} {
		options-show
		exit 0
................................................................................
		exec-with-stderr sh $::autosetup(dir)/config.sub $alias
	} else {
		return $alias
	}
}

# @define name ?value=1?
#
# Defines the named variable to the given value.
# These (name, value) pairs represent the results of the configuration check
# and are available to be checked, modified and substituted.
#
proc define {name {value 1}} {
	set ::define($name) $value
	#dputs "$name <= $value"
................................................................................
proc quote-argv {argv} {
	set args {}
	foreach arg $argv {
		lappend args [quote-if-needed $arg]
	}
	join $args
}

# @suffix suf list
#
# Takes a list and returns a new list with $suf appended
# to each element
#
## suffix .c {a b c} => {a.c b.c c.c}
#
proc suffix {suf list} {
	set result {}
	foreach p $list {
		lappend result $p$suf
	}
	return $result
}

# @prefix pre list
#
# Takes a list and returns a new list with $pre prepended
# to each element
#
## prefix jim- {a.c b.c} => {jim-a.c jim-b.c}
#
proc prefix {pre list} {
	set result {}
	foreach p $list {
		lappend result $pre$p
	}
	return $result
}

# @find-executable name
#
# Searches the path for an executable with the given name.
# Note that the name may include some parameters, e.g. "cc -mbig-endian",
# in which case the parameters are ignored.
# Returns 1 if found, or 0 if not.
................................................................................
# Copyright (c) 2006 WorkWare Systems http://www.workware.net.au/
# All rights reserved

# Simple getopt module

# Parse everything out of the argv list which looks like an option
# Knows about --enable-thing and --disable-thing as alternatives for --thing=0 or --thing=1
# Everything which doesn't look like an option, or is after --, is left unchanged
proc getopt {argvname} {
	upvar $argvname argv
	set nargv {}

	for {set i 0} {$i < [llength $argv]} {incr i} {
		set arg [lindex $argv $i]

		#dputs arg=$arg

		if {$arg eq "--"} {
			# End of options
			incr i
			lappend nargv {*}[lrange $argv $i end]
			break
		}

		if {[regexp {^--([^=][^=]+)=(.*)$} $arg -> name value]} {
			lappend opts($name) $value
		} elseif {[regexp {^--(enable-|disable-)?([^=]*)$} $arg -> prefix name]} {
			if {$prefix eq "disable-"} {
				set value 0
			} else {
				set value 1
			}
			lappend opts($name) $value
		} else {
			lappend nargv $arg
		}
	}

	#puts "getopt: argv=[join $argv] => [join $nargv]"
	#parray opts

	set argv $nargv

	return [array get opts]
}

proc opt_val {optarrayname options {default {}}} {
	upvar $optarrayname opts

................................................................................
			user-notice "Warning: Initialising from the development version of autosetup"

			writefile configure "#!/bin/sh\nWRAPPER=\"\$0\" exec $::autosetup(dir)/autosetup \"\$@\"\n"
		} else {
			writefile configure \
{#!/bin/sh
dir="`dirname "$0"`/autosetup"
WRAPPER="$0" exec "`$dir/find-tclsh`" "$dir/autosetup" "$@"
}
		}
		catch {exec chmod 755 configure}
	}
	if {![file exists auto.def]} {
		puts "I don't see auto.def, so I will create a default one."
		writefile auto.def {# Initial auto.def created by 'autosetup --init'
................................................................................

use cc

# Add any user options here
options {
}

make-config-header config.h
make-template Makefile.in
}
	}
	if {![file exists Makefile.in]} {
		puts "Note: I don't see Makefile.in. You will probably need to create one."
	}

................................................................................
	# (Assume that Tcl does this for us)
	proc getenv {name args} {
		string map {\\ /} [env $name {*}$args]
	}
	# Jim uses system() for exec under mingw, so
	# we need to fetch the output ourselves
	proc exec-with-stderr {args} {
			set tmpfile auto[format %04x [rand 10000]].tmp
			set rc [catch [list exec {*}$args >$tmpfile 2>&1] result]
			set result [readfile $tmpfile]
			file delete $tmpfile
			return -code $rc $result
	}
} else {
	# Jim on unix is simple

#
proc cc-check-endian {} {
	cc-check-includes sys/types.h sys/param.h
	set rc 0
	msg-checking "Checking endian..."
	cc-with {-includes {sys/types.h sys/param.h}} {
		if {[cctest -code {
			#if! defined(BIG_ENDIAN) || !defined(BYTE_ORDER)
				#error unknown
			#elif BYTE_ORDER != BIG_ENDIAN
				#error little
			#endif
		}]} {
			define-feature big-endian
			msg-result "big"
			set rc 1
		} elseif {[cctest -code {
			#if! defined(LITTLE_ENDIAN) || !defined(BYTE_ORDER)
				#error unknown
			#elif BYTE_ORDER != LITTLE_ENDIAN
				#error big
			#endif
		}]} {
			define-feature little-endian
			msg-result "little"

#
proc cc-check-endian {} {
	cc-check-includes sys/types.h sys/param.h
	set rc 0
	msg-checking "Checking endian..."
	cc-with {-includes {sys/types.h sys/param.h}} {
		if {[cctest -code {
			#if !defined(BIG_ENDIAN) || !defined(BYTE_ORDER)
				#error unknown
			#elif BYTE_ORDER != BIG_ENDIAN
				#error little
			#endif
		}]} {
			define-feature big-endian
			msg-result "big"
			set rc 1
		} elseif {[cctest -code {
			#if !defined(LITTLE_ENDIAN) || !defined(BYTE_ORDER)
				#error unknown
			#elif BYTE_ORDER != LITTLE_ENDIAN
				#error big
			#endif
		}]} {
			define-feature little-endian
			msg-result "little"

		define SH_LDFLAGS -shared
		define SHOBJ_LDFLAGS -shared
	}
	*-*-cygwin {
		define SH_LDFLAGS -shared
		define SHOBJ_LDFLAGS -shared
	}















	* {
		# Generic Unix settings
		define SH_LINKFLAGS -rdynamic
		define SH_CFLAGS -fPIC
		define SH_LDFLAGS -shared
		define SHOBJ_CFLAGS -fPIC
		define SHOBJ_LDFLAGS "-shared -nostartfiles"
	}
}

		define SH_LDFLAGS -shared
		define SHOBJ_LDFLAGS -shared
	}
	*-*-cygwin {
		define SH_LDFLAGS -shared
		define SHOBJ_LDFLAGS -shared
	}
	*-*-solaris* {
		# XXX: These haven't been fully tested. 
		#define SH_LINKFLAGS -Wl,-export-dynamic
		define SH_CFLAGS -Kpic
		define SHOBJ_CFLAGS -Kpic
		define SHOBJ_LDFLAGS "-G"
	}
	*-*-hpux {
		# XXX: These haven't been tested
		define SH_LINKFLAGS -Wl,+s
		define SH_CFLAGS +z
		define SHOBJ_CFLAGS "+O3 +z"
		define SHOBJ_LDFLAGS -b
		define LD_LIBRARY_PATH SHLIB_PATH
	}
	* {
		# Generic Unix settings
		define SH_LINKFLAGS -rdynamic
		define SH_CFLAGS -fpic
		define SH_LDFLAGS -shared
		define SHOBJ_CFLAGS -fpic
		define SHOBJ_LDFLAGS "-shared -nostartfiles"
	}
}

# Similar to cc-add-settings, but each given setting
# simply replaces the existing value.
#
# Returns the previous settings
proc cc-update-settings {args} {
	set prev [cc-get-settings]
	array set new $prev

	foreach {name value} $args {
		set new($name) $value
	}
	cc-store-settings $new

	return $prev
}

# @cc-with settings ?{ script }?
#
# Sets the given 'cctest' settings and then runs the tests in 'script'.
# Note that settings such as -lang replace the current setting, while
................................................................................
##   return 0;
## }
#
# Any failures are recorded in 'config.log'
#
proc cctest {args} {
	set src conftest__.c
	set tmp conftest__.o

	# Easiest way to merge in the settings
	cc-with $args {
		array set opts [cc-get-settings]
	}

	if {[info exists opts(-sourcefile)]} {
................................................................................
		}
		default {
			autosetup-error "cctest called with unknown language: $opts(-lang)"
		}
	}

	if {!$opts(-link)} {

		lappend cmdline -c
	}
	lappend cmdline {*}$opts(-cflags)

	switch -glob -- [get-define host] {
		*-*-darwin* {
			# Don't generate .dSYM directories

# Similar to cc-add-settings, but each given setting
# simply replaces the existing value.
#
# Returns the previous settings
proc cc-update-settings {args} {
	set prev [cc-get-settings]





	cc-store-settings [dict merge $prev $args]

	return $prev
}

# @cc-with settings ?{ script }?
#
# Sets the given 'cctest' settings and then runs the tests in 'script'.
# Note that settings such as -lang replace the current setting, while
................................................................................
##   return 0;
## }
#
# Any failures are recorded in 'config.log'
#
proc cctest {args} {
	set src conftest__.c
	set tmp conftest__

	# Easiest way to merge in the settings
	cc-with $args {
		array set opts [cc-get-settings]
	}

	if {[info exists opts(-sourcefile)]} {
................................................................................
		}
		default {
			autosetup-error "cctest called with unknown language: $opts(-lang)"
		}
	}

	if {!$opts(-link)} {
		set tmp conftest__.o
		lappend cmdline -c
	}
	lappend cmdline {*}$opts(-cflags)

	switch -glob -- [get-define host] {
		*-*-darwin* {
			# Don't generate .dSYM directories

# @synopsis:
#
# This module supports common system interrogation and options
# such as --host, --build, --prefix, and setting srcdir, builddir, and EXEXT.
#
# It also support the 'feature' naming convention, where searching
# for a feature such as sys/type.h defines HAVE_SYS_TYPES_H

# Note that the hidden options are supported for autoconf compatibility

module-options {
	host:host-alias =>		{a complete or partial cpu-vendor-opsys for the system where
							the application will run (defaults to the same value as --build)}
	build:build-alias =>	{a complete or partial cpu-vendor-opsys for the system
							where the application will be built (defaults to the
							result of running config.guess)}
	prefix:dir =>			{the target directory for the build (defaults to /usr/local)}





	includedir:
	mandir:
	infodir:
	libexecdir:


	sysconfdir:

	localstatedir:

	maintainer-mode=0
	dependency-tracking=0
}

# Returns 1 if exists, or 0 if  not
#
proc check-feature {name code} {
................................................................................
# Each pattern of the form @define@ is replaced the the corresponding
# define, if it exists, or left unchanged if not.
# 
# The special value @srcdir@ is subsituted with the relative
# path to the source directory from the directory where the output
# file is created. Use @top_srcdir@ for the absolute path.
#


















proc make-template {template {out {}}} {
	set infile [file join $::autosetup(srcdir) $template]

	if {![file exists $infile]} {
		user-error "Template $template is missing"
	}

................................................................................
	# Set up srcdir to be relative to the target dir
	define srcdir [relative-path [file join $::autosetup(srcdir) $outdir] $outdir]

	set mapping {}
	foreach {n v} [array get ::define] {
		lappend mapping @$n@ $v
	}
































	writefile $out [string map $mapping [readfile $infile]]\n

	msg-result "Created [relative-path $out] from [relative-path $template]"
}

# build/host tuples and cross-compilation prefix
set build [opt-val build]
define build_alias $build
................................................................................
define target [get-define host]
define prefix $prefix
define builddir $autosetup(builddir)
define srcdir $autosetup(srcdir)
# Allow this to come from the environment
define top_srcdir [get-env top_srcdir [get-define srcdir]]

# And less common ones too
define exec_prefix \${prefix}

define bindir \${exec_prefix}/bin
define sbindir \${exec_prefix}/sbin
define libexecdir [get-env libexecdir \${exec_prefix}/libexec]

define datadir \${prefix}/share
define sysconfdir [get-env sysconfdir \${prefix}/etc]
define sharedstatedir \${prefix}/com
define localstatedir [get-env localstatedir \${prefix}/var]
define libdir \${exec_prefix}/lib
define infodir [get-env infodir \${prefix}/share/info]
define mandir [get-env mandir \${prefix}/share/man]
define includedir [get-env includdir \${prefix}/include]




define SHELL [get-env SHELL [find-an-executable sh bash ksh]]

# Windows vs. non-Windows
switch -glob -- [get-define host] {
	*-*-ming* - *-*-cygwin {
		define-feature windows

# @synopsis:
#
# This module supports common system interrogation and options
# such as --host, --build, --prefix, and setting srcdir, builddir, and EXEXT.
#
# It also support the 'feature' naming convention, where searching
# for a feature such as sys/type.h defines HAVE_SYS_TYPES_H
#


module-options {
	host:host-alias =>		{a complete or partial cpu-vendor-opsys for the system where
							the application will run (defaults to the same value as --build)}
	build:build-alias =>	{a complete or partial cpu-vendor-opsys for the system
							where the application will be built (defaults to the
							result of running config.guess)}
	prefix:dir =>			{the target directory for the build (defaults to /usr/local)}

	# These (hidden) options are supported for autoconf/automake compatibility
	exec-prefix:
	bindir:
	sbindir:
	includedir:
	mandir:
	infodir:
	libexecdir:
	datadir:
	libdir:
	sysconfdir:
	sharedstatedir:
	localstatedir:

	maintainer-mode=0
	dependency-tracking=0
}

# Returns 1 if exists, or 0 if  not
#
proc check-feature {name code} {
................................................................................
# Each pattern of the form @define@ is replaced the the corresponding
# define, if it exists, or left unchanged if not.
# 
# The special value @srcdir@ is subsituted with the relative
# path to the source directory from the directory where the output
# file is created. Use @top_srcdir@ for the absolute path.
#
# Conditional sections may be specified as follows:
## @if name == value
## lines
## @else
## lines
## @endif
#
# Where 'name' is a defined variable name and @else is optional.
# If the expression does not match, all lines through '@endif' are ignored.
#
# The alternative forms may also be used:
## @if name
## @if name != value
#
# Where the first form is true if the variable is defined, but not empty or 0
#
# Currently these expressions can't be nested.
#
proc make-template {template {out {}}} {
	set infile [file join $::autosetup(srcdir) $template]

	if {![file exists $infile]} {
		user-error "Template $template is missing"
	}

................................................................................
	# Set up srcdir to be relative to the target dir
	define srcdir [relative-path [file join $::autosetup(srcdir) $outdir] $outdir]

	set mapping {}
	foreach {n v} [array get ::define] {
		lappend mapping @$n@ $v
	}
	set result {}
	foreach line [split [readfile $infile] \n] {
		if {[info exists cond]} {
			set l [string trimright $line]
			if {$l eq "@endif"} {
				unset cond
				continue
			}
			if {$l eq "@else"} {
				set cond [expr {!$cond}]
				continue
			}
			if {$cond} {
				lappend result $line
			}
			continue
		}
		if {[regexp {^@if\s+(\w+)(.*)} $line -> name expression]} {
			lassign $expression equal value
			set varval [get-define $name ""]
			if {$equal eq ""} {
				set cond [expr {$varval ni {"" 0}}]
			} else {
				set cond [expr {$varval eq $value}]
				if {$equal ne "=="} {
					set cond [expr {!$cond}]
				}
			}
			continue
		}
		lappend result $line
	}
	writefile $out [string map $mapping [join $result \n]]\n

	msg-result "Created [relative-path $out] from [relative-path $template]"
}

# build/host tuples and cross-compilation prefix
set build [opt-val build]
define build_alias $build
................................................................................
define target [get-define host]
define prefix $prefix
define builddir $autosetup(builddir)
define srcdir $autosetup(srcdir)
# Allow this to come from the environment
define top_srcdir [get-env top_srcdir [get-define srcdir]]

# autoconf supports all of these
define exec_prefix [opt-val exec-prefix [get-env exec-prefix \${prefix}]]
foreach {name defpath} {
	bindir \${exec_prefix}/bin
	sbindir \${exec_prefix}/sbin
	libexecdir \${exec_prefix}/libexec
	libdir \${exec_prefix}/lib
	datadir \${prefix}/share
	sysconfdir \${prefix}/etc
	sharedstatedir \${prefix}/com
	localstatedir \${prefix}/var

	infodir \${prefix}/share/info
	mandir \${prefix}/share/man
	includedir \${prefix}/include
} {
	define $name [opt-val $name [get-env $name $defpath]]
}

define SHELL [get-env SHELL [find-an-executable sh bash ksh]]

# Windows vs. non-Windows
switch -glob -- [get-define host] {
	*-*-ming* - *-*-cygwin {
		define-feature windows

#!/bin/sh
dir="`dirname "$0"`/autosetup"
WRAPPER="$0" exec `"$dir/find-tclsh" || echo false` "$dir/autosetup" "$@"

#!/bin/sh
dir="`dirname "$0"`/autosetup"
WRAPPER="$0" exec "`$dir/find-tclsh`" "$dir/autosetup" "$@"

  if( db_exists("SELECT 1 FROM vfile"
                " WHERE pathname=%Q COLLATE %s", zPath, zCollate) ){
    db_multi_exec("UPDATE vfile SET deleted=0"
                  " WHERE pathname=%Q COLLATE %s", zPath, zCollate);
  }else{
    char *zFullname = mprintf("%s%s", g.zLocalRoot, zPath);
    db_multi_exec(
      "INSERT INTO vfile(vid,deleted,rid,mrid,pathname,isexe)"
      "VALUES(%d,0,0,0,%Q,%d)",
      vid, zPath, file_isexe(zFullname));
    fossil_free(zFullname);
  }
  if( db_changes() ){
    fossil_print("ADDED  %s\n", zPath);
    return 1;
  }else{
    fossil_print("SKIP   %s\n", zPath);
................................................................................
  );
  while( db_step(&q)==SQLITE_ROW ){
    const char * zFile;
    const char * zPath;

    zFile = db_column_text(&q, 0);
    zPath = db_column_text(&q, 1);
    if( !file_isfile(zPath) ){
      if( !isTest ){
        db_multi_exec("UPDATE vfile SET deleted=1 WHERE pathname=%Q", zFile);
      }
      fossil_print("DELETED  %s\n", zFile);
      nDelete++;
    }
  }

  if( db_exists("SELECT 1 FROM vfile"
                " WHERE pathname=%Q COLLATE %s", zPath, zCollate) ){
    db_multi_exec("UPDATE vfile SET deleted=0"
                  " WHERE pathname=%Q COLLATE %s", zPath, zCollate);
  }else{
    char *zFullname = mprintf("%s%s", g.zLocalRoot, zPath);
    db_multi_exec(
      "INSERT INTO vfile(vid,deleted,rid,mrid,pathname,isexe,islink)"
      "VALUES(%d,0,0,0,%Q,%d,%d)",
      vid, zPath, file_isexe(zFullname), file_islink(zFullname));
    fossil_free(zFullname);
  }
  if( db_changes() ){
    fossil_print("ADDED  %s\n", zPath);
    return 1;
  }else{
    fossil_print("SKIP   %s\n", zPath);
................................................................................
  );
  while( db_step(&q)==SQLITE_ROW ){
    const char * zFile;
    const char * zPath;

    zFile = db_column_text(&q, 0);
    zPath = db_column_text(&q, 1);
    if( !file_isfile_or_link(zPath) ){
      if( !isTest ){
        db_multi_exec("UPDATE vfile SET deleted=1 WHERE pathname=%Q", zFile);
      }
      fossil_print("DELETED  %s\n", zFile);
      nDelete++;
    }
  }

  if( bisect.bad==0 ){
    fossil_fatal("no \"bad\" version has been identified");
  }
  bisect.good = db_lget_int("bisect-good", 0);
  if( bisect.good==0 ){
    fossil_fatal("no \"good\" version has been identified");
  }
  p = path_shortest(bisect.good, bisect.bad, bisect_option("direct-only"));
  if( p==0 ){
    char *zBad = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", bisect.bad);
    char *zGood = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", bisect.good);
    fossil_fatal("no path from good ([%S]) to bad ([%S]) or back",
                 zGood, zBad);
  }
}

  if( bisect.bad==0 ){
    fossil_fatal("no \"bad\" version has been identified");
  }
  bisect.good = db_lget_int("bisect-good", 0);
  if( bisect.good==0 ){
    fossil_fatal("no \"good\" version has been identified");
  }
  p = path_shortest(bisect.good, bisect.bad, bisect_option("direct-only"), 0);
  if( p==0 ){
    char *zBad = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", bisect.bad);
    char *zGood = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", bisect.good);
    fossil_fatal("no path from good ([%S]) to bad ([%S]) or back",
                 zGood, zBad);
  }
}

  got = fread(blob_buffer(pBlob), 1, size, in);
  fclose(in);
  if( got<size ){
    blob_resize(pBlob, got);
  }
  return got;
}



























/*
** Write the content of a blob into a file.
**
** If the filename is blank or "-" then write to standard output.
**
** Return the number of bytes written.

  got = fread(blob_buffer(pBlob), 1, size, in);
  fclose(in);
  if( got<size ){
    blob_resize(pBlob, got);
  }
  return got;
}

/*
** Reads symlink destination path and puts int into blob.
** Any prior content of the blob is discarded, not freed.
**
** Returns length of destination path.
**
** On windows, zeros blob and returns 0.
*/
int blob_read_link(Blob *pBlob, const char *zFilename){
#if !defined(_WIN32)
  char zBuf[1024];
  ssize_t len = readlink(zFilename, zBuf, 1023);
  if( len < 0 ){
    fossil_panic("cannot read symbolic link %s", zFilename);
  }
  zBuf[len] = 0;   /* null-terminate */
  blob_zero(pBlob);
  blob_appendf(pBlob, "%s", zBuf);
  return len;
#else
  blob_zero(pBlob);
  return 0;
#endif
}


/*
** Write the content of a blob into a file.
**
** If the filename is blank or "-" then write to standard output.
**
** Return the number of bytes written.

** Show a timeline of all branches
*/
void brlist_page(void){
  Stmt q;
  int cnt;
  int showClosed = P("closed")!=0;
  int showAll = P("all")!=0;


  login_check_credentials();
  if( !g.okRead ){ login_needed(); return; }





  style_header(showClosed ? "Closed Branches" :
                  showAll ? "All Branches" : "Open Branches");
  style_submenu_element("Timeline", "Timeline", "brtimeline");
  if( showClosed ){
    style_submenu_element("All", "All", "brlist?all");
    style_submenu_element("Open","Open","brlist");
................................................................................
  }else if( showAll ){
    style_submenu_element("Closed", "Closed", "brlist?closed");
    style_submenu_element("Open","Open","brlist");
  }else{
    style_submenu_element("All", "All", "brlist?all");
    style_submenu_element("Closed","Closed","brlist?closed");
  }





  login_anonymous_available();
  style_sidebox_begin("Nomenclature:", "33%");
  @ <ol>
  @ <li> An <div class="sideboxDescribed"><a href="brlist">
  @ open branch</a></div> is a branch that has one or
  @ more <a href="leaves">open leaves.</a>
  @ The presence of open leaves presumably means
................................................................................
  style_sidebox_end();

  prepareBranchQuery(&q, showAll, showClosed);
  cnt = 0;
  while( db_step(&q)==SQLITE_ROW ){
    const char *zBr = db_column_text(&q, 0);
    if( cnt==0 ){




      if( showClosed ){
        @ <h2>Closed Branches:</h2>
      }else{
        @ <h2>Open Branches:</h2>
      }
      @ <ul>
      cnt++;
    }




    if( g.okHistory ){
      @ <li><a href="%s(g.zTop)/timeline?r=%T(zBr)">%h(zBr)</a></li>
    }else{
      @ <li><b>%h(zBr)</b></li>
    }
  }
  if( cnt ){
    @ </ul>
  }

** Show a timeline of all branches
*/
void brlist_page(void){
  Stmt q;
  int cnt;
  int showClosed = P("closed")!=0;
  int showAll = P("all")!=0;
  int colorTest = P("colortest")!=0;

  login_check_credentials();
  if( !g.okRead ){ login_needed(); return; }
  if( colorTest ){
    showClosed = 0;
    showAll = 1;
  }

  style_header(showClosed ? "Closed Branches" :
                  showAll ? "All Branches" : "Open Branches");
  style_submenu_element("Timeline", "Timeline", "brtimeline");
  if( showClosed ){
    style_submenu_element("All", "All", "brlist?all");
    style_submenu_element("Open","Open","brlist");
................................................................................
  }else if( showAll ){
    style_submenu_element("Closed", "Closed", "brlist?closed");
    style_submenu_element("Open","Open","brlist");
  }else{
    style_submenu_element("All", "All", "brlist?all");
    style_submenu_element("Closed","Closed","brlist?closed");
  }
  if( !colorTest ){
    style_submenu_element("Color-Test", "Color-Test", "brlist?colortest");
  }else{
    style_submenu_element("All", "All", "brlist?all");
  }
  login_anonymous_available();
  style_sidebox_begin("Nomenclature:", "33%");
  @ <ol>
  @ <li> An <div class="sideboxDescribed"><a href="brlist">
  @ open branch</a></div> is a branch that has one or
  @ more <a href="leaves">open leaves.</a>
  @ The presence of open leaves presumably means
................................................................................
  style_sidebox_end();

  prepareBranchQuery(&q, showAll, showClosed);
  cnt = 0;
  while( db_step(&q)==SQLITE_ROW ){
    const char *zBr = db_column_text(&q, 0);
    if( cnt==0 ){
      if( colorTest ){
        @ <h2>Default background colors for all branches:</h2>
      }else if( showAll ){
        @ <h2>All Branches:</h2>
      }else if( showClosed ){
        @ <h2>Closed Branches:</h2>
      }else{
        @ <h2>Open Branches:</h2>
      }
      @ <ul>
      cnt++;
    }
    if( colorTest ){
      const char *zColor = hash_color(zBr);
      @ <li><span style="background-color: %s(zColor)">
      @ %h(zBr) &rarr; %s(zColor)</span></li>
    }else if( g.okHistory ){
      @ <li><a href="%s(g.zTop)/timeline?r=%T(zBr)")>%h(zBr)</a></li>
    }else{
      @ <li><b>%h(zBr)</b></li>
    }
  }
  if( cnt ){
    @ </ul>
  }

      if( zDisplayName[0]=='.' && zDisplayName[1]=='/' ){
        zDisplayName += 2;  /* no unnecessary ./ prefix */
      }
    }
    blob_append(report, zPrefix, nPrefix);
    if( isDeleted ){
      blob_appendf(report, "DELETED    %s\n", zDisplayName);
    }else if( !file_isfile(zFullName) ){
      if( file_access(zFullName, 0)==0 ){
        blob_appendf(report, "NOT_A_FILE %s\n", zDisplayName);
        if( missingIsFatal ){
          fossil_warning("not a file: %s", zDisplayName);
          nErr++;
        }
      }else{
................................................................................
    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    if( isBrief ){
      fossil_print("%s\n", zPathname);
    }else if( isNew ){
      fossil_print("ADDED      %s\n", zPathname);
    }else if( isDeleted ){
      fossil_print("DELETED    %s\n", zPathname);
    }else if( !file_isfile(zFullName) ){
      if( file_access(zFullName, 0)==0 ){
        fossil_print("NOT_A_FILE %s\n", zPathname);
      }else{
        fossil_print("MISSING    %s\n", zPathname);
      }
    }else if( chnged ){
      fossil_print("EDITED     %s\n", zPathname);
................................................................................
    pFile = 0;
  }
  blob_appendf(pOut, "C %F\n", blob_str(pComment));
  zDate = date_in_standard_format(zDateOvrd ? zDateOvrd : "now");
  blob_appendf(pOut, "D %s\n", zDate);
  zDate[10] = ' ';
  db_prepare(&q,
    "SELECT pathname, uuid, origname, blob.rid, isexe,"
    "       file_is_selected(vfile.id)"
    "  FROM vfile JOIN blob ON vfile.mrid=blob.rid"
    " WHERE (NOT deleted OR NOT file_is_selected(vfile.id))"
    "   AND vfile.vid=%d"
    " ORDER BY 1", vid);
  blob_zero(&filename);
  blob_appendf(&filename, "%s", g.zLocalRoot);
................................................................................
  nBasename = blob_size(&filename);
  while( db_step(&q)==SQLITE_ROW ){
    const char *zName = db_column_text(&q, 0);
    const char *zUuid = db_column_text(&q, 1);
    const char *zOrig = db_column_text(&q, 2);
    int frid = db_column_int(&q, 3);
    int isexe = db_column_int(&q, 4);

    int isSelected = db_column_int(&q, 5);
    const char *zPerm;
    int cmp;
#if !defined(_WIN32)
    /* For unix, extract the "executable" permission bit directly from
    ** the filesystem.  On windows, the "executable" bit is retained
    ** unchanged from the original. 
    */
    blob_resize(&filename, nBasename);
    blob_append(&filename, zName, -1);
    isexe = file_isexe(blob_str(&filename));





#endif
    if( isexe ){
      zPerm = " x";


    }else{
      zPerm = "";
    }
    if( !g.markPrivate ) content_make_public(frid);
    while( pFile && fossil_strcmp(pFile->zName,zName)<0 ){
      blob_appendf(pOut, "F %F\n", pFile->zName);
      pFile = manifest_file_next(pBaseline, 0);
................................................................................

    id = db_column_int(&q, 0);
    zFullname = db_column_text(&q, 1);
    rid = db_column_int(&q, 2);
    crnlOk = db_column_int(&q, 3);

    blob_zero(&content);




    blob_read_from_file(&content, zFullname);

    if( !crnlOk ) cr_warning(&content, zFullname);
    nrid = content_put(&content);
    blob_reset(&content);
    if( rid>0 ){
      content_deltify(rid, nrid, 0);
    }
    db_multi_exec("UPDATE vfile SET mrid=%d, rid=%d WHERE id=%d", nrid,nrid,id);

      if( zDisplayName[0]=='.' && zDisplayName[1]=='/' ){
        zDisplayName += 2;  /* no unnecessary ./ prefix */
      }
    }
    blob_append(report, zPrefix, nPrefix);
    if( isDeleted ){
      blob_appendf(report, "DELETED    %s\n", zDisplayName);
    }else if( !file_isfile_or_link(zFullName) ){
      if( file_access(zFullName, 0)==0 ){
        blob_appendf(report, "NOT_A_FILE %s\n", zDisplayName);
        if( missingIsFatal ){
          fossil_warning("not a file: %s", zDisplayName);
          nErr++;
        }
      }else{
................................................................................
    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    if( isBrief ){
      fossil_print("%s\n", zPathname);
    }else if( isNew ){
      fossil_print("ADDED      %s\n", zPathname);
    }else if( isDeleted ){
      fossil_print("DELETED    %s\n", zPathname);
    }else if( !file_isfile_or_link(zFullName) ){
      if( file_access(zFullName, 0)==0 ){
        fossil_print("NOT_A_FILE %s\n", zPathname);
      }else{
        fossil_print("MISSING    %s\n", zPathname);
      }
    }else if( chnged ){
      fossil_print("EDITED     %s\n", zPathname);
................................................................................
    pFile = 0;
  }
  blob_appendf(pOut, "C %F\n", blob_str(pComment));
  zDate = date_in_standard_format(zDateOvrd ? zDateOvrd : "now");
  blob_appendf(pOut, "D %s\n", zDate);
  zDate[10] = ' ';
  db_prepare(&q,
    "SELECT pathname, uuid, origname, blob.rid, isexe, islink,"
    "       file_is_selected(vfile.id)"
    "  FROM vfile JOIN blob ON vfile.mrid=blob.rid"
    " WHERE (NOT deleted OR NOT file_is_selected(vfile.id))"
    "   AND vfile.vid=%d"
    " ORDER BY 1", vid);
  blob_zero(&filename);
  blob_appendf(&filename, "%s", g.zLocalRoot);
................................................................................
  nBasename = blob_size(&filename);
  while( db_step(&q)==SQLITE_ROW ){
    const char *zName = db_column_text(&q, 0);
    const char *zUuid = db_column_text(&q, 1);
    const char *zOrig = db_column_text(&q, 2);
    int frid = db_column_int(&q, 3);
    int isexe = db_column_int(&q, 4);
    int isLink = db_column_int(&q, 5);
    int isSelected = db_column_int(&q, 6);
    const char *zPerm;
    int cmp;
#if !defined(_WIN32)
    /* For unix, extract the "executable" permission bit directly from
    ** the filesystem.  On windows, the "executable" bit is retained
    ** unchanged from the original. 
    */
    blob_resize(&filename, nBasename);
    blob_append(&filename, zName, -1);
    isexe = file_isexe(blob_str(&filename));
    
    /* For unix, check if the file on the filesystem is symlink.
    ** On windows, the bit is retained unchanged from original. 
    */
    isLink = file_islink(blob_str(&filename));
#endif
    if( isexe ){
      zPerm = " x";
    }else if( isLink ){
      zPerm = " l"; /* note: symlinks don't have executable bit on unix */
    }else{
      zPerm = "";
    }
    if( !g.markPrivate ) content_make_public(frid);
    while( pFile && fossil_strcmp(pFile->zName,zName)<0 ){
      blob_appendf(pOut, "F %F\n", pFile->zName);
      pFile = manifest_file_next(pBaseline, 0);
................................................................................

    id = db_column_int(&q, 0);
    zFullname = db_column_text(&q, 1);
    rid = db_column_int(&q, 2);
    crnlOk = db_column_int(&q, 3);

    blob_zero(&content);
    if( file_islink(zFullname) ){
      /* Instead of file content, put link destination path */
      blob_read_link(&content, zFullname);
    }else{
      blob_read_from_file(&content, zFullname);        
    }
    if( !crnlOk ) cr_warning(&content, zFullname);
    nrid = content_put(&content);
    blob_reset(&content);
    if( rid>0 ){
      content_deltify(rid, nrid, 0);
    }
    db_multi_exec("UPDATE vfile SET mrid=%d, rid=%d WHERE id=%d", nrid,nrid,id);

  db_bind_text(&s, ":path", zFilename);
  db_step(&s);
  db_reset(&s);
}

/*
** Set or clear the execute permission bit (as appropriate) for all
** files in the current check-out.

*/
void checkout_set_all_exe(int vid){
  Blob filename;
  int baseLen;
  Manifest *pManifest;
  ManifestFile *pFile;

  db_bind_text(&s, ":path", zFilename);
  db_step(&s);
  db_reset(&s);
}

/*
** Set or clear the execute permission bit (as appropriate) for all
** files in the current check-out, and replace files that have
** symlink bit with actual symlinks.
*/
void checkout_set_all_exe(int vid){
  Blob filename;
  int baseLen;
  Manifest *pManifest;
  ManifestFile *pFile;

  blob_reset(&out);
}


/*
** COMMAND: configuration
**
** Usage: %fossil configure METHOD ... ?-R|--repository REPOSITORY?
**
** Where METHOD is one of: export import merge pull push reset.  All methods
** accept the -R or --repository option to specific a repository.
**
**    %fossil configuration export AREA FILENAME
**
**         Write to FILENAME exported configuraton information for AREA.

  blob_reset(&out);
}


/*
** COMMAND: configuration
**
** Usage: %fossil configuration METHOD ... ?-R|--repository REPOSITORY?
**
** Where METHOD is one of: export import merge pull push reset.  All methods
** accept the -R or --repository option to specific a repository.
**
**    %fossil configuration export AREA FILENAME
**
**         Write to FILENAME exported configuraton information for AREA.

  }else{
    g.dbConfig = openDatabase(zDbName);
  }
  g.configOpen = 1;
  free(zDbName);
}




















/*
** If zDbName is a valid local database file, open it and return
** true.  If it is not a valid local database file, return 0.
*/
static int isValidLocalDb(const char *zDbName){
  i64 lsize;
  int rc;
  sqlite3_stmt *pStmt;

  if( file_access(zDbName, F_OK) ) return 0;
  lsize = file_size(zDbName);
  if( lsize%1024!=0 || lsize<4096 ) return 0;
  db_open_or_attach(zDbName, "localdb");
  g.localOpen = 1;
  db_open_config(0);
  db_open_repository(0);

  /* If the "isexe" column is missing from the vfile table, then
  ** add it now.   This code added on 2010-03-06.  After all users have
  ** upgraded, this code can be safely deleted. 
  */
  rc = sqlite3_prepare(g.db, "SELECT isexe FROM vfile", -1, &pStmt, 0);
  nPrepare++;
  sqlite3_finalize(pStmt);
  if( rc==SQLITE_ERROR ){
    sqlite3_exec(g.db, "ALTER TABLE vfile ADD COLUMN isexe BOOLEAN", 0, 0, 0);
  }

#if 0
  /* If the "mtime" column is missing from the vfile table, then
  ** add it now.   This code added on 2008-12-06.  After all users have
  ** upgraded, this code can be safely deleted. 
  */
  rc = sqlite3_prepare(g.db, "SELECT mtime FROM vfile", -1, &pStmt, 0);
  sqlite3_finalize(pStmt);
  if( rc==SQLITE_ERROR ){
    sqlite3_exec(g.db, "ALTER TABLE vfile ADD COLUMN mtime INTEGER", 0, 0, 0);
  }
#endif

#if 0
  /* If the "origname" column is missing from the vfile table, then
  ** add it now.   This code added on 2008-11-09.  After all users have
  ** upgraded, this code can be safely deleted. 
  */
  rc = sqlite3_prepare(g.db, "SELECT origname FROM vfile", -1, &pStmt, 0);
  sqlite3_finalize(pStmt);
  if( rc==SQLITE_ERROR ){
    sqlite3_exec(g.db, "ALTER TABLE vfile ADD COLUMN origname TEXT", 0, 0, 0);
  }
#endif

  return 1;
}

/*
** Locate the root directory of the local repository tree.  The root
** directory is found by searching for a file named "_FOSSIL_" or ".fos"
................................................................................
    }else{
      fossil_panic("not a valid repository: %s", zDbName);
    }
  }
  db_open_or_attach(zDbName, "repository");
  g.repositoryOpen = 1;
  g.zRepositoryName = mprintf("%s", zDbName);


}

/*
** Flags for the db_find_and_open_repository() function.
*/
#if INTERFACE
#define OPEN_OK_NOT_FOUND    0x001      /* Do not error out if not found */
................................................................................
      zVersionedSetting = fossil_strdup(cacheEntry->zValue);
      break;
    }
    cacheEntry = cacheEntry->next;
  }
  /* Attempt to read value from file in checkout if there wasn't a cache hit
  ** and a checkout is open. */
  if( cacheEntry==0 && db_open_local() ){
    Blob versionedPathname;
    char *zVersionedPathname;
    blob_zero(&versionedPathname);
    blob_appendf(&versionedPathname, "%s/.fossil-settings/%s",
                 g.zLocalRoot, zName);
    zVersionedPathname = blob_str(&versionedPathname);
    if( file_size(zVersionedPathname)>=0 ){
................................................................................
    z = db_text(0, "SELECT value FROM config WHERE name=%Q", zName);
  }
  if( z==0 && g.configOpen ){
    db_swap_connections();
    z = db_text(0, "SELECT value FROM global_config WHERE name=%Q", zName);
    db_swap_connections();
  }
  if( ctrlSetting!=0 && ctrlSetting->versionable ){
    /* This is a versionable setting, try and get the info from a checked out file */
    z = db_get_do_versionable(zName, z);
  }
  if( z==0 ){
    z = zDefault;
  }
  return z;
................................................................................
  int width;            /* Width of display.  0 for boolean values */
  int versionable;      /* Is this setting versionable? */
  char const *def;      /* Default value */
};
#endif /* INTERFACE */
struct stControlSettings const ctrlSettings[] = {
  { "access-log",    0,                0, 0, "off"                 },

  { "auto-captcha",  "autocaptcha",    0, 0, "on"                  },
  { "auto-shun",     0,                0, 0, "on"                  },
  { "autosync",      0,                0, 0, "on"                  },
  { "binary-glob",   0,               32, 1, ""                    },
  { "clearsign",     0,                0, 0, "off"                 },
  { "case-sensitive",0,                0, 0, "on"                  },
  { "crnl-glob",     0,               16, 1, ""                    },
................................................................................
**
** Settings marked as versionable are overridden by the contents of the
** file named .fossil-settings/PROPERTY in the checked out files, if that
** file exists.
**
** The "unset" command clears a property setting.
**






**
**    auto-captcha     If enabled, the Login page provides a button to
**                     fill in the captcha password.  Default: on
**
**    auto-shun        If enabled, automatically pull the shunning list
**                     from a server to which the client autosyncs.
**                     Default: on

  }else{
    g.dbConfig = openDatabase(zDbName);
  }
  g.configOpen = 1;
  free(zDbName);
}


/*
 * * Returns TRUE if zTable exists in the local database.
 */
static int db_local_table_exists(const char *zTable){
  return db_exists("SELECT 1 FROM %s.sqlite_master"
                   " WHERE name=='%s'",
                   db_name("localdb"), zTable);
}

/*
** Returns TRUE if zColumn exists in zTable in the local database.
*/
static int db_local_column_exists(const char *zTable, const char *zColumn){
  return db_exists("SELECT 1 FROM %s.sqlite_master"
                   " WHERE name=='%s' AND sql GLOB '* %s *'",
                   db_name("localdb"), zTable, zColumn);
}

/*
** If zDbName is a valid local database file, open it and return
** true.  If it is not a valid local database file, return 0.
*/
static int isValidLocalDb(const char *zDbName){
  i64 lsize;



  if( file_access(zDbName, F_OK) ) return 0;
  lsize = file_size(zDbName);
  if( lsize%1024!=0 || lsize<4096 ) return 0;
  db_open_or_attach(zDbName, "localdb");
  g.localOpen = 1;
  db_open_config(0);
  db_open_repository(0);

  /* If the "isexe" column is missing from the vfile table, then
  ** add it now.   This code added on 2010-03-06.  After all users have
  ** upgraded, this code can be safely deleted. 
  */
  if( !db_local_column_exists("vfile", "isexe") )
    db_multi_exec("ALTER TABLE vfile ADD COLUMN isexe BOOLEAN DEFAULT 0");

  /* If "islink"/"isLink" columns are missing from tables, then
  ** add them now.   This code added on 2011-01-17 and 2011-08-27.
  ** After all users have upgraded, this code can be safely deleted. 
  */
  if( !db_local_column_exists("vfile", "islink") )
    db_multi_exec("ALTER TABLE vfile ADD COLUMN islink BOOLEAN DEFAULT 0");
  
  if( !db_local_column_exists("stashfile", "isLink") &&
       db_local_table_exists("stashfile") )
    db_multi_exec("ALTER TABLE stashfile ADD COLUMN isLink BOOLEAN DEFAULT 0");

  if( !db_local_column_exists("undo", "isLink") &&
       db_local_table_exists("undo") )
    db_multi_exec("ALTER TABLE undo ADD COLUMN isLink BOOLEAN DEFAULT 0");
  
  if( !db_local_column_exists("undo_vfile", "islink") &&
       db_local_table_exists("undo_vfile") )
    db_multi_exec("ALTER TABLE undo_vfile ADD COLUMN islink BOOLEAN DEFAULT 0");










  return 1;
}

/*
** Locate the root directory of the local repository tree.  The root
** directory is found by searching for a file named "_FOSSIL_" or ".fos"
................................................................................
    }else{
      fossil_panic("not a valid repository: %s", zDbName);
    }
  }
  db_open_or_attach(zDbName, "repository");
  g.repositoryOpen = 1;
  g.zRepositoryName = mprintf("%s", zDbName);
  /* Cache "allow-symlinks" option, because we'll need it on every stat call */
  g.allowSymlinks = db_get_boolean("allow-symlinks", 0);
}

/*
** Flags for the db_find_and_open_repository() function.
*/
#if INTERFACE
#define OPEN_OK_NOT_FOUND    0x001      /* Do not error out if not found */
................................................................................
      zVersionedSetting = fossil_strdup(cacheEntry->zValue);
      break;
    }
    cacheEntry = cacheEntry->next;
  }
  /* Attempt to read value from file in checkout if there wasn't a cache hit
  ** and a checkout is open. */
  if( cacheEntry==0 ){
    Blob versionedPathname;
    char *zVersionedPathname;
    blob_zero(&versionedPathname);
    blob_appendf(&versionedPathname, "%s/.fossil-settings/%s",
                 g.zLocalRoot, zName);
    zVersionedPathname = blob_str(&versionedPathname);
    if( file_size(zVersionedPathname)>=0 ){
................................................................................
    z = db_text(0, "SELECT value FROM config WHERE name=%Q", zName);
  }
  if( z==0 && g.configOpen ){
    db_swap_connections();
    z = db_text(0, "SELECT value FROM global_config WHERE name=%Q", zName);
    db_swap_connections();
  }
  if( ctrlSetting!=0 && ctrlSetting->versionable && g.localOpen ){
    /* This is a versionable setting, try and get the info from a checked out file */
    z = db_get_do_versionable(zName, z);
  }
  if( z==0 ){
    z = zDefault;
  }
  return z;
................................................................................
  int width;            /* Width of display.  0 for boolean values */
  int versionable;      /* Is this setting versionable? */
  char const *def;      /* Default value */
};
#endif /* INTERFACE */
struct stControlSettings const ctrlSettings[] = {
  { "access-log",    0,                0, 0, "off"                 },
  { "allow-symlinks",0,                0, 0, "off"                 },
  { "auto-captcha",  "autocaptcha",    0, 0, "on"                  },
  { "auto-shun",     0,                0, 0, "on"                  },
  { "autosync",      0,                0, 0, "on"                  },
  { "binary-glob",   0,               32, 1, ""                    },
  { "clearsign",     0,                0, 0, "off"                 },
  { "case-sensitive",0,                0, 0, "on"                  },
  { "crnl-glob",     0,               16, 1, ""                    },
................................................................................
**
** Settings marked as versionable are overridden by the contents of the
** file named .fossil-settings/PROPERTY in the checked out files, if that
** file exists.
**
** The "unset" command clears a property setting.
**
**
**    allow-symlinks   If enabled, don't follow symlinks, and instead treat
**                     them as symlinks on Unix. Has no effect on Windows
**                     (existing links in repository created on Unix become 
**                     plain-text files with link destination path inside).
**                     Default: off
**
**    auto-captcha     If enabled, the Login page provides a button to
**                     fill in the captcha password.  Default: on
**
**    auto-shun        If enabled, automatically pull the shunning list
**                     from a server to which the client autosyncs.
**                     Default: on

    const char *zName2;       /* Name of zFile2 for display */

    /* Read content of zFile2 into memory */
    blob_zero(&file2);
    if( file_size(zFile2)<0 ){
      zName2 = "/dev/null";
    }else{



      blob_read_from_file(&file2, zFile2);

      zName2 = zName;
    }

    /* Compute and output the differences */
    blob_zero(&out);
    text_diff(pFile1, &file2, &out, 5, ignoreEolWs);
    if( blob_size(&out) ){
................................................................................
  const char *zFrom,        /* Name of file */
  const char *zDiffCmd,     /* Use this "diff" command */
  int ignoreEolWs,          /* Ignore whitespace changes at end of lines */
  const char *zFileTreeName
){
  Blob fname;
  Blob content;

  file_tree_name(zFileTreeName, &fname, 1);
  historical_version_of_file(zFrom, blob_str(&fname), &content, 0, 0);



  diff_file(&content, zFileTreeName, zFileTreeName, zDiffCmd, ignoreEolWs);

  blob_reset(&content);
  blob_reset(&fname);
}

/*
** Run a diff between the version zFrom and files on disk.  zFrom might
** be NULL which means to simply show the difference between the edited
................................................................................
  if( zFrom ){
    int rid = name_to_typed_rid(zFrom, "ci");
    if( !is_a_version(rid) ){
      fossil_fatal("no such check-in: %s", zFrom);
    }
    load_vfile_from_rid(rid);
    blob_appendf(&sql,
      "SELECT v2.pathname, v2.deleted, v2.chnged, v2.rid==0, v1.rid"
      "  FROM vfile v1, vfile v2 "
      " WHERE v1.pathname=v2.pathname AND v1.vid=%d AND v2.vid=%d"
      "   AND (v2.deleted OR v2.chnged OR v1.mrid!=v2.rid)"
      "UNION "
      "SELECT pathname, 1, 0, 0, 0"
      "  FROM vfile v1"
      " WHERE v1.vid=%d"
      "   AND NOT EXISTS(SELECT 1 FROM vfile v2"
                        " WHERE v2.vid=%d AND v2.pathname=v1.pathname)"
      "UNION "
      "SELECT pathname, 0, 0, 1, 0"
      "  FROM vfile v2"
      " WHERE v2.vid=%d"
      "   AND NOT EXISTS(SELECT 1 FROM vfile v1"
                        " WHERE v1.vid=%d AND v1.pathname=v2.pathname)"
      " ORDER BY 1",
      rid, vid, rid, vid, vid, rid
    );
  }else{
    blob_appendf(&sql,
      "SELECT pathname, deleted, chnged , rid==0, rid"
      "  FROM vfile"
      " WHERE vid=%d"
      "   AND (deleted OR chnged OR rid==0)"
      " ORDER BY pathname",
      vid
    );
  }
................................................................................
  db_prepare(&q, blob_str(&sql));
  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isChnged = db_column_int(&q,2);
    int isNew = db_column_int(&q,3);
    int srcid = db_column_int(&q, 4);

    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    char *zToFree = zFullName;
    int showDiff = 1;
    if( isDeleted ){
      diff_printf("DELETED  %s\n", zPathname);
      if( !asNewFile ){ showDiff = 0; zFullName = "/dev/null"; }
    }else if( file_access(zFullName, 0) ){
................................................................................
    }else if( isChnged==3 ){
      diff_printf("ADDED_BY_MERGE %s\n", zPathname);
      srcid = 0;
      if( !asNewFile ){ showDiff = 0; }
    }
    if( showDiff ){
      Blob content;






      if( srcid>0 ){
        content_get(srcid, &content);
      }else{
        blob_zero(&content);
      }
      diff_print_index(zPathname);
      diff_file(&content, zFullName, zPathname, zDiffCmd, ignoreEolWs);
................................................................................
  const char *zDiffCmd,
  int ignoreEolWs,
  const char *zFileTreeName
){
  char *zName;
  Blob fname;
  Blob v1, v2;

  file_tree_name(zFileTreeName, &fname, 1);
  zName = blob_str(&fname);
  historical_version_of_file(zFrom, zName, &v1, 0, 0);
  historical_version_of_file(zTo, zName, &v2, 0, 0);




  diff_file_mem(&v1, &v2, zName, zDiffCmd, ignoreEolWs);

  blob_reset(&v1);
  blob_reset(&v2);
  blob_reset(&fname);
}

/*
** Show the difference between two files identified by ManifestFile

    const char *zName2;       /* Name of zFile2 for display */

    /* Read content of zFile2 into memory */
    blob_zero(&file2);
    if( file_size(zFile2)<0 ){
      zName2 = "/dev/null";
    }else{
      if( file_islink(zFile2) ){
        blob_read_link(&file2, zFile2);
      }else{
        blob_read_from_file(&file2, zFile2);
      }
      zName2 = zName;
    }

    /* Compute and output the differences */
    blob_zero(&out);
    text_diff(pFile1, &file2, &out, 5, ignoreEolWs);
    if( blob_size(&out) ){
................................................................................
  const char *zFrom,        /* Name of file */
  const char *zDiffCmd,     /* Use this "diff" command */
  int ignoreEolWs,          /* Ignore whitespace changes at end of lines */
  const char *zFileTreeName
){
  Blob fname;
  Blob content;
  int isLink;
  file_tree_name(zFileTreeName, &fname, 1);
  historical_version_of_file(zFrom, blob_str(&fname), &content, &isLink, 0, 0);
  if( !isLink != !file_islink(zFrom) ){
    diff_printf("cannot compute difference between symlink and regular file\n");
  }else{
    diff_file(&content, zFileTreeName, zFileTreeName, zDiffCmd, ignoreEolWs);
  }
  blob_reset(&content);
  blob_reset(&fname);
}

/*
** Run a diff between the version zFrom and files on disk.  zFrom might
** be NULL which means to simply show the difference between the edited
................................................................................
  if( zFrom ){
    int rid = name_to_typed_rid(zFrom, "ci");
    if( !is_a_version(rid) ){
      fossil_fatal("no such check-in: %s", zFrom);
    }
    load_vfile_from_rid(rid);
    blob_appendf(&sql,
      "SELECT v2.pathname, v2.deleted, v2.chnged, v2.rid==0, v1.rid, v1.islink"
      "  FROM vfile v1, vfile v2 "
      " WHERE v1.pathname=v2.pathname AND v1.vid=%d AND v2.vid=%d"
      "   AND (v2.deleted OR v2.chnged OR v1.mrid!=v2.rid)"
      "UNION "
      "SELECT pathname, 1, 0, 0, 0, islink"
      "  FROM vfile v1"
      " WHERE v1.vid=%d"
      "   AND NOT EXISTS(SELECT 1 FROM vfile v2"
                        " WHERE v2.vid=%d AND v2.pathname=v1.pathname)"
      "UNION "
      "SELECT pathname, 0, 0, 1, 0, islink"
      "  FROM vfile v2"
      " WHERE v2.vid=%d"
      "   AND NOT EXISTS(SELECT 1 FROM vfile v1"
                        " WHERE v1.vid=%d AND v1.pathname=v2.pathname)"
      " ORDER BY 1",
      rid, vid, rid, vid, vid, rid
    );
  }else{
    blob_appendf(&sql,
      "SELECT pathname, deleted, chnged , rid==0, rid, islink"
      "  FROM vfile"
      " WHERE vid=%d"
      "   AND (deleted OR chnged OR rid==0)"
      " ORDER BY pathname",
      vid
    );
  }
................................................................................
  db_prepare(&q, blob_str(&sql));
  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isChnged = db_column_int(&q,2);
    int isNew = db_column_int(&q,3);
    int srcid = db_column_int(&q, 4);
    int isLink = db_column_int(&q, 5);
    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    char *zToFree = zFullName;
    int showDiff = 1;
    if( isDeleted ){
      diff_printf("DELETED  %s\n", zPathname);
      if( !asNewFile ){ showDiff = 0; zFullName = "/dev/null"; }
    }else if( file_access(zFullName, 0) ){
................................................................................
    }else if( isChnged==3 ){
      diff_printf("ADDED_BY_MERGE %s\n", zPathname);
      srcid = 0;
      if( !asNewFile ){ showDiff = 0; }
    }
    if( showDiff ){
      Blob content;
      if( !isLink != !file_islink(zFullName) ){
        diff_print_index(zPathname);
        diff_printf("--- %s\n+++ %s\n", zPathname, zPathname);
        diff_printf("cannot compute difference between symlink and regular file\n");
        continue;
      }
      if( srcid>0 ){
        content_get(srcid, &content);
      }else{
        blob_zero(&content);
      }
      diff_print_index(zPathname);
      diff_file(&content, zFullName, zPathname, zDiffCmd, ignoreEolWs);
................................................................................
  const char *zDiffCmd,
  int ignoreEolWs,
  const char *zFileTreeName
){
  char *zName;
  Blob fname;
  Blob v1, v2;
  int isLink1, isLink2;
  file_tree_name(zFileTreeName, &fname, 1);
  zName = blob_str(&fname);
  historical_version_of_file(zFrom, zName, &v1, &isLink1, 0, 0);
  historical_version_of_file(zTo, zName, &v2, &isLink2, 0, 0);
  if( isLink1 != isLink2 ){
    diff_printf("--- %s\n+++ %s\n", zName, zName);
    diff_printf("cannot compute difference between symlink and regular file\n");
  }else{
    diff_file_mem(&v1, &v2, zName, zDiffCmd, ignoreEolWs);
  }
  blob_reset(&v1);
  blob_reset(&v2);
  blob_reset(&fname);
}

/*
** Show the difference between two files identified by ManifestFile

    );
    while( db_step(&q4)==SQLITE_ROW ){
      const char *zName = db_column_text(&q4,0);
      int zNew = db_column_int(&q4,1);
      int mPerm = db_column_int(&q4,2);
      if( zNew==0)
        printf("D %s\n", zName);
      else if( bag_find(&blobs, zNew) )






        printf("M %s :%d %s\n", mPerm ? "100755" : "100644", BLOBMARK(zNew), zName);

    }
    db_finalize(&q4);
    db_finalize(&q3);
    printf("\n");
  }
  db_finalize(&q2);
  db_finalize(&q);

    );
    while( db_step(&q4)==SQLITE_ROW ){
      const char *zName = db_column_text(&q4,0);
      int zNew = db_column_int(&q4,1);
      int mPerm = db_column_int(&q4,2);
      if( zNew==0)
        printf("D %s\n", zName);
      else if( bag_find(&blobs, zNew) ) {
        const char *zPerm;
        switch( mPerm ){
          case PERM_LNK:  zPerm = "120000";   break;
          case PERM_EXE:  zPerm = "100755";   break;
          default:        zPerm = "100644";   break;
        }
        printf("M %s :%d %s\n", zPerm, BLOBMARK(zNew), zName);
      }
    }
    db_finalize(&q4);
    db_finalize(&q3);
    printf("\n");
  }
  db_finalize(&q2);
  db_finalize(&q);

/*
** The file status information from the most recent stat() call.
**
** Use _stati64 rather than stat on windows, in order to handle files
** larger than 2GB.
*/
#if defined(_WIN32) && defined(__MSVCRT__)
  static struct _stati64 fileStat;
# define stat _stati64
#else

  static struct stat fileStat;










#endif
static int fileStatValid = 0;


/*
** Fill in the fileStat variable for the file named zFilename.
** If zFilename==0, then use the previous value of fileStat if
** there is a previous value.
**
** Return the number of errors.  No error messages are generated.
................................................................................
*/
static int getStat(const char *zFilename){
  int rc = 0;
  if( zFilename==0 ){
    if( fileStatValid==0 ) rc = 1;
  }else{
    char *zMbcs = fossil_utf8_to_mbcs(zFilename);
    if( stat(zMbcs, &fileStat)!=0 ){
      fileStatValid = 0;
      rc = 1;
    }else{
      fileStatValid = 1;
      rc = 0;
    }
    fossil_mbcs_free(zMbcs);
................................................................................
** Return the modification time for a file.  Return -1 if the file
** does not exist.  If zFilename is NULL return the size of the most
** recently stat-ed file.
*/
i64 file_mtime(const char *zFilename){
  return getStat(zFilename) ? -1 : fileStat.st_mtime;
}















/*
** Return TRUE if the named file is an ordinary file.  Return false
** for directories, devices, fifos, symlinks, etc.
*/
int file_isfile(const char *zFilename){
  return getStat(zFilename) ? 0 : S_ISREG(fileStat.st_mode);
}

/*
** Return TRUE if the named file is an executable.  Return false
** for directories, devices, fifos, symlinks, etc.















































*/
int file_isexe(const char *zFilename){
  if( getStat(zFilename) || !S_ISREG(fileStat.st_mode) ) return 0;
#if defined(_WIN32)
#  if defined(__DMC__) || defined(_MSC_VER)
#    define S_IXUSR  _S_IEXEC
#  endif
  return ((S_IXUSR)&fileStat.st_mode)!=0;

#else



  return ((S_IXUSR|S_IXGRP|S_IXOTH)&fileStat.st_mode)!=0;





#endif
}



















/*
** Return 1 if zFilename is a directory.  Return 0 if zFilename
** does not exist.  Return 2 if zFilename exists but is something
** other than a directory.
*/
int file_isdir(const char *zFilename){
................................................................................
    char *zFN = mprintf("%s", zFilename);
    file_simplify_name(zFN, -1);
    rc = getStat(zFN);
    free(zFN);
  }else{
    rc = getStat(0);
  }




  return rc ? 0 : (S_ISDIR(fileStat.st_mode) ? 1 : 2);




}

/*
** Wrapper around the access() system call.
*/
int file_access(const char *zFilename, int flags){
  char *zMbcs = fossil_utf8_to_mbcs(zFilename);
................................................................................
** Set or clear the execute bit on a file.  Return true if a change
** occurred and false if this routine is a no-op.
*/
int file_setexe(const char *zFilename, int onoff){
  int rc = 0;
#if !defined(_WIN32)
  struct stat buf;
  if( stat(zFilename, &buf)!=0 ) return 0;
  if( onoff ){
    int targetMode = (buf.st_mode & 0444)>>2;
    if( (buf.st_mode & 0111)!=targetMode ){
      chmod(zFilename, buf.st_mode | targetMode);
      rc = 1;
    }
  }else{
................................................................................
    fossil_print("[%s] -> [%s]\n", zName, blob_buffer(&x));
    blob_reset(&x);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", file_size(zName));
    fossil_print("  file_size   = %s\n", zBuf);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", file_mtime(zName));
    fossil_print("  file_mtime  = %s\n", zBuf);
    fossil_print("  file_isfile = %d\n", file_isfile(zName));


    fossil_print("  file_isexe  = %d\n", file_isexe(zName));
    fossil_print("  file_isdir  = %d\n", file_isdir(zName));
  }
}

/*
** Return TRUE if the given filename is canonical.
................................................................................
  i64 iSize;
  int rc;
  Blob onDisk;

  iSize = file_size(zName);
  if( iSize<0 ) return 0;
  if( iSize!=blob_size(pContent) ) return 0;



  blob_read_from_file(&onDisk, zName);

  rc = blob_compare(&onDisk, pContent);
  blob_reset(&onDisk);
  return rc==0;
}


/**************************************************************************

/*
** The file status information from the most recent stat() call.
**
** Use _stati64 rather than stat on windows, in order to handle files
** larger than 2GB.
*/
#if defined(_WIN32) && defined(__MSVCRT__)

# define stat _stati64
#endif
static int fileStatValid = 0;
static struct stat fileStat;

static int fossil_stat(const char *zFilename, struct stat *buf){
#if !defined(_WIN32)
  if( g.allowSymlinks ){
    return lstat(zFilename, buf);
  }else{
    return stat(zFilename, buf);
  }
#else
  return stat(zFilename, buf);
#endif

}

/*
** Fill in the fileStat variable for the file named zFilename.
** If zFilename==0, then use the previous value of fileStat if
** there is a previous value.
**
** Return the number of errors.  No error messages are generated.
................................................................................
*/
static int getStat(const char *zFilename){
  int rc = 0;
  if( zFilename==0 ){
    if( fileStatValid==0 ) rc = 1;
  }else{
    char *zMbcs = fossil_utf8_to_mbcs(zFilename);
    if( fossil_stat(zMbcs, &fileStat)!=0 ){
      fileStatValid = 0;
      rc = 1;
    }else{
      fileStatValid = 1;
      rc = 0;
    }
    fossil_mbcs_free(zMbcs);
................................................................................
** Return the modification time for a file.  Return -1 if the file
** does not exist.  If zFilename is NULL return the size of the most
** recently stat-ed file.
*/
i64 file_mtime(const char *zFilename){
  return getStat(zFilename) ? -1 : fileStat.st_mtime;
}

/*
** Return TRUE if the named file is an ordinary file or symlink 
** and symlinks are allowed.
** Return false for directories, devices, fifos, etc.
*/
int file_isfile_or_link(const char *zFilename){
#if !defined(_WIN32)
  if ( g.allowSymlinks ){
    return getStat(zFilename) ? 0 : S_ISREG(fileStat.st_mode) || S_ISLNK(fileStat.st_mode);
  }
#endif
  return getStat(zFilename) ? 0 : S_ISREG(fileStat.st_mode);    
}

/*
** Return TRUE if the named file is an ordinary file.  Return false
** for directories, devices, fifos, symlinks, etc.
*/
int file_isfile(const char *zFilename){
  return getStat(zFilename) ? 0 : S_ISREG(fileStat.st_mode);
}

/*
** Create symlink to file on Unix, or plain-text file with
** symlink target if "allow-symlinks" is off or we're on Windows.
**
** Arguments: target file (symlink will point to it), link file
**/
void create_symlink(const char *zTargetFile, const char *zLinkFile){
#if !defined(_WIN32)
  if( g.allowSymlinks ){
    int i, nName;
    char *zName, zBuf[1000];

    nName = strlen(zLinkFile);
    if( nName>=sizeof(zBuf) ){
      zName = mprintf("%s", zLinkFile);
    }else{
      zName = zBuf;
      memcpy(zName, zLinkFile, nName+1);
    }
    nName = file_simplify_name(zName, nName);
    for(i=1; i<nName; i++){
      if( zName[i]=='/' ){
        zName[i] = 0;
          if( file_mkdir(zName, 1) ){
            fossil_fatal_recursive("unable to create directory %s", zName);
            return;
          }
        zName[i] = '/';
      }
    }
    if( zName!=zBuf ) free(zName);

    if( symlink(zTargetFile, zName)!=0 ){
      fossil_fatal_recursive("unable to create symlink \"%s\"", zName);      
    }
  }else
#endif 
  {
    Blob content;
    blob_set(&content, zTargetFile);
    blob_write_to_file(&content, zLinkFile);
    blob_reset(&content);
  }
}

/*
** Return file permissions (normal, executable, or symlink):
**   - PERM_EXE if file is executable;
**   - PERM_LNK on Unix if file is symlink and allow-symlinks option is on;
**   - PERM_REG for all other cases (regular file, directory, fifo, etc).
*/
int file_perm(const char *zFilename){
  if( getStat(zFilename) ) return PERM_REG;
#if defined(_WIN32)
#  if defined(__DMC__) || defined(_MSC_VER)
#    define S_IXUSR  _S_IEXEC
#  endif
  if( S_ISREG(fileStat.st_mode) && ((S_IXUSR)&fileStat.st_mode)!=0 )
    return PERM_EXE;
  else
    return PERM_REG;
#else
  if( S_ISREG(fileStat.st_mode) && 
      ((S_IXUSR|S_IXGRP|S_IXOTH)&fileStat.st_mode)!=0 )
    return PERM_EXE;
  else if( g.allowSymlinks && S_ISLNK(fileStat.st_mode) )
    return PERM_LNK;
  else
    return PERM_REG;
#endif
}

/*
** Return TRUE if the named file is an executable.  Return false
** for directories, devices, fifos, symlinks, etc.
*/
int file_isexe(const char *zFilename){
  return file_perm(zFilename)==PERM_EXE;
}

/*
** Return TRUE if the named file is a symlink and symlinks are allowed.
** Return false for all other cases.
**
** On Windows, always return False.
*/
int file_islink(const char *zFilename){
  return file_perm(zFilename)==PERM_LNK;
}

/*
** Return 1 if zFilename is a directory.  Return 0 if zFilename
** does not exist.  Return 2 if zFilename exists but is something
** other than a directory.
*/
int file_isdir(const char *zFilename){
................................................................................
    char *zFN = mprintf("%s", zFilename);
    file_simplify_name(zFN, -1);
    rc = getStat(zFN);
    free(zFN);
  }else{
    rc = getStat(0);
  }
#if !defined(_WIN32)
  if( g.allowSymlinks ){
    return rc ? 0 : (S_ISDIR(fileStat.st_mode) && !S_ISLNK(fileStat.st_mode) ? 1 : 2);
  }else{
    return rc ? 0 : (S_ISDIR(fileStat.st_mode) ? 1 : 2);    
  }
#else
  return rc ? 0 : (S_ISDIR(fileStat.st_mode) ? 1 : 2);
#endif
}

/*
** Wrapper around the access() system call.
*/
int file_access(const char *zFilename, int flags){
  char *zMbcs = fossil_utf8_to_mbcs(zFilename);
................................................................................
** Set or clear the execute bit on a file.  Return true if a change
** occurred and false if this routine is a no-op.
*/
int file_setexe(const char *zFilename, int onoff){
  int rc = 0;
#if !defined(_WIN32)
  struct stat buf;
  if( fossil_stat(zFilename, &buf)!=0 || S_ISLNK(buf.st_mode) ) return 0;
  if( onoff ){
    int targetMode = (buf.st_mode & 0444)>>2;
    if( (buf.st_mode & 0111)!=targetMode ){
      chmod(zFilename, buf.st_mode | targetMode);
      rc = 1;
    }
  }else{
................................................................................
    fossil_print("[%s] -> [%s]\n", zName, blob_buffer(&x));
    blob_reset(&x);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", file_size(zName));
    fossil_print("  file_size   = %s\n", zBuf);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", file_mtime(zName));
    fossil_print("  file_mtime  = %s\n", zBuf);
    fossil_print("  file_isfile = %d\n", file_isfile(zName));
    fossil_print("  file_isfile_or_link = %d\n", file_isfile_or_link(zName));
    fossil_print("  file_islink = %d\n", file_islink(zName));
    fossil_print("  file_isexe  = %d\n", file_isexe(zName));
    fossil_print("  file_isdir  = %d\n", file_isdir(zName));
  }
}

/*
** Return TRUE if the given filename is canonical.
................................................................................
  i64 iSize;
  int rc;
  Blob onDisk;

  iSize = file_size(zName);
  if( iSize<0 ) return 0;
  if( iSize!=blob_size(pContent) ) return 0;
  if( file_islink(zName) ){
    blob_read_link(&onDisk, zName);
  }else{
    blob_read_from_file(&onDisk, zName);
  }
  rc = blob_compare(&onDisk, pContent);
  blob_reset(&onDisk);
  return rc==0;
}


/**************************************************************************

  }else if( find_option("print","p",0) ){
    Blob record;
    Blob fname;
    const char *zRevision = find_option("revision", "r", 1);

    file_tree_name(g.argv[2], &fname, 1);
    if( zRevision ){
      historical_version_of_file(zRevision, blob_str(&fname), &record, 0, 0);
    }else{
      int rid = db_int(0, "SELECT rid FROM vfile WHERE pathname=%B", &fname);
      if( rid==0 ){
        fossil_fatal("no history for file: %b", &fname);
      }
      content_get(rid, &record);
    }

  }else if( find_option("print","p",0) ){
    Blob record;
    Blob fname;
    const char *zRevision = find_option("revision", "r", 1);

    file_tree_name(g.argv[2], &fname, 1);
    if( zRevision ){
      historical_version_of_file(zRevision, blob_str(&fname), &record, 0, 0, 0);
    }else{
      int rid = db_int(0, "SELECT rid FROM vfile WHERE pathname=%B", &fname);
      if( rid==0 ){
        fossil_fatal("no history for file: %b", &fname);
      }
      content_get(rid, &record);
    }

    BIO_puts(mem, "\n\nSHA1 Fingerprint:\n\n ");
    if(X509_digest(cert, EVP_sha1(), md, &mdLength)){
      int j;
      for( j = 0; j < mdLength; ++j ) {
        BIO_printf(mem, " %02x", md[j]);
      }
    }
    BIO_write(mem, "", 1); // null-terminate mem buffer
    BIO_get_mem_data(mem, &desc);
    
    if( hasSavedCertificate ){
      warning = "WARNING: Certificate doesn't match the "
                "saved certificate for this host!";
    }
    prompt = mprintf("\nUnknown SSL certificate:\n\n%s\n\n%s\n"
................................................................................
      return 1;
    }
    if( blob_str(&ans)[0]=='a' ) {
      ssl_save_certificate(cert);
    }
    blob_reset(&ans);
  }











  X509_free(cert);
  return 0;
}

/*
** Save certificate to global config.
*/
void ssl_save_certificate(X509 *cert){
  BIO *mem;
  char *zCert, *zHost;

  mem = BIO_new(BIO_s_mem());
  PEM_write_bio_X509(mem, cert);
  BIO_write(mem, "", 1); // null-terminate mem buffer
  BIO_get_mem_data(mem, &zCert);
  zHost = mprintf("cert:%s", g.urlName);
  db_set(zHost, zCert, 1);
  free(zHost);
  BIO_free(mem);  
}

    BIO_puts(mem, "\n\nSHA1 Fingerprint:\n\n ");
    if(X509_digest(cert, EVP_sha1(), md, &mdLength)){
      int j;
      for( j = 0; j < mdLength; ++j ) {
        BIO_printf(mem, " %02x", md[j]);
      }
    }
    BIO_write(mem, "", 1); /* null-terminate mem buffer */
    BIO_get_mem_data(mem, &desc);
    
    if( hasSavedCertificate ){
      warning = "WARNING: Certificate doesn't match the "
                "saved certificate for this host!";
    }
    prompt = mprintf("\nUnknown SSL certificate:\n\n%s\n\n%s\n"
................................................................................
      return 1;
    }
    if( blob_str(&ans)[0]=='a' ) {
      ssl_save_certificate(cert);
    }
    blob_reset(&ans);
  }

  /* Set the Global.zIpAddr variable to the server we are talking to.
  ** This is used to populate the ipaddr column of the rcvfrom table,
  ** if any files are received from the server.
  */
  {
      /* IPv4 only code */
      const unsigned char *ip = (const unsigned char *) BIO_get_conn_ip(iBio);
      g.zIpAddr = mprintf("%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
  }

  X509_free(cert);
  return 0;
}

/*
** Save certificate to global config.
*/
void ssl_save_certificate(X509 *cert){
  BIO *mem;
  char *zCert, *zHost;

  mem = BIO_new(BIO_s_mem());
  PEM_write_bio_X509(mem, cert);
  BIO_write(mem, "", 1); /* null-terminate mem buffer */
  BIO_get_mem_data(mem, &zCert);
  zHost = mprintf("cert:%s", g.urlName);
  db_set(zHost, zCert, 1);
  free(zHost);
  BIO_free(mem);  
}

*/
struct ImportFile { 
  char *zName;           /* Name of a file */
  char *zUuid;           /* UUID of the file */
  char *zPrior;          /* Prior name if the name was changed */
  char isFrom;           /* True if obtained from the parent */
  char isExe;            /* True if executable */

};
#endif


/*
** State information about an on-going fast-import parse.
*/
................................................................................
  int nMerge;                 /* Number of merge values */
  int nMergeAlloc;            /* Number of slots in azMerge[] */
  char **azMerge;             /* Merge values */
  int nFile;                  /* Number of aFile values */
  int nFileAlloc;             /* Number of slots in aFile[] */
  ImportFile *aFile;          /* Information about files in a commit */
  int fromLoaded;             /* True zFrom content loaded into aFile[] */

  int tagCommit;              /* True if the commit adds a tag */
} gg;

/*
** Duplicate a string.
*/
char *fossil_strdup(const char *zOrig){
................................................................................
  blob_appendf(&record, "D %s\n", gg.zDate);
  for(i=0; i<gg.nFile; i++){
    const char *zUuid = gg.aFile[i].zUuid;
    if( zUuid==0 ) continue;
    blob_appendf(&record, "F %F %s", gg.aFile[i].zName, zUuid);
    if( gg.aFile[i].isExe ){
      blob_append(&record, " x\n", 3);



    }else{
      blob_append(&record, "\n", 1);
    }
  }
  if( gg.zFrom ){
    blob_appendf(&record, "P %s", gg.zFrom);
    for(i=0; i<gg.nMerge; i++){
................................................................................
  p = manifest_get(rid, CFTYPE_MANIFEST);
  if( p==0 ) return;
  manifest_file_rewind(p);
  while( (pOld = manifest_file_next(p, 0))!=0 ){
    pNew = import_add_file();
    pNew->zName = fossil_strdup(pOld->zName);
    pNew->isExe = pOld->zPerm && strstr(pOld->zPerm, "x")!=0;

    pNew->zUuid = fossil_strdup(pOld->zUuid);
    pNew->isFrom = 1;
  }
  manifest_destroy(p);
}

/*
................................................................................
      i = 0;
      pFile = import_find_file(zName, &i, gg.nFile);
      if( pFile==0 ){
        pFile = import_add_file();
        pFile->zName = fossil_strdup(zName);
      }
      pFile->isExe = (fossil_strcmp(zPerm, "100755")==0);

      fossil_free(pFile->zUuid);
      pFile->zUuid = resolve_committish(zUuid);
      pFile->isFrom = 0;
    }else
    if( memcmp(zLine, "D ", 2)==0 ){
      import_prior_files();
      z = &zLine[2];
................................................................................
        pFile = &gg.aFile[i-1];
        if( strlen(pFile->zName)>nFrom ){
          pNew->zName = mprintf("%s%s", zTo, pFile->zName[nFrom]);
        }else{
          pNew->zName = fossil_strdup(pFile->zName);
        }
        pNew->isExe = pFile->isExe;

        pNew->zUuid = fossil_strdup(pFile->zUuid);
        pNew->isFrom = 0;
      }
    }else
    if( memcmp(zLine, "R ", 2)==0 ){
      int nFrom;
      import_prior_files();
................................................................................
        if( strlen(pFile->zName)>nFrom ){
          pNew->zName = mprintf("%s%s", zTo, pFile->zName[nFrom]);
        }else{
          pNew->zName = fossil_strdup(pFile->zName);
        }
        pNew->zPrior = pFile->zName;
        pNew->isExe = pFile->isExe;

        pNew->zUuid = pFile->zUuid;
        pNew->isFrom = 0;
        gg.nFile--;
        *pFile = *pNew;
        memset(pNew, 0, sizeof(*pNew));
      }
      fossil_fatal("cannot handle R records, use --full-tree");
................................................................................
    }else

    {
      goto malformed_line;
    }
  }
  gg.xFinish();



  import_reset(1);
  return;

malformed_line:
  trim_newline(zLine);
  fossil_fatal("bad fast-import line: [%s]", zLine);
  return;

*/
struct ImportFile { 
  char *zName;           /* Name of a file */
  char *zUuid;           /* UUID of the file */
  char *zPrior;          /* Prior name if the name was changed */
  char isFrom;           /* True if obtained from the parent */
  char isExe;            /* True if executable */
  char isLink;           /* True if symlink */
};
#endif


/*
** State information about an on-going fast-import parse.
*/
................................................................................
  int nMerge;                 /* Number of merge values */
  int nMergeAlloc;            /* Number of slots in azMerge[] */
  char **azMerge;             /* Merge values */
  int nFile;                  /* Number of aFile values */
  int nFileAlloc;             /* Number of slots in aFile[] */
  ImportFile *aFile;          /* Information about files in a commit */
  int fromLoaded;             /* True zFrom content loaded into aFile[] */
  int hasLinks;               /* True if git repository contains symlinks */
  int tagCommit;              /* True if the commit adds a tag */
} gg;

/*
** Duplicate a string.
*/
char *fossil_strdup(const char *zOrig){
................................................................................
  blob_appendf(&record, "D %s\n", gg.zDate);
  for(i=0; i<gg.nFile; i++){
    const char *zUuid = gg.aFile[i].zUuid;
    if( zUuid==0 ) continue;
    blob_appendf(&record, "F %F %s", gg.aFile[i].zName, zUuid);
    if( gg.aFile[i].isExe ){
      blob_append(&record, " x\n", 3);
    }else if( gg.aFile[i].isLink ){
      blob_append(&record, " l\n", 3);
      gg.hasLinks = 1;
    }else{
      blob_append(&record, "\n", 1);
    }
  }
  if( gg.zFrom ){
    blob_appendf(&record, "P %s", gg.zFrom);
    for(i=0; i<gg.nMerge; i++){
................................................................................
  p = manifest_get(rid, CFTYPE_MANIFEST);
  if( p==0 ) return;
  manifest_file_rewind(p);
  while( (pOld = manifest_file_next(p, 0))!=0 ){
    pNew = import_add_file();
    pNew->zName = fossil_strdup(pOld->zName);
    pNew->isExe = pOld->zPerm && strstr(pOld->zPerm, "x")!=0;
    pNew->isLink = pOld->zPerm && strstr(pOld->zPerm, "l")!=0;
    pNew->zUuid = fossil_strdup(pOld->zUuid);
    pNew->isFrom = 1;
  }
  manifest_destroy(p);
}

/*
................................................................................
      i = 0;
      pFile = import_find_file(zName, &i, gg.nFile);
      if( pFile==0 ){
        pFile = import_add_file();
        pFile->zName = fossil_strdup(zName);
      }
      pFile->isExe = (fossil_strcmp(zPerm, "100755")==0);
      pFile->isLink = (fossil_strcmp(zPerm, "120000")==0);      
      fossil_free(pFile->zUuid);
      pFile->zUuid = resolve_committish(zUuid);
      pFile->isFrom = 0;
    }else
    if( memcmp(zLine, "D ", 2)==0 ){
      import_prior_files();
      z = &zLine[2];
................................................................................
        pFile = &gg.aFile[i-1];
        if( strlen(pFile->zName)>nFrom ){
          pNew->zName = mprintf("%s%s", zTo, pFile->zName[nFrom]);
        }else{
          pNew->zName = fossil_strdup(pFile->zName);
        }
        pNew->isExe = pFile->isExe;
        pNew->isLink = pFile->isLink;
        pNew->zUuid = fossil_strdup(pFile->zUuid);
        pNew->isFrom = 0;
      }
    }else
    if( memcmp(zLine, "R ", 2)==0 ){
      int nFrom;
      import_prior_files();
................................................................................
        if( strlen(pFile->zName)>nFrom ){
          pNew->zName = mprintf("%s%s", zTo, pFile->zName[nFrom]);
        }else{
          pNew->zName = fossil_strdup(pFile->zName);
        }
        pNew->zPrior = pFile->zName;
        pNew->isExe = pFile->isExe;
        pNew->isLink = pFile->isLink;
        pNew->zUuid = pFile->zUuid;
        pNew->isFrom = 0;
        gg.nFile--;
        *pFile = *pNew;
        memset(pNew, 0, sizeof(*pNew));
      }
      fossil_fatal("cannot handle R records, use --full-tree");
................................................................................
    }else

    {
      goto malformed_line;
    }
  }
  gg.xFinish();
  if( gg.hasLinks ){
    db_set_int("allow-symlinks", 1, 0);
  }
  import_reset(1);
  return;

malformed_line:
  trim_newline(zLine);
  fossil_fatal("bad fast-import line: [%s]", zLine);
  return;

*/
static void append_file_change_line(
  const char *zName,    /* Name of the file that has changed */
  const char *zOld,     /* blob.uuid before change.  NULL for added files */
  const char *zNew,     /* blob.uuid after change.  NULL for deletes */
  const char *zOldName, /* Prior name.  NULL if no name change. */
  int showDiff,         /* Show edit diffs if true */
  int mperm             /* EXE permission for zNew */
){
  if( !g.okHistory ){
    if( zNew==0 ){
      @ <p>Deleted %h(zName)</p>
    }else if( zOld==0 ){
      @ <p>Added %h(zName)</p>
    }else if( zOldName!=0 && fossil_strcmp(zName,zOldName)!=0 ){
      @ <p>Name change from %h(zOldName) to %h(zName)
    }else if( fossil_strcmp(zNew, zOld)==0 ){
      @ <p>Execute permission %s(mperm?"set":"cleared") for %h(zName)</p>

    }else{
      @ <p>Changes to %h(zName)</p>
    }
    if( showDiff ){
      @ <blockquote><pre>
      append_diff(zOld, zNew);
      @ </pre></blockquote>
................................................................................
        @ from <a href="%s(g.zTop)/artifact/%s(zOld)">[%S(zOld)]</a>
        @ to <a href="%s(g.zTop)/artifact/%s(zNew)">[%S(zNew)].</a>
      }else if( zOldName!=0 && fossil_strcmp(zName,zOldName)!=0 ){
        @ <p>Name change from
        @ from <a href="%s(g.zTop)/finfo?name=%T(zOldName)">%h(zOldName)</a>
        @ to <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>.
      }else{
        @ <p>Execute permission %s(mperm?"set":"cleared") for
        @ <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
      }
    }else if( zOld ){
      @ <p>Deleted <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
      @ version <a href="%s(g.zTop)/artifact/%s(zOld)">[%S(zOld)]</a>
    }else{
      @ <p>Added <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
................................................................................
  Blob *pDownloadName      /* Fill with an appropriate download name */
){
  Stmt q;
  int cnt = 0;
  int nWiki = 0;
  char *zUuid = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", rid);



  db_prepare(&q,
    "SELECT filename.name, datetime(event.mtime),"
    "       coalesce(event.ecomment,event.comment),"
    "       coalesce(event.euser,event.user),"
    "       b.uuid"


    "  FROM mlink, filename, event, blob a, blob b"
    " WHERE filename.fnid=mlink.fnid"
    "   AND event.objid=mlink.mid"
    "   AND a.rid=mlink.fid"
    "   AND b.rid=mlink.mid"
    "   AND mlink.fid=%d",
    rid

  );

  while( db_step(&q)==SQLITE_ROW ){
    const char *zName = db_column_text(&q, 0);
    const char *zDate = db_column_text(&q, 1);
    const char *zCom = db_column_text(&q, 2);
    const char *zUser = db_column_text(&q, 3);
    const char *zVers = db_column_text(&q, 4);
    if( cnt>0 ){
      @ Also file








    }else{
      @ File
    }
    if( g.okHistory ){
      @ <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
    }else{
      @ %h(zName)
    }





    @ part of check-in
    hyperlink_to_uuid(zVers);







    @ - %w(zCom) by 
    hyperlink_to_user(zUser,zDate," on");
    hyperlink_to_date(zDate,".");

    if( g.okHistory ){
      @ <a href="%s(g.zTop)/annotate?checkin=%S(zVers)&filename=%T(zName)">
      @ [annotate]</a>
    }
    cnt++;
    if( pDownloadName && blob_size(pDownloadName)==0 ){
      blob_append(pDownloadName, zName, -1);
    }
  }


  db_finalize(&q);
  db_prepare(&q, 
    "SELECT substr(tagname, 6, 10000), datetime(event.mtime),"
    "       coalesce(event.euser, event.user)"
    "  FROM tagxref, tag, event"
    " WHERE tagxref.rid=%d"
    "   AND tag.tagid=tagxref.tagid" 
................................................................................
  blob_reset(&c2);
  if( !isPatch ){
    style_header("Diff");
    style_submenu_element("Patch", "Patch", "%s/fdiff?v1=%T&v2=%T&patch",
                          g.zTop, P("v1"), P("v2"));
    @ <h2>Differences From
    @ Artifact <a href="%s(g.zTop)/artifact/%S(zV1)">[%S(zV1)]</a>:</h2>
    @ <blockquote><p>
    object_description(v1, 1, 0);
    @ </p></blockquote>
    @ <h2>To Artifact <a href="%s(g.zTop)/artifact/%S(zV2)">[%S(zV2)]</a>:</h2>
    @ <blockquote><p>
    object_description(v2, 1, 0);
    @ </p></blockquote>
    @ <hr />
    @ <blockquote><pre>
    @ %h(blob_str(&diff))
    @ </pre></blockquote>
    blob_reset(&diff);
    style_footer();
  }
................................................................................
      style_submenu_element("Shun","Shun", "%s/shun?shun=%s#addshun",
            g.zTop, zUuid);
    }
  }
  style_header("Hex Artifact Content");
  zUuid = db_text("?","SELECT uuid FROM blob WHERE rid=%d", rid);
  @ <h2>Artifact %s(zUuid):</h2>
  @ <blockquote><p>
  blob_zero(&downloadName);
  object_description(rid, 0, &downloadName);
  style_submenu_element("Download", "Download", 
        "%s/raw/%T?name=%s", g.zTop, blob_str(&downloadName), zUuid);
  @ </p></blockquote>
  @ <hr />
  content_get(rid, &content);
  @ <blockquote><pre>
  hexdump(&content);
  @ </pre></blockquote>
  style_footer();
}
................................................................................
      style_submenu_element("Shun","Shun", "%s/shun?shun=%s#addshun",
            g.zTop, zUuid);
    }
  }
  style_header("Artifact Content");
  zUuid = db_text("?", "SELECT uuid FROM blob WHERE rid=%d", rid);
  @ <h2>Artifact %s(zUuid)</h2>
  @ <blockquote><p>
  blob_zero(&downloadName);
  object_description(rid, 0, &downloadName);
  style_submenu_element("Download", "Download", 
          "%s/raw/%T?name=%s", g.zTop, blob_str(&downloadName), zUuid);
  zMime = mimetype_from_name(blob_str(&downloadName));
  if( zMime ){
    if( fossil_strcmp(zMime, "text/html")==0 ){
................................................................................
      }else{
        renderAsWiki = 1;
        style_submenu_element("Text", "Text",
                              "%s/artifact/%s?txt=1", g.zTop, zUuid);
      }
    }
  }
  @ </p></blockquote>
  @ <hr />
  content_get(rid, &content);
  if( renderAsWiki ){
    wiki_convert(&content, 0, 0);
  }else if( renderAsHtml ){
    @ <div>
    cgi_append_content(blob_buffer(&content), blob_size(&content));

*/
static void append_file_change_line(
  const char *zName,    /* Name of the file that has changed */
  const char *zOld,     /* blob.uuid before change.  NULL for added files */
  const char *zNew,     /* blob.uuid after change.  NULL for deletes */
  const char *zOldName, /* Prior name.  NULL if no name change. */
  int showDiff,         /* Show edit diffs if true */
  int mperm             /* executable or symlink permission for zNew */
){
  if( !g.okHistory ){
    if( zNew==0 ){
      @ <p>Deleted %h(zName)</p>
    }else if( zOld==0 ){
      @ <p>Added %h(zName)</p>
    }else if( zOldName!=0 && fossil_strcmp(zName,zOldName)!=0 ){
      @ <p>Name change from %h(zOldName) to %h(zName)
    }else if( fossil_strcmp(zNew, zOld)==0 ){
      @ <p>Execute permission %s(( mperm==PERM_EXE )?"set":"cleared")
      @  for %h(zName)</p>
    }else{
      @ <p>Changes to %h(zName)</p>
    }
    if( showDiff ){
      @ <blockquote><pre>
      append_diff(zOld, zNew);
      @ </pre></blockquote>
................................................................................
        @ from <a href="%s(g.zTop)/artifact/%s(zOld)">[%S(zOld)]</a>
        @ to <a href="%s(g.zTop)/artifact/%s(zNew)">[%S(zNew)].</a>
      }else if( zOldName!=0 && fossil_strcmp(zName,zOldName)!=0 ){
        @ <p>Name change from
        @ from <a href="%s(g.zTop)/finfo?name=%T(zOldName)">%h(zOldName)</a>
        @ to <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>.
      }else{
        @ <p>Execute permission %s(( mperm==PERM_EXE )?"set":"cleared") for
        @ <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
      }
    }else if( zOld ){
      @ <p>Deleted <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
      @ version <a href="%s(g.zTop)/artifact/%s(zOld)">[%S(zOld)]</a>
    }else{
      @ <p>Added <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
................................................................................
  Blob *pDownloadName      /* Fill with an appropriate download name */
){
  Stmt q;
  int cnt = 0;
  int nWiki = 0;
  char *zUuid = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", rid);

  char *prevName = 0;

  db_prepare(&q,
    "SELECT filename.name, datetime(event.mtime),"
    "       coalesce(event.ecomment,event.comment),"
    "       coalesce(event.euser,event.user),"
    "       b.uuid, mlink.mperm,"
    "       coalesce((SELECT value FROM tagxref"
                    "  WHERE tagid=%d AND tagtype>0 AND rid=mlink.mid),'trunk')"
    "  FROM mlink, filename, event, blob a, blob b"
    " WHERE filename.fnid=mlink.fnid"
    "   AND event.objid=mlink.mid"
    "   AND a.rid=mlink.fid"
    "   AND b.rid=mlink.mid"
    "   AND mlink.fid=%d"
    "   ORDER BY filename.name, event.mtime",
    TAG_BRANCH, rid
  );
  @ <ul>
  while( db_step(&q)==SQLITE_ROW ){
    const char *zName = db_column_text(&q, 0);
    const char *zDate = db_column_text(&q, 1);
    const char *zCom = db_column_text(&q, 2);
    const char *zUser = db_column_text(&q, 3);
    const char *zVers = db_column_text(&q, 4);
    int mPerm = db_column_int(&q, 5);
    const char *zBr = db_column_text(&q, 6);
    if( !prevName || fossil_strcmp(zName, prevName) ) {
      if( prevName ) {
        @ </ul>
      }
      if( mPerm==PERM_LNK ){
        @ <li>Symbolic link
      }else if( mPerm==PERM_EXE ){
        @ <li>Executable file
      }else{
        @ <li>File        
      }
      if( g.okHistory ){
        @ <a href="%s(g.zTop)/finfo?name=%T(zName)">%h(zName)</a>
      }else{
        @ %h(zName)
      }
      @ <ul>
      prevName = fossil_strdup(zName);
    }
    @ <li>
    hyperlink_to_date(zDate,"");
    @ - part of checkin
    hyperlink_to_uuid(zVers);
    if( zBr && zBr[0] ){
      if( g.okHistory ){
        @ on branch <a href="%s(g.zTop)/timeline?r=%T(zBr)">%h(zBr)</a>
      }else{
        @ on branch %h(zBr)
      }
    }
    @ - %w(zCom) (user:
    hyperlink_to_user(zUser,zDate,"");

    @ )
    if( g.okHistory ){
      @ <a href="%s(g.zTop)/annotate?checkin=%S(zVers)&filename=%T(zName)">
      @ [annotate]</a>
    }
    cnt++;
    if( pDownloadName && blob_size(pDownloadName)==0 ){
      blob_append(pDownloadName, zName, -1);
    }
  }
  @ </ul></ul>
  free(prevName);
  db_finalize(&q);
  db_prepare(&q, 
    "SELECT substr(tagname, 6, 10000), datetime(event.mtime),"
    "       coalesce(event.euser, event.user)"
    "  FROM tagxref, tag, event"
    " WHERE tagxref.rid=%d"
    "   AND tag.tagid=tagxref.tagid" 
................................................................................
  blob_reset(&c2);
  if( !isPatch ){
    style_header("Diff");
    style_submenu_element("Patch", "Patch", "%s/fdiff?v1=%T&v2=%T&patch",
                          g.zTop, P("v1"), P("v2"));
    @ <h2>Differences From
    @ Artifact <a href="%s(g.zTop)/artifact/%S(zV1)">[%S(zV1)]</a>:</h2>

    object_description(v1, 0, 0);

    @ <h2>To Artifact <a href="%s(g.zTop)/artifact/%S(zV2)">[%S(zV2)]</a>:</h2>

    object_description(v2, 0, 0);

    @ <hr />
    @ <blockquote><pre>
    @ %h(blob_str(&diff))
    @ </pre></blockquote>
    blob_reset(&diff);
    style_footer();
  }
................................................................................
      style_submenu_element("Shun","Shun", "%s/shun?shun=%s#addshun",
            g.zTop, zUuid);
    }
  }
  style_header("Hex Artifact Content");
  zUuid = db_text("?","SELECT uuid FROM blob WHERE rid=%d", rid);
  @ <h2>Artifact %s(zUuid):</h2>

  blob_zero(&downloadName);
  object_description(rid, 0, &downloadName);
  style_submenu_element("Download", "Download", 
        "%s/raw/%T?name=%s", g.zTop, blob_str(&downloadName), zUuid);

  @ <hr />
  content_get(rid, &content);
  @ <blockquote><pre>
  hexdump(&content);
  @ </pre></blockquote>
  style_footer();
}
................................................................................
      style_submenu_element("Shun","Shun", "%s/shun?shun=%s#addshun",
            g.zTop, zUuid);
    }
  }
  style_header("Artifact Content");
  zUuid = db_text("?", "SELECT uuid FROM blob WHERE rid=%d", rid);
  @ <h2>Artifact %s(zUuid)</h2>

  blob_zero(&downloadName);
  object_description(rid, 0, &downloadName);
  style_submenu_element("Download", "Download", 
          "%s/raw/%T?name=%s", g.zTop, blob_str(&downloadName), zUuid);
  zMime = mimetype_from_name(blob_str(&downloadName));
  if( zMime ){
    if( fossil_strcmp(zMime, "text/html")==0 ){
................................................................................
      }else{
        renderAsWiki = 1;
        style_submenu_element("Text", "Text",
                              "%s/artifact/%s?txt=1", g.zTop, zUuid);
      }
    }
  }

  @ <hr />
  content_get(rid, &content);
  if( renderAsWiki ){
    wiki_convert(&content, 0, 0);
  }else if( renderAsHtml ){
    @ <div>
    cgi_append_content(blob_buffer(&content), blob_size(&content));

  /* Storage for the aux() and/or option() SQL function arguments */
  int nAux;                    /* Number of distinct aux() or option() values */
  const char *azAuxName[MX_AUX]; /* Name of each aux() or option() value */
  char *azAuxParam[MX_AUX];      /* Param of each aux() or option() value */
  const char *azAuxVal[MX_AUX];  /* Value of each aux() or option() value */
  const char **azAuxOpt[MX_AUX]; /* Options of each option() value */
  int anAuxCols[MX_AUX];         /* Number of columns for option() values */


};

/*
** Macro for debugging:
*/
#define CGIDEBUG(X)  if( g.fDebug ) cgi_debug X

  /* Storage for the aux() and/or option() SQL function arguments */
  int nAux;                    /* Number of distinct aux() or option() values */
  const char *azAuxName[MX_AUX]; /* Name of each aux() or option() value */
  char *azAuxParam[MX_AUX];      /* Param of each aux() or option() value */
  const char *azAuxVal[MX_AUX];  /* Value of each aux() or option() value */
  const char **azAuxOpt[MX_AUX]; /* Options of each option() value */
  int anAuxCols[MX_AUX];         /* Number of columns for option() values */
  
  int allowSymlinks;             /* Cached "allow-symlinks" option */
};

/*
** Macro for debugging:
*/
#define CGIDEBUG(X)  if( g.fDebug ) cgi_debug X

#define CFTYPE_CLUSTER    2
#define CFTYPE_CONTROL    3
#define CFTYPE_WIKI       4
#define CFTYPE_TICKET     5
#define CFTYPE_ATTACHMENT 6
#define CFTYPE_EVENT      7








/*
** A single F-card within a manifest
*/
struct ManifestFile { 
  char *zName;           /* Name of a file */
  char *zUuid;           /* UUID of the file */
  char *zPerm;           /* File permissions */
................................................................................
}

/*
** Compute an appropriate mlink.mperm integer for the permission string
** of a file.
*/
int manifest_file_mperm(ManifestFile *pFile){
  int mperm = 0;

  if( pFile && pFile->zPerm && strstr(pFile->zPerm,"x")!=0 ){
    mperm = 1;


  }
  return mperm;
}

/*
** Add a single entry to the mlink table.  Also add the filename to
** the filename table if it is not there already.
................................................................................
static void add_one_mlink(
  int mid,                  /* The record ID of the manifest */
  const char *zFromUuid,    /* UUID for the mlink.pid. "" to add file */
  const char *zToUuid,      /* UUID for the mlink.fid. "" to delele */
  const char *zFilename,    /* Filename */
  const char *zPrior,       /* Previous filename. NULL if unchanged */
  int isPublic,             /* True if mid is not a private manifest */
  int mperm                 /* 1: exec */
){
  int fnid, pfnid, pid, fid;
  static Stmt s1;

  fnid = filename_to_fnid(zFilename);
  if( zPrior==0 ){
    pfnid = 0;

#define CFTYPE_CLUSTER    2
#define CFTYPE_CONTROL    3
#define CFTYPE_WIKI       4
#define CFTYPE_TICKET     5
#define CFTYPE_ATTACHMENT 6
#define CFTYPE_EVENT      7

/*
** File permissions used by Fossil internally.
*/
#define PERM_REG          0     /*  regular file  */
#define PERM_EXE          1     /*  executable    */
#define PERM_LNK          2     /*  symlink       */

/*
** A single F-card within a manifest
*/
struct ManifestFile { 
  char *zName;           /* Name of a file */
  char *zUuid;           /* UUID of the file */
  char *zPerm;           /* File permissions */
................................................................................
}

/*
** Compute an appropriate mlink.mperm integer for the permission string
** of a file.
*/
int manifest_file_mperm(ManifestFile *pFile){
  int mperm = PERM_REG;
  if( pFile && pFile->zPerm){
    if( strstr(pFile->zPerm,"x")!=0 )
      mperm = PERM_EXE;
    else if( strstr(pFile->zPerm,"l")!=0 )
      mperm = PERM_LNK;
  }
  return mperm;
}

/*
** Add a single entry to the mlink table.  Also add the filename to
** the filename table if it is not there already.
................................................................................
static void add_one_mlink(
  int mid,                  /* The record ID of the manifest */
  const char *zFromUuid,    /* UUID for the mlink.pid. "" to add file */
  const char *zToUuid,      /* UUID for the mlink.fid. "" to delele */
  const char *zFilename,    /* Filename */
  const char *zPrior,       /* Previous filename. NULL if unchanged */
  int isPublic,             /* True if mid is not a private manifest */
  int mperm                 /* 1: exec, 2: symlink */
){
  int fnid, pfnid, pid, fid;
  static Stmt s1;

  fnid = filename_to_fnid(zFilename);
  if( zPrior==0 ){
    pfnid = 0;

    fossil_fatal("not a version: record #%d", pid);
  }
  vfile_check_signature(vid, 1, 0);
  db_begin_transaction();
  if( !nochangeFlag ) undo_begin();
  load_vfile_from_rid(mid);
  load_vfile_from_rid(pid);










  /*
  ** The vfile.pathname field is used to match files against each other.  The
  ** FV table contains one row for each each unique filename in
  ** in the current checkout, the pivot, and the version being merged.
  */
  db_multi_exec(
................................................................................
    "  idm INTEGER,"              /* VFILE entry for version merging in */
    "  chnged BOOLEAN,"           /* True if current version has been edited */
    "  ridv INTEGER,"             /* Record ID for current version */
    "  ridp INTEGER,"             /* Record ID for pivot */
    "  ridm INTEGER,"             /* Record ID for merge */
    "  isexe BOOLEAN,"            /* Execute permission enabled */
    "  fnp TEXT,"                 /* The filename in the pivot */
    "  fnm TEXT"                  /* the filename in the merged version */


    ");",
    caseSensitive ? "binary" : "nocase"
  );

  /* Add files found in V
  */
  db_multi_exec(
................................................................................
    " FROM vfile WHERE vid=%d",
    vid
  );

  /*
  ** Compute name changes from P->V
  */
  find_filename_changes(vid, pid, &nChng, &aChng);
  if( nChng ){
    for(i=0; i<nChng; i++){
      char *z;
      z = db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i*2+1]);
      db_multi_exec(
        "UPDATE fv SET fnp=%Q, fnm=%Q"
        " WHERE fn=(SELECT name FROM filename WHERE fnid=%d)",
        z, z, aChng[i*2]
      );
      free(z);
    }
    fossil_free(aChng);
    db_multi_exec("UPDATE fv SET fnm=fnp WHERE fnp!=fn");
  }

................................................................................
    "  WHERE vid=%d AND pathname NOT IN (SELECT fnp FROM fv)",
    pid
  );

  /*
  ** Compute name changes from P->M
  */
  find_filename_changes(pid, mid, &nChng, &aChng);
  if( nChng ){
    if( nChng>4 ) db_multi_exec("CREATE INDEX fv_fnp ON fv(fnp)");
    for(i=0; i<nChng; i++){
      db_multi_exec(
        "UPDATE fv SET fnm=(SELECT name FROM filename WHERE fnid=%d)"
        " WHERE fnp=(SELECT name FROM filename WHERE fnid=%d)",
        aChng[i*2+1], aChng[i*2]
................................................................................
  ** Compute the file version ids for P and M.
  */
  db_multi_exec(
    "UPDATE fv SET"
    " idp=coalesce((SELECT id FROM vfile WHERE vid=%d AND pathname=fnp),0),"
    " ridp=coalesce((SELECT rid FROM vfile WHERE vid=%d AND pathname=fnp),0),"
    " idm=coalesce((SELECT id FROM vfile WHERE vid=%d AND pathname=fnm),0),"
    " ridm=coalesce((SELECT rid FROM vfile WHERE vid=%d AND pathname=fnm),0)",




    pid, pid, mid, mid
  );

  if( debugFlag ){
    db_prepare(&q,
       "SELECT rowid, fn, fnp, fnm, chnged, ridv, ridp, ridm, isexe FROM fv"

    );
    while( db_step(&q)==SQLITE_ROW ){
       fossil_print("%3d: ridv=%-4d ridp=%-4d ridm=%-4d chnged=%d isexe=%d\n",

          db_column_int(&q, 0),
          db_column_int(&q, 5),
          db_column_int(&q, 6),
          db_column_int(&q, 7),
          db_column_int(&q, 4),
          db_column_int(&q, 8));


       fossil_print("     fn  = [%s]\n", db_column_text(&q, 1));
       fossil_print("     fnp = [%s]\n", db_column_text(&q, 2));
       fossil_print("     fnm = [%s]\n", db_column_text(&q, 3));
    }
    db_finalize(&q);
  }

................................................................................
  );
  while( db_step(&q)==SQLITE_ROW ){
    int idm = db_column_int(&q, 0);
    int rowid = db_column_int(&q, 1);
    int idv;
    const char *zName;
    db_multi_exec(
      "INSERT INTO vfile(vid,chnged,deleted,rid,mrid,isexe,pathname)"
      "  SELECT %d,3,0,rid,mrid,isexe,pathname FROM vfile WHERE id=%d",
      vid, idm
    );
    idv = db_last_insert_rowid();
    db_multi_exec("UPDATE fv SET idv=%d WHERE rowid=%d", idv, rowid);
    zName = db_column_text(&q, 2);
    fossil_print("ADDED %s\n", zName);
    if( !nochangeFlag ){
      undo_save(zName);
      vfile_to_disk(0, idm, 0, 0);
    }
  }
  db_finalize(&q);

  /*
  ** Find files that have changed from P->M but not P->V.
  ** Copy the M content over into V.
  */
  db_prepare(&q,
    "SELECT idv, ridm, fn FROM fv"
    " WHERE idp>0 AND idv>0 AND idm>0"
    "   AND ridm!=ridp AND ridv=ridp AND NOT chnged"
  );
  while( db_step(&q)==SQLITE_ROW ){
    int idv = db_column_int(&q, 0);
    int ridm = db_column_int(&q, 1);
    const char *zName = db_column_text(&q, 2);

    /* Copy content from idm over into idv.  Overwrite idv. */
    fossil_print("UPDATE %s\n", zName);
    if( !nochangeFlag ){
      undo_save(zName);
      db_multi_exec(
        "UPDATE vfile SET mtime=0, mrid=%d, chnged=2 WHERE id=%d", ridm, idv

      );
      vfile_to_disk(0, idv, 0, 0);
    }
  }
  db_finalize(&q);

  /*
  ** Do a three-way merge on files that have changes on both P->M and P->V.
  */
  db_prepare(&q,
    "SELECT ridm, idv, ridp, ridv, %s, fn, isexe FROM fv"
    " WHERE idp>0 AND idv>0 AND idm>0"
    "   AND ridm!=ridp AND (ridv!=ridp OR chnged)",
    glob_expr("fv.fn", zBinGlob)
  );
  while( db_step(&q)==SQLITE_ROW ){
    int ridm = db_column_int(&q, 0);
    int idv = db_column_int(&q, 1);
    int ridp = db_column_int(&q, 2);
    int ridv = db_column_int(&q, 3);
    int isBinary = db_column_int(&q, 4);
    const char *zName = db_column_text(&q, 5);
    int isExe = db_column_int(&q, 6);


    int rc;
    char *zFullPath;
    Blob m, p, r;
    /* Do a 3-way merge of idp->idm into idp->idv.  The results go into idv. */
    if( detailFlag ){
      fossil_print("MERGE %s  (pivot=%d v1=%d v2=%d)\n", 
                   zName, ridp, ridm, ridv);
    }else{
      fossil_print("MERGE %s\n", zName);
    }




    undo_save(zName);
    zFullPath = mprintf("%s/%s", g.zLocalRoot, zName);
    content_get(ridp, &p);
    content_get(ridm, &m);
    if( isBinary ){
      rc = -1;
      blob_zero(&r);
    }else{
      rc = merge_3way(&p, zFullPath, &m, &r);
    }
    if( rc>=0 ){
      if( !nochangeFlag ){
        blob_write_to_file(&r, zFullPath);
        file_setexe(zFullPath, isExe);
      }
      db_multi_exec("UPDATE vfile SET mtime=0 WHERE id=%d", idv);
      if( rc>0 ){
        fossil_print("***** %d merge conflicts in %s\n", rc, zName);
        nConflict++;
      }
    }else{
      fossil_print("***** Cannot merge binary file %s\n", zName);
      nConflict++;
    }
    blob_reset(&p);
    blob_reset(&m);
    blob_reset(&r);

    db_multi_exec("INSERT OR IGNORE INTO vmerge(id,merge) VALUES(%d,%d)",
                  idv,ridm);
  }
  db_finalize(&q);

  /*
  ** Drop files that are in P and V but not in M

    fossil_fatal("not a version: record #%d", pid);
  }
  vfile_check_signature(vid, 1, 0);
  db_begin_transaction();
  if( !nochangeFlag ) undo_begin();
  load_vfile_from_rid(mid);
  load_vfile_from_rid(pid);
  if( debugFlag ){
    char *z;
    z = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", pid);
    fossil_print("P=%d %z\n", pid, z);
    z = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", mid);
    fossil_print("M=%d %z\n", mid, z);
    z = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", vid);
    fossil_print("V=%d %z\n", vid, z);
  }

  /*
  ** The vfile.pathname field is used to match files against each other.  The
  ** FV table contains one row for each each unique filename in
  ** in the current checkout, the pivot, and the version being merged.
  */
  db_multi_exec(
................................................................................
    "  idm INTEGER,"              /* VFILE entry for version merging in */
    "  chnged BOOLEAN,"           /* True if current version has been edited */
    "  ridv INTEGER,"             /* Record ID for current version */
    "  ridp INTEGER,"             /* Record ID for pivot */
    "  ridm INTEGER,"             /* Record ID for merge */
    "  isexe BOOLEAN,"            /* Execute permission enabled */
    "  fnp TEXT,"                 /* The filename in the pivot */
    "  fnm TEXT,"                 /* the filename in the merged version */
    "  islinkv BOOLEAN,"          /* True if current version is a symlink */
    "  islinkm BOOLEAN"           /* True if merged version in is a symlink */
    ");",
    caseSensitive ? "binary" : "nocase"
  );

  /* Add files found in V
  */
  db_multi_exec(
................................................................................
    " FROM vfile WHERE vid=%d",
    vid
  );

  /*
  ** Compute name changes from P->V
  */
  find_filename_changes(pid, vid, 0, &nChng, &aChng, debugFlag ? "P->V" : 0);
  if( nChng ){
    for(i=0; i<nChng; i++){
      char *z;
      z = db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i*2]);
      db_multi_exec(
        "UPDATE fv SET fnp=%Q, fnm=%Q"
        " WHERE fn=(SELECT name FROM filename WHERE fnid=%d)",
        z, z, aChng[i*2+1]
      );
      free(z);
    }
    fossil_free(aChng);
    db_multi_exec("UPDATE fv SET fnm=fnp WHERE fnp!=fn");
  }

................................................................................
    "  WHERE vid=%d AND pathname NOT IN (SELECT fnp FROM fv)",
    pid
  );

  /*
  ** Compute name changes from P->M
  */
  find_filename_changes(pid, mid, 0, &nChng, &aChng, debugFlag ? "P->M" : 0);
  if( nChng ){
    if( nChng>4 ) db_multi_exec("CREATE INDEX fv_fnp ON fv(fnp)");
    for(i=0; i<nChng; i++){
      db_multi_exec(
        "UPDATE fv SET fnm=(SELECT name FROM filename WHERE fnid=%d)"
        " WHERE fnp=(SELECT name FROM filename WHERE fnid=%d)",
        aChng[i*2+1], aChng[i*2]
................................................................................
  ** Compute the file version ids for P and M.
  */
  db_multi_exec(
    "UPDATE fv SET"
    " idp=coalesce((SELECT id FROM vfile WHERE vid=%d AND pathname=fnp),0),"
    " ridp=coalesce((SELECT rid FROM vfile WHERE vid=%d AND pathname=fnp),0),"
    " idm=coalesce((SELECT id FROM vfile WHERE vid=%d AND pathname=fnm),0),"
    " ridm=coalesce((SELECT rid FROM vfile WHERE vid=%d AND pathname=fnm),0),"
    " islinkv=coalesce((SELECT islink FROM vfile"
                    " WHERE vid=%d AND pathname=fnm),0),"
    " islinkm=coalesce((SELECT islink FROM vfile"
                    " WHERE vid=%d AND pathname=fnm),0)",
    pid, pid, mid, mid, vid, mid
  );

  if( debugFlag ){
    db_prepare(&q,
       "SELECT rowid, fn, fnp, fnm, chnged, ridv, ridp, ridm, "
       "       isexe, islinkv, islinkm FROM fv"
    );
    while( db_step(&q)==SQLITE_ROW ){
       fossil_print("%3d: ridv=%-4d ridp=%-4d ridm=%-4d chnged=%d isexe=%d "
                    " islinkv=%d islinkm=%d\n",
          db_column_int(&q, 0),
          db_column_int(&q, 5),
          db_column_int(&q, 6),
          db_column_int(&q, 7),
          db_column_int(&q, 4),
          db_column_int(&q, 8),
          db_column_int(&q, 9),
          db_column_int(&q, 10));
       fossil_print("     fn  = [%s]\n", db_column_text(&q, 1));
       fossil_print("     fnp = [%s]\n", db_column_text(&q, 2));
       fossil_print("     fnm = [%s]\n", db_column_text(&q, 3));
    }
    db_finalize(&q);
  }

................................................................................
  );
  while( db_step(&q)==SQLITE_ROW ){
    int idm = db_column_int(&q, 0);
    int rowid = db_column_int(&q, 1);
    int idv;
    const char *zName;
    db_multi_exec(
      "INSERT INTO vfile(vid,chnged,deleted,rid,mrid,isexe,islink,pathname)"
      "  SELECT %d,3,0,rid,mrid,isexe,islink,pathname FROM vfile WHERE id=%d",
      vid, idm
    );
    idv = db_last_insert_rowid();
    db_multi_exec("UPDATE fv SET idv=%d WHERE rowid=%d", idv, rowid);
    zName = db_column_text(&q, 2);
    fossil_print("ADDED %s\n", zName);
    if( !nochangeFlag ){
      undo_save(zName);
      vfile_to_disk(0, idm, 0, 0);
    }
  }
  db_finalize(&q);
  
  /*
  ** Find files that have changed from P->M but not P->V. 
  ** Copy the M content over into V.
  */
  db_prepare(&q,
    "SELECT idv, ridm, fn, islinkm FROM fv"
    " WHERE idp>0 AND idv>0 AND idm>0"
    "   AND ridm!=ridp AND ridv=ridp AND NOT chnged"
  );
  while( db_step(&q)==SQLITE_ROW ){
    int idv = db_column_int(&q, 0);
    int ridm = db_column_int(&q, 1);
    const char *zName = db_column_text(&q, 2);
    int islinkm = db_column_int(&q, 3);
    /* Copy content from idm over into idv.  Overwrite idv. */
    fossil_print("UPDATE %s\n", zName);
    if( !nochangeFlag ){
      undo_save(zName);
      db_multi_exec(
        "UPDATE vfile SET mtime=0, mrid=%d, chnged=2, islink=%d "
        " WHERE id=%d", ridm, islinkm, idv
      );
      vfile_to_disk(0, idv, 0, 0);
    }
  }
  db_finalize(&q);

  /*
  ** Do a three-way merge on files that have changes on both P->M and P->V.
  */
  db_prepare(&q,
    "SELECT ridm, idv, ridp, ridv, %s, fn, isexe, islinkv, islinkm FROM fv"
    " WHERE idp>0 AND idv>0 AND idm>0"
    "   AND ridm!=ridp AND (ridv!=ridp OR chnged)",
    glob_expr("fv.fn", zBinGlob)
  );
  while( db_step(&q)==SQLITE_ROW ){
    int ridm = db_column_int(&q, 0);
    int idv = db_column_int(&q, 1);
    int ridp = db_column_int(&q, 2);
    int ridv = db_column_int(&q, 3);
    int isBinary = db_column_int(&q, 4);
    const char *zName = db_column_text(&q, 5);
    int isExe = db_column_int(&q, 6);
    int islinkv = db_column_int(&q, 7);
    int islinkm = db_column_int(&q, 8);
    int rc;
    char *zFullPath;
    Blob m, p, r;
    /* Do a 3-way merge of idp->idm into idp->idv.  The results go into idv. */
    if( detailFlag ){
      fossil_print("MERGE %s  (pivot=%d v1=%d v2=%d)\n", 
                   zName, ridp, ridm, ridv);
    }else{
      fossil_print("MERGE %s\n", zName);
    }
    if( islinkv || islinkm /* || file_islink(zFullPath) */ ){
      fossil_print("***** Cannot merge symlink %s\n", zName);
      nConflict++;        
    }else{
      undo_save(zName);
      zFullPath = mprintf("%s/%s", g.zLocalRoot, zName);
      content_get(ridp, &p);
      content_get(ridm, &m);
      if( isBinary ){
        rc = -1;
        blob_zero(&r);
      }else{
        rc = merge_3way(&p, zFullPath, &m, &r);
      }
      if( rc>=0 ){
        if( !nochangeFlag ){
          blob_write_to_file(&r, zFullPath);
          file_setexe(zFullPath, isExe);
        }
        db_multi_exec("UPDATE vfile SET mtime=0 WHERE id=%d", idv);
        if( rc>0 ){
          fossil_print("***** %d merge conflicts in %s\n", rc, zName);
          nConflict++;
        }
      }else{
        fossil_print("***** Cannot merge binary file %s\n", zName);
        nConflict++;
      }
      blob_reset(&p);
      blob_reset(&m);
      blob_reset(&r);
    }
    db_multi_exec("INSERT OR IGNORE INTO vmerge(id,merge) VALUES(%d,%d)",
                  idv,ridm);
  }
  db_finalize(&q);

  /*
  ** Drop files that are in P and V but not in M

  PathNode *p;
  while( path.pAll ){
    p = path.pAll;
    path.pAll = p->pAll;
    fossil_free(p);
  }
  bag_clear(&path.seen);
  path.pCurrent = 0;
  path.pAll = 0;
  path.pEnd = 0;
  path.nStep = 0;
}

/*
** Construct the path from path.pStart to path.pEnd in the u.pTo fields.
*/
void path_reverse_path(void){
  PathNode *p;
................................................................................
**
** Return a pointer to the beginning of the path (the iFrom node).  
** Elements of the path can be traversed by following the PathNode.u.pTo
** pointer chain.
**
** Return NULL if no path is found.
*/
PathNode *path_shortest(int iFrom, int iTo, int directOnly){





  Stmt s;
  PathNode *pPrev;
  PathNode *p;

  path_reset();
  path.pStart = path_new_node(iFrom, 0, 0);
  if( iTo==iFrom ){
    path.pEnd = path.pStart;
    return path.pStart;
  }




  if( directOnly ){
    db_prepare(&s, 
        "SELECT cid, 1 FROM plink WHERE pid=:pid AND isprim "
        "UNION ALL "
        "SELECT pid, 0 FROM plink WHERE cid=:pid AND isprim"
    );
  }else{
    db_prepare(&s, 
................................................................................
*/
void shortest_path_test_cmd(void){
  int iFrom;
  int iTo;
  PathNode *p;
  int n;
  int directOnly;


  db_find_and_open_repository(0,0);
  directOnly = find_option("no-merge",0,0)!=0;

  if( g.argc!=4 ) usage("VERSION1 VERSION2");
  iFrom = name_to_rid(g.argv[2]);
  iTo = name_to_rid(g.argv[3]);
  p = path_shortest(iFrom, iTo, directOnly);
  if( p==0 ){
    fossil_fatal("no path from %s to %s", g.argv[1], g.argv[2]);
  }
  for(n=1, p=path.pStart; p; p=p->u.pTo, n++){
    char *z;
    z = db_text(0,
      "SELECT substr(uuid,1,12) || ' ' || datetime(mtime)"
      "  FROM blob, event"
      " WHERE blob.rid=%d AND event.objid=%d AND event.type='ci'",
      p->rid, p->rid);
    fossil_print("%4d: %s", n, z);
    fossil_free(z);
    if( p->u.pTo ){
      fossil_print(" is a %s of\n", 
                   p->u.pTo->fromIsParent ? "parent" : "child");
    }else{
      fossil_print("\n");
    }
................................................................................
  for(n=1, p=path.pStart; p; p=p->u.pTo, n++){
    char *z;
    z = db_text(0,
      "SELECT substr(uuid,1,12) || ' ' || datetime(mtime)"
      "  FROM blob, event"
      " WHERE blob.rid=%d AND event.objid=%d AND event.type='ci'",
      p->rid, p->rid);
    fossil_print("%4d: %s", n, z);
    fossil_free(z);
    if( p->rid==iFrom ) fossil_print(" VERSION1");
    if( p->rid==iTo ) fossil_print(" VERSION2");
    if( p->rid==iPivot ) fossil_print(" PIVOT");
    fossil_print("\n");
  }
}
................................................................................

/*
** Compute all file name changes that occur going from checkin iFrom
** to checkin iTo.
**
** The number of name changes is written into *pnChng.  For each name
** change, two integers are allocated for *piChng.  The first is the 
** filename.fnid for the original name and the second is for new name.


** Space to hold *piChng is obtained from fossil_malloc() and should
** be released by the caller.
**
** This routine really has nothing to do with pathion.  It is located
** in this path.c module in order to leverage some of the path
** infrastructure.
*/
void find_filename_changes(
  int iFrom,
  int iTo,
  int *pnChng,

  int **aiChng

){
  PathNode *p;           /* For looping over path from iFrom to iTo */
  NameChange *pAll = 0;    /* List of all name changes seen so far */
  NameChange *pChng;       /* For looping through the name change list */
  int nChng = 0;           /* Number of files whose names have changed */
  int *aChng;              /* Two integers per name change */
  int i;                   /* Loop counter */
  Stmt q1;                 /* Query of name changes */

  *pnChng = 0;
  *aiChng = 0;
  if( iFrom==iTo ) return;
  path_reset();
  p = path_shortest(iFrom, iTo, 1);
  if( p==0 ) return;
  path_reverse_path();
  db_prepare(&q1,
     "SELECT pfnid, fnid FROM mlink WHERE mid=:mid AND pfnid>0"


  );
  for(p=path.pStart; p; p=p->u.pTo){
    int fnid, pfnid;
    if( !p->fromIsParent && (p->u.pTo==0 || p->u.pTo->fromIsParent) ){
      /* Skip nodes where the parent is not on the path */
      continue;
    }
    db_bind_int(&q1, ":mid", p->rid);
    while( db_step(&q1)==SQLITE_ROW ){
      if( p->fromIsParent ){
        fnid = db_column_int(&q1, 1);
        pfnid = db_column_int(&q1, 0);
      }else{


        fnid = db_column_int(&q1, 0);




        pfnid = db_column_int(&q1, 1);









      }
      for(pChng=pAll; pChng; pChng=pChng->pNext){
        if( pChng->curName==pfnid ){
          pChng->newName = fnid;
          break;
        }
      }
      if( pChng==0 ){
        pChng = fossil_malloc( sizeof(*pChng) );
        pChng->pNext = pAll;
        pAll = pChng;
        pChng->origName = pfnid;
        pChng->curName = pfnid;
        pChng->newName = fnid;
        nChng++;
      }
    }
    for(pChng=pAll; pChng; pChng=pChng->pNext) pChng->curName = pChng->newName;


    db_reset(&q1);
  }
  db_finalize(&q1);
  if( nChng ){
    *pnChng = nChng;
    aChng = *aiChng = fossil_malloc( nChng*2*sizeof(int) );
    for(pChng=pAll, i=0; pChng; pChng=pChng->pNext, i+=2){



      aChng[i] = pChng->origName;
      aChng[i+1] = pChng->newName;







    }



    while( pAll ){
      pChng = pAll;
      pAll = pAll->pNext;
      fossil_free(pChng);
    }
  }
}

/*
** COMMAND: test-name-changes
**
** Usage: %fossil test-name-changes VERSION1 VERSION2
**
** Show all filename changes that occur going from VERSION1 to VERSION2
*/
void test_name_change(void){
  int iFrom;
  int iTo;
  int *aChng;
  int nChng;
  int i;



  db_find_and_open_repository(0,0);


  if( g.argc!=4 ) usage("VERSION1 VERSION2");

  iFrom = name_to_rid(g.argv[2]);
  iTo = name_to_rid(g.argv[3]);
  find_filename_changes(iFrom, iTo, &nChng, &aChng);


  for(i=0; i<nChng; i++){
    char *zFrom, *zTo;

    zFrom = db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i*2]);
    zTo = db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i*2+1]);
    fossil_print("[%s] -> [%s]\n", zFrom, zTo);
    fossil_free(zFrom);
    fossil_free(zTo);
  }
  fossil_free(aChng);


}

  PathNode *p;
  while( path.pAll ){
    p = path.pAll;
    path.pAll = p->pAll;
    fossil_free(p);
  }
  bag_clear(&path.seen);
  memset(&path, 0, sizeof(&path));



}

/*
** Construct the path from path.pStart to path.pEnd in the u.pTo fields.
*/
void path_reverse_path(void){
  PathNode *p;
................................................................................
**
** Return a pointer to the beginning of the path (the iFrom node).  
** Elements of the path can be traversed by following the PathNode.u.pTo
** pointer chain.
**
** Return NULL if no path is found.
*/
PathNode *path_shortest(
  int iFrom,          /* Path starts here */
  int iTo,            /* Path ends here */
  int directOnly,     /* No merge links if true */
  int oneWayOnly      /* Parent->child only if true */
){
  Stmt s;
  PathNode *pPrev;
  PathNode *p;

  path_reset();
  path.pStart = path_new_node(iFrom, 0, 0);
  if( iTo==iFrom ){
    path.pEnd = path.pStart;
    return path.pStart;
  }
  if( oneWayOnly ){
    db_prepare(&s, 
        "SELECT cid, 1 FROM plink WHERE pid=:pid "
    );
  }else if( directOnly ){
    db_prepare(&s, 
        "SELECT cid, 1 FROM plink WHERE pid=:pid AND isprim "
        "UNION ALL "
        "SELECT pid, 0 FROM plink WHERE cid=:pid AND isprim"
    );
  }else{
    db_prepare(&s, 
................................................................................
*/
void shortest_path_test_cmd(void){
  int iFrom;
  int iTo;
  PathNode *p;
  int n;
  int directOnly;
  int oneWay;

  db_find_and_open_repository(0,0);
  directOnly = find_option("no-merge",0,0)!=0;
  oneWay = find_option("one-way",0,0)!=0;
  if( g.argc!=4 ) usage("VERSION1 VERSION2");
  iFrom = name_to_rid(g.argv[2]);
  iTo = name_to_rid(g.argv[3]);
  p = path_shortest(iFrom, iTo, directOnly, oneWay);
  if( p==0 ){
    fossil_fatal("no path from %s to %s", g.argv[1], g.argv[2]);
  }
  for(n=1, p=path.pStart; p; p=p->u.pTo, n++){
    char *z;
    z = db_text(0,
      "SELECT substr(uuid,1,12) || ' ' || datetime(mtime)"
      "  FROM blob, event"
      " WHERE blob.rid=%d AND event.objid=%d AND event.type='ci'",
      p->rid, p->rid);
    fossil_print("%4d: %5d %s", n, p->rid, z);
    fossil_free(z);
    if( p->u.pTo ){
      fossil_print(" is a %s of\n", 
                   p->u.pTo->fromIsParent ? "parent" : "child");
    }else{
      fossil_print("\n");
    }
................................................................................
  for(n=1, p=path.pStart; p; p=p->u.pTo, n++){
    char *z;
    z = db_text(0,
      "SELECT substr(uuid,1,12) || ' ' || datetime(mtime)"
      "  FROM blob, event"
      " WHERE blob.rid=%d AND event.objid=%d AND event.type='ci'",
      p->rid, p->rid);
    fossil_print("%4d: %5d %s", n, p->rid, z);
    fossil_free(z);
    if( p->rid==iFrom ) fossil_print(" VERSION1");
    if( p->rid==iTo ) fossil_print(" VERSION2");
    if( p->rid==iPivot ) fossil_print(" PIVOT");
    fossil_print("\n");
  }
}
................................................................................

/*
** Compute all file name changes that occur going from checkin iFrom
** to checkin iTo.
**
** The number of name changes is written into *pnChng.  For each name
** change, two integers are allocated for *piChng.  The first is the 
** filename.fnid for the original name as seen in check-in iFrom and
** the second is for new name as it is used in check-in iTo.
**
** Space to hold *piChng is obtained from fossil_malloc() and should
** be released by the caller.
**
** This routine really has nothing to do with path.  It is located
** in this path.c module in order to leverage some of the path
** infrastructure.
*/
void find_filename_changes(
  int iFrom,               /* Ancestor check-in */
  int iTo,                 /* Recent check-in */
  int revOk,               /* Ok to move backwards (child->parent) if true */
  int *pnChng,             /* Number of name changes along the path */
  int **aiChng,            /* Name changes */
  const char *zDebug       /* Generate trace output if no NULL */
){
  PathNode *p;             /* For looping over path from iFrom to iTo */
  NameChange *pAll = 0;    /* List of all name changes seen so far */
  NameChange *pChng;       /* For looping through the name change list */
  int nChng = 0;           /* Number of files whose names have changed */
  int *aChng;              /* Two integers per name change */
  int i;                   /* Loop counter */
  Stmt q1;                 /* Query of name changes */

  *pnChng = 0;
  *aiChng = 0;
  if( iFrom==iTo ) return;
  path_reset();
  p = path_shortest(iFrom, iTo, 1, revOk==0);
  if( p==0 ) return;
  path_reverse_path();
  db_prepare(&q1,
     "SELECT pfnid, fnid FROM mlink"
     " WHERE mid=:mid AND (pfnid>0 OR fid==0)"
     " ORDER BY pfnid"
  );
  for(p=path.pStart; p; p=p->u.pTo){
    int fnid, pfnid;
    if( !p->fromIsParent && (p->u.pTo==0 || p->u.pTo->fromIsParent) ){
      /* Skip nodes where the parent is not on the path */
      continue;
    }
    db_bind_int(&q1, ":mid", p->rid);
    while( db_step(&q1)==SQLITE_ROW ){

      fnid = db_column_int(&q1, 1);
      pfnid = db_column_int(&q1, 0);

      if( pfnid==0 ){
        pfnid = fnid;
        fnid = 0;
      }
      if( !p->fromIsParent ){
        int t = fnid;
        fnid = pfnid;
        pfnid = t;
      }
      if( zDebug ){
        fossil_print("%s at %d%s %.10z: %d[%z] -> %d[%z]\n",
           zDebug, p->rid, p->fromIsParent ? ">" : "<",
           db_text(0, "SELECT uuid FROM blob WHERE rid=%d", p->rid),
           pfnid,
           db_text(0, "SELECT name FROM filename WHERE fnid=%d", pfnid),
           fnid,
           db_text(0, "SELECT name FROM filename WHERE fnid=%d", fnid));
      }
      for(pChng=pAll; pChng; pChng=pChng->pNext){
        if( pChng->curName==pfnid ){
          pChng->newName = fnid;
          break;
        }
      }
      if( pChng==0 && fnid>0 ){
        pChng = fossil_malloc( sizeof(*pChng) );
        pChng->pNext = pAll;
        pAll = pChng;
        pChng->origName = pfnid;
        pChng->curName = pfnid;
        pChng->newName = fnid;
        nChng++;
      }
    }
    for(pChng=pAll; pChng; pChng=pChng->pNext){
      pChng->curName = pChng->newName;
    }
    db_reset(&q1);
  }
  db_finalize(&q1);
  if( nChng ){

    aChng = *aiChng = fossil_malloc( nChng*2*sizeof(int) );
    for(pChng=pAll, i=0; pChng; pChng=pChng->pNext){
      if( pChng->newName==0 ) continue;
      if( pChng->origName==0 ) continue;
      if( pChng->newName==pChng->origName ) continue;
      aChng[i] = pChng->origName;
      aChng[i+1] = pChng->newName;
      if( zDebug ){
        fossil_print("%s summary %d[%z] -> %d[%z]\n",
           zDebug,
           aChng[i],
           db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i]),
           aChng[i+1],
           db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i+1]));
      }
      i += 2;
    }
    *pnChng = i/2;
    while( pAll ){
      pChng = pAll;
      pAll = pAll->pNext;
      fossil_free(pChng);
    }
  }
}

/*
** COMMAND: test-name-changes
**
** Usage: %fossil test-name-changes [--debug] VERSION1 VERSION2
**
** Show all filename changes that occur going from VERSION1 to VERSION2
*/
void test_name_change(void){
  int iFrom;
  int iTo;
  int *aChng;
  int nChng;
  int i;
  const char *zDebug = 0;
  int revOk = 0;

  db_find_and_open_repository(0,0);
  zDebug = find_option("debug",0,0)!=0 ? "debug" : 0;
  revOk = find_option("bidirectional",0,0)!=0;
  if( g.argc<4 ) usage("VERSION1 VERSION2");
  while( g.argc>=4 ){
    iFrom = name_to_rid(g.argv[2]);
    iTo = name_to_rid(g.argv[3]);
    find_filename_changes(iFrom, iTo, revOk, &nChng, &aChng, zDebug);
    fossil_print("------ Changes for (%d) %s -> (%d) %s\n",
                 iFrom, g.argv[2], iTo, g.argv[3]);
    for(i=0; i<nChng; i++){
      char *zFrom, *zTo;

      zFrom = db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i*2]);
      zTo = db_text(0, "SELECT name FROM filename WHERE fnid=%d", aChng[i*2+1]);
      fossil_print("[%s] -> [%s]\n", zFrom, zTo);
      fossil_free(zFrom);
      fossil_free(zTo);
    }
    fossil_free(aChng);
    g.argv += 2;
    g.argc -= 2;
  }
}

      rc = SQLITE_DENY;
      break;
    }
  }
  return rc;
}













/*
** Check the given SQL to see if is a valid query that does not
** attempt to do anything dangerous.  Return 0 on success and a
** pointer to an error message string (obtained from malloc) if
** there is a problem.
*/
................................................................................
        return mprintf("Semi-colon detected! "
                       "Only a single SQL statement is allowed");
      }
    }
  }
  
  /* Compile the statement and check for illegal accesses or syntax errors. */
  sqlite3_set_authorizer(g.db, report_query_authorizer, (void*)&zErr);
  rc = sqlite3_prepare(g.db, zSql, -1, &pStmt, &zTail);
  if( rc!=SQLITE_OK ){
    zErr = mprintf("Syntax error: %s", sqlite3_errmsg(g.db));
  }
  if( !sqlite3_stmt_readonly(pStmt) ){
    zErr = mprintf("SQL must not modify the database");
  }
  if( pStmt ){
    sqlite3_finalize(pStmt);
  }
  sqlite3_set_authorizer(g.db, 0, 0);
  return zErr;
}

/*
** WEBPAGE: /rptsql
*/
void view_see_sql(void){
................................................................................
    }
    style_header(zTitle);
    output_color_key(zClrKey, 1, 
        "border=\"0\" cellpadding=\"3\" cellspacing=\"0\" class=\"report\"");
    @ <table border="1" cellpadding="2" cellspacing="0" class="report">
    sState.rn = rn;
    sState.nCount = 0;
    (void)fossil_localtime(0);  /* initialize the g.fTimeFormat variable */
    sqlite3_set_authorizer(g.db, report_query_authorizer, (void*)&zErr1);
    sqlite3_exec_readonly(g.db, zSql, generate_html, &sState, &zErr2);
    sqlite3_set_authorizer(g.db, 0, 0);

    @ </table>
    if( zErr1 ){
      @ <p class="reportError">Error: %h(zErr1)</p>
    }else if( zErr2 ){
      @ <p class="reportError">Error: %h(zErr2)</p>
    }
    style_footer();
  }else{
    sqlite3_set_authorizer(g.db, report_query_authorizer, (void*)&zErr1);
    sqlite3_exec_readonly(g.db, zSql, output_tab_separated, &count, &zErr2);
    sqlite3_set_authorizer(g.db, 0, 0);
    cgi_set_content_type("text/plain");
  }
}

/*
** report number for full table ticket export
*/
................................................................................
  }
  if( zFilter ){
    zSql = mprintf("SELECT * FROM (%s) WHERE %s",zSql,zFilter);
  }
  count = 0;
  tktEncode = enc;
  zSep = zSepIn;
  sqlite3_set_authorizer(g.db, report_query_authorizer, (void*)&zErr1);
  sqlite3_exec_readonly(g.db, zSql, output_separated_file, &count, &zErr2);
  sqlite3_set_authorizer(g.db, 0, 0);
  if( zFilter ){
    free(zSql);
  }
}

      rc = SQLITE_DENY;
      break;
    }
  }
  return rc;
}

/*
** Activate the query authorizer
*/
static void report_restrict_sql(char **pzErr){
  (void)fossil_localtime(0);
  sqlite3_set_authorizer(g.db, report_query_authorizer, (void*)pzErr);
}
static void report_unrestrict_sql(void){
  sqlite3_set_authorizer(g.db, 0, 0);
}


/*
** Check the given SQL to see if is a valid query that does not
** attempt to do anything dangerous.  Return 0 on success and a
** pointer to an error message string (obtained from malloc) if
** there is a problem.
*/
................................................................................
        return mprintf("Semi-colon detected! "
                       "Only a single SQL statement is allowed");
      }
    }
  }
  
  /* Compile the statement and check for illegal accesses or syntax errors. */
  report_restrict_sql(&zErr);
  rc = sqlite3_prepare(g.db, zSql, -1, &pStmt, &zTail);
  if( rc!=SQLITE_OK ){
    zErr = mprintf("Syntax error: %s", sqlite3_errmsg(g.db));
  }
  if( !sqlite3_stmt_readonly(pStmt) ){
    zErr = mprintf("SQL must not modify the database");
  }
  if( pStmt ){
    sqlite3_finalize(pStmt);
  }
  report_unrestrict_sql();
  return zErr;
}

/*
** WEBPAGE: /rptsql
*/
void view_see_sql(void){
................................................................................
    }
    style_header(zTitle);
    output_color_key(zClrKey, 1, 
        "border=\"0\" cellpadding=\"3\" cellspacing=\"0\" class=\"report\"");
    @ <table border="1" cellpadding="2" cellspacing="0" class="report">
    sState.rn = rn;
    sState.nCount = 0;
    report_restrict_sql(&zErr1);

    sqlite3_exec_readonly(g.db, zSql, generate_html, &sState, &zErr2);

    report_unrestrict_sql();
    @ </table>
    if( zErr1 ){
      @ <p class="reportError">Error: %h(zErr1)</p>
    }else if( zErr2 ){
      @ <p class="reportError">Error: %h(zErr2)</p>
    }
    style_footer();
  }else{
    report_restrict_sql(&zErr1);
    sqlite3_exec_readonly(g.db, zSql, output_tab_separated, &count, &zErr2);
    report_unrestrict_sql();
    cgi_set_content_type("text/plain");
  }
}

/*
** report number for full table ticket export
*/
................................................................................
  }
  if( zFilter ){
    zSql = mprintf("SELECT * FROM (%s) WHERE %s",zSql,zFilter);
  }
  count = 0;
  tktEncode = enc;
  zSep = zSepIn;
  report_restrict_sql(&zErr1);
  sqlite3_exec_readonly(g.db, zSql, output_separated_file, &count, &zErr2);
  report_unrestrict_sql();
  if( zFilter ){
    free(zSql);
  }
}

@ --
@ CREATE TABLE vfile(
@   id INTEGER PRIMARY KEY,           -- ID of the checked out file
@   vid INTEGER REFERENCES blob,      -- The baseline this file is part of.
@   chnged INT DEFAULT 0,             -- 0:unchnged 1:edited 2:m-chng 3:m-add
@   deleted BOOLEAN DEFAULT 0,        -- True if deleted 
@   isexe BOOLEAN,                    -- True if file should be executable

@   rid INTEGER,                      -- Originally from this repository record
@   mrid INTEGER,                     -- Based on this record due to a merge
@   mtime INTEGER,                    -- Mtime of file on disk. sec since 1970
@   pathname TEXT,                    -- Full pathname relative to root
@   origname TEXT,                    -- Original pathname. NULL if unchanged
@   UNIQUE(pathname,vid)
@ );

@ --
@ CREATE TABLE vfile(
@   id INTEGER PRIMARY KEY,           -- ID of the checked out file
@   vid INTEGER REFERENCES blob,      -- The baseline this file is part of.
@   chnged INT DEFAULT 0,             -- 0:unchnged 1:edited 2:m-chng 3:m-add
@   deleted BOOLEAN DEFAULT 0,        -- True if deleted 
@   isexe BOOLEAN,                    -- True if file should be executable
@   islink BOOLEAN,                    -- True if file should be symlink
@   rid INTEGER,                      -- Originally from this repository record
@   mrid INTEGER,                     -- Based on this record due to a merge
@   mtime INTEGER,                    -- Mtime of file on disk. sec since 1970
@   pathname TEXT,                    -- Full pathname relative to root
@   origname TEXT,                    -- Original pathname. NULL if unchanged
@   UNIQUE(pathname,vid)
@ );

  login_check_credentials();
  if( !g.okSetup ){
    login_needed();
  }

  style_header("Settings");

  db_begin_transaction();
  @ <p>This page provides a simple interface to the "fossil setting" command.
  @ See the "fossil help setting" output below for further information on
  @ the meaning of each setting.</p><hr />
  @ <form action="%s(g.zTop)/setup_settings" method="post"><div>
  @ <table border="0"><tr><td valign="top">
  login_insert_csrf_secret();

  login_check_credentials();
  if( !g.okSetup ){
    login_needed();
  }

  style_header("Settings");
  db_open_local();
  db_begin_transaction();
  @ <p>This page provides a simple interface to the "fossil setting" command.
  @ See the "fossil help setting" output below for further information on
  @ the meaning of each setting.</p><hr />
  @ <form action="%s(g.zTop)/setup_settings" method="post"><div>
  @ <table border="0"><tr><td valign="top">
  login_insert_csrf_secret();

/*
 * blk0() and blk() perform the initial expand.
 * I got the idea of expanding during the round function from SSLeay
 *
 * blk0le() for little-endian and blk0be() for big-endian.
 */
#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))


















#define blk0le(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
    |(rol(block->l[i],8)&0x00FF00FF))
#define blk0be(i) block->l[i]
#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \

    ^block->l[(i+2)&15]^block->l[i&15],1))

/*
 * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
 *
 * Rl0() for little-endian and Rb0() for big-endian.  Endianness is 
 * determined at run-time.
 */
#define Rl0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0le(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define Rb0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0be(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R1(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R2(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
#define R3(v,w,x,y,z,i) \
    z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
#define R4(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);

typedef union {
    unsigned char c[64];
    unsigned int l[16];
} CHAR64LONG16;

/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */






void SHA1Transform(unsigned int state[5], const unsigned char buffer[64])
{
  unsigned int a, b, c, d, e;
  CHAR64LONG16 *block;
  static int one = 1;
  CHAR64LONG16 workspace;

  block = &workspace;

  (void)memcpy(block, buffer, 64);


  /* Copy context->state[] to working vars */

  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];


  /* 4 rounds of 20 operations each. Loop unrolled. */
  if( 1 == *(unsigned char*)&one ){
    Rl0(a,b,c,d,e, 0); Rl0(e,a,b,c,d, 1); Rl0(d,e,a,b,c, 2); Rl0(c,d,e,a,b, 3);
    Rl0(b,c,d,e,a, 4); Rl0(a,b,c,d,e, 5); Rl0(e,a,b,c,d, 6); Rl0(d,e,a,b,c, 7);
    Rl0(c,d,e,a,b, 8); Rl0(b,c,d,e,a, 9); Rl0(a,b,c,d,e,10); Rl0(e,a,b,c,d,11);
    Rl0(d,e,a,b,c,12); Rl0(c,d,e,a,b,13); Rl0(b,c,d,e,a,14); Rl0(a,b,c,d,e,15);
................................................................................

  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;

  /* Wipe variables */
  a = b = c = d = e = 0;
}


/*
 * SHA1Init - Initialize new context
 */
static void SHA1Init(SHA1Context *context){
................................................................................
** Convert a digest into base-16.  digest should be declared as
** "unsigned char digest[20]" in the calling function.  The SHA1
** digest is stored in the first 20 bytes.  zBuf should
** be "char zBuf[41]".
*/
static void DigestToBase16(unsigned char *digest, char *zBuf){
  static char const zEncode[] = "0123456789abcdef";
  int i, j;

  for(j=i=0; i<20; i++){
    int a = digest[i];
    zBuf[j++] = zEncode[(a>>4)&0xf];
    zBuf[j++] = zEncode[a & 0xf];
  }
  zBuf[j] = 0;

}

/*
** The state of a incremental SHA1 checksum computation.  Only one
** such computation can be underway at a time, of course.
*/
static SHA1Context incrCtx;
................................................................................
** Return the number of errors.
*/
int sha1sum_file(const char *zFilename, Blob *pCksum){
  FILE *in;
  SHA1Context ctx;
  unsigned char zResult[20];
  char zBuf[10240];












  in = fossil_fopen(zFilename,"rb");
  if( in==0 ){
    return 1;
  }
  SHA1Init(&ctx);
  for(;;){

/*
 * blk0() and blk() perform the initial expand.
 * I got the idea of expanding during the round function from SSLeay
 *
 * blk0le() for little-endian and blk0be() for big-endian.
 */
#if __GNUC__ && (defined(__i386__) || defined(__x86_64__))
/*
 * GCC by itself only generates left rotates.  Use right rotates if
 * possible to be kinder to dinky implementations with iterative rotate
 * instructions.
 */
#define SHA_ROT(op, x, k) \
        ({ unsigned int y; asm(op " %1,%0" : "=r" (y) : "I" (k), "0" (x)); y; })
#define rol(x,k) SHA_ROT("roll", x, k)
#define ror(x,k) SHA_ROT("rorl", x, k)

#else
/* Generic C equivalent */
#define SHA_ROT(x,l,r) ((x) << (l) | (x) >> (r))
#define rol(x,k) SHA_ROT(x,k,32-(k))
#define ror(x,k) SHA_ROT(x,32-(k),k)
#endif


#define blk0le(i) (block[i] = (ror(block[i],8)&0xFF00FF00) \
    |(rol(block[i],8)&0x00FF00FF))
#define blk0be(i) block[i]

#define blk(i) (block[i&15] = rol(block[(i+13)&15]^block[(i+8)&15] \
    ^block[(i+2)&15]^block[i&15],1))

/*
 * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
 *
 * Rl0() for little-endian and Rb0() for big-endian.  Endianness is 
 * determined at run-time.
 */
#define Rl0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0le(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define Rb0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0be(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define R1(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define R2(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=ror(w,2);
#define R3(v,w,x,y,z,i) \
    z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=ror(w,2);
#define R4(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=ror(w,2);






/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */
#define a qq[0]
#define b qq[1]
#define c qq[2]
#define d qq[3]
#define e qq[4]

void SHA1Transform(unsigned int state[5], const unsigned char buffer[64])
{
  unsigned int qq[5]; // a, b, c, d, e;

  static int one = 1;



  unsigned int block[16];
  memcpy(block, buffer, 64);
  memcpy(qq,state,5*sizeof(unsigned int));

  /* Copy context->state[] to working vars */
  /*
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];
  */

  /* 4 rounds of 20 operations each. Loop unrolled. */
  if( 1 == *(unsigned char*)&one ){
    Rl0(a,b,c,d,e, 0); Rl0(e,a,b,c,d, 1); Rl0(d,e,a,b,c, 2); Rl0(c,d,e,a,b, 3);
    Rl0(b,c,d,e,a, 4); Rl0(a,b,c,d,e, 5); Rl0(e,a,b,c,d, 6); Rl0(d,e,a,b,c, 7);
    Rl0(c,d,e,a,b, 8); Rl0(b,c,d,e,a, 9); Rl0(a,b,c,d,e,10); Rl0(e,a,b,c,d,11);
    Rl0(d,e,a,b,c,12); Rl0(c,d,e,a,b,13); Rl0(b,c,d,e,a,14); Rl0(a,b,c,d,e,15);
................................................................................

  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;



}


/*
 * SHA1Init - Initialize new context
 */
static void SHA1Init(SHA1Context *context){
................................................................................
** Convert a digest into base-16.  digest should be declared as
** "unsigned char digest[20]" in the calling function.  The SHA1
** digest is stored in the first 20 bytes.  zBuf should
** be "char zBuf[41]".
*/
static void DigestToBase16(unsigned char *digest, char *zBuf){
  static char const zEncode[] = "0123456789abcdef";
  int ix;

  for(ix=0; ix<20; ix++){
    *zBuf++ = zEncode[(*digest>>4)&0xf];
    *zBuf++ = zEncode[*digest++ & 0xf];

  }

  *zBuf = '\0';
}

/*
** The state of a incremental SHA1 checksum computation.  Only one
** such computation can be underway at a time, of course.
*/
static SHA1Context incrCtx;
................................................................................
** Return the number of errors.
*/
int sha1sum_file(const char *zFilename, Blob *pCksum){
  FILE *in;
  SHA1Context ctx;
  unsigned char zResult[20];
  char zBuf[10240];

  if( file_islink(zFilename) ){
    /* Instead of file content, return sha1 of link destination path */
    Blob destinationPath;
    int rc;
    
    blob_read_link(&destinationPath, zFilename);
    rc = sha1sum_blob(&destinationPath, pCksum);
    blob_reset(&destinationPath);
    return rc;
  }

  in = fossil_fopen(zFilename,"rb");
  if( in==0 ){
    return 1;
  }
  SHA1Init(&ctx);
  for(;;){

#endif

/*
** Exactly one of the following macros must be defined in order to
** specify which memory allocation subsystem to use.
**
**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()

**     SQLITE_MEMDEBUG               // Debugging version of system malloc()





**
** (Historical note:  There used to be several other options, but we've
** pared it down to just these two.)
**
** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
** the default.
*/
#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)>1
# error "At most one of the following compile-time configuration options\
 is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG"
#endif
#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)==0
# define SQLITE_SYSTEM_MALLOC 1
#endif

/*
** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
** sizes of memory allocations below this value where possible.
*/
................................................................................
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.7.8"
#define SQLITE_VERSION_NUMBER 3007008
#define SQLITE_SOURCE_ID      "2011-08-16 02:07:04 9650d7962804d61f56cac944ff9bb2c7bc111957"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
................................................................................
** and that this object is only useful to a tiny minority of applications
** with specialized memory allocation requirements.  This object is
** also used during testing of SQLite in order to specify an alternative
** memory allocator that simulates memory out-of-memory conditions in
** order to verify that SQLite recovers gracefully from such
** conditions.
**
** The xMalloc and xFree methods must work like the
** malloc() and free() functions from the standard C library.
** The xRealloc method must work like realloc() from the standard C library
** with the exception that if the second argument to xRealloc is zero,
** xRealloc must be a no-op - it must not perform any allocation or
** deallocation.  ^SQLite guarantees that the second argument to
** xRealloc is always a value returned by a prior call to xRoundup.
** And so in cases where xRoundup always returns a positive number,
** xRealloc can perform exactly as the standard library realloc() and
** still be in compliance with this specification.
**
** xSize should return the allocated size of a memory allocation
** previously obtained from xMalloc or xRealloc.  The allocated size
** is always at least as big as the requested size but may be larger.
**
** The xRoundup method returns what would be the allocated size of
** a memory allocation given a particular requested size.  Most memory
................................................................................
** WHERE clause might influence the choice of query plan for a statement,
** then the statement will be automatically recompiled, as if there had been 
** a schema change, on the first  [sqlite3_step()] call following any change
** to the [sqlite3_bind_text | bindings] of that [parameter]. 
** ^The specific value of WHERE-clause [parameter] might influence the 
** choice of query plan if the parameter is the left-hand side of a [LIKE]
** or [GLOB] operator or if the parameter is compared to an indexed column
** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
** the 
** </li>
** </ol>
*/
SQLITE_API int sqlite3_prepare(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
................................................................................
** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
** that can be stored in a u32 without loss of data.  The value
** is 0x00000000ffffffff.  But because of quirks of some compilers, we
** have to specify the value in the less intuitive manner shown:
*/
#define SQLITE_MAX_U32  ((((u64)1)<<32)-1)

/*
** The datatype used to store estimates of the number of rows in a
** table or index.  This is an unsigned integer type.  For 99.9% of
** the world, a 32-bit integer is sufficient.  But a 64-bit integer
** can be used at compile-time if desired.
*/
#ifdef SQLITE_64BIT_STATS
 typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
#else
 typedef u32 tRowcnt;    /* 32-bit is the default */
#endif

/*
** Macros to determine whether the machine is big or little endian,
** evaluated at runtime.
*/
#ifdef SQLITE_AMALGAMATION
SQLITE_PRIVATE const int sqlite3one = 1;
#else
................................................................................
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_


/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
** in the source file sqliteVdbe.c are allowed to see the insides
** of this structure.
*/
typedef struct Vdbe Vdbe;
................................................................................
    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
    CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
    Mem *pMem;             /* Used when p4type is P4_MEM */
    VTable *pVtab;         /* Used when p4type is P4_VTAB */
    KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
    int *ai;               /* Used when p4type is P4_INTARRAY */
    SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */

  } p4;
#ifdef SQLITE_DEBUG
  char *zComment;          /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  int cnt;                 /* Number of times this instruction was executed */
  u64 cycles;              /* Total time spent executing this instruction */
................................................................................
#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
#define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
#define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */


/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
** is made.  That copy is freed when the Vdbe is finalized.  But if the
** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
** gets freed when the Vdbe is finalized so it still should be obtained
** from a single sqliteMalloc().  But no copy is made and the calling
** function should *not* try to free the KeyInfo.
................................................................................
#define OP_ReadCookie                          35
#define OP_SetCookie                           36
#define OP_VerifyCookie                        37
#define OP_OpenRead                            38
#define OP_OpenWrite                           39
#define OP_OpenAutoindex                       40
#define OP_OpenEphemeral                       41

#define OP_OpenPseudo                          42
#define OP_Close                               43
#define OP_SeekLt                              44
#define OP_SeekLe                              45
#define OP_SeekGe                              46
#define OP_SeekGt                              47
#define OP_Seek                                48
#define OP_NotFound                            49
#define OP_Found                               50
#define OP_IsUnique                            51
#define OP_NotExists                           52
#define OP_Sequence                            53
#define OP_NewRowid                            54
#define OP_Insert                              55
#define OP_InsertInt                           56
#define OP_Delete                              57
#define OP_ResetCount                          58


#define OP_RowKey                              59
#define OP_RowData                             60
#define OP_Rowid                               61
#define OP_NullRow                             62
#define OP_Last                                63

#define OP_Sort                                64
#define OP_Rewind                              65

#define OP_Prev                                66
#define OP_Next                                67

#define OP_IdxInsert                           70
#define OP_IdxDelete                           71
#define OP_IdxRowid                            72
#define OP_IdxLT                               81
#define OP_IdxGE                               92
#define OP_Destroy                             95
#define OP_Clear                               96
#define OP_CreateIndex                         97
#define OP_CreateTable                         98
#define OP_ParseSchema                         99
#define OP_LoadAnalysis                       100
#define OP_DropTable                          101
#define OP_DropIndex                          102
#define OP_DropTrigger                        103
#define OP_IntegrityCk                        104
#define OP_RowSetAdd                          105
#define OP_RowSetRead                         106
#define OP_RowSetTest                         107
#define OP_Program                            108
#define OP_Param                              109
#define OP_FkCounter                          110
#define OP_FkIfZero                           111
#define OP_MemMax                             112
#define OP_IfPos                              113
#define OP_IfNeg                              114
#define OP_IfZero                             115
#define OP_AggStep                            116
#define OP_AggFinal                           117
#define OP_Checkpoint                         118
#define OP_JournalMode                        119
#define OP_Vacuum                             120
#define OP_IncrVacuum                         121
#define OP_Expire                             122
#define OP_TableLock                          123
#define OP_VBegin                             124
#define OP_VCreate                            125
#define OP_VDestroy                           126
#define OP_VOpen                              127
#define OP_VFilter                            128
#define OP_VColumn                            129
#define OP_VNext                              131
#define OP_VRename                            132
#define OP_VUpdate                            133
#define OP_Pagecount                          134
#define OP_MaxPgcnt                           135
#define OP_Trace                              136
#define OP_Noop                               137
#define OP_Explain                            138

/* The following opcode values are never used */
#define OP_NotUsed_139                        139
#define OP_NotUsed_140                        140


/* Properties such as "out2" or "jump" that are specified in
** comments following the "case" for each opcode in the vdbe.c
** are encoded into bitvectors as follows:
*/
#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */
................................................................................
#define OPFLG_OUT3            0x0040  /* out3:  P3 is an output */
#define OPFLG_INITIALIZER {\
/*   0 */ 0x00, 0x01, 0x05, 0x04, 0x04, 0x10, 0x00, 0x02,\
/*   8 */ 0x02, 0x02, 0x02, 0x02, 0x02, 0x00, 0x24, 0x24,\
/*  16 */ 0x00, 0x00, 0x00, 0x24, 0x04, 0x05, 0x04, 0x00,\
/*  24 */ 0x00, 0x01, 0x05, 0x05, 0x00, 0x00, 0x00, 0x02,\
/*  32 */ 0x00, 0x00, 0x00, 0x02, 0x10, 0x00, 0x00, 0x00,\
/*  40 */ 0x00, 0x00, 0x00, 0x00, 0x11, 0x11, 0x11, 0x11,\
/*  48 */ 0x08, 0x11, 0x11, 0x11, 0x11, 0x02, 0x02, 0x00,\
/*  56 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01,\
/*  64 */ 0x01, 0x01, 0x01, 0x01, 0x4c, 0x4c, 0x08, 0x00,\
/*  72 */ 0x02, 0x05, 0x05, 0x15, 0x15, 0x15, 0x15, 0x15,\
/*  80 */ 0x15, 0x01, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c,\
/*  88 */ 0x4c, 0x4c, 0x4c, 0x4c, 0x01, 0x24, 0x02, 0x02,\

/*  96 */ 0x00, 0x02, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 104 */ 0x00, 0x0c, 0x45, 0x15, 0x01, 0x02, 0x00, 0x01,\
/* 112 */ 0x08, 0x05, 0x05, 0x05, 0x00, 0x00, 0x00, 0x02,\
/* 120 */ 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 128 */ 0x01, 0x00, 0x02, 0x01, 0x00, 0x00, 0x02, 0x02,\
/* 136 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x04, 0x04,\
/* 144 */ 0x04, 0x04,}

/************** End of opcodes.h *********************************************/
/************** Continuing where we left off in vdbe.h ***********************/

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
................................................................................
SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);
SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*);
................................................................................
** Allowed values for the flags parameter to sqlite3PagerOpen().
**
** NOTE: These values must match the corresponding BTREE_ values in btree.h.
*/
#define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
#define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
#define PAGER_MEMORY        0x0004    /* In-memory database */


/*
** Valid values for the second argument to sqlite3PagerLockingMode().
*/
#define PAGER_LOCKINGMODE_QUERY      -1
#define PAGER_LOCKINGMODE_NORMAL      0
#define PAGER_LOCKINGMODE_EXCLUSIVE   1
................................................................................
struct Table {
  char *zName;         /* Name of the table or view */
  int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
  int nCol;            /* Number of columns in this table */
  Column *aCol;        /* Information about each column */
  Index *pIndex;       /* List of SQL indexes on this table. */
  int tnum;            /* Root BTree node for this table (see note above) */
  tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
  Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
  u16 nRef;            /* Number of pointers to this Table */
  u8 tabFlags;         /* Mask of TF_* values */
  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
  FKey *pFKey;         /* Linked list of all foreign keys in this table */
  char *zColAff;       /* String defining the affinity of each column */
#ifndef SQLITE_OMIT_CHECK
................................................................................
** algorithm to employ whenever an attempt is made to insert a non-unique
** element.
*/
struct Index {
  char *zName;     /* Name of this index */
  int nColumn;     /* Number of columns in the table used by this index */
  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
  tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
  Table *pTable;   /* The SQL table being indexed */
  int tnum;        /* Page containing root of this index in database file */
  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
  u8 bUnordered;   /* Use this index for == or IN queries only */
  u8 nSample;      /* Number of elements in aSample[] */
  char *zColAff;   /* String defining the affinity of each column */
  Index *pNext;    /* The next index associated with the same table */
  Schema *pSchema; /* Schema containing this index */
  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
  char **azColl;   /* Array of collation sequence names for index */
#ifdef SQLITE_ENABLE_STAT3
  tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
#endif
};

/*
** Each sample stored in the sqlite_stat2 table is represented in memory 
** using a structure of this type.
*/
struct IndexSample {
  union {
    char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
    double r;       /* Value if eType is SQLITE_FLOAT */
    i64 i;          /* Value if eType is SQLITE_INTEGER */
  } u;
  u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
  u16 nByte;        /* Size in byte of text or blob. */
  tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
  tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
  tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
};

/*
** Each token coming out of the lexer is an instance of
** this structure.  Tokens are also used as part of an expression.
**
** Note if Token.z==0 then Token.dyn and Token.n are undefined and
................................................................................
*/
struct AggInfo {
  u8 directMode;          /* Direct rendering mode means take data directly
                          ** from source tables rather than from accumulators */
  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
                          ** than the source table */
  int sortingIdx;         /* Cursor number of the sorting index */

  ExprList *pGroupBy;     /* The group by clause */
  int nSortingColumn;     /* Number of columns in the sorting index */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    int iTable;              /* Cursor number of the source table */
    int iColumn;             /* Column number within the source table */
    int iSorterColumn;       /* Column number in the sorting index */
................................................................................
*/
#define SF_Distinct        0x0001  /* Output should be DISTINCT */
#define SF_Resolved        0x0002  /* Identifiers have been resolved */
#define SF_Aggregate       0x0004  /* Contains aggregate functions */
#define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
#define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
#define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */



/*
** The results of a select can be distributed in several ways.  The
** "SRT" prefix means "SELECT Result Type".
*/
#define SRT_Union        1  /* Store result as keys in an index */
................................................................................
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);
#else
# define sqlite3ViewGetColumnNames(A,B) 0
#endif

SQLITE_PRIVATE void sqlite3DropTable(Parse*, SrcList*, int, int);
SQLITE_PRIVATE void sqlite3CodeDropTable(Parse*, Table*, int, int);
SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3*, Table*);
#ifndef SQLITE_OMIT_AUTOINCREMENT
SQLITE_PRIVATE   void sqlite3AutoincrementBegin(Parse *pParse);
SQLITE_PRIVATE   void sqlite3AutoincrementEnd(Parse *pParse);
#else
# define sqlite3AutoincrementBegin(X)
# define sqlite3AutoincrementEnd(X)
................................................................................
SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);
SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);
SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                        void(*)(void*));
SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);
SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);
SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
#ifdef SQLITE_ENABLE_STAT3
SQLITE_PRIVATE char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
#endif
SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION
SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];
SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
................................................................................
#endif
#ifdef SQLITE_ENABLE_RTREE
  "ENABLE_RTREE",
#endif
#ifdef SQLITE_ENABLE_STAT2
  "ENABLE_STAT2",
#endif
#ifdef SQLITE_ENABLE_STAT3
  "ENABLE_STAT3",
#endif
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
  "ENABLE_UNLOCK_NOTIFY",
#endif
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  "ENABLE_UPDATE_DELETE_LIMIT",
#endif
#ifdef SQLITE_HAS_CODEC
................................................................................
#endif
#ifdef SQLITE_INT64_TYPE
  "INT64_TYPE",
#endif
#ifdef SQLITE_LOCK_TRACE
  "LOCK_TRACE",
#endif



#ifdef SQLITE_MEMDEBUG
  "MEMDEBUG",
#endif
#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
  "MIXED_ENDIAN_64BIT_FLOAT",
#endif
#ifdef SQLITE_NO_SYNC
................................................................................
  "OMIT_LOCALTIME",
#endif
#ifdef SQLITE_OMIT_LOOKASIDE
  "OMIT_LOOKASIDE",
#endif
#ifdef SQLITE_OMIT_MEMORYDB
  "OMIT_MEMORYDB",



#endif
#ifdef SQLITE_OMIT_OR_OPTIMIZATION
  "OMIT_OR_OPTIMIZATION",
#endif
#ifdef SQLITE_OMIT_PAGER_PRAGMAS
  "OMIT_PAGER_PRAGMAS",
#endif
................................................................................
  "OMIT_WAL",
#endif
#ifdef SQLITE_OMIT_WSD
  "OMIT_WSD",
#endif
#ifdef SQLITE_OMIT_XFER_OPT
  "OMIT_XFER_OPT",



#endif
#ifdef SQLITE_PERFORMANCE_TRACE
  "PERFORMANCE_TRACE",
#endif
#ifdef SQLITE_PROXY_DEBUG
  "PROXY_DEBUG",
#endif
................................................................................
typedef struct VdbeOp Op;

/*
** Boolean values
*/
typedef unsigned char Bool;




/*
** A cursor is a pointer into a single BTree within a database file.
** The cursor can seek to a BTree entry with a particular key, or
** loop over all entries of the Btree.  You can also insert new BTree
** entries or retrieve the key or data from the entry that the cursor
** is currently pointing to.
** 
................................................................................
  Bool atFirst;         /* True if pointing to first entry */
  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
  Bool nullRow;         /* True if pointing to a row with no data */
  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
  Bool isTable;         /* True if a table requiring integer keys */
  Bool isIndex;         /* True if an index containing keys only - no data */
  Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */

  sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
  const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
  i64 seqCount;         /* Sequence counter */
  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */


  /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or 
  ** OP_IsUnique opcode on this cursor. */
  int seekResult;

  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to.  Only valid if cacheStatus matches
................................................................................
SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem*);
SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
SQLITE_PRIVATE void sqlite3VdbeMemReleaseExternal(Mem *p);



SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*);
SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);
SQLITE_PRIVATE void sqlite3VdbeMemStoreType(Mem *pMem);



















#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
#else
# define sqlite3VdbeEnter(X)
# define sqlite3VdbeLeave(X)
................................................................................
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
**      ISBM 0-943396-61-1
**      Willmann-Bell, Inc
**      Richmond, Virginia (USA)
*/


#include <time.h>

#ifndef SQLITE_OMIT_DATETIME_FUNCS


/*
** A structure for holding a single date and time.
................................................................................
#ifdef __GLIBC__
  extern int backtrace(void**,int);
  extern void backtrace_symbols_fd(void*const*,int,int);
#else
# define backtrace(A,B) 1
# define backtrace_symbols_fd(A,B,C)
#endif


/*
** Each memory allocation looks like this:
**
**  ------------------------------------------------------------------------
**  | Title |  backtrace pointers |  MemBlockHdr |  allocation |  EndGuard |
**  ------------------------------------------------------------------------
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Memory allocation functions used throughout sqlite.
*/


/*
** Attempt to release up to n bytes of non-essential memory currently
** held by SQLite. An example of non-essential memory is memory used to
** cache database pages that are not currently in use.
*/
SQLITE_API int sqlite3_release_memory(int n){
................................................................................
**
**
** BOM or Byte Order Mark:
**     0xff 0xfe   little-endian utf-16 follows
**     0xfe 0xff   big-endian utf-16 follows
**
*/


#ifndef SQLITE_AMALGAMATION
/*
** The following constant value is used by the SQLITE_BIGENDIAN and
** SQLITE_LITTLEENDIAN macros.
*/
SQLITE_PRIVATE const int sqlite3one = 1;
................................................................................
** is set to the length of the returned string in bytes. The call should
** arrange to call sqlite3DbFree() on the returned pointer when it is
** no longer required.
** 
** If a malloc failure occurs, NULL is returned and the db.mallocFailed
** flag set.
*/
#ifdef SQLITE_ENABLE_STAT3
SQLITE_PRIVATE char *sqlite3Utf8to16(sqlite3 *db, u8 enc, char *z, int n, int *pnOut){
  Mem m;
  memset(&m, 0, sizeof(m));
  m.db = db;
  sqlite3VdbeMemSetStr(&m, z, n, SQLITE_UTF8, SQLITE_STATIC);
  if( sqlite3VdbeMemTranslate(&m, enc) ){
    assert( db->mallocFailed );
................................................................................
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
*/

#ifdef SQLITE_HAVE_ISNAN
# include <math.h>
#endif

/*
** Routine needed to support the testcase() macro.
*/
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the implementation of generic hash-tables
** used in SQLite.
*/


/* Turn bulk memory into a hash table object by initializing the
** fields of the Hash structure.
**
** "pNew" is a pointer to the hash table that is to be initialized.
*/
SQLITE_PRIVATE void sqlite3HashInit(Hash *pNew){
................................................................................
     /*  35 */ "ReadCookie",
     /*  36 */ "SetCookie",
     /*  37 */ "VerifyCookie",
     /*  38 */ "OpenRead",
     /*  39 */ "OpenWrite",
     /*  40 */ "OpenAutoindex",
     /*  41 */ "OpenEphemeral",
     /*  42 */ "OpenPseudo",
     /*  43 */ "Close",
     /*  44 */ "SeekLt",
     /*  45 */ "SeekLe",
     /*  46 */ "SeekGe",
     /*  47 */ "SeekGt",
     /*  48 */ "Seek",
     /*  49 */ "NotFound",
     /*  50 */ "Found",
     /*  51 */ "IsUnique",
     /*  52 */ "NotExists",
     /*  53 */ "Sequence",
     /*  54 */ "NewRowid",
     /*  55 */ "Insert",
     /*  56 */ "InsertInt",
     /*  57 */ "Delete",
     /*  58 */ "ResetCount",
     /*  59 */ "RowKey",
     /*  60 */ "RowData",
     /*  61 */ "Rowid",
     /*  62 */ "NullRow",
     /*  63 */ "Last",
     /*  64 */ "Sort",
     /*  65 */ "Rewind",
     /*  66 */ "Prev",
     /*  67 */ "Next",
     /*  68 */ "Or",
     /*  69 */ "And",
     /*  70 */ "IdxInsert",
     /*  71 */ "IdxDelete",
     /*  72 */ "IdxRowid",
     /*  73 */ "IsNull",
     /*  74 */ "NotNull",
     /*  75 */ "Ne",
     /*  76 */ "Eq",
     /*  77 */ "Gt",
     /*  78 */ "Le",
     /*  79 */ "Lt",
     /*  80 */ "Ge",
     /*  81 */ "IdxLT",
     /*  82 */ "BitAnd",
     /*  83 */ "BitOr",
     /*  84 */ "ShiftLeft",
     /*  85 */ "ShiftRight",
     /*  86 */ "Add",
     /*  87 */ "Subtract",
     /*  88 */ "Multiply",
     /*  89 */ "Divide",
     /*  90 */ "Remainder",
     /*  91 */ "Concat",
     /*  92 */ "IdxGE",
     /*  93 */ "BitNot",
     /*  94 */ "String8",
     /*  95 */ "Destroy",
     /*  96 */ "Clear",
     /*  97 */ "CreateIndex",
     /*  98 */ "CreateTable",
     /*  99 */ "ParseSchema",
     /* 100 */ "LoadAnalysis",
     /* 101 */ "DropTable",
     /* 102 */ "DropIndex",
     /* 103 */ "DropTrigger",
     /* 104 */ "IntegrityCk",
     /* 105 */ "RowSetAdd",
     /* 106 */ "RowSetRead",
     /* 107 */ "RowSetTest",
     /* 108 */ "Program",
     /* 109 */ "Param",
     /* 110 */ "FkCounter",
     /* 111 */ "FkIfZero",
     /* 112 */ "MemMax",
     /* 113 */ "IfPos",
     /* 114 */ "IfNeg",
     /* 115 */ "IfZero",
     /* 116 */ "AggStep",
     /* 117 */ "AggFinal",
     /* 118 */ "Checkpoint",
     /* 119 */ "JournalMode",
     /* 120 */ "Vacuum",
     /* 121 */ "IncrVacuum",
     /* 122 */ "Expire",
     /* 123 */ "TableLock",
     /* 124 */ "VBegin",
     /* 125 */ "VCreate",
     /* 126 */ "VDestroy",
     /* 127 */ "VOpen",
     /* 128 */ "VFilter",
     /* 129 */ "VColumn",
     /* 130 */ "Real",
     /* 131 */ "VNext",
     /* 132 */ "VRename",
     /* 133 */ "VUpdate",
     /* 134 */ "Pagecount",
     /* 135 */ "MaxPgcnt",
     /* 136 */ "Trace",
     /* 137 */ "Noop",
     /* 138 */ "Explain",
     /* 139 */ "NotUsed_139",
     /* 140 */ "NotUsed_140",
     /* 141 */ "ToText",
     /* 142 */ "ToBlob",
     /* 143 */ "ToNumeric",
     /* 144 */ "ToInt",
     /* 145 */ "ToReal",




  };
  return azName[i];
}
#endif

/************** End of opcodes.c *********************************************/
/************** Begin file os_os2.c ******************************************/
................................................................................
** macro to SQLITE_DEBUG and some older makefiles have not yet made the
** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#ifdef SQLITE_DEBUG
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
................................................................................
/*
** standard include files.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include <sys/time.h>
#include <errno.h>
#ifndef SQLITE_OMIT_WAL
#include <sys/mman.h>
#endif

#if SQLITE_ENABLE_LOCKING_STYLE
................................................................................
#define SQLITE_FSFLAGS_IS_MSDOS     0x1

/*
** If we are to be thread-safe, include the pthreads header and define
** the SQLITE_UNIX_THREADS macro.
*/
#if SQLITE_THREADSAFE

# define SQLITE_UNIX_THREADS 1
#endif

/*
** Default permissions when creating a new file
*/
#ifndef SQLITE_DEFAULT_FILE_PERMISSIONS
................................................................................

/*
** Allowed values for the unixFile.ctrlFlags bitmask:
*/
#define UNIXFILE_EXCL        0x01     /* Connections from one process only */
#define UNIXFILE_RDONLY      0x02     /* Connection is read only */
#define UNIXFILE_PERSIST_WAL 0x04     /* Persistent WAL mode */

#define UNIXFILE_DIRSYNC     0x08     /* Directory sync needed */




/*
** Include code that is common to all os_*.c files
*/
/************** Include os_common.h in the middle of os_unix.c ***************/
/************** Begin file os_common.h ***************************************/
/*
................................................................................
** macro to SQLITE_DEBUG and some older makefiles have not yet made the
** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#ifdef SQLITE_DEBUG
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
................................................................................
** to a non-zero value otherwise *pResOut is set to zero.  The return value
** is set to SQLITE_OK unless an I/O error occurs during lock checking.
*/
static int afpCheckReservedLock(sqlite3_file *id, int *pResOut){
  int rc = SQLITE_OK;
  int reserved = 0;
  unixFile *pFile = (unixFile*)id;

  
  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
  
  assert( pFile );
  afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;
  if( context->reserved ){
    *pResOut = 1;
    return SQLITE_OK;
  }
  unixEnterMutex(); /* Because pFile->pInode is shared across threads */
  
  /* Check if a thread in this process holds such a lock */
................................................................................
    }
  }
  
  /* If control gets to this point, then actually go ahead and make
  ** operating system calls for the specified lock.
  */
  if( eFileLock==SHARED_LOCK ){
    int lrc1, lrc2, lrc1Errno;
    long lk, mask;
    
    assert( pInode->nShared==0 );
    assert( pInode->eFileLock==0 );
        
    mask = (sizeof(long)==8) ? LARGEST_INT64 : 0x7fffffff;
    /* Now get the read-lock SHARED_LOCK */
................................................................................
#endif
  TIMER_START;
#if defined(USE_PREAD)
  do{ got = osPwrite(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
#elif defined(USE_PREAD64)
  do{ got = osPwrite64(id->h, pBuf, cnt, offset);}while( got<0 && errno==EINTR);
#else

  newOffset = lseek(id->h, offset, SEEK_SET);
  SimulateIOError( newOffset-- );
  if( newOffset!=offset ){
    if( newOffset == -1 ){
      ((unixFile*)id)->lastErrno = errno;
    }else{
      ((unixFile*)id)->lastErrno = 0;			
    }
    return -1;
  }
  do{ got = osWrite(id->h, pBuf, cnt); }while( got<0 && errno==EINTR );

#endif
  TIMER_END;
  if( got<0 ){
    ((unixFile*)id)->lastErrno = errno;
  }

  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));
................................................................................
*/
SQLITE_API int sqlite3_sync_count = 0;
SQLITE_API int sqlite3_fullsync_count = 0;
#endif

/*
** We do not trust systems to provide a working fdatasync().  Some do.
** Others do no.  To be safe, we will stick with the (slower) fsync().
** If you know that your system does support fdatasync() correctly,
** then simply compile with -Dfdatasync=fdatasync
*/
#if !defined(fdatasync) && !defined(__linux__)
# define fdatasync fsync
#endif

/*
** Define HAVE_FULLFSYNC to 0 or 1 depending on whether or not
** the F_FULLFSYNC macro is defined.  F_FULLFSYNC is currently
** only available on Mac OS X.  But that could change.
................................................................................
    int dirfd;
    OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,
            HAVE_FULLFSYNC, isFullsync));
    rc = osOpenDirectory(pFile->zPath, &dirfd);
    if( rc==SQLITE_OK && dirfd>=0 ){
      full_fsync(dirfd, 0, 0);
      robust_close(pFile, dirfd, __LINE__);


    }
    pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;
  }
  return rc;
}

/*
................................................................................
** proxying locking division.
*/
static int proxyFileControl(sqlite3_file*,int,void*);
#endif

/* 
** This function is called to handle the SQLITE_FCNTL_SIZE_HINT 
** file-control operation.
**
** If the user has configured a chunk-size for this file, it could be
** that the file needs to be extended at this point. Otherwise, the
** SQLITE_FCNTL_SIZE_HINT operation is a no-op for Unix.
*/
static int fcntlSizeHint(unixFile *pFile, i64 nByte){
  { /* preserve indentation of removed "if" */

    i64 nSize;                    /* Required file size */
    i64 szChunk;                  /* Chunk size */
    struct stat buf;              /* Used to hold return values of fstat() */
   
    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;

    szChunk = pFile->szChunk;
    if( szChunk==0 ){
      nSize = nByte;
    }else{
      nSize = ((nByte+szChunk-1) / szChunk) * szChunk;
    }
    if( nSize>(i64)buf.st_size ){

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
      /* The code below is handling the return value of osFallocate() 
      ** correctly. posix_fallocate() is defined to "returns zero on success, 
      ** or an error number on  failure". See the manpage for details. */
      int err;
................................................................................
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {


      return fcntlSizeHint(pFile, *(i64 *)pArg);


    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = (pFile->ctrlFlags & UNIXFILE_PERSIST_WAL)!=0;
      }else if( bPersist==0 ){
        pFile->ctrlFlags &= ~UNIXFILE_PERSIST_WAL;
................................................................................
** All other fields are read/write.  The unixShm.pFile->mutex must be held
** while accessing any read/write fields.
*/
struct unixShm {
  unixShmNode *pShmNode;     /* The underlying unixShmNode object */
  unixShm *pNext;            /* Next unixShm with the same unixShmNode */
  u8 hasMutex;               /* True if holding the unixShmNode mutex */

  u16 sharedMask;            /* Mask of shared locks held */
  u16 exclMask;              /* Mask of exclusive locks held */
#ifdef SQLITE_DEBUG
  u8 id;                     /* Id of this connection within its unixShmNode */
#endif
};

/*
** Constants used for locking
*/
#define UNIX_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)         /* first lock byte */
#define UNIX_SHM_DMS    (UNIX_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
................................................................................
  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);
  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
  int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
#if SQLITE_ENABLE_LOCKING_STYLE
  int isAutoProxy  = (flags & SQLITE_OPEN_AUTOPROXY);
#endif




  /* If creating a master or main-file journal, this function will open
  ** a file-descriptor on the directory too. The first time unixSync()
  ** is called the directory file descriptor will be fsync()ed and close()d.
  */
  int syncDir = (isCreate && (
        eType==SQLITE_OPEN_MASTER_JOURNAL 
................................................................................
  osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
#endif

  noLock = eType!=SQLITE_OPEN_MAIN_DB;

  
#if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
  struct statfs fsInfo;
  if( fstatfs(fd, &fsInfo) == -1 ){
    ((unixFile*)pFile)->lastErrno = errno;
    robust_close(p, fd, __LINE__);
    return SQLITE_IOERR_ACCESS;
  }
  if (0 == strncmp("msdos", fsInfo.f_fstypename, 5)) {
    ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;
................................................................................
    int useProxy = 0;

    /* SQLITE_FORCE_PROXY_LOCKING==1 means force always use proxy, 0 means 
    ** never use proxy, NULL means use proxy for non-local files only.  */
    if( envforce!=NULL ){
      useProxy = atoi(envforce)>0;
    }else{
      struct statfs fsInfo;
      if( statfs(zPath, &fsInfo) == -1 ){
        /* In theory, the close(fd) call is sub-optimal. If the file opened
        ** with fd is a database file, and there are other connections open
        ** on that file that are currently holding advisory locks on it,
        ** then the call to close() will cancel those locks. In practice,
        ** we're assuming that statfs() doesn't fail very often. At least
        ** not while other file descriptors opened by the same process on
................................................................................
#else
      if( fsync(fd) )
#endif
      {
        rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
      }
      robust_close(0, fd, __LINE__);


    }
  }
#endif
  return rc;
}

/*
................................................................................
      int err = errno;
      if( pError ){
        *pError = err;
      }
      return SQLITE_IOERR;
    }
  }


#endif
#ifdef SQLITE_TEST
  /* simulate multiple hosts by creating unique hostid file paths */
  if( sqlite3_hostid_num != 0){
    pHostID[0] = (char)(pHostID[0] + (char)(sqlite3_hostid_num & 0xFF));
  }
#endif
................................................................................
static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
  proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 
  unixFile *conchFile = pCtx->conchFile;
  int rc = SQLITE_OK;
  int nTries = 0;
  struct timespec conchModTime;
  

  do {
    rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
    nTries ++;
    if( rc==SQLITE_BUSY ){
      /* If the lock failed (busy):
       * 1st try: get the mod time of the conch, wait 0.5s and try again. 
       * 2nd try: fail if the mod time changed or host id is different, wait 
................................................................................
        }
      }
      conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, SHARED_LOCK);
      
    end_takeconch:
      OSTRACE(("TRANSPROXY: CLOSE  %d\n", pFile->h));
      if( rc==SQLITE_OK && pFile->openFlags ){

        if( pFile->h>=0 ){
          robust_close(pFile, pFile->h, __LINE__);
        }
        pFile->h = -1;
        int fd = robust_open(pCtx->dbPath, pFile->openFlags,
                      SQLITE_DEFAULT_FILE_PERMISSIONS);
        OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
        if( fd>=0 ){
          pFile->h = fd;
        }else{
          rc=SQLITE_CANTOPEN_BKPT; /* SQLITE_BUSY? proxyTakeConch called
           during locking */
................................................................................
** macro to SQLITE_DEBUG and some older makefiles have not yet made the
** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#ifdef SQLITE_DEBUG
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
................................................................................
  HANDLE hMutex;          /* Mutex used to control access to shared lock */  
  HANDLE hShared;         /* Shared memory segment used for locking */
  winceLock local;        /* Locks obtained by this instance of winFile */
  winceLock *shared;      /* Global shared lock memory for the file  */
#endif
};








































































/*
** Forward prototypes.
*/
static int getSectorSize(
    sqlite3_vfs *pVfs,
    const char *zRelative     /* UTF-8 file name */
................................................................................
      GetVersionEx(&sInfo);
      sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return sqlite3_os_type==2;
  }
#endif /* SQLITE_OS_WINCE */























































































































































































/*
** Convert a UTF-8 string to microsoft unicode (UTF-16?). 
**
** Space to hold the returned string is obtained from malloc.
*/
static WCHAR *utf8ToUnicode(const char *zFilename){
  int nChar;
................................................................................
/*************************************************************************
** This section contains code for WinCE only.
*/
/*
** WindowsCE does not have a localtime() function.  So create a
** substitute.
*/

struct tm *__cdecl localtime(const time_t *t)
{
  static struct tm y;
  FILETIME uTm, lTm;
  SYSTEMTIME pTm;
  sqlite3_int64 t64;
  t64 = *t;
................................................................................
  SimulateIOError(return SQLITE_IOERR_TRUNCATE);

  /* If the user has configured a chunk-size for this file, truncate the
  ** file so that it consists of an integer number of chunks (i.e. the
  ** actual file size after the operation may be larger than the requested
  ** size).
  */
  if( pFile->szChunk ){
    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
  }

  /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
  if( seekWinFile(pFile, nByte) ){
    rc = winLogError(SQLITE_IOERR_TRUNCATE, "winTruncate1", pFile->zPath);
  }else if( 0==SetEndOfFile(pFile->h) ){
................................................................................
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {




      sqlite3_int64 sz = *(sqlite3_int64*)pArg;

      SimulateIOErrorBenign(1);
      winTruncate(id, sz);
      SimulateIOErrorBenign(0);




      return SQLITE_OK;
    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = pFile->bPersistWal;
      }else{
................................................................................


typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;
typedef struct PGroup PGroup;




/* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
** of one or more PCaches that are able to recycle each others unpinned
** pages when they are under memory pressure.  A PGroup is an instance of
** the following object.
**
** This page cache implementation works in one of two modes:
**
................................................................................
struct PGroup {
  sqlite3_mutex *mutex;          /* MUTEX_STATIC_LRU or NULL */
  int nMaxPage;                  /* Sum of nMax for purgeable caches */
  int nMinPage;                  /* Sum of nMin for purgeable caches */
  int mxPinned;                  /* nMaxpage + 10 - nMinPage */
  int nCurrentPage;              /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;   /* LRU list of unpinned pages */




};























































/* Each page cache is an instance of the following object.  Every
** open database file (including each in-memory database and each
** temporary or transient database) has a single page cache which
** is an instance of this object.
**
** Pointers to structures of this type are cast and returned as 
** opaque sqlite3_pcache* handles.
................................................................................
** a pointer to a block of szPage bytes of data and the return value is
** a pointer to the associated PgHdr1 structure.
**
**   assert( PGHDR1_TO_PAGE(PAGE_TO_PGHDR1(pCache, X))==X );
*/
#define PGHDR1_TO_PAGE(p)    (void*)(((char*)p) - p->pCache->szPage)
#define PAGE_TO_PGHDR1(c, p) (PgHdr1*)(((char*)p) + c->szPage)












/*
** Macros to enter and leave the PCache LRU mutex.
*/
#define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
#define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)

................................................................................
    iSize = sqlite3MallocSize(p);
    sqlite3MemdebugSetType(p, MEMTYPE_PCACHE);
    return iSize;
  }
}
#endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */

































/*
** Allocate a new page object initially associated with cache pCache.
*/
static PgHdr1 *pcache1AllocPage(PCache1 *pCache){
  int nByte = sizeof(PgHdr1) + pCache->szPage;
  void *pPg = pcache1Alloc(nByte);
  PgHdr1 *p;





































































































  if( pPg ){
    p = PAGE_TO_PGHDR1(pCache, pPg);
    if( pCache->bPurgeable ){
      pCache->pGroup->nCurrentPage++;
    }
  }else{
    p = 0;
  }

  return p;
}

/*
** Free a page object allocated by pcache1AllocPage().
**
** The pointer is allowed to be NULL, which is prudent.  But it turns out
** that the current implementation happens to never call this routine
** with a NULL pointer, so we mark the NULL test with ALWAYS().
*/
static void pcache1FreePage(PgHdr1 *p){
  if( ALWAYS(p) ){
    PCache1 *pCache = p->pCache;











































    if( pCache->bPurgeable ){
      pCache->pGroup->nCurrentPage--;
    }
    pcache1Free(PGHDR1_TO_PAGE(p));
  }
}

/*
** Malloc function used by SQLite to obtain space from the buffer configured
** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer
** exists, this function falls back to sqlite3Malloc().
................................................................................
  }

  /* Step 5. If a usable page buffer has still not been found, 
  ** attempt to allocate a new one. 
  */
  if( !pPage ){
    if( createFlag==1 ) sqlite3BeginBenignMalloc();
    pcache1LeaveMutex(pGroup);
    pPage = pcache1AllocPage(pCache);
    pcache1EnterMutex(pGroup);
    if( createFlag==1 ) sqlite3EndBenignMalloc();
  }

  if( pPage ){
    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
................................................................................
**
** nReq is the number of bytes of memory required. Once this much has
** been released, the function returns. The return value is the total number 
** of bytes of memory released.
*/
SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int nReq){
  int nFree = 0;



  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  assert( sqlite3_mutex_notheld(pcache1.mutex) );
  if( pcache1.pStart==0 ){
    PgHdr1 *p;
    pcache1EnterMutex(&pcache1.grp);
    while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
      nFree += pcache1MemSize(PGHDR1_TO_PAGE(p));
................................................................................
  u8 noSync;                  /* Do not sync the journal if true */
  u8 fullSync;                /* Do extra syncs of the journal for robustness */
  u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
  u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
  u8 tempFile;                /* zFilename is a temporary file */
  u8 readOnly;                /* True for a read-only database */
  u8 memDb;                   /* True to inhibit all file I/O */


  /**************************************************************************
  ** The following block contains those class members that change during
  ** routine opertion.  Class members not in this block are either fixed
  ** when the pager is first created or else only change when there is a
  ** significant mode change (such as changing the page_size, locking_mode,
  ** or the journal_mode).  From another view, these class members describe
................................................................................
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager){
  u8 *pTmp = (u8 *)pPager->pTmpSpace;


  disable_simulated_io_errors();
  sqlite3BeginBenignMalloc();
  /* pPager->errCode = 0; */
  pPager->exclusiveMode = 0;
#ifndef SQLITE_OMIT_WAL
  sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags, pPager->pageSize, pTmp);
  pPager->pWal = 0;
................................................................................
  ** Spilling is also prohibited when in an error state since that could
  ** lead to database corruption.   In the current implementaton it 
  ** is impossible for sqlite3PCacheFetch() to be called with createFlag==1
  ** while in the error state, hence it is impossible for this routine to
  ** be called in the error state.  Nevertheless, we include a NEVER()
  ** test for the error state as a safeguard against future changes.
  */

  if( NEVER(pPager->errCode) ) return SQLITE_OK;
  if( pPager->doNotSpill ) return SQLITE_OK;
  if( pPager->doNotSyncSpill && (pPg->flags & PGHDR_NEED_SYNC)!=0 ){
    return SQLITE_OK;
  }

  pPg->pDirty = 0;
................................................................................
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
      u8 *pCell = findCell(pPage, i);
      if( eType==PTRMAP_OVERFLOW1 ){
        CellInfo info;
        btreeParseCellPtr(pPage, pCell, &info);
        if( info.iOverflow ){

          if( iFrom==get4byte(&pCell[info.iOverflow]) ){

            put4byte(&pCell[info.iOverflow], iTo);
            break;
          }
        }
      }else{
        if( get4byte(pCell)==iFrom ){
          put4byte(pCell, iTo);
          break;
        }
      }
................................................................................
  assert( wrFlag==0 || p->inTrans==TRANS_WRITE );
  assert( pBt->pPage1 && pBt->pPage1->aData );

  if( NEVER(wrFlag && pBt->readOnly) ){
    return SQLITE_READONLY;
  }
  if( iTable==1 && btreePagecount(pBt)==0 ){
    return SQLITE_EMPTY;

  }

  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables and link the cursor into the BtShared list.  */
  pCur->pgnoRoot = (Pgno)iTable;
  pCur->iPage = -1;
  pCur->pKeyInfo = pKeyInfo;
................................................................................

  if( pCur->iPage>=0 ){
    int i;
    for(i=1; i<=pCur->iPage; i++){
      releasePage(pCur->apPage[i]);
    }
    pCur->iPage = 0;



  }else{
    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]);
    if( rc!=SQLITE_OK ){
      pCur->eState = CURSOR_INVALID;
      return rc;
    }
    pCur->iPage = 0;
................................................................................
  int rc;

  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  rc = moveToRoot(pCur);
  if( rc==SQLITE_OK ){
    if( pCur->eState==CURSOR_INVALID ){
      assert( pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
      assert( pCur->apPage[pCur->iPage]->nCell>0 );
      *pRes = 0;
      rc = moveToLeftmost(pCur);
    }
  }
................................................................................
#endif
    return SQLITE_OK;
  }

  rc = moveToRoot(pCur);
  if( rc==SQLITE_OK ){
    if( CURSOR_INVALID==pCur->eState ){
      assert( pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
      assert( pCur->eState==CURSOR_VALID );
      *pRes = 0;
      rc = moveToRightmost(pCur);
      pCur->atLast = rc==SQLITE_OK ?1:0;
    }
................................................................................
    }
  }

  rc = moveToRoot(pCur);
  if( rc ){
    return rc;
  }
  assert( pCur->apPage[pCur->iPage] );
  assert( pCur->apPage[pCur->iPage]->isInit );
  assert( pCur->apPage[pCur->iPage]->nCell>0 || pCur->eState==CURSOR_INVALID );
  if( pCur->eState==CURSOR_INVALID ){
    *pRes = -1;
    assert( pCur->apPage[pCur->iPage]->nCell==0 );
    return SQLITE_OK;
  }
  assert( pCur->apPage[0]->intKey || pIdxKey );
  for(;;){
    int lwr, upr, idx;
    Pgno chldPg;
    MemPage *pPage = pCur->apPage[pCur->iPage];
................................................................................
  u32 ovflPageSize;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  btreeParseCellPtr(pPage, pCell, &info);
  if( info.iOverflow==0 ){
    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
  }



  ovflPgno = get4byte(&pCell[info.iOverflow]);
  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( ovflPgno==0 || nOvfl>0 );
  while( nOvfl-- ){
    Pgno iNext = 0;
................................................................................
** SQLITE_OK is returned if the operation is successfully executed. 
** Otherwise, if an error is encountered (i.e. an IO error or database
** corruption) an SQLite error code is returned.
*/
SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){
  i64 nEntry = 0;                      /* Value to return in *pnEntry */
  int rc;                              /* Return code */





  rc = moveToRoot(pCur);

  /* Unless an error occurs, the following loop runs one iteration for each
  ** page in the B-Tree structure (not including overflow pages). 
  */
  while( rc==SQLITE_OK ){
    int iIdx;                          /* Index of child node in parent */
................................................................................
** "write version" (single byte at byte offset 19) fields in the database
** header to iVersion.
*/
SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
  BtShared *pBt = pBtree->pBt;
  int rc;                         /* Return code */
 
  assert( pBtree->inTrans==TRANS_NONE );
  assert( iVersion==1 || iVersion==2 );

  /* If setting the version fields to 1, do not automatically open the
  ** WAL connection, even if the version fields are currently set to 2.
  */
  pBt->doNotUseWAL = (u8)(iVersion==1);

................................................................................
    }
  
    /* Update the schema version field in the destination database. This
    ** is to make sure that the schema-version really does change in
    ** the case where the source and destination databases have the
    ** same schema version.
    */
    if( rc==SQLITE_DONE 
     && (rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1))==SQLITE_OK
    ){
      int nDestTruncate;
  
      if( p->pDestDb ){
        sqlite3ResetInternalSchema(p->pDestDb, -1);
      }






      /* Set nDestTruncate to the final number of pages in the destination
      ** database. The complication here is that the destination page
      ** size may be different to the source page size. 
      **
      ** If the source page size is smaller than the destination page size, 
      ** round up. In this case the call to sqlite3OsTruncate() below will
      ** fix the size of the file. However it is important to call
      ** sqlite3PagerTruncateImage() here so that any pages in the 
      ** destination file that lie beyond the nDestTruncate page mark are
      ** journalled by PagerCommitPhaseOne() before they are destroyed
      ** by the file truncation.
      */
      assert( pgszSrc==sqlite3BtreeGetPageSize(p->pSrc) );
      assert( pgszDest==sqlite3BtreeGetPageSize(p->pDest) );
      if( pgszSrc<pgszDest ){
        int ratio = pgszDest/pgszSrc;
        nDestTruncate = (nSrcPage+ratio-1)/ratio;
        if( nDestTruncate==(int)PENDING_BYTE_PAGE(p->pDest->pBt) ){
          nDestTruncate--;
        }
      }else{
        nDestTruncate = nSrcPage * (pgszSrc/pgszDest);
      }
      sqlite3PagerTruncateImage(pDestPager, nDestTruncate);

      if( pgszSrc<pgszDest ){
        /* If the source page-size is smaller than the destination page-size,
        ** two extra things may need to happen:
        **
        **   * The destination may need to be truncated, and
        **
        **   * Data stored on the pages immediately following the 
        **     pending-byte page in the source database may need to be
        **     copied into the destination database.
        */
        const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
        sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
        i64 iOff;
        i64 iEnd;

        assert( pFile );
        assert( (i64)nDestTruncate*(i64)pgszDest >= iSize || (
              nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1)
           && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
        ));

        /* This call ensures that all data required to recreate the original
        ** database has been stored in the journal for pDestPager and the
        ** journal synced to disk. So at this point we may safely modify
        ** the database file in any way, knowing that if a power failure
        ** occurs, the original database will be reconstructed from the 
        ** journal file.  */
        rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);

        /* Write the extra pages and truncate the database file as required. */
        iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
        for(
          iOff=PENDING_BYTE+pgszSrc; 
          rc==SQLITE_OK && iOff<iEnd; 
          iOff+=pgszSrc
        ){
          PgHdr *pSrcPg = 0;
          const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
          rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
          if( rc==SQLITE_OK ){
            u8 *zData = sqlite3PagerGetData(pSrcPg);
            rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
          }
          sqlite3PagerUnref(pSrcPg);
        }
        if( rc==SQLITE_OK ){
          rc = backupTruncateFile(pFile, iSize);
        }

        /* Sync the database file to disk. */
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerSync(pDestPager);
        }
      }else{
        rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
      }
  
      /* Finish committing the transaction to the destination database. */
      if( SQLITE_OK==rc
       && SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest, 0))
      ){
        rc = SQLITE_DONE;

      }
    }
  
    /* If bCloseTrans is true, then this function opened a read transaction
    ** on the source database. Close the read transaction here. There is
    ** no need to check the return values of the btree methods here, as
    ** "committing" a read-only transaction cannot fail.
................................................................................
/*
** If the memory cell contains a string value that must be freed by
** invoking an external callback, free it now. Calling this function
** does not free any Mem.zMalloc buffer.
*/
SQLITE_PRIVATE void sqlite3VdbeMemReleaseExternal(Mem *p){
  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
  testcase( p->flags & MEM_Agg );
  testcase( p->flags & MEM_Dyn );
  testcase( p->flags & MEM_RowSet );
  testcase( p->flags & MEM_Frame );
  if( p->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame) ){
    if( p->flags&MEM_Agg ){
      sqlite3VdbeMemFinalize(p, p->u.pDef);
      assert( (p->flags & MEM_Agg)==0 );
      sqlite3VdbeMemRelease(p);
    }else if( p->flags&MEM_Dyn && p->xDel ){
      assert( (p->flags&MEM_RowSet)==0 );
      p->xDel((void *)p->z);
      p->xDel = 0;
    }else if( p->flags&MEM_RowSet ){
      sqlite3RowSetClear(p->u.pRowSet);
    }else if( p->flags&MEM_Frame ){
      sqlite3VdbeMemSetNull(p);
    }
  }
}

/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.type==SQLITE_TEXT).
*/
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p){
  sqlite3VdbeMemReleaseExternal(p);
  sqlite3DbFree(p->db, p->zMalloc);
  p->z = 0;
  p->zMalloc = 0;
  p->xDel = 0;
}

/*
................................................................................
** Make an shallow copy of pFrom into pTo.  Prior contents of
** pTo are freed.  The pFrom->z field is not duplicated.  If
** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
** and flags gets srcType (either MEM_Ephem or MEM_Static).
*/
SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
  assert( (pFrom->flags & MEM_RowSet)==0 );
  sqlite3VdbeMemReleaseExternal(pTo);
  memcpy(pTo, pFrom, MEMCELLSIZE);
  pTo->xDel = 0;
  if( (pFrom->flags&MEM_Static)==0 ){
    pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
    assert( srcType==MEM_Ephem || srcType==MEM_Static );
    pTo->flags |= srcType;
  }
................................................................................
** Make a full copy of pFrom into pTo.  Prior contents of pTo are
** freed before the copy is made.
*/
SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
  int rc = SQLITE_OK;

  assert( (pFrom->flags & MEM_RowSet)==0 );
  sqlite3VdbeMemReleaseExternal(pTo);
  memcpy(pTo, pFrom, MEMCELLSIZE);
  pTo->flags &= ~MEM_Dyn;

  if( pTo->flags&(MEM_Str|MEM_Blob) ){
    if( 0==(pFrom->flags&MEM_Static) ){
      pTo->flags |= MEM_Ephem;
      rc = sqlite3VdbeMemMakeWriteable(pTo);
................................................................................

  if( !pExpr ){
    *ppVal = 0;
    return SQLITE_OK;
  }
  op = pExpr->op;

  /* op can only be TK_REGISTER if we have compiled with SQLITE_ENABLE_STAT3.
  ** The ifdef here is to enable us to achieve 100% branch test coverage even
  ** when SQLITE_ENABLE_STAT3 is omitted.
  */
#ifdef SQLITE_ENABLE_STAT3
  if( op==TK_REGISTER ) op = pExpr->op2;
#else
  if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
#endif

  /* Handle negative integers in a single step.  This is needed in the
  ** case when the value is -9223372036854775808.
................................................................................
    }else if( opcode==OP_VFilter ){
      int n;
      assert( p->nOp - i >= 3 );
      assert( pOp[-1].opcode==OP_Integer );
      n = pOp[-1].p1;
      if( n>nMaxArgs ) nMaxArgs = n;
#endif






    }

    if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
      assert( -1-pOp->p2<p->nLabel );
      pOp->p2 = aLabel[-1-pOp->p2];
    }
  }
................................................................................

/*
** Change the value of the P1 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqlite3VdbeAddOpList but we want to make a
** few minor changes to the program.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe *p, int addr, int val){
  assert( p!=0 );
  assert( addr>=0 );
  if( p->nOp>addr ){
    p->aOp[addr].p1 = val;
  }
}

/*
** Change the value of the P2 operand for a specific instruction.
** This routine is useful for setting a jump destination.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe *p, int addr, int val){
  assert( p!=0 );
  assert( addr>=0 );
  if( p->nOp>addr ){
    p->aOp[addr].p2 = val;
  }
}

/*
** Change the value of the P3 operand for a specific instruction.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe *p, int addr, int val){
  assert( p!=0 );
  assert( addr>=0 );
  if( p->nOp>addr ){
    p->aOp[addr].p3 = val;
  }
}

/*
** Change the value of the P5 operand for the most recently
** added operation.
................................................................................
}

/*
** Change the P2 operand of instruction addr so that it points to
** the address of the next instruction to be coded.
*/
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
  assert( addr>=0 || p->db->mallocFailed );
  if( addr>=0 ) sqlite3VdbeChangeP2(p, addr, p->nOp);
}


/*
** If the input FuncDef structure is ephemeral, then free it.  If
** the FuncDef is not ephermal, then do nothing.
*/
................................................................................
    case P4_INTARRAY: {
      sqlite3_snprintf(nTemp, zTemp, "intarray");
      break;
    }
    case P4_SUBPROGRAM: {
      sqlite3_snprintf(nTemp, zTemp, "program");
      break;




    }
    default: {
      zP4 = pOp->p4.z;
      if( zP4==0 ){
        zP4 = zTemp;
        zTemp[0] = 0;
      }
................................................................................
** Close a VDBE cursor and release all the resources that cursor 
** happens to hold.
*/
SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
  if( pCx==0 ){
    return;
  }

  if( pCx->pBt ){
    sqlite3BtreeClose(pCx->pBt);
    /* The pCx->pCursor will be close automatically, if it exists, by
    ** the call above. */
  }else if( pCx->pCursor ){
    sqlite3BtreeCloseCursor(pCx->pCursor);
  }
................................................................................

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)








/*
** Argument pMem points at a register that will be passed to a
** user-defined function or returned to the user as the result of a query.
** This routine sets the pMem->type variable used by the sqlite3_value_*() 
** routines.
*/
SQLITE_PRIVATE void sqlite3VdbeMemStoreType(Mem *pMem){
................................................................................
      Mem sMem;          /* For storing the record being decoded */
      u8 *zIdx;          /* Index into header */
      u8 *zEndHdr;       /* Pointer to first byte after the header */
      u32 offset;        /* Offset into the data */
      u32 szField;       /* Number of bytes in the content of a field */
      int szHdr;         /* Size of the header size field at start of record */
      int avail;         /* Number of bytes of available data */

      Mem *pReg;         /* PseudoTable input register */
    } am;
    struct OP_Affinity_stack_vars {
      const char *zAffinity;   /* The affinity to be applied */
      char cAff;               /* A single character of affinity */
    } an;
    struct OP_MakeRecord_stack_vars {
................................................................................
      Btree *pX;
      VdbeCursor *pCur;
      Db *pDb;
    } aw;
    struct OP_OpenEphemeral_stack_vars {
      VdbeCursor *pCx;
    } ax;



    struct OP_OpenPseudo_stack_vars {
      VdbeCursor *pCx;
    } ay;
    struct OP_SeekGt_stack_vars {
      int res;
      int oc;
      VdbeCursor *pC;
      UnpackedRecord r;
      int nField;
      i64 iKey;      /* The rowid we are to seek to */
    } az;
    struct OP_Seek_stack_vars {
      VdbeCursor *pC;
    } ba;
    struct OP_Found_stack_vars {
      int alreadyExists;
      VdbeCursor *pC;
      int res;
      UnpackedRecord *pIdxKey;
      UnpackedRecord r;
      char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
    } bb;
    struct OP_IsUnique_stack_vars {
      u16 ii;
      VdbeCursor *pCx;
      BtCursor *pCrsr;
      u16 nField;
      Mem *aMx;
      UnpackedRecord r;                  /* B-Tree index search key */
      i64 R;                             /* Rowid stored in register P3 */
    } bc;
    struct OP_NotExists_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
      u64 iKey;
    } bd;
    struct OP_NewRowid_stack_vars {
      i64 v;                 /* The new rowid */
      VdbeCursor *pC;        /* Cursor of table to get the new rowid */
      int res;               /* Result of an sqlite3BtreeLast() */
      int cnt;               /* Counter to limit the number of searches */
      Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */
      VdbeFrame *pFrame;     /* Root frame of VDBE */
    } be;
    struct OP_InsertInt_stack_vars {
      Mem *pData;       /* MEM cell holding data for the record to be inserted */
      Mem *pKey;        /* MEM cell holding key  for the record */
      i64 iKey;         /* The integer ROWID or key for the record to be inserted */
      VdbeCursor *pC;   /* Cursor to table into which insert is written */
      int nZero;        /* Number of zero-bytes to append */
      int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
      const char *zDb;  /* database name - used by the update hook */
      const char *zTbl; /* Table name - used by the opdate hook */
      int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
    } bf;
    struct OP_Delete_stack_vars {
      i64 iKey;
      VdbeCursor *pC;
    } bg;







    struct OP_RowData_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      u32 n;
      i64 n64;
    } bh;
    struct OP_Rowid_stack_vars {
      VdbeCursor *pC;
      i64 v;
      sqlite3_vtab *pVtab;
      const sqlite3_module *pModule;
    } bi;
    struct OP_NullRow_stack_vars {
      VdbeCursor *pC;
    } bj;
    struct OP_Last_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
    } bk;
    struct OP_Rewind_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
    } bl;
    struct OP_Next_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
    } bm;
    struct OP_IdxInsert_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int nKey;
      const char *zKey;
    } bn;
    struct OP_IdxDelete_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
      UnpackedRecord r;
    } bo;
    struct OP_IdxRowid_stack_vars {
      BtCursor *pCrsr;
      VdbeCursor *pC;
      i64 rowid;
    } bp;
    struct OP_IdxGE_stack_vars {
      VdbeCursor *pC;
      int res;
      UnpackedRecord r;
    } bq;
    struct OP_Destroy_stack_vars {
      int iMoved;
      int iCnt;
      Vdbe *pVdbe;
      int iDb;
    } br;
    struct OP_Clear_stack_vars {
      int nChange;
    } bs;
    struct OP_CreateTable_stack_vars {
      int pgno;
      int flags;
      Db *pDb;
    } bt;
    struct OP_ParseSchema_stack_vars {
      int iDb;
      const char *zMaster;
      char *zSql;
      InitData initData;
    } bu;
    struct OP_IntegrityCk_stack_vars {
      int nRoot;      /* Number of tables to check.  (Number of root pages.) */
      int *aRoot;     /* Array of rootpage numbers for tables to be checked */
      int j;          /* Loop counter */
      int nErr;       /* Number of errors reported */
      char *z;        /* Text of the error report */
      Mem *pnErr;     /* Register keeping track of errors remaining */
    } bv;
    struct OP_RowSetRead_stack_vars {
      i64 val;
    } bw;
    struct OP_RowSetTest_stack_vars {
      int iSet;
      int exists;
    } bx;
    struct OP_Program_stack_vars {
      int nMem;               /* Number of memory registers for sub-program */
      int nByte;              /* Bytes of runtime space required for sub-program */
      Mem *pRt;               /* Register to allocate runtime space */
      Mem *pMem;              /* Used to iterate through memory cells */
      Mem *pEnd;              /* Last memory cell in new array */
      VdbeFrame *pFrame;      /* New vdbe frame to execute in */
      SubProgram *pProgram;   /* Sub-program to execute */
      void *t;                /* Token identifying trigger */
    } by;
    struct OP_Param_stack_vars {
      VdbeFrame *pFrame;
      Mem *pIn;
    } bz;
    struct OP_MemMax_stack_vars {
      Mem *pIn1;
      VdbeFrame *pFrame;
    } ca;
    struct OP_AggStep_stack_vars {
      int n;
      int i;
      Mem *pMem;
      Mem *pRec;
      sqlite3_context ctx;
      sqlite3_value **apVal;
    } cb;
    struct OP_AggFinal_stack_vars {
      Mem *pMem;
    } cc;
    struct OP_Checkpoint_stack_vars {
      int i;                          /* Loop counter */
      int aRes[3];                    /* Results */
      Mem *pMem;                      /* Write results here */
    } cd;
    struct OP_JournalMode_stack_vars {
      Btree *pBt;                     /* Btree to change journal mode of */
      Pager *pPager;                  /* Pager associated with pBt */
      int eNew;                       /* New journal mode */
      int eOld;                       /* The old journal mode */
      const char *zFilename;          /* Name of database file for pPager */
    } ce;
    struct OP_IncrVacuum_stack_vars {
      Btree *pBt;
    } cf;
    struct OP_VBegin_stack_vars {
      VTable *pVTab;
    } cg;
    struct OP_VOpen_stack_vars {
      VdbeCursor *pCur;
      sqlite3_vtab_cursor *pVtabCursor;
      sqlite3_vtab *pVtab;
      sqlite3_module *pModule;
    } ch;
    struct OP_VFilter_stack_vars {
      int nArg;
      int iQuery;
      const sqlite3_module *pModule;
      Mem *pQuery;
      Mem *pArgc;
      sqlite3_vtab_cursor *pVtabCursor;
      sqlite3_vtab *pVtab;
      VdbeCursor *pCur;
      int res;
      int i;
      Mem **apArg;
    } ci;
    struct OP_VColumn_stack_vars {
      sqlite3_vtab *pVtab;
      const sqlite3_module *pModule;
      Mem *pDest;
      sqlite3_context sContext;
    } cj;
    struct OP_VNext_stack_vars {
      sqlite3_vtab *pVtab;
      const sqlite3_module *pModule;
      int res;
      VdbeCursor *pCur;
    } ck;
    struct OP_VRename_stack_vars {
      sqlite3_vtab *pVtab;
      Mem *pName;
    } cl;
    struct OP_VUpdate_stack_vars {
      sqlite3_vtab *pVtab;
      sqlite3_module *pModule;
      int nArg;
      int i;
      sqlite_int64 rowid;
      Mem **apArg;
      Mem *pX;
    } cm;
    struct OP_Trace_stack_vars {
      char *zTrace;
      char *z;
    } cn;
  } u;
  /* End automatically generated code
  ********************************************************************/

  assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
  sqlite3VdbeEnter(p);
  if( p->rc==SQLITE_NOMEM ){
................................................................................
    */
    assert( pOp->opflags==sqlite3OpcodeProperty[pOp->opcode] );
    if( pOp->opflags & OPFLG_OUT2_PRERELEASE ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=p->nMem );
      pOut = &aMem[pOp->p2];
      memAboutToChange(p, pOut);
      sqlite3VdbeMemReleaseExternal(pOut);
      pOut->flags = MEM_Int;
    }

    /* Sanity checking on other operands */
#ifdef SQLITE_DEBUG
    if( (pOp->opflags & OPFLG_IN1)!=0 ){
      assert( pOp->p1>0 );
................................................................................
  Mem sMem;          /* For storing the record being decoded */
  u8 *zIdx;          /* Index into header */
  u8 *zEndHdr;       /* Pointer to first byte after the header */
  u32 offset;        /* Offset into the data */
  u32 szField;       /* Number of bytes in the content of a field */
  int szHdr;         /* Size of the header size field at start of record */
  int avail;         /* Number of bytes of available data */

  Mem *pReg;         /* PseudoTable input register */
#endif /* local variables moved into u.am */


  u.am.p1 = pOp->p1;
  u.am.p2 = pOp->p2;
  u.am.pC = 0;
  memset(&u.am.sMem, 0, sizeof(u.am.sMem));
  assert( u.am.p1<p->nCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.am.pDest = &aMem[pOp->p3];
  memAboutToChange(p, u.am.pDest);
  MemSetTypeFlag(u.am.pDest, MEM_Null);
  u.am.zRec = 0;

  /* This block sets the variable u.am.payloadSize to be the total number of
  ** bytes in the record.
  **
  ** u.am.zRec is set to be the complete text of the record if it is available.
  ** The complete record text is always available for pseudo-tables
................................................................................
      assert( (u.am.payloadSize64 & SQLITE_MAX_U32)==(u64)u.am.payloadSize64 );
      u.am.payloadSize = (u32)u.am.payloadSize64;
    }else{
      assert( sqlite3BtreeCursorIsValid(u.am.pCrsr) );
      rc = sqlite3BtreeDataSize(u.am.pCrsr, &u.am.payloadSize);
      assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
    }
  }else if( u.am.pC->pseudoTableReg>0 ){
    u.am.pReg = &aMem[u.am.pC->pseudoTableReg];
    assert( u.am.pReg->flags & MEM_Blob );
    assert( memIsValid(u.am.pReg) );
    u.am.payloadSize = u.am.pReg->n;
    u.am.zRec = u.am.pReg->z;
    u.am.pC->cacheStatus = (pOp->p5&OPFLAG_CLEARCACHE) ? CACHE_STALE : p->cacheCtr;
    assert( u.am.payloadSize==0 || u.am.zRec!=0 );
  }else{
    /* Consider the row to be NULL */
    u.am.payloadSize = 0;
  }

  /* If u.am.payloadSize is 0, then just store a NULL */

  if( u.am.payloadSize==0 ){
    assert( u.am.pDest->flags&MEM_Null );

    goto op_column_out;
  }
  assert( db->aLimit[SQLITE_LIMIT_LENGTH]>=0 );
  if( u.am.payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
    goto too_big;
  }

................................................................................
    ** arrays.  u.am.aType[u.am.i] will contain the type integer for the u.am.i-th
    ** column and u.am.aOffset[u.am.i] will contain the u.am.offset from the beginning
    ** of the record to the start of the data for the u.am.i-th column
    */
    for(u.am.i=0; u.am.i<u.am.nField; u.am.i++){
      if( u.am.zIdx<u.am.zEndHdr ){
        u.am.aOffset[u.am.i] = u.am.offset;






        u.am.zIdx += getVarint32(u.am.zIdx, u.am.aType[u.am.i]);
        u.am.szField = sqlite3VdbeSerialTypeLen(u.am.aType[u.am.i]);
        u.am.offset += u.am.szField;
        if( u.am.offset<u.am.szField ){  /* True if u.am.offset overflows */
          u.am.zIdx = &u.am.zEndHdr[1];  /* Forces SQLITE_CORRUPT return below */
          break;
        }
      }else{
        /* If u.am.i is less that u.am.nField, then there are less fields in this
................................................................................
  ** then there are not enough fields in the record to satisfy the
  ** request.  In this case, set the value NULL or to P4 if P4 is
  ** a pointer to a Mem object.
  */
  if( u.am.aOffset[u.am.p2] ){
    assert( rc==SQLITE_OK );
    if( u.am.zRec ){
      sqlite3VdbeMemReleaseExternal(u.am.pDest);
      sqlite3VdbeSerialGet((u8 *)&u.am.zRec[u.am.aOffset[u.am.p2]], u.am.aType[u.am.p2], u.am.pDest);
    }else{
      u.am.len = sqlite3VdbeSerialTypeLen(u.am.aType[u.am.p2]);
      sqlite3VdbeMemMove(&u.am.sMem, u.am.pDest);
      rc = sqlite3VdbeMemFromBtree(u.am.pCrsr, u.am.aOffset[u.am.p2], u.am.len, u.am.pC->isIndex, &u.am.sMem);
      if( rc!=SQLITE_OK ){
        goto op_column_out;
................................................................................
      sqlite3VdbeSerialGet((u8*)u.am.zData, u.am.aType[u.am.p2], u.am.pDest);
    }
    u.am.pDest->enc = encoding;
  }else{
    if( pOp->p4type==P4_MEM ){
      sqlite3VdbeMemShallowCopy(u.am.pDest, pOp->p4.pMem, MEM_Static);
    }else{
      assert( u.am.pDest->flags&MEM_Null );
    }
  }

  /* If we dynamically allocated space to hold the data (in the
  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
  ** dynamically allocated space over to the u.am.pDest structure.
  ** This prevents a memory copy.
................................................................................
case OP_Count: {         /* out2-prerelease */
#if 0  /* local variables moved into u.ap */
  i64 nEntry;
  BtCursor *pCrsr;
#endif /* local variables moved into u.ap */

  u.ap.pCrsr = p->apCsr[pOp->p1]->pCursor;
  if( u.ap.pCrsr ){
    rc = sqlite3BtreeCount(u.ap.pCrsr, &u.ap.nEntry);
  }else{
    u.ap.nEntry = 0;
  }
  pOut->u.i = u.ap.nEntry;
  break;
}
................................................................................
  u.aw.pCur = allocateCursor(p, pOp->p1, u.aw.nField, u.aw.iDb, 1);
  if( u.aw.pCur==0 ) goto no_mem;
  u.aw.pCur->nullRow = 1;
  u.aw.pCur->isOrdered = 1;
  rc = sqlite3BtreeCursor(u.aw.pX, u.aw.p2, u.aw.wrFlag, u.aw.pKeyInfo, u.aw.pCur->pCursor);
  u.aw.pCur->pKeyInfo = u.aw.pKeyInfo;

  /* Since it performs no memory allocation or IO, the only values that
  ** sqlite3BtreeCursor() may return are SQLITE_EMPTY and SQLITE_OK.
  ** SQLITE_EMPTY is only returned when attempting to open the table
  ** rooted at page 1 of a zero-byte database.  */
  assert( rc==SQLITE_EMPTY || rc==SQLITE_OK );
  if( rc==SQLITE_EMPTY ){
    u.aw.pCur->pCursor = 0;
    rc = SQLITE_OK;
  }

  /* Set the VdbeCursor.isTable and isIndex variables. Previous versions of
  ** SQLite used to check if the root-page flags were sane at this point
  ** and report database corruption if they were not, but this check has
  ** since moved into the btree layer.  */
  u.aw.pCur->isTable = pOp->p4type!=P4_KEYINFO;
  u.aw.pCur->isIndex = !u.aw.pCur->isTable;
  break;
}

/* Opcode: OpenEphemeral P1 P2 * P4 *
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if 
** the main database is read-only.  The ephemeral
** table is deleted automatically when the cursor is closed.
**
** P2 is the number of columns in the ephemeral table.
................................................................................
** that defines the format of keys in the index.
**
** This opcode was once called OpenTemp.  But that created
** confusion because the term "temp table", might refer either
** to a TEMP table at the SQL level, or to a table opened by
** this opcode.  Then this opcode was call OpenVirtual.  But
** that created confusion with the whole virtual-table idea.





*/
/* Opcode: OpenAutoindex P1 P2 * P4 *
**
** This opcode works the same as OP_OpenEphemeral.  It has a
** different name to distinguish its use.  Tables created using
** by this opcode will be used for automatically created transient
** indices in joins.
................................................................................
      u.ax.pCx->isTable = 1;
    }
  }
  u.ax.pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  u.ax.pCx->isIndex = !u.ax.pCx->isTable;
  break;
}

























/* Opcode: OpenPseudo P1 P2 P3 * *
**
** Open a new cursor that points to a fake table that contains a single
** row of data.  The content of that one row in the content of memory
** register P2.  In other words, cursor P1 becomes an alias for the 
** MEM_Blob content contained in register P2.
................................................................................
** individual columns using the OP_Column opcode.  The OP_Column opcode
** is the only cursor opcode that works with a pseudo-table.
**
** P3 is the number of fields in the records that will be stored by
** the pseudo-table.
*/
case OP_OpenPseudo: {
#if 0  /* local variables moved into u.ay */
  VdbeCursor *pCx;
#endif /* local variables moved into u.ay */

  assert( pOp->p1>=0 );
  u.ay.pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
  if( u.ay.pCx==0 ) goto no_mem;
  u.ay.pCx->nullRow = 1;
  u.ay.pCx->pseudoTableReg = pOp->p2;
  u.ay.pCx->isTable = 1;
  u.ay.pCx->isIndex = 0;
  break;
}

/* Opcode: Close P1 * * * *
**
** Close a cursor previously opened as P1.  If P1 is not
** currently open, this instruction is a no-op.
................................................................................
**
** See also: Found, NotFound, Distinct, SeekGt, SeekGe, SeekLt
*/
case OP_SeekLt:         /* jump, in3 */
case OP_SeekLe:         /* jump, in3 */
case OP_SeekGe:         /* jump, in3 */
case OP_SeekGt: {       /* jump, in3 */
#if 0  /* local variables moved into u.az */
  int res;
  int oc;
  VdbeCursor *pC;
  UnpackedRecord r;
  int nField;
  i64 iKey;      /* The rowid we are to seek to */
#endif /* local variables moved into u.az */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p2!=0 );
  u.az.pC = p->apCsr[pOp->p1];
  assert( u.az.pC!=0 );
  assert( u.az.pC->pseudoTableReg==0 );
  assert( OP_SeekLe == OP_SeekLt+1 );
  assert( OP_SeekGe == OP_SeekLt+2 );
  assert( OP_SeekGt == OP_SeekLt+3 );
  assert( u.az.pC->isOrdered );
  if( u.az.pC->pCursor!=0 ){
    u.az.oc = pOp->opcode;
    u.az.pC->nullRow = 0;
    if( u.az.pC->isTable ){
      /* The input value in P3 might be of any type: integer, real, string,
      ** blob, or NULL.  But it needs to be an integer before we can do
      ** the seek, so covert it. */
      pIn3 = &aMem[pOp->p3];
      applyNumericAffinity(pIn3);
      u.az.iKey = sqlite3VdbeIntValue(pIn3);
      u.az.pC->rowidIsValid = 0;

      /* If the P3 value could not be converted into an integer without
      ** loss of information, then special processing is required... */
      if( (pIn3->flags & MEM_Int)==0 ){
        if( (pIn3->flags & MEM_Real)==0 ){
          /* If the P3 value cannot be converted into any kind of a number,
          ** then the seek is not possible, so jump to P2 */
................................................................................
          pc = pOp->p2 - 1;
          break;
        }
        /* If we reach this point, then the P3 value must be a floating
        ** point number. */
        assert( (pIn3->flags & MEM_Real)!=0 );

        if( u.az.iKey==SMALLEST_INT64 && (pIn3->r<(double)u.az.iKey || pIn3->r>0) ){
          /* The P3 value is too large in magnitude to be expressed as an
          ** integer. */
          u.az.res = 1;
          if( pIn3->r<0 ){
            if( u.az.oc>=OP_SeekGe ){  assert( u.az.oc==OP_SeekGe || u.az.oc==OP_SeekGt );
              rc = sqlite3BtreeFirst(u.az.pC->pCursor, &u.az.res);
              if( rc!=SQLITE_OK ) goto abort_due_to_error;
            }
          }else{
            if( u.az.oc<=OP_SeekLe ){  assert( u.az.oc==OP_SeekLt || u.az.oc==OP_SeekLe );
              rc = sqlite3BtreeLast(u.az.pC->pCursor, &u.az.res);
              if( rc!=SQLITE_OK ) goto abort_due_to_error;
            }
          }
          if( u.az.res ){
            pc = pOp->p2 - 1;
          }
          break;
        }else if( u.az.oc==OP_SeekLt || u.az.oc==OP_SeekGe ){
          /* Use the ceiling() function to convert real->int */
          if( pIn3->r > (double)u.az.iKey ) u.az.iKey++;
        }else{
          /* Use the floor() function to convert real->int */
          assert( u.az.oc==OP_SeekLe || u.az.oc==OP_SeekGt );
          if( pIn3->r < (double)u.az.iKey ) u.az.iKey--;
        }
      }
      rc = sqlite3BtreeMovetoUnpacked(u.az.pC->pCursor, 0, (u64)u.az.iKey, 0, &u.az.res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      if( u.az.res==0 ){
        u.az.pC->rowidIsValid = 1;
        u.az.pC->lastRowid = u.az.iKey;
      }
    }else{
      u.az.nField = pOp->p4.i;
      assert( pOp->p4type==P4_INT32 );
      assert( u.az.nField>0 );
      u.az.r.pKeyInfo = u.az.pC->pKeyInfo;
      u.az.r.nField = (u16)u.az.nField;

      /* The next line of code computes as follows, only faster:
      **   if( u.az.oc==OP_SeekGt || u.az.oc==OP_SeekLe ){
      **     u.az.r.flags = UNPACKED_INCRKEY;
      **   }else{
      **     u.az.r.flags = 0;
      **   }
      */
      u.az.r.flags = (u16)(UNPACKED_INCRKEY * (1 & (u.az.oc - OP_SeekLt)));
      assert( u.az.oc!=OP_SeekGt || u.az.r.flags==UNPACKED_INCRKEY );
      assert( u.az.oc!=OP_SeekLe || u.az.r.flags==UNPACKED_INCRKEY );
      assert( u.az.oc!=OP_SeekGe || u.az.r.flags==0 );
      assert( u.az.oc!=OP_SeekLt || u.az.r.flags==0 );

      u.az.r.aMem = &aMem[pOp->p3];
#ifdef SQLITE_DEBUG
      { int i; for(i=0; i<u.az.r.nField; i++) assert( memIsValid(&u.az.r.aMem[i]) ); }
#endif
      ExpandBlob(u.az.r.aMem);
      rc = sqlite3BtreeMovetoUnpacked(u.az.pC->pCursor, &u.az.r, 0, 0, &u.az.res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      u.az.pC->rowidIsValid = 0;
    }
    u.az.pC->deferredMoveto = 0;
    u.az.pC->cacheStatus = CACHE_STALE;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
    if( u.az.oc>=OP_SeekGe ){  assert( u.az.oc==OP_SeekGe || u.az.oc==OP_SeekGt );
      if( u.az.res<0 || (u.az.res==0 && u.az.oc==OP_SeekGt) ){
        rc = sqlite3BtreeNext(u.az.pC->pCursor, &u.az.res);
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
        u.az.pC->rowidIsValid = 0;
      }else{
        u.az.res = 0;
      }
    }else{
      assert( u.az.oc==OP_SeekLt || u.az.oc==OP_SeekLe );
      if( u.az.res>0 || (u.az.res==0 && u.az.oc==OP_SeekLt) ){
        rc = sqlite3BtreePrevious(u.az.pC->pCursor, &u.az.res);
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
        u.az.pC->rowidIsValid = 0;
      }else{
        /* u.az.res might be negative because the table is empty.  Check to
        ** see if this is the case.
        */
        u.az.res = sqlite3BtreeEof(u.az.pC->pCursor);
      }
    }
    assert( pOp->p2>0 );
    if( u.az.res ){
      pc = pOp->p2 - 1;
    }
  }else{
    /* This happens when attempting to open the sqlite3_master table
    ** for read access returns SQLITE_EMPTY. In this case always
    ** take the jump (since there are no records in the table).
    */
................................................................................
** for P1 to move so that it points to the rowid given by P2.
**
** This is actually a deferred seek.  Nothing actually happens until
** the cursor is used to read a record.  That way, if no reads
** occur, no unnecessary I/O happens.
*/
case OP_Seek: {    /* in2 */
#if 0  /* local variables moved into u.ba */
  VdbeCursor *pC;
#endif /* local variables moved into u.ba */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.ba.pC = p->apCsr[pOp->p1];
  assert( u.ba.pC!=0 );
  if( ALWAYS(u.ba.pC->pCursor!=0) ){
    assert( u.ba.pC->isTable );
    u.ba.pC->nullRow = 0;
    pIn2 = &aMem[pOp->p2];
    u.ba.pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
    u.ba.pC->rowidIsValid = 0;
    u.ba.pC->deferredMoveto = 1;
  }
  break;
}
  

/* Opcode: Found P1 P2 P3 P4 *
**
................................................................................
** falls through to the next instruction and P1 is left pointing at the
** matching entry.
**
** See also: Found, NotExists, IsUnique
*/
case OP_NotFound:       /* jump, in3 */
case OP_Found: {        /* jump, in3 */
#if 0  /* local variables moved into u.bb */
  int alreadyExists;
  VdbeCursor *pC;
  int res;
  UnpackedRecord *pIdxKey;
  UnpackedRecord r;
  char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
#endif /* local variables moved into u.bb */

#ifdef SQLITE_TEST
  sqlite3_found_count++;
#endif

  u.bb.alreadyExists = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p4type==P4_INT32 );
  u.bb.pC = p->apCsr[pOp->p1];
  assert( u.bb.pC!=0 );
  pIn3 = &aMem[pOp->p3];
  if( ALWAYS(u.bb.pC->pCursor!=0) ){

    assert( u.bb.pC->isTable==0 );
    if( pOp->p4.i>0 ){
      u.bb.r.pKeyInfo = u.bb.pC->pKeyInfo;
      u.bb.r.nField = (u16)pOp->p4.i;
      u.bb.r.aMem = pIn3;
#ifdef SQLITE_DEBUG
      { int i; for(i=0; i<u.bb.r.nField; i++) assert( memIsValid(&u.bb.r.aMem[i]) ); }
#endif
      u.bb.r.flags = UNPACKED_PREFIX_MATCH;
      u.bb.pIdxKey = &u.bb.r;
    }else{
      assert( pIn3->flags & MEM_Blob );
      assert( (pIn3->flags & MEM_Zero)==0 );  /* zeroblobs already expanded */
      u.bb.pIdxKey = sqlite3VdbeRecordUnpack(u.bb.pC->pKeyInfo, pIn3->n, pIn3->z,
                                        u.bb.aTempRec, sizeof(u.bb.aTempRec));
      if( u.bb.pIdxKey==0 ){
        goto no_mem;
      }
      u.bb.pIdxKey->flags |= UNPACKED_PREFIX_MATCH;
    }
    rc = sqlite3BtreeMovetoUnpacked(u.bb.pC->pCursor, u.bb.pIdxKey, 0, 0, &u.bb.res);
    if( pOp->p4.i==0 ){
      sqlite3VdbeDeleteUnpackedRecord(u.bb.pIdxKey);
    }
    if( rc!=SQLITE_OK ){
      break;
    }
    u.bb.alreadyExists = (u.bb.res==0);
    u.bb.pC->deferredMoveto = 0;
    u.bb.pC->cacheStatus = CACHE_STALE;
  }
  if( pOp->opcode==OP_Found ){
    if( u.bb.alreadyExists ) pc = pOp->p2 - 1;
  }else{
    if( !u.bb.alreadyExists ) pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: IsUnique P1 P2 P3 P4 *
**
** Cursor P1 is open on an index b-tree - that is to say, a btree which
................................................................................
** to instruction P2. Otherwise, the rowid of the conflicting index
** entry is copied to register P3 and control falls through to the next
** instruction.
**
** See also: NotFound, NotExists, Found
*/
case OP_IsUnique: {        /* jump, in3 */
#if 0  /* local variables moved into u.bc */
  u16 ii;
  VdbeCursor *pCx;
  BtCursor *pCrsr;
  u16 nField;
  Mem *aMx;
  UnpackedRecord r;                  /* B-Tree index search key */
  i64 R;                             /* Rowid stored in register P3 */
#endif /* local variables moved into u.bc */

  pIn3 = &aMem[pOp->p3];
  u.bc.aMx = &aMem[pOp->p4.i];
  /* Assert that the values of parameters P1 and P4 are in range. */
  assert( pOp->p4type==P4_INT32 );
  assert( pOp->p4.i>0 && pOp->p4.i<=p->nMem );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  /* Find the index cursor. */
  u.bc.pCx = p->apCsr[pOp->p1];
  assert( u.bc.pCx->deferredMoveto==0 );
  u.bc.pCx->seekResult = 0;
  u.bc.pCx->cacheStatus = CACHE_STALE;
  u.bc.pCrsr = u.bc.pCx->pCursor;

  /* If any of the values are NULL, take the jump. */
  u.bc.nField = u.bc.pCx->pKeyInfo->nField;
  for(u.bc.ii=0; u.bc.ii<u.bc.nField; u.bc.ii++){
    if( u.bc.aMx[u.bc.ii].flags & MEM_Null ){
      pc = pOp->p2 - 1;
      u.bc.pCrsr = 0;
      break;
    }
  }
  assert( (u.bc.aMx[u.bc.nField].flags & MEM_Null)==0 );

  if( u.bc.pCrsr!=0 ){
    /* Populate the index search key. */
    u.bc.r.pKeyInfo = u.bc.pCx->pKeyInfo;
    u.bc.r.nField = u.bc.nField + 1;
    u.bc.r.flags = UNPACKED_PREFIX_SEARCH;
    u.bc.r.aMem = u.bc.aMx;
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<u.bc.r.nField; i++) assert( memIsValid(&u.bc.r.aMem[i]) ); }
#endif

    /* Extract the value of u.bc.R from register P3. */
    sqlite3VdbeMemIntegerify(pIn3);
    u.bc.R = pIn3->u.i;

    /* Search the B-Tree index. If no conflicting record is found, jump
    ** to P2. Otherwise, copy the rowid of the conflicting record to
    ** register P3 and fall through to the next instruction.  */
    rc = sqlite3BtreeMovetoUnpacked(u.bc.pCrsr, &u.bc.r, 0, 0, &u.bc.pCx->seekResult);
    if( (u.bc.r.flags & UNPACKED_PREFIX_SEARCH) || u.bc.r.rowid==u.bc.R ){
      pc = pOp->p2 - 1;
    }else{
      pIn3->u.i = u.bc.r.rowid;
    }
  }
  break;
}

/* Opcode: NotExists P1 P2 P3 * *
**
................................................................................
** operation assumes the key is an integer and that P1 is a table whereas
** NotFound assumes key is a blob constructed from MakeRecord and
** P1 is an index.
**
** See also: Found, NotFound, IsUnique
*/
case OP_NotExists: {        /* jump, in3 */
#if 0  /* local variables moved into u.bd */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  u64 iKey;
#endif /* local variables moved into u.bd */

  pIn3 = &aMem[pOp->p3];
  assert( pIn3->flags & MEM_Int );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bd.pC = p->apCsr[pOp->p1];
  assert( u.bd.pC!=0 );
  assert( u.bd.pC->isTable );
  assert( u.bd.pC->pseudoTableReg==0 );
  u.bd.pCrsr = u.bd.pC->pCursor;
  if( u.bd.pCrsr!=0 ){
    u.bd.res = 0;
    u.bd.iKey = pIn3->u.i;
    rc = sqlite3BtreeMovetoUnpacked(u.bd.pCrsr, 0, u.bd.iKey, 0, &u.bd.res);
    u.bd.pC->lastRowid = pIn3->u.i;
    u.bd.pC->rowidIsValid = u.bd.res==0 ?1:0;
    u.bd.pC->nullRow = 0;
    u.bd.pC->cacheStatus = CACHE_STALE;
    u.bd.pC->deferredMoveto = 0;
    if( u.bd.res!=0 ){
      pc = pOp->p2 - 1;
      assert( u.bd.pC->rowidIsValid==0 );
    }
    u.bd.pC->seekResult = u.bd.res;
  }else{
    /* This happens when an attempt to open a read cursor on the
    ** sqlite_master table returns SQLITE_EMPTY.
    */
    pc = pOp->p2 - 1;
    assert( u.bd.pC->rowidIsValid==0 );
    u.bd.pC->seekResult = 0;
  }
  break;
}

/* Opcode: Sequence P1 P2 * * *
**
** Find the next available sequence number for cursor P1.
................................................................................
** the largest previously generated record number. No new record numbers are
** allowed to be less than this value. When this value reaches its maximum, 
** an SQLITE_FULL error is generated. The P3 register is updated with the '
** generated record number. This P3 mechanism is used to help implement the
** AUTOINCREMENT feature.
*/
case OP_NewRowid: {           /* out2-prerelease */
#if 0  /* local variables moved into u.be */
  i64 v;                 /* The new rowid */
  VdbeCursor *pC;        /* Cursor of table to get the new rowid */
  int res;               /* Result of an sqlite3BtreeLast() */
  int cnt;               /* Counter to limit the number of searches */
  Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */
  VdbeFrame *pFrame;     /* Root frame of VDBE */
#endif /* local variables moved into u.be */

  u.be.v = 0;
  u.be.res = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.be.pC = p->apCsr[pOp->p1];
  assert( u.be.pC!=0 );
  if( NEVER(u.be.pC->pCursor==0) ){
    /* The zero initialization above is all that is needed */
  }else{
    /* The next rowid or record number (different terms for the same
    ** thing) is obtained in a two-step algorithm.
    **
    ** First we attempt to find the largest existing rowid and add one
    ** to that.  But if the largest existing rowid is already the maximum
................................................................................
    ** probabilistic algorithm
    **
    ** The second algorithm is to select a rowid at random and see if
    ** it already exists in the table.  If it does not exist, we have
    ** succeeded.  If the random rowid does exist, we select a new one
    ** and try again, up to 100 times.
    */
    assert( u.be.pC->isTable );

#ifdef SQLITE_32BIT_ROWID
#   define MAX_ROWID 0x7fffffff
#else
    /* Some compilers complain about constants of the form 0x7fffffffffffffff.
    ** Others complain about 0x7ffffffffffffffffLL.  The following macro seems
    ** to provide the constant while making all compilers happy.
    */
#   define MAX_ROWID  (i64)( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
#endif

    if( !u.be.pC->useRandomRowid ){
      u.be.v = sqlite3BtreeGetCachedRowid(u.be.pC->pCursor);
      if( u.be.v==0 ){
        rc = sqlite3BtreeLast(u.be.pC->pCursor, &u.be.res);
        if( rc!=SQLITE_OK ){
          goto abort_due_to_error;
        }
        if( u.be.res ){
          u.be.v = 1;   /* IMP: R-61914-48074 */
        }else{
          assert( sqlite3BtreeCursorIsValid(u.be.pC->pCursor) );
          rc = sqlite3BtreeKeySize(u.be.pC->pCursor, &u.be.v);
          assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
          if( u.be.v==MAX_ROWID ){
            u.be.pC->useRandomRowid = 1;
          }else{
            u.be.v++;   /* IMP: R-29538-34987 */
          }
        }
      }

#ifndef SQLITE_OMIT_AUTOINCREMENT
      if( pOp->p3 ){
        /* Assert that P3 is a valid memory cell. */
        assert( pOp->p3>0 );
        if( p->pFrame ){
          for(u.be.pFrame=p->pFrame; u.be.pFrame->pParent; u.be.pFrame=u.be.pFrame->pParent);
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=u.be.pFrame->nMem );
          u.be.pMem = &u.be.pFrame->aMem[pOp->p3];
        }else{
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=p->nMem );
          u.be.pMem = &aMem[pOp->p3];
          memAboutToChange(p, u.be.pMem);
        }
        assert( memIsValid(u.be.pMem) );

        REGISTER_TRACE(pOp->p3, u.be.pMem);
        sqlite3VdbeMemIntegerify(u.be.pMem);
        assert( (u.be.pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
        if( u.be.pMem->u.i==MAX_ROWID || u.be.pC->useRandomRowid ){
          rc = SQLITE_FULL;   /* IMP: R-12275-61338 */
          goto abort_due_to_error;
        }
        if( u.be.v<u.be.pMem->u.i+1 ){
          u.be.v = u.be.pMem->u.i + 1;
        }
        u.be.pMem->u.i = u.be.v;
      }
#endif

      sqlite3BtreeSetCachedRowid(u.be.pC->pCursor, u.be.v<MAX_ROWID ? u.be.v+1 : 0);
    }
    if( u.be.pC->useRandomRowid ){
      /* IMPLEMENTATION-OF: R-07677-41881 If the largest ROWID is equal to the
      ** largest possible integer (9223372036854775807) then the database
      ** engine starts picking positive candidate ROWIDs at random until
      ** it finds one that is not previously used. */
      assert( pOp->p3==0 );  /* We cannot be in random rowid mode if this is
                             ** an AUTOINCREMENT table. */
      /* on the first attempt, simply do one more than previous */
      u.be.v = lastRowid;
      u.be.v &= (MAX_ROWID>>1); /* ensure doesn't go negative */
      u.be.v++; /* ensure non-zero */
      u.be.cnt = 0;
      while(   ((rc = sqlite3BtreeMovetoUnpacked(u.be.pC->pCursor, 0, (u64)u.be.v,
                                                 0, &u.be.res))==SQLITE_OK)
            && (u.be.res==0)
            && (++u.be.cnt<100)){
        /* collision - try another random rowid */
        sqlite3_randomness(sizeof(u.be.v), &u.be.v);
        if( u.be.cnt<5 ){
          /* try "small" random rowids for the initial attempts */
          u.be.v &= 0xffffff;
        }else{
          u.be.v &= (MAX_ROWID>>1); /* ensure doesn't go negative */
        }
        u.be.v++; /* ensure non-zero */
      }
      if( rc==SQLITE_OK && u.be.res==0 ){
        rc = SQLITE_FULL;   /* IMP: R-38219-53002 */
        goto abort_due_to_error;
      }
      assert( u.be.v>0 );  /* EV: R-40812-03570 */
    }
    u.be.pC->rowidIsValid = 0;
    u.be.pC->deferredMoveto = 0;
    u.be.pC->cacheStatus = CACHE_STALE;
  }
  pOut->u.i = u.be.v;
  break;
}

/* Opcode: Insert P1 P2 P3 P4 P5
**
** Write an entry into the table of cursor P1.  A new entry is
** created if it doesn't already exist or the data for an existing
................................................................................
/* Opcode: InsertInt P1 P2 P3 P4 P5
**
** This works exactly like OP_Insert except that the key is the
** integer value P3, not the value of the integer stored in register P3.
*/
case OP_Insert: 
case OP_InsertInt: {
#if 0  /* local variables moved into u.bf */
  Mem *pData;       /* MEM cell holding data for the record to be inserted */
  Mem *pKey;        /* MEM cell holding key  for the record */
  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
  VdbeCursor *pC;   /* Cursor to table into which insert is written */
  int nZero;        /* Number of zero-bytes to append */
  int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
  const char *zDb;  /* database name - used by the update hook */
  const char *zTbl; /* Table name - used by the opdate hook */
  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
#endif /* local variables moved into u.bf */

  u.bf.pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(u.bf.pData) );
  u.bf.pC = p->apCsr[pOp->p1];
  assert( u.bf.pC!=0 );
  assert( u.bf.pC->pCursor!=0 );
  assert( u.bf.pC->pseudoTableReg==0 );
  assert( u.bf.pC->isTable );
  REGISTER_TRACE(pOp->p2, u.bf.pData);

  if( pOp->opcode==OP_Insert ){
    u.bf.pKey = &aMem[pOp->p3];
    assert( u.bf.pKey->flags & MEM_Int );
    assert( memIsValid(u.bf.pKey) );
    REGISTER_TRACE(pOp->p3, u.bf.pKey);
    u.bf.iKey = u.bf.pKey->u.i;
  }else{
    assert( pOp->opcode==OP_InsertInt );
    u.bf.iKey = pOp->p3;
  }

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = u.bf.iKey;
  if( u.bf.pData->flags & MEM_Null ){
    u.bf.pData->z = 0;
    u.bf.pData->n = 0;
  }else{
    assert( u.bf.pData->flags & (MEM_Blob|MEM_Str) );
  }
  u.bf.seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? u.bf.pC->seekResult : 0);
  if( u.bf.pData->flags & MEM_Zero ){
    u.bf.nZero = u.bf.pData->u.nZero;
  }else{
    u.bf.nZero = 0;
  }
  sqlite3BtreeSetCachedRowid(u.bf.pC->pCursor, 0);
  rc = sqlite3BtreeInsert(u.bf.pC->pCursor, 0, u.bf.iKey,
                          u.bf.pData->z, u.bf.pData->n, u.bf.nZero,
                          pOp->p5 & OPFLAG_APPEND, u.bf.seekResult
  );
  u.bf.pC->rowidIsValid = 0;
  u.bf.pC->deferredMoveto = 0;
  u.bf.pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
    u.bf.zDb = db->aDb[u.bf.pC->iDb].zName;
    u.bf.zTbl = pOp->p4.z;
    u.bf.op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
    assert( u.bf.pC->isTable );
    db->xUpdateCallback(db->pUpdateArg, u.bf.op, u.bf.zDb, u.bf.zTbl, u.bf.iKey);
    assert( u.bf.pC->iDb>=0 );
  }
  break;
}

/* Opcode: Delete P1 P2 * P4 *
**
** Delete the record at which the P1 cursor is currently pointing.
................................................................................
**
** If P4 is not NULL, then it is the name of the table that P1 is
** pointing to.  The update hook will be invoked, if it exists.
** If P4 is not NULL then the P1 cursor must have been positioned
** using OP_NotFound prior to invoking this opcode.
*/
case OP_Delete: {
#if 0  /* local variables moved into u.bg */
  i64 iKey;
  VdbeCursor *pC;
#endif /* local variables moved into u.bg */

  u.bg.iKey = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bg.pC = p->apCsr[pOp->p1];
  assert( u.bg.pC!=0 );
  assert( u.bg.pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */

  /* If the update-hook will be invoked, set u.bg.iKey to the rowid of the
  ** row being deleted.
  */
  if( db->xUpdateCallback && pOp->p4.z ){
    assert( u.bg.pC->isTable );
    assert( u.bg.pC->rowidIsValid );  /* lastRowid set by previous OP_NotFound */
    u.bg.iKey = u.bg.pC->lastRowid;
  }

  /* The OP_Delete opcode always follows an OP_NotExists or OP_Last or
  ** OP_Column on the same table without any intervening operations that
  ** might move or invalidate the cursor.  Hence cursor u.bg.pC is always pointing
  ** to the row to be deleted and the sqlite3VdbeCursorMoveto() operation
  ** below is always a no-op and cannot fail.  We will run it anyhow, though,
  ** to guard against future changes to the code generator.
  **/
  assert( u.bg.pC->deferredMoveto==0 );
  rc = sqlite3VdbeCursorMoveto(u.bg.pC);
  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  sqlite3BtreeSetCachedRowid(u.bg.pC->pCursor, 0);
  rc = sqlite3BtreeDelete(u.bg.pC->pCursor);
  u.bg.pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
    const char *zDb = db->aDb[u.bg.pC->iDb].zName;
    const char *zTbl = pOp->p4.z;
    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, u.bg.iKey);
    assert( u.bg.pC->iDb>=0 );
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
/* Opcode: ResetCount * * * * *
**
** The value of the change counter is copied to the database handle
................................................................................
** This is used by trigger programs.
*/
case OP_ResetCount: {
  sqlite3VdbeSetChanges(db, p->nChange);
  p->nChange = 0;
  break;
}












































/* Opcode: RowData P1 P2 * * *
**
** Write into register P2 the complete row data for cursor P1.
** There is no interpretation of the data.  
** It is just copied onto the P2 register exactly as 
** it is found in the database file.
................................................................................
** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/
case OP_RowKey:
case OP_RowData: {
#if 0  /* local variables moved into u.bh */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  u32 n;
  i64 n64;
#endif /* local variables moved into u.bh */

  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bh.pC = p->apCsr[pOp->p1];

  assert( u.bh.pC->isTable || pOp->opcode==OP_RowKey );
  assert( u.bh.pC->isIndex || pOp->opcode==OP_RowData );
  assert( u.bh.pC!=0 );
  assert( u.bh.pC->nullRow==0 );
  assert( u.bh.pC->pseudoTableReg==0 );

  assert( u.bh.pC->pCursor!=0 );
  u.bh.pCrsr = u.bh.pC->pCursor;
  assert( sqlite3BtreeCursorIsValid(u.bh.pCrsr) );

  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
  ** the cursor.  Hence the following sqlite3VdbeCursorMoveto() call is always
  ** a no-op and can never fail.  But we leave it in place as a safety.
  */
  assert( u.bh.pC->deferredMoveto==0 );
  rc = sqlite3VdbeCursorMoveto(u.bh.pC);
  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  if( u.bh.pC->isIndex ){
    assert( !u.bh.pC->isTable );
    rc = sqlite3BtreeKeySize(u.bh.pCrsr, &u.bh.n64);
    assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
    if( u.bh.n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    u.bh.n = (u32)u.bh.n64;
  }else{
    rc = sqlite3BtreeDataSize(u.bh.pCrsr, &u.bh.n);
    assert( rc==SQLITE_OK );    /* DataSize() cannot fail */
    if( u.bh.n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
  }
  if( sqlite3VdbeMemGrow(pOut, u.bh.n, 0) ){
    goto no_mem;
  }
  pOut->n = u.bh.n;
  MemSetTypeFlag(pOut, MEM_Blob);
  if( u.bh.pC->isIndex ){
    rc = sqlite3BtreeKey(u.bh.pCrsr, 0, u.bh.n, pOut->z);
  }else{
    rc = sqlite3BtreeData(u.bh.pCrsr, 0, u.bh.n, pOut->z);
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Rowid P1 P2 * * *
................................................................................
** P1 is currently point to.
**
** P1 can be either an ordinary table or a virtual table.  There used to
** be a separate OP_VRowid opcode for use with virtual tables, but this
** one opcode now works for both table types.
*/
case OP_Rowid: {                 /* out2-prerelease */
#if 0  /* local variables moved into u.bi */
  VdbeCursor *pC;
  i64 v;
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
#endif /* local variables moved into u.bi */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bi.pC = p->apCsr[pOp->p1];
  assert( u.bi.pC!=0 );
  assert( u.bi.pC->pseudoTableReg==0 );
  if( u.bi.pC->nullRow ){
    pOut->flags = MEM_Null;
    break;
  }else if( u.bi.pC->deferredMoveto ){
    u.bi.v = u.bi.pC->movetoTarget;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  }else if( u.bi.pC->pVtabCursor ){
    u.bi.pVtab = u.bi.pC->pVtabCursor->pVtab;
    u.bi.pModule = u.bi.pVtab->pModule;
    assert( u.bi.pModule->xRowid );
    rc = u.bi.pModule->xRowid(u.bi.pC->pVtabCursor, &u.bi.v);
    importVtabErrMsg(p, u.bi.pVtab);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  }else{
    assert( u.bi.pC->pCursor!=0 );
    rc = sqlite3VdbeCursorMoveto(u.bi.pC);
    if( rc ) goto abort_due_to_error;
    if( u.bi.pC->rowidIsValid ){
      u.bi.v = u.bi.pC->lastRowid;
    }else{
      rc = sqlite3BtreeKeySize(u.bi.pC->pCursor, &u.bi.v);
      assert( rc==SQLITE_OK );  /* Always so because of CursorMoveto() above */
    }
  }
  pOut->u.i = u.bi.v;
  break;
}

/* Opcode: NullRow P1 * * * *
**
** Move the cursor P1 to a null row.  Any OP_Column operations
** that occur while the cursor is on the null row will always
** write a NULL.
*/
case OP_NullRow: {
#if 0  /* local variables moved into u.bj */
  VdbeCursor *pC;
#endif /* local variables moved into u.bj */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bj.pC = p->apCsr[pOp->p1];
  assert( u.bj.pC!=0 );
  u.bj.pC->nullRow = 1;
  u.bj.pC->rowidIsValid = 0;

  if( u.bj.pC->pCursor ){
    sqlite3BtreeClearCursor(u.bj.pC->pCursor);
  }
  break;
}

/* Opcode: Last P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Last: {        /* jump */
#if 0  /* local variables moved into u.bk */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
#endif /* local variables moved into u.bk */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bk.pC = p->apCsr[pOp->p1];
  assert( u.bk.pC!=0 );
  u.bk.pCrsr = u.bk.pC->pCursor;
  if( u.bk.pCrsr==0 ){
    u.bk.res = 1;
  }else{
    rc = sqlite3BtreeLast(u.bk.pCrsr, &u.bk.res);
  }
  u.bk.pC->nullRow = (u8)u.bk.res;
  u.bk.pC->deferredMoveto = 0;
  u.bk.pC->rowidIsValid = 0;
  u.bk.pC->cacheStatus = CACHE_STALE;
  if( pOp->p2>0 && u.bk.res ){
    pc = pOp->p2 - 1;
  }
  break;
}


/* Opcode: Sort P1 P2 * * *
................................................................................
** Sorting is accomplished by writing records into a sorting index,
** then rewinding that index and playing it back from beginning to
** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
** rewinding so that the global variable will be incremented and
** regression tests can determine whether or not the optimizer is
** correctly optimizing out sorts.
*/




case OP_Sort: {        /* jump */
#ifdef SQLITE_TEST
  sqlite3_sort_count++;
  sqlite3_search_count--;
#endif
  p->aCounter[SQLITE_STMTSTATUS_SORT-1]++;
  /* Fall through into OP_Rewind */
................................................................................
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Rewind: {        /* jump */
#if 0  /* local variables moved into u.bl */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
#endif /* local variables moved into u.bl */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bl.pC = p->apCsr[pOp->p1];
  assert( u.bl.pC!=0 );

  u.bl.res = 1;
  if( (u.bl.pCrsr = u.bl.pC->pCursor)!=0 ){





    rc = sqlite3BtreeFirst(u.bl.pCrsr, &u.bl.res);
    u.bl.pC->atFirst = u.bl.res==0 ?1:0;
    u.bl.pC->deferredMoveto = 0;
    u.bl.pC->cacheStatus = CACHE_STALE;
    u.bl.pC->rowidIsValid = 0;
  }
  u.bl.pC->nullRow = (u8)u.bl.res;
  assert( pOp->p2>0 && pOp->p2<p->nOp );
  if( u.bl.res ){
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: Next P1 P2 * * P5
**
** Advance cursor P1 so that it points to the next key/data pair in its
** table or index.  If there are no more key/value pairs then fall through
** to the following instruction.  But if the cursor advance was successful,
** jump immediately to P2.
**
** The P1 cursor must be for a real table, not a pseudo-table.



**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
**
** See also: Prev
*/
/* Opcode: Prev P1 P2 * * P5
................................................................................
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index.  If there is no previous key/value pairs then fall through
** to the following instruction.  But if the cursor backup was successful,
** jump immediately to P2.
**
** The P1 cursor must be for a real table, not a pseudo-table.



**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
*/




case OP_Prev:          /* jump */
case OP_Next: {        /* jump */
#if 0  /* local variables moved into u.bm */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
#endif /* local variables moved into u.bm */

  CHECK_FOR_INTERRUPT;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p5<=ArraySize(p->aCounter) );
  u.bm.pC = p->apCsr[pOp->p1];
  if( u.bm.pC==0 ){
    break;  /* See ticket #2273 */
  }
  u.bm.pCrsr = u.bm.pC->pCursor;
  if( u.bm.pCrsr==0 ){
    u.bm.pC->nullRow = 1;
    break;
  }
  u.bm.res = 1;
  assert( u.bm.pC->deferredMoveto==0 );
  rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(u.bm.pCrsr, &u.bm.res) :
                              sqlite3BtreePrevious(u.bm.pCrsr, &u.bm.res);



  u.bm.pC->nullRow = (u8)u.bm.res;
  u.bm.pC->cacheStatus = CACHE_STALE;
  if( u.bm.res==0 ){
    pc = pOp->p2 - 1;
    if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
  }
  u.bm.pC->rowidIsValid = 0;
  break;
}

/* Opcode: IdxInsert P1 P2 P3 * P5
**
** Register P2 holds an SQL index key made using the
** MakeRecord instructions.  This opcode writes that key
................................................................................
**
** P3 is a flag that provides a hint to the b-tree layer that this
** insert is likely to be an append.
**
** This instruction only works for indices.  The equivalent instruction
** for tables is OP_Insert.
*/




case OP_IdxInsert: {        /* in2 */
#if 0  /* local variables moved into u.bn */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int nKey;
  const char *zKey;
#endif /* local variables moved into u.bn */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bn.pC = p->apCsr[pOp->p1];
  assert( u.bn.pC!=0 );

  pIn2 = &aMem[pOp->p2];
  assert( pIn2->flags & MEM_Blob );
  u.bn.pCrsr = u.bn.pC->pCursor;
  if( ALWAYS(u.bn.pCrsr!=0) ){
    assert( u.bn.pC->isTable==0 );
    rc = ExpandBlob(pIn2);
    if( rc==SQLITE_OK ){



      u.bn.nKey = pIn2->n;
      u.bn.zKey = pIn2->z;
      rc = sqlite3BtreeInsert(u.bn.pCrsr, u.bn.zKey, u.bn.nKey, "", 0, 0, pOp->p3,

          ((pOp->p5 & OPFLAG_USESEEKRESULT) ? u.bn.pC->seekResult : 0)
      );
      assert( u.bn.pC->deferredMoveto==0 );
      u.bn.pC->cacheStatus = CACHE_STALE;

    }
  }
  break;
}

/* Opcode: IdxDelete P1 P2 P3 * *
**
** The content of P3 registers starting at register P2 form
** an unpacked index key. This opcode removes that entry from the 
** index opened by cursor P1.
*/
case OP_IdxDelete: {
#if 0  /* local variables moved into u.bo */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  UnpackedRecord r;
#endif /* local variables moved into u.bo */

  assert( pOp->p3>0 );
  assert( pOp->p2>0 && pOp->p2+pOp->p3<=p->nMem+1 );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bo.pC = p->apCsr[pOp->p1];
  assert( u.bo.pC!=0 );
  u.bo.pCrsr = u.bo.pC->pCursor;
  if( ALWAYS(u.bo.pCrsr!=0) ){
    u.bo.r.pKeyInfo = u.bo.pC->pKeyInfo;
    u.bo.r.nField = (u16)pOp->p3;
    u.bo.r.flags = 0;
    u.bo.r.aMem = &aMem[pOp->p2];
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<u.bo.r.nField; i++) assert( memIsValid(&u.bo.r.aMem[i]) ); }
#endif
    rc = sqlite3BtreeMovetoUnpacked(u.bo.pCrsr, &u.bo.r, 0, 0, &u.bo.res);
    if( rc==SQLITE_OK && u.bo.res==0 ){
      rc = sqlite3BtreeDelete(u.bo.pCrsr);
    }
    assert( u.bo.pC->deferredMoveto==0 );
    u.bo.pC->cacheStatus = CACHE_STALE;
  }
  break;
}

/* Opcode: IdxRowid P1 P2 * * *
**
** Write into register P2 an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1.  This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeRecord.
*/
case OP_IdxRowid: {              /* out2-prerelease */
#if 0  /* local variables moved into u.bp */
  BtCursor *pCrsr;
  VdbeCursor *pC;
  i64 rowid;
#endif /* local variables moved into u.bp */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bp.pC = p->apCsr[pOp->p1];
  assert( u.bp.pC!=0 );
  u.bp.pCrsr = u.bp.pC->pCursor;
  pOut->flags = MEM_Null;
  if( ALWAYS(u.bp.pCrsr!=0) ){
    rc = sqlite3VdbeCursorMoveto(u.bp.pC);
    if( NEVER(rc) ) goto abort_due_to_error;
    assert( u.bp.pC->deferredMoveto==0 );
    assert( u.bp.pC->isTable==0 );
    if( !u.bp.pC->nullRow ){
      rc = sqlite3VdbeIdxRowid(db, u.bp.pCrsr, &u.bp.rowid);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pOut->u.i = u.bp.rowid;
      pOut->flags = MEM_Int;
    }
  }
  break;
}

/* Opcode: IdxGE P1 P2 P3 P4 P5
................................................................................
** Otherwise fall through to the next instruction.
**
** If P5 is non-zero then the key value is increased by an epsilon prior 
** to the comparison.  This makes the opcode work like IdxLE.
*/
case OP_IdxLT:          /* jump */
case OP_IdxGE: {        /* jump */
#if 0  /* local variables moved into u.bq */
  VdbeCursor *pC;
  int res;
  UnpackedRecord r;
#endif /* local variables moved into u.bq */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bq.pC = p->apCsr[pOp->p1];
  assert( u.bq.pC!=0 );
  assert( u.bq.pC->isOrdered );
  if( ALWAYS(u.bq.pC->pCursor!=0) ){
    assert( u.bq.pC->deferredMoveto==0 );
    assert( pOp->p5==0 || pOp->p5==1 );
    assert( pOp->p4type==P4_INT32 );
    u.bq.r.pKeyInfo = u.bq.pC->pKeyInfo;
    u.bq.r.nField = (u16)pOp->p4.i;
    if( pOp->p5 ){
      u.bq.r.flags = UNPACKED_INCRKEY | UNPACKED_IGNORE_ROWID;
    }else{
      u.bq.r.flags = UNPACKED_IGNORE_ROWID;
    }
    u.bq.r.aMem = &aMem[pOp->p3];
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<u.bq.r.nField; i++) assert( memIsValid(&u.bq.r.aMem[i]) ); }
#endif
    rc = sqlite3VdbeIdxKeyCompare(u.bq.pC, &u.bq.r, &u.bq.res);
    if( pOp->opcode==OP_IdxLT ){
      u.bq.res = -u.bq.res;
    }else{
      assert( pOp->opcode==OP_IdxGE );
      u.bq.res++;
    }
    if( u.bq.res>0 ){
      pc = pOp->p2 - 1 ;
    }
  }
  break;
}

/* Opcode: Destroy P1 P2 P3 * *
................................................................................
** movement was required (because the table being dropped was already 
** the last one in the database) then a zero is stored in register P2.
** If AUTOVACUUM is disabled then a zero is stored in register P2.
**
** See also: Clear
*/
case OP_Destroy: {     /* out2-prerelease */
#if 0  /* local variables moved into u.br */
  int iMoved;
  int iCnt;
  Vdbe *pVdbe;
  int iDb;
#endif /* local variables moved into u.br */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  u.br.iCnt = 0;
  for(u.br.pVdbe=db->pVdbe; u.br.pVdbe; u.br.pVdbe = u.br.pVdbe->pNext){
    if( u.br.pVdbe->magic==VDBE_MAGIC_RUN && u.br.pVdbe->inVtabMethod<2 && u.br.pVdbe->pc>=0 ){
      u.br.iCnt++;
    }
  }
#else
  u.br.iCnt = db->activeVdbeCnt;
#endif
  pOut->flags = MEM_Null;
  if( u.br.iCnt>1 ){
    rc = SQLITE_LOCKED;
    p->errorAction = OE_Abort;
  }else{
    u.br.iDb = pOp->p3;
    assert( u.br.iCnt==1 );
    assert( (p->btreeMask & (((yDbMask)1)<<u.br.iDb))!=0 );
    rc = sqlite3BtreeDropTable(db->aDb[u.br.iDb].pBt, pOp->p1, &u.br.iMoved);
    pOut->flags = MEM_Int;
    pOut->u.i = u.br.iMoved;
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( rc==SQLITE_OK && u.br.iMoved!=0 ){
      sqlite3RootPageMoved(db, u.br.iDb, u.br.iMoved, pOp->p1);
      /* All OP_Destroy operations occur on the same btree */
      assert( resetSchemaOnFault==0 || resetSchemaOnFault==u.br.iDb+1 );
      resetSchemaOnFault = u.br.iDb+1;
    }
#endif
  }
  break;
}

/* Opcode: Clear P1 P2 P3
................................................................................
** count is incremented by the number of rows in the table being cleared. 
** If P3 is greater than zero, then the value stored in register P3 is
** also incremented by the number of rows in the table being cleared.
**
** See also: Destroy
*/
case OP_Clear: {
#if 0  /* local variables moved into u.bs */
  int nChange;
#endif /* local variables moved into u.bs */

  u.bs.nChange = 0;
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p2))!=0 );
  rc = sqlite3BtreeClearTable(
      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &u.bs.nChange : 0)
  );
  if( pOp->p3 ){
    p->nChange += u.bs.nChange;
    if( pOp->p3>0 ){
      assert( memIsValid(&aMem[pOp->p3]) );
      memAboutToChange(p, &aMem[pOp->p3]);
      aMem[pOp->p3].u.i += u.bs.nChange;
    }
  }
  break;
}

/* Opcode: CreateTable P1 P2 * * *
**
................................................................................
** P1>1.  Write the root page number of the new table into
** register P2.
**
** See documentation on OP_CreateTable for additional information.
*/
case OP_CreateIndex:            /* out2-prerelease */
case OP_CreateTable: {          /* out2-prerelease */
#if 0  /* local variables moved into u.bt */
  int pgno;
  int flags;
  Db *pDb;
#endif /* local variables moved into u.bt */

  u.bt.pgno = 0;
  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
  u.bt.pDb = &db->aDb[pOp->p1];
  assert( u.bt.pDb->pBt!=0 );
  if( pOp->opcode==OP_CreateTable ){
    /* u.bt.flags = BTREE_INTKEY; */
    u.bt.flags = BTREE_INTKEY;
  }else{
    u.bt.flags = BTREE_BLOBKEY;
  }
  rc = sqlite3BtreeCreateTable(u.bt.pDb->pBt, &u.bt.pgno, u.bt.flags);
  pOut->u.i = u.bt.pgno;
  break;
}

/* Opcode: ParseSchema P1 * * P4 *
**
** Read and parse all entries from the SQLITE_MASTER table of database P1
** that match the WHERE clause P4. 
**
** This opcode invokes the parser to create a new virtual machine,
** then runs the new virtual machine.  It is thus a re-entrant opcode.
*/
case OP_ParseSchema: {
#if 0  /* local variables moved into u.bu */
  int iDb;
  const char *zMaster;
  char *zSql;
  InitData initData;
#endif /* local variables moved into u.bu */

  /* Any prepared statement that invokes this opcode will hold mutexes
  ** on every btree.  This is a prerequisite for invoking
  ** sqlite3InitCallback().
  */
#ifdef SQLITE_DEBUG
  for(u.bu.iDb=0; u.bu.iDb<db->nDb; u.bu.iDb++){
    assert( u.bu.iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[u.bu.iDb].pBt) );
  }
#endif

  u.bu.iDb = pOp->p1;
  assert( u.bu.iDb>=0 && u.bu.iDb<db->nDb );
  assert( DbHasProperty(db, u.bu.iDb, DB_SchemaLoaded) );
  /* Used to be a conditional */ {
    u.bu.zMaster = SCHEMA_TABLE(u.bu.iDb);
    u.bu.initData.db = db;
    u.bu.initData.iDb = pOp->p1;
    u.bu.initData.pzErrMsg = &p->zErrMsg;
    u.bu.zSql = sqlite3MPrintf(db,
       "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
       db->aDb[u.bu.iDb].zName, u.bu.zMaster, pOp->p4.z);
    if( u.bu.zSql==0 ){
      rc = SQLITE_NOMEM;
    }else{
      assert( db->init.busy==0 );
      db->init.busy = 1;
      u.bu.initData.rc = SQLITE_OK;
      assert( !db->mallocFailed );
      rc = sqlite3_exec(db, u.bu.zSql, sqlite3InitCallback, &u.bu.initData, 0);
      if( rc==SQLITE_OK ) rc = u.bu.initData.rc;
      sqlite3DbFree(db, u.bu.zSql);
      db->init.busy = 0;
    }
  }
  if( rc==SQLITE_NOMEM ){
    goto no_mem;
  }
  break;
................................................................................
**
** If P5 is not zero, the check is done on the auxiliary database
** file, not the main database file.
**
** This opcode is used to implement the integrity_check pragma.
*/
case OP_IntegrityCk: {
#if 0  /* local variables moved into u.bv */
  int nRoot;      /* Number of tables to check.  (Number of root pages.) */
  int *aRoot;     /* Array of rootpage numbers for tables to be checked */
  int j;          /* Loop counter */
  int nErr;       /* Number of errors reported */
  char *z;        /* Text of the error report */
  Mem *pnErr;     /* Register keeping track of errors remaining */
#endif /* local variables moved into u.bv */

  u.bv.nRoot = pOp->p2;
  assert( u.bv.nRoot>0 );
  u.bv.aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(u.bv.nRoot+1) );
  if( u.bv.aRoot==0 ) goto no_mem;
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.bv.pnErr = &aMem[pOp->p3];
  assert( (u.bv.pnErr->flags & MEM_Int)!=0 );
  assert( (u.bv.pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &aMem[pOp->p1];
  for(u.bv.j=0; u.bv.j<u.bv.nRoot; u.bv.j++){
    u.bv.aRoot[u.bv.j] = (int)sqlite3VdbeIntValue(&pIn1[u.bv.j]);
  }
  u.bv.aRoot[u.bv.j] = 0;
  assert( pOp->p5<db->nDb );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p5))!=0 );
  u.bv.z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, u.bv.aRoot, u.bv.nRoot,
                                 (int)u.bv.pnErr->u.i, &u.bv.nErr);
  sqlite3DbFree(db, u.bv.aRoot);
  u.bv.pnErr->u.i -= u.bv.nErr;
  sqlite3VdbeMemSetNull(pIn1);
  if( u.bv.nErr==0 ){
    assert( u.bv.z==0 );
  }else if( u.bv.z==0 ){
    goto no_mem;
  }else{
    sqlite3VdbeMemSetStr(pIn1, u.bv.z, -1, SQLITE_UTF8, sqlite3_free);
  }
  UPDATE_MAX_BLOBSIZE(pIn1);
  sqlite3VdbeChangeEncoding(pIn1, encoding);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

................................................................................
/* Opcode: RowSetRead P1 P2 P3 * *
**
** Extract the smallest value from boolean index P1 and put that value into
** register P3.  Or, if boolean index P1 is initially empty, leave P3
** unchanged and jump to instruction P2.
*/
case OP_RowSetRead: {       /* jump, in1, out3 */
#if 0  /* local variables moved into u.bw */
  i64 val;
#endif /* local variables moved into u.bw */
  CHECK_FOR_INTERRUPT;
  pIn1 = &aMem[pOp->p1];
  if( (pIn1->flags & MEM_RowSet)==0
   || sqlite3RowSetNext(pIn1->u.pRowSet, &u.bw.val)==0
  ){
    /* The boolean index is empty */
    sqlite3VdbeMemSetNull(pIn1);
    pc = pOp->p2 - 1;
  }else{
    /* A value was pulled from the index */
    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], u.bw.val);
  }
  break;
}

/* Opcode: RowSetTest P1 P2 P3 P4
**
** Register P3 is assumed to hold a 64-bit integer value. If register P1
................................................................................
** (b) when P4==-1 there is no need to insert the value, as it will
** never be tested for, and (c) when a value that is part of set X is
** inserted, there is no need to search to see if the same value was
** previously inserted as part of set X (only if it was previously
** inserted as part of some other set).
*/
case OP_RowSetTest: {                     /* jump, in1, in3 */
#if 0  /* local variables moved into u.bx */
  int iSet;
  int exists;
#endif /* local variables moved into u.bx */

  pIn1 = &aMem[pOp->p1];
  pIn3 = &aMem[pOp->p3];
  u.bx.iSet = pOp->p4.i;
  assert( pIn3->flags&MEM_Int );

  /* If there is anything other than a rowset object in memory cell P1,
  ** delete it now and initialize P1 with an empty rowset
  */
  if( (pIn1->flags & MEM_RowSet)==0 ){
    sqlite3VdbeMemSetRowSet(pIn1);
    if( (pIn1->flags & MEM_RowSet)==0 ) goto no_mem;
  }

  assert( pOp->p4type==P4_INT32 );
  assert( u.bx.iSet==-1 || u.bx.iSet>=0 );
  if( u.bx.iSet ){
    u.bx.exists = sqlite3RowSetTest(pIn1->u.pRowSet,
                               (u8)(u.bx.iSet>=0 ? u.bx.iSet & 0xf : 0xff),
                               pIn3->u.i);
    if( u.bx.exists ){
      pc = pOp->p2 - 1;
      break;
    }
  }
  if( u.bx.iSet>=0 ){
    sqlite3RowSetInsert(pIn1->u.pRowSet, pIn3->u.i);
  }
  break;
}


#ifndef SQLITE_OMIT_TRIGGER
................................................................................
** exception using the RAISE() function. Register P3 contains the address 
** of a memory cell in this (the parent) VM that is used to allocate the 
** memory required by the sub-vdbe at runtime.
**
** P4 is a pointer to the VM containing the trigger program.
*/
case OP_Program: {        /* jump */
#if 0  /* local variables moved into u.by */
  int nMem;               /* Number of memory registers for sub-program */
  int nByte;              /* Bytes of runtime space required for sub-program */
  Mem *pRt;               /* Register to allocate runtime space */
  Mem *pMem;              /* Used to iterate through memory cells */
  Mem *pEnd;              /* Last memory cell in new array */
  VdbeFrame *pFrame;      /* New vdbe frame to execute in */
  SubProgram *pProgram;   /* Sub-program to execute */
  void *t;                /* Token identifying trigger */
#endif /* local variables moved into u.by */

  u.by.pProgram = pOp->p4.pProgram;
  u.by.pRt = &aMem[pOp->p3];
  assert( memIsValid(u.by.pRt) );
  assert( u.by.pProgram->nOp>0 );

  /* If the p5 flag is clear, then recursive invocation of triggers is
  ** disabled for backwards compatibility (p5 is set if this sub-program
  ** is really a trigger, not a foreign key action, and the flag set
  ** and cleared by the "PRAGMA recursive_triggers" command is clear).
  **
  ** It is recursive invocation of triggers, at the SQL level, that is
  ** disabled. In some cases a single trigger may generate more than one
  ** SubProgram (if the trigger may be executed with more than one different
  ** ON CONFLICT algorithm). SubProgram structures associated with a
  ** single trigger all have the same value for the SubProgram.token
  ** variable.  */
  if( pOp->p5 ){
    u.by.t = u.by.pProgram->token;
    for(u.by.pFrame=p->pFrame; u.by.pFrame && u.by.pFrame->token!=u.by.t; u.by.pFrame=u.by.pFrame->pParent);
    if( u.by.pFrame ) break;
  }

  if( p->nFrame>=db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
    rc = SQLITE_ERROR;
    sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
    break;
  }

  /* Register u.by.pRt is used to store the memory required to save the state
  ** of the current program, and the memory required at runtime to execute
  ** the trigger program. If this trigger has been fired before, then u.by.pRt
  ** is already allocated. Otherwise, it must be initialized.  */
  if( (u.by.pRt->flags&MEM_Frame)==0 ){
    /* SubProgram.nMem is set to the number of memory cells used by the
    ** program stored in SubProgram.aOp. As well as these, one memory
    ** cell is required for each cursor used by the program. Set local
    ** variable u.by.nMem (and later, VdbeFrame.nChildMem) to this value.
    */
    u.by.nMem = u.by.pProgram->nMem + u.by.pProgram->nCsr;
    u.by.nByte = ROUND8(sizeof(VdbeFrame))
              + u.by.nMem * sizeof(Mem)
              + u.by.pProgram->nCsr * sizeof(VdbeCursor *);
    u.by.pFrame = sqlite3DbMallocZero(db, u.by.nByte);
    if( !u.by.pFrame ){
      goto no_mem;
    }
    sqlite3VdbeMemRelease(u.by.pRt);
    u.by.pRt->flags = MEM_Frame;
    u.by.pRt->u.pFrame = u.by.pFrame;

    u.by.pFrame->v = p;
    u.by.pFrame->nChildMem = u.by.nMem;
    u.by.pFrame->nChildCsr = u.by.pProgram->nCsr;
    u.by.pFrame->pc = pc;
    u.by.pFrame->aMem = p->aMem;
    u.by.pFrame->nMem = p->nMem;
    u.by.pFrame->apCsr = p->apCsr;
    u.by.pFrame->nCursor = p->nCursor;
    u.by.pFrame->aOp = p->aOp;
    u.by.pFrame->nOp = p->nOp;
    u.by.pFrame->token = u.by.pProgram->token;

    u.by.pEnd = &VdbeFrameMem(u.by.pFrame)[u.by.pFrame->nChildMem];
    for(u.by.pMem=VdbeFrameMem(u.by.pFrame); u.by.pMem!=u.by.pEnd; u.by.pMem++){
      u.by.pMem->flags = MEM_Null;
      u.by.pMem->db = db;
    }
  }else{
    u.by.pFrame = u.by.pRt->u.pFrame;
    assert( u.by.pProgram->nMem+u.by.pProgram->nCsr==u.by.pFrame->nChildMem );
    assert( u.by.pProgram->nCsr==u.by.pFrame->nChildCsr );
    assert( pc==u.by.pFrame->pc );
  }

  p->nFrame++;
  u.by.pFrame->pParent = p->pFrame;
  u.by.pFrame->lastRowid = lastRowid;
  u.by.pFrame->nChange = p->nChange;
  p->nChange = 0;
  p->pFrame = u.by.pFrame;
  p->aMem = aMem = &VdbeFrameMem(u.by.pFrame)[-1];
  p->nMem = u.by.pFrame->nChildMem;
  p->nCursor = (u16)u.by.pFrame->nChildCsr;
  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
  p->aOp = aOp = u.by.pProgram->aOp;
  p->nOp = u.by.pProgram->nOp;
  pc = -1;

  break;
}

/* Opcode: Param P1 P2 * * *
**
................................................................................
** and old.* values.
**
** The address of the cell in the parent frame is determined by adding
** the value of the P1 argument to the value of the P1 argument to the
** calling OP_Program instruction.
*/
case OP_Param: {           /* out2-prerelease */
#if 0  /* local variables moved into u.bz */
  VdbeFrame *pFrame;
  Mem *pIn;
#endif /* local variables moved into u.bz */
  u.bz.pFrame = p->pFrame;
  u.bz.pIn = &u.bz.pFrame->aMem[pOp->p1 + u.bz.pFrame->aOp[u.bz.pFrame->pc].p1];
  sqlite3VdbeMemShallowCopy(pOut, u.bz.pIn, MEM_Ephem);
  break;
}

#endif /* #ifndef SQLITE_OMIT_TRIGGER */

#ifndef SQLITE_OMIT_FOREIGN_KEY
/* Opcode: FkCounter P1 P2 * * *
................................................................................
** within a sub-program). Set the value of register P1 to the maximum of 
** its current value and the value in register P2.
**
** This instruction throws an error if the memory cell is not initially
** an integer.
*/
case OP_MemMax: {        /* in2 */
#if 0  /* local variables moved into u.ca */
  Mem *pIn1;
  VdbeFrame *pFrame;
#endif /* local variables moved into u.ca */
  if( p->pFrame ){
    for(u.ca.pFrame=p->pFrame; u.ca.pFrame->pParent; u.ca.pFrame=u.ca.pFrame->pParent);
    u.ca.pIn1 = &u.ca.pFrame->aMem[pOp->p1];
  }else{
    u.ca.pIn1 = &aMem[pOp->p1];
  }
  assert( memIsValid(u.ca.pIn1) );
  sqlite3VdbeMemIntegerify(u.ca.pIn1);
  pIn2 = &aMem[pOp->p2];
  sqlite3VdbeMemIntegerify(pIn2);
  if( u.ca.pIn1->u.i<pIn2->u.i){
    u.ca.pIn1->u.i = pIn2->u.i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: IfPos P1 P2 * * *
**
................................................................................
** structure that specifies the function.  Use register
** P3 as the accumulator.
**
** The P5 arguments are taken from register P2 and its
** successors.
*/
case OP_AggStep: {
#if 0  /* local variables moved into u.cb */
  int n;
  int i;
  Mem *pMem;
  Mem *pRec;
  sqlite3_context ctx;
  sqlite3_value **apVal;
#endif /* local variables moved into u.cb */

  u.cb.n = pOp->p5;
  assert( u.cb.n>=0 );
  u.cb.pRec = &aMem[pOp->p2];
  u.cb.apVal = p->apArg;
  assert( u.cb.apVal || u.cb.n==0 );
  for(u.cb.i=0; u.cb.i<u.cb.n; u.cb.i++, u.cb.pRec++){
    assert( memIsValid(u.cb.pRec) );
    u.cb.apVal[u.cb.i] = u.cb.pRec;
    memAboutToChange(p, u.cb.pRec);
    sqlite3VdbeMemStoreType(u.cb.pRec);
  }
  u.cb.ctx.pFunc = pOp->p4.pFunc;
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.cb.ctx.pMem = u.cb.pMem = &aMem[pOp->p3];
  u.cb.pMem->n++;
  u.cb.ctx.s.flags = MEM_Null;
  u.cb.ctx.s.z = 0;
  u.cb.ctx.s.zMalloc = 0;
  u.cb.ctx.s.xDel = 0;
  u.cb.ctx.s.db = db;
  u.cb.ctx.isError = 0;
  u.cb.ctx.pColl = 0;
  if( u.cb.ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p4type==P4_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    u.cb.ctx.pColl = pOp[-1].p4.pColl;
  }
  (u.cb.ctx.pFunc->xStep)(&u.cb.ctx, u.cb.n, u.cb.apVal); /* IMP: R-24505-23230 */
  if( u.cb.ctx.isError ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&u.cb.ctx.s));
    rc = u.cb.ctx.isError;
  }

  sqlite3VdbeMemRelease(&u.cb.ctx.s);

  break;
}

/* Opcode: AggFinal P1 P2 * P4 *
**
** Execute the finalizer function for an aggregate.  P1 is
................................................................................
** P4 is a pointer to the FuncDef for this function.  The P2
** argument is not used by this opcode.  It is only there to disambiguate
** functions that can take varying numbers of arguments.  The
** P4 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {
#if 0  /* local variables moved into u.cc */
  Mem *pMem;
#endif /* local variables moved into u.cc */
  assert( pOp->p1>0 && pOp->p1<=p->nMem );
  u.cc.pMem = &aMem[pOp->p1];
  assert( (u.cc.pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(u.cc.pMem, pOp->p4.pFunc);
  if( rc ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(u.cc.pMem));
  }
  sqlite3VdbeChangeEncoding(u.cc.pMem, encoding);
  UPDATE_MAX_BLOBSIZE(u.cc.pMem);
  if( sqlite3VdbeMemTooBig(u.cc.pMem) ){
    goto too_big;
  }
  break;
}

#ifndef SQLITE_OMIT_WAL
/* Opcode: Checkpoint P1 P2 P3 * *
................................................................................
** SQLITE_BUSY or not, respectively.  Write the number of pages in the
** WAL after the checkpoint into mem[P3+1] and the number of pages
** in the WAL that have been checkpointed after the checkpoint
** completes into mem[P3+2].  However on an error, mem[P3+1] and
** mem[P3+2] are initialized to -1.
*/
case OP_Checkpoint: {
#if 0  /* local variables moved into u.cd */
  int i;                          /* Loop counter */
  int aRes[3];                    /* Results */
  Mem *pMem;                      /* Write results here */
#endif /* local variables moved into u.cd */

  u.cd.aRes[0] = 0;
  u.cd.aRes[1] = u.cd.aRes[2] = -1;
  assert( pOp->p2==SQLITE_CHECKPOINT_PASSIVE
       || pOp->p2==SQLITE_CHECKPOINT_FULL
       || pOp->p2==SQLITE_CHECKPOINT_RESTART
  );
  rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &u.cd.aRes[1], &u.cd.aRes[2]);
  if( rc==SQLITE_BUSY ){
    rc = SQLITE_OK;
    u.cd.aRes[0] = 1;
  }
  for(u.cd.i=0, u.cd.pMem = &aMem[pOp->p3]; u.cd.i<3; u.cd.i++, u.cd.pMem++){
    sqlite3VdbeMemSetInt64(u.cd.pMem, (i64)u.cd.aRes[u.cd.i]);
  }
  break;
};  
#endif

#ifndef SQLITE_OMIT_PRAGMA
/* Opcode: JournalMode P1 P2 P3 * P5
................................................................................
** operation. No IO is required.
**
** If changing into or out of WAL mode the procedure is more complicated.
**
** Write a string containing the final journal-mode to register P2.
*/
case OP_JournalMode: {    /* out2-prerelease */
#if 0  /* local variables moved into u.ce */
  Btree *pBt;                     /* Btree to change journal mode of */
  Pager *pPager;                  /* Pager associated with pBt */
  int eNew;                       /* New journal mode */
  int eOld;                       /* The old journal mode */
  const char *zFilename;          /* Name of database file for pPager */
#endif /* local variables moved into u.ce */

  u.ce.eNew = pOp->p3;
  assert( u.ce.eNew==PAGER_JOURNALMODE_DELETE
       || u.ce.eNew==PAGER_JOURNALMODE_TRUNCATE
       || u.ce.eNew==PAGER_JOURNALMODE_PERSIST
       || u.ce.eNew==PAGER_JOURNALMODE_OFF
       || u.ce.eNew==PAGER_JOURNALMODE_MEMORY
       || u.ce.eNew==PAGER_JOURNALMODE_WAL
       || u.ce.eNew==PAGER_JOURNALMODE_QUERY
  );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );

  u.ce.pBt = db->aDb[pOp->p1].pBt;
  u.ce.pPager = sqlite3BtreePager(u.ce.pBt);
  u.ce.eOld = sqlite3PagerGetJournalMode(u.ce.pPager);
  if( u.ce.eNew==PAGER_JOURNALMODE_QUERY ) u.ce.eNew = u.ce.eOld;
  if( !sqlite3PagerOkToChangeJournalMode(u.ce.pPager) ) u.ce.eNew = u.ce.eOld;

#ifndef SQLITE_OMIT_WAL
  u.ce.zFilename = sqlite3PagerFilename(u.ce.pPager);

  /* Do not allow a transition to journal_mode=WAL for a database
  ** in temporary storage or if the VFS does not support shared memory
  */
  if( u.ce.eNew==PAGER_JOURNALMODE_WAL
   && (u.ce.zFilename[0]==0                         /* Temp file */
       || !sqlite3PagerWalSupported(u.ce.pPager))   /* No shared-memory support */
  ){
    u.ce.eNew = u.ce.eOld;
  }

  if( (u.ce.eNew!=u.ce.eOld)
   && (u.ce.eOld==PAGER_JOURNALMODE_WAL || u.ce.eNew==PAGER_JOURNALMODE_WAL)
  ){
    if( !db->autoCommit || db->activeVdbeCnt>1 ){
      rc = SQLITE_ERROR;
      sqlite3SetString(&p->zErrMsg, db,
          "cannot change %s wal mode from within a transaction",
          (u.ce.eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
      );
      break;
    }else{

      if( u.ce.eOld==PAGER_JOURNALMODE_WAL ){
        /* If leaving WAL mode, close the log file. If successful, the call
        ** to PagerCloseWal() checkpoints and deletes the write-ahead-log
        ** file. An EXCLUSIVE lock may still be held on the database file
        ** after a successful return.
        */
        rc = sqlite3PagerCloseWal(u.ce.pPager);
        if( rc==SQLITE_OK ){
          sqlite3PagerSetJournalMode(u.ce.pPager, u.ce.eNew);
        }
      }else if( u.ce.eOld==PAGER_JOURNALMODE_MEMORY ){
        /* Cannot transition directly from MEMORY to WAL.  Use mode OFF
        ** as an intermediate */
        sqlite3PagerSetJournalMode(u.ce.pPager, PAGER_JOURNALMODE_OFF);
      }

      /* Open a transaction on the database file. Regardless of the journal
      ** mode, this transaction always uses a rollback journal.
      */
      assert( sqlite3BtreeIsInTrans(u.ce.pBt)==0 );
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeSetVersion(u.ce.pBt, (u.ce.eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
      }
    }
  }
#endif /* ifndef SQLITE_OMIT_WAL */

  if( rc ){
    u.ce.eNew = u.ce.eOld;
  }
  u.ce.eNew = sqlite3PagerSetJournalMode(u.ce.pPager, u.ce.eNew);

  pOut = &aMem[pOp->p2];
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = (char *)sqlite3JournalModename(u.ce.eNew);
  pOut->n = sqlite3Strlen30(pOut->z);
  pOut->enc = SQLITE_UTF8;
  sqlite3VdbeChangeEncoding(pOut, encoding);
  break;
};
#endif /* SQLITE_OMIT_PRAGMA */

................................................................................
/* Opcode: IncrVacuum P1 P2 * * *
**
** Perform a single step of the incremental vacuum procedure on
** the P1 database. If the vacuum has finished, jump to instruction
** P2. Otherwise, fall through to the next instruction.
*/
case OP_IncrVacuum: {        /* jump */
#if 0  /* local variables moved into u.cf */
  Btree *pBt;
#endif /* local variables moved into u.cf */

  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
  u.cf.pBt = db->aDb[pOp->p1].pBt;
  rc = sqlite3BtreeIncrVacuum(u.cf.pBt);
  if( rc==SQLITE_DONE ){
    pc = pOp->p2 - 1;
    rc = SQLITE_OK;
  }
  break;
}
#endif
................................................................................
** xBegin method for that table.
**
** Also, whether or not P4 is set, check that this is not being called from
** within a callback to a virtual table xSync() method. If it is, the error
** code will be set to SQLITE_LOCKED.
*/
case OP_VBegin: {
#if 0  /* local variables moved into u.cg */
  VTable *pVTab;
#endif /* local variables moved into u.cg */
  u.cg.pVTab = pOp->p4.pVtab;
  rc = sqlite3VtabBegin(db, u.cg.pVTab);
  if( u.cg.pVTab ) importVtabErrMsg(p, u.cg.pVTab->pVtab);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VCreate P1 * * P4 *
**
................................................................................
/* Opcode: VOpen P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number.  This opcode opens a cursor to the virtual
** table and stores that cursor in P1.
*/
case OP_VOpen: {
#if 0  /* local variables moved into u.ch */
  VdbeCursor *pCur;
  sqlite3_vtab_cursor *pVtabCursor;
  sqlite3_vtab *pVtab;
  sqlite3_module *pModule;
#endif /* local variables moved into u.ch */

  u.ch.pCur = 0;
  u.ch.pVtabCursor = 0;
  u.ch.pVtab = pOp->p4.pVtab->pVtab;
  u.ch.pModule = (sqlite3_module *)u.ch.pVtab->pModule;
  assert(u.ch.pVtab && u.ch.pModule);
  rc = u.ch.pModule->xOpen(u.ch.pVtab, &u.ch.pVtabCursor);
  importVtabErrMsg(p, u.ch.pVtab);
  if( SQLITE_OK==rc ){
    /* Initialize sqlite3_vtab_cursor base class */
    u.ch.pVtabCursor->pVtab = u.ch.pVtab;

    /* Initialise vdbe cursor object */
    u.ch.pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
    if( u.ch.pCur ){
      u.ch.pCur->pVtabCursor = u.ch.pVtabCursor;
      u.ch.pCur->pModule = u.ch.pVtabCursor->pVtab->pModule;
    }else{
      db->mallocFailed = 1;
      u.ch.pModule->xClose(u.ch.pVtabCursor);
    }
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
** xFilter method. Registers P3+2..P3+1+argc are the argc
** additional parameters which are passed to
** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
**
** A jump is made to P2 if the result set after filtering would be empty.
*/
case OP_VFilter: {   /* jump */
#if 0  /* local variables moved into u.ci */
  int nArg;
  int iQuery;
  const sqlite3_module *pModule;
  Mem *pQuery;
  Mem *pArgc;
  sqlite3_vtab_cursor *pVtabCursor;
  sqlite3_vtab *pVtab;
  VdbeCursor *pCur;
  int res;
  int i;
  Mem **apArg;
#endif /* local variables moved into u.ci */

  u.ci.pQuery = &aMem[pOp->p3];
  u.ci.pArgc = &u.ci.pQuery[1];
  u.ci.pCur = p->apCsr[pOp->p1];
  assert( memIsValid(u.ci.pQuery) );
  REGISTER_TRACE(pOp->p3, u.ci.pQuery);
  assert( u.ci.pCur->pVtabCursor );
  u.ci.pVtabCursor = u.ci.pCur->pVtabCursor;
  u.ci.pVtab = u.ci.pVtabCursor->pVtab;
  u.ci.pModule = u.ci.pVtab->pModule;

  /* Grab the index number and argc parameters */
  assert( (u.ci.pQuery->flags&MEM_Int)!=0 && u.ci.pArgc->flags==MEM_Int );
  u.ci.nArg = (int)u.ci.pArgc->u.i;
  u.ci.iQuery = (int)u.ci.pQuery->u.i;

  /* Invoke the xFilter method */
  {
    u.ci.res = 0;
    u.ci.apArg = p->apArg;
    for(u.ci.i = 0; u.ci.i<u.ci.nArg; u.ci.i++){
      u.ci.apArg[u.ci.i] = &u.ci.pArgc[u.ci.i+1];
      sqlite3VdbeMemStoreType(u.ci.apArg[u.ci.i]);
    }

    p->inVtabMethod = 1;
    rc = u.ci.pModule->xFilter(u.ci.pVtabCursor, u.ci.iQuery, pOp->p4.z, u.ci.nArg, u.ci.apArg);
    p->inVtabMethod = 0;
    importVtabErrMsg(p, u.ci.pVtab);
    if( rc==SQLITE_OK ){
      u.ci.res = u.ci.pModule->xEof(u.ci.pVtabCursor);
    }

    if( u.ci.res ){
      pc = pOp->p2 - 1;
    }
  }
  u.ci.pCur->nullRow = 0;

  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VColumn P1 P2 P3 * *
**
** Store the value of the P2-th column of
** the row of the virtual-table that the 
** P1 cursor is pointing to into register P3.
*/
case OP_VColumn: {
#if 0  /* local variables moved into u.cj */
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  Mem *pDest;
  sqlite3_context sContext;
#endif /* local variables moved into u.cj */

  VdbeCursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->pVtabCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.cj.pDest = &aMem[pOp->p3];
  memAboutToChange(p, u.cj.pDest);
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(u.cj.pDest);
    break;
  }
  u.cj.pVtab = pCur->pVtabCursor->pVtab;
  u.cj.pModule = u.cj.pVtab->pModule;
  assert( u.cj.pModule->xColumn );
  memset(&u.cj.sContext, 0, sizeof(u.cj.sContext));

  /* The output cell may already have a buffer allocated. Move
  ** the current contents to u.cj.sContext.s so in case the user-function
  ** can use the already allocated buffer instead of allocating a
  ** new one.
  */
  sqlite3VdbeMemMove(&u.cj.sContext.s, u.cj.pDest);
  MemSetTypeFlag(&u.cj.sContext.s, MEM_Null);

  rc = u.cj.pModule->xColumn(pCur->pVtabCursor, &u.cj.sContext, pOp->p2);
  importVtabErrMsg(p, u.cj.pVtab);
  if( u.cj.sContext.isError ){
    rc = u.cj.sContext.isError;
  }

  /* Copy the result of the function to the P3 register. We
  ** do this regardless of whether or not an error occurred to ensure any
  ** dynamic allocation in u.cj.sContext.s (a Mem struct) is  released.
  */
  sqlite3VdbeChangeEncoding(&u.cj.sContext.s, encoding);
  sqlite3VdbeMemMove(u.cj.pDest, &u.cj.sContext.s);
  REGISTER_TRACE(pOp->p3, u.cj.pDest);
  UPDATE_MAX_BLOBSIZE(u.cj.pDest);

  if( sqlite3VdbeMemTooBig(u.cj.pDest) ){
    goto too_big;
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
/* Opcode: VNext P1 P2 * * *
**
** Advance virtual table P1 to the next row in its result set and
** jump to instruction P2.  Or, if the virtual table has reached
** the end of its result set, then fall through to the next instruction.
*/
case OP_VNext: {   /* jump */
#if 0  /* local variables moved into u.ck */
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  int res;
  VdbeCursor *pCur;
#endif /* local variables moved into u.ck */

  u.ck.res = 0;
  u.ck.pCur = p->apCsr[pOp->p1];
  assert( u.ck.pCur->pVtabCursor );
  if( u.ck.pCur->nullRow ){
    break;
  }
  u.ck.pVtab = u.ck.pCur->pVtabCursor->pVtab;
  u.ck.pModule = u.ck.pVtab->pModule;
  assert( u.ck.pModule->xNext );

  /* Invoke the xNext() method of the module. There is no way for the
  ** underlying implementation to return an error if one occurs during
  ** xNext(). Instead, if an error occurs, true is returned (indicating that
  ** data is available) and the error code returned when xColumn or
  ** some other method is next invoked on the save virtual table cursor.
  */
  p->inVtabMethod = 1;
  rc = u.ck.pModule->xNext(u.ck.pCur->pVtabCursor);
  p->inVtabMethod = 0;
  importVtabErrMsg(p, u.ck.pVtab);
  if( rc==SQLITE_OK ){
    u.ck.res = u.ck.pModule->xEof(u.ck.pCur->pVtabCursor);
  }

  if( !u.ck.res ){
    /* If there is data, jump to P2 */
    pc = pOp->p2 - 1;
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

................................................................................
/* Opcode: VRename P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xRename method. The value
** in register P1 is passed as the zName argument to the xRename method.
*/
case OP_VRename: {
#if 0  /* local variables moved into u.cl */
  sqlite3_vtab *pVtab;
  Mem *pName;
#endif /* local variables moved into u.cl */

  u.cl.pVtab = pOp->p4.pVtab->pVtab;
  u.cl.pName = &aMem[pOp->p1];
  assert( u.cl.pVtab->pModule->xRename );
  assert( memIsValid(u.cl.pName) );
  REGISTER_TRACE(pOp->p1, u.cl.pName);
  assert( u.cl.pName->flags & MEM_Str );
  rc = u.cl.pVtab->pModule->xRename(u.cl.pVtab, u.cl.pName->z);
  importVtabErrMsg(p, u.cl.pVtab);
  p->expired = 0;

  break;
}
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
** a row to delete.
**
** P1 is a boolean flag. If it is set to true and the xUpdate call
** is successful, then the value returned by sqlite3_last_insert_rowid() 
** is set to the value of the rowid for the row just inserted.
*/
case OP_VUpdate: {
#if 0  /* local variables moved into u.cm */
  sqlite3_vtab *pVtab;
  sqlite3_module *pModule;
  int nArg;
  int i;
  sqlite_int64 rowid;
  Mem **apArg;
  Mem *pX;
#endif /* local variables moved into u.cm */

  assert( pOp->p2==1        || pOp->p5==OE_Fail   || pOp->p5==OE_Rollback
       || pOp->p5==OE_Abort || pOp->p5==OE_Ignore || pOp->p5==OE_Replace
  );
  u.cm.pVtab = pOp->p4.pVtab->pVtab;
  u.cm.pModule = (sqlite3_module *)u.cm.pVtab->pModule;
  u.cm.nArg = pOp->p2;
  assert( pOp->p4type==P4_VTAB );
  if( ALWAYS(u.cm.pModule->xUpdate) ){
    u8 vtabOnConflict = db->vtabOnConflict;
    u.cm.apArg = p->apArg;
    u.cm.pX = &aMem[pOp->p3];
    for(u.cm.i=0; u.cm.i<u.cm.nArg; u.cm.i++){
      assert( memIsValid(u.cm.pX) );
      memAboutToChange(p, u.cm.pX);
      sqlite3VdbeMemStoreType(u.cm.pX);
      u.cm.apArg[u.cm.i] = u.cm.pX;
      u.cm.pX++;
    }
    db->vtabOnConflict = pOp->p5;
    rc = u.cm.pModule->xUpdate(u.cm.pVtab, u.cm.nArg, u.cm.apArg, &u.cm.rowid);
    db->vtabOnConflict = vtabOnConflict;
    importVtabErrMsg(p, u.cm.pVtab);
    if( rc==SQLITE_OK && pOp->p1 ){
      assert( u.cm.nArg>1 && u.cm.apArg[0] && (u.cm.apArg[0]->flags&MEM_Null) );
      db->lastRowid = lastRowid = u.cm.rowid;
    }
    if( rc==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
      if( pOp->p5==OE_Ignore ){
        rc = SQLITE_OK;
      }else{
        p->errorAction = ((pOp->p5==OE_Replace) ? OE_Abort : pOp->p5);
      }
................................................................................
#ifndef SQLITE_OMIT_TRACE
/* Opcode: Trace * * * P4 *
**
** If tracing is enabled (by the sqlite3_trace()) interface, then
** the UTF-8 string contained in P4 is emitted on the trace callback.
*/
case OP_Trace: {
#if 0  /* local variables moved into u.cn */
  char *zTrace;
  char *z;
#endif /* local variables moved into u.cn */

  if( db->xTrace && (u.cn.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0 ){
    u.cn.z = sqlite3VdbeExpandSql(p, u.cn.zTrace);
    db->xTrace(db->pTraceArg, u.cn.z);
    sqlite3DbFree(db, u.cn.z);
  }
#ifdef SQLITE_DEBUG
  if( (db->flags & SQLITE_SqlTrace)!=0
   && (u.cn.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){
    sqlite3DebugPrintf("SQL-trace: %s\n", u.cn.zTrace);
  }
#endif /* SQLITE_DEBUG */
  break;
}
#endif


................................................................................
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

#endif /* #ifndef SQLITE_OMIT_INCRBLOB */

/************** End of vdbeblob.c ********************************************/
























































































































































































































































































































































































































































































































































































































































































































































































































































































































































/************** Begin file journal.c *****************************************/
/*
** 2007 August 22
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for walking the parser tree for
** an SQL statement.
*/




/*
** Walk an expression tree.  Invoke the callback once for each node
** of the expression, while decending.  (In other words, the callback
** is invoked before visiting children.)
**
................................................................................
**
*************************************************************************
**
** This file contains routines used for walking the parser tree and
** resolve all identifiers by associating them with a particular
** table and column.
*/



/*
** Turn the pExpr expression into an alias for the iCol-th column of the
** result set in pEList.
**
** If the result set column is a simple column reference, then this routine
** makes an exact copy.  But for any other kind of expression, this
................................................................................
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        inReg = pCol->iMem;
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdx,
                              pCol->iSorterColumn, target);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){
................................................................................
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** The ANALYZE command gather statistics about the content of tables
** and indices.  These statistics are made available to the query planner
** to help it make better decisions about how to perform queries.
**
** The following system tables are or have been supported:
**
**    CREATE TABLE sqlite_stat1(tbl, idx, stat);
**    CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample);
**    CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample);
**
** Additional tables might be added in future releases of SQLite.
** The sqlite_stat2 table is not created or used unless the SQLite version
** is between 3.6.18 and 3.7.7, inclusive, and unless SQLite is compiled
** with SQLITE_ENABLE_STAT2.  The sqlite_stat2 table is deprecated.
** The sqlite_stat2 table is superceded by sqlite_stat3, which is only
** created and used by SQLite versions after 2011-08-09 with
** SQLITE_ENABLE_STAT3 defined.  The fucntionality of sqlite_stat3
** is a superset of sqlite_stat2.  
**
** Format of sqlite_stat1:
**
** There is normally one row per index, with the index identified by the
** name in the idx column.  The tbl column is the name of the table to
** which the index belongs.  In each such row, the stat column will be
** a string consisting of a list of integers.  The first integer in this
** list is the number of rows in the index and in the table.  The second
** integer is the average number of rows in the index that have the same
** value in the first column of the index.  The third integer is the average
** number of rows in the index that have the same value for the first two
** columns.  The N-th integer (for N>1) is the average number of rows in 
** the index which have the same value for the first N-1 columns.  For
** a K-column index, there will be K+1 integers in the stat column.  If
** the index is unique, then the last integer will be 1.
**
** The list of integers in the stat column can optionally be followed
** by the keyword "unordered".  The "unordered" keyword, if it is present,
** must be separated from the last integer by a single space.  If the
** "unordered" keyword is present, then the query planner assumes that
** the index is unordered and will not use the index for a range query.
** 
** If the sqlite_stat1.idx column is NULL, then the sqlite_stat1.stat
** column contains a single integer which is the (estimated) number of
** rows in the table identified by sqlite_stat1.tbl.
**
** Format of sqlite_stat2:
**
** The sqlite_stat2 is only created and is only used if SQLite is compiled
** with SQLITE_ENABLE_STAT2 and if the SQLite version number is between
** 3.6.18 and 3.7.7.  The "stat2" table contains additional information
** about the distribution of keys within an index.  The index is identified by
** the "idx" column and the "tbl" column is the name of the table to which
** the index belongs.  There are usually 10 rows in the sqlite_stat2
** table for each index.
**
** The sqlite_stat2 entries for an index that have sampleno between 0 and 9
** inclusive are samples of the left-most key value in the index taken at
** evenly spaced points along the index.  Let the number of samples be S
** (10 in the standard build) and let C be the number of rows in the index.
** Then the sampled rows are given by:
**
**     rownumber = (i*C*2 + C)/(S*2)
**
** For i between 0 and S-1.  Conceptually, the index space is divided into
** S uniform buckets and the samples are the middle row from each bucket.
**
** The format for sqlite_stat2 is recorded here for legacy reference.  This
** version of SQLite does not support sqlite_stat2.  It neither reads nor
** writes the sqlite_stat2 table.  This version of SQLite only supports
** sqlite_stat3.
**
** Format for sqlite_stat3:
**
** The sqlite_stat3 is an enhancement to sqlite_stat2.  A new name is
** used to avoid compatibility problems.  
**
** The format of the sqlite_stat3 table is similar to the format for
** the sqlite_stat2 table, with the following changes:  (1)
** The sampleno column is removed.  (2) Every sample has nEq, nLt, and nDLt
** columns which hold the approximate number of rows in the table that
** exactly match the sample, the approximate number of rows with values
** less than the sample, and the approximate number of distinct key values
** less than the sample, respectively.  (3) The number of samples can vary 
** from one table to the next; the sample count does not have to be 
** exactly 10 as it is with sqlite_stat2.
**
** The ANALYZE command will typically generate sqlite_stat3 tables
** that contain between 10 and 40 samples which are distributed across
** the key space, though not uniformly, and which include samples with
** largest possible nEq values.
*/
#ifndef SQLITE_OMIT_ANALYZE

/*
** This routine generates code that opens the sqlite_stat1 table for
** writing with cursor iStatCur. If the library was built with the
** SQLITE_ENABLE_STAT2 macro defined, then the sqlite_stat2 table is
................................................................................
  const char *zWhereType  /* Either "tbl" or "idx" */
){
  static const struct {
    const char *zName;
    const char *zCols;
  } aTable[] = {
    { "sqlite_stat1", "tbl,idx,stat" },
#ifdef SQLITE_ENABLE_STAT3
    { "sqlite_stat3", "tbl,idx,neq,nlt,ndlt,sample" },
#endif
  };
  static const char *azToDrop[] = { 
    "sqlite_stat2",
#ifndef SQLITE_ENABLE_STAT3
    "sqlite_stat3",
#endif
  };

  int aRoot[] = {0, 0};
  u8 aCreateTbl[] = {0, 0};

  int i;
................................................................................
  Db *pDb;
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];

  /* Drop all statistics tables that this version of SQLite does not
  ** understand.
  */
  for(i=0; i<ArraySize(azToDrop); i++){
    Table *pTab = sqlite3FindTable(db, azToDrop[i], pDb->zName);
    if( pTab ) sqlite3CodeDropTable(pParse, pTab, iDb, 0);
  }

  /* Create new statistic tables if they do not exist, or clear them
  ** if they do already exist.
  */
  for(i=0; i<ArraySize(aTable); i++){
    const char *zTab = aTable[i].zName;
    Table *pStat;
    if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){
      /* The sqlite_stat[12] table does not exist. Create it. Note that a 
      ** side-effect of the CREATE TABLE statement is to leave the rootpage 
      ** of the new table in register pParse->regRoot. This is important 
................................................................................
      }else{
        /* The sqlite_stat[12] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  /* Open the sqlite_stat[13] tables for writing. */
  for(i=0; i<ArraySize(aTable); i++){
    sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb);
    sqlite3VdbeChangeP4(v, -1, (char *)3, P4_INT32);
    sqlite3VdbeChangeP5(v, aCreateTbl[i]);
  }
}

/*
** Recommended number of samples for sqlite_stat3
*/
#ifndef SQLITE_STAT3_SAMPLES
# define SQLITE_STAT3_SAMPLES 24
#endif

/*
** Three SQL functions - stat3_init(), stat3_push(), and stat3_pop() -
** share an instance of the following structure to hold their state
** information.
*/
typedef struct Stat3Accum Stat3Accum;
struct Stat3Accum {
  tRowcnt nRow;             /* Number of rows in the entire table */
  tRowcnt nPSample;         /* How often to do a periodic sample */
  int iMin;                 /* Index of entry with minimum nEq and hash */
  int mxSample;             /* Maximum number of samples to accumulate */
  int nSample;              /* Current number of samples */
  u32 iPrn;                 /* Pseudo-random number used for sampling */
  struct Stat3Sample {
    i64 iRowid;                /* Rowid in main table of the key */
    tRowcnt nEq;               /* sqlite_stat3.nEq */
    tRowcnt nLt;               /* sqlite_stat3.nLt */
    tRowcnt nDLt;              /* sqlite_stat3.nDLt */
    u8 isPSample;              /* True if a periodic sample */
    u32 iHash;                 /* Tiebreaker hash */
  } *a;                     /* An array of samples */
};

#ifdef SQLITE_ENABLE_STAT3
/*
** Implementation of the stat3_init(C,S) SQL function.  The two parameters
** are the number of rows in the table or index (C) and the number of samples
** to accumulate (S).
**
** This routine allocates the Stat3Accum object.
**
** The return value is the Stat3Accum object (P).
*/
static void stat3Init(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Stat3Accum *p;
  tRowcnt nRow;
  int mxSample;
  int n;

  UNUSED_PARAMETER(argc);
  nRow = (tRowcnt)sqlite3_value_int64(argv[0]);
  mxSample = sqlite3_value_int(argv[1]);
  n = sizeof(*p) + sizeof(p->a[0])*mxSample;
  p = sqlite3_malloc( n );
  if( p==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }
  memset(p, 0, n);
  p->a = (struct Stat3Sample*)&p[1];
  p->nRow = nRow;
  p->mxSample = mxSample;
  p->nPSample = p->nRow/(mxSample/3+1) + 1;
  sqlite3_randomness(sizeof(p->iPrn), &p->iPrn);
  sqlite3_result_blob(context, p, sizeof(p), sqlite3_free);
}
static const FuncDef stat3InitFuncdef = {
  2,                /* nArg */
  SQLITE_UTF8,      /* iPrefEnc */
  0,                /* flags */
  0,                /* pUserData */
  0,                /* pNext */
  stat3Init,        /* xFunc */
  0,                /* xStep */
  0,                /* xFinalize */
  "stat3_init",     /* zName */
  0,                /* pHash */
  0                 /* pDestructor */
};


/*
** Implementation of the stat3_push(nEq,nLt,nDLt,rowid,P) SQL function.  The
** arguments describe a single key instance.  This routine makes the 
** decision about whether or not to retain this key for the sqlite_stat3
** table.
**
** The return value is NULL.
*/
static void stat3Push(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[4]);
  tRowcnt nEq = sqlite3_value_int64(argv[0]);
  tRowcnt nLt = sqlite3_value_int64(argv[1]);
  tRowcnt nDLt = sqlite3_value_int64(argv[2]);
  i64 rowid = sqlite3_value_int64(argv[3]);
  u8 isPSample = 0;
  u8 doInsert = 0;
  int iMin = p->iMin;
  struct Stat3Sample *pSample;
  int i;
  u32 h;

  UNUSED_PARAMETER(context);
  UNUSED_PARAMETER(argc);
  if( nEq==0 ) return;
  h = p->iPrn = p->iPrn*1103515245 + 12345;
  if( (nLt/p->nPSample)!=((nEq+nLt)/p->nPSample) ){
    doInsert = isPSample = 1;
  }else if( p->nSample<p->mxSample ){
    doInsert = 1;
  }else{
    if( nEq>p->a[iMin].nEq || (nEq==p->a[iMin].nEq && h>p->a[iMin].iHash) ){
      doInsert = 1;
    }
  }
  if( !doInsert ) return;
  if( p->nSample==p->mxSample ){
    if( iMin<p->nSample ){
      memcpy(&p->a[iMin], &p->a[iMin+1], sizeof(p->a[0])*(p->nSample-iMin));
    }
    pSample = &p->a[p->nSample-1];
  }else{
    pSample = &p->a[p->nSample++];
  }
  pSample->iRowid = rowid;
  pSample->nEq = nEq;
  pSample->nLt = nLt;
  pSample->nDLt = nDLt;
  pSample->iHash = h;
  pSample->isPSample = isPSample;

  /* Find the new minimum */
  if( p->nSample==p->mxSample ){
    pSample = p->a;
    i = 0;
    while( pSample->isPSample ){
      i++;
      pSample++;
      assert( i<p->nSample );
    }
    nEq = pSample->nEq;
    h = pSample->iHash;
    iMin = i;
    for(i++, pSample++; i<p->nSample; i++, pSample++){
      if( pSample->isPSample ) continue;
      if( pSample->nEq<nEq
       || (pSample->nEq==nEq && pSample->iHash<h)
      ){
        iMin = i;
        nEq = pSample->nEq;
        h = pSample->iHash;
      }
    }
    p->iMin = iMin;
  }
}
static const FuncDef stat3PushFuncdef = {
  5,                /* nArg */
  SQLITE_UTF8,      /* iPrefEnc */
  0,                /* flags */
  0,                /* pUserData */
  0,                /* pNext */
  stat3Push,        /* xFunc */
  0,                /* xStep */
  0,                /* xFinalize */
  "stat3_push",     /* zName */
  0,                /* pHash */
  0                 /* pDestructor */
};

/*
** Implementation of the stat3_get(P,N,...) SQL function.  This routine is
** used to query the results.  Content is returned for the Nth sqlite_stat3
** row where N is between 0 and S-1 and S is the number of samples.  The
** value returned depends on the number of arguments.
**
**   argc==2    result:  rowid
**   argc==3    result:  nEq
**   argc==4    result:  nLt
**   argc==5    result:  nDLt
*/
static void stat3Get(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int n = sqlite3_value_int(argv[1]);
  Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[0]);

  assert( p!=0 );
  if( p->nSample<=n ) return;
  switch( argc ){
    case 2: sqlite3_result_int64(context, p->a[n].iRowid); break;
    case 3: sqlite3_result_int64(context, p->a[n].nEq);    break;
    case 4: sqlite3_result_int64(context, p->a[n].nLt);    break;
    case 5: sqlite3_result_int64(context, p->a[n].nDLt);   break;
  }
}
static const FuncDef stat3GetFuncdef = {
  -1,               /* nArg */
  SQLITE_UTF8,      /* iPrefEnc */
  0,                /* flags */
  0,                /* pUserData */
  0,                /* pNext */
  stat3Get,         /* xFunc */
  0,                /* xStep */
  0,                /* xFinalize */
  "stat3_get",     /* zName */
  0,                /* pHash */
  0                 /* pDestructor */
};
#endif /* SQLITE_ENABLE_STAT3 */




/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
  Parse *pParse,   /* Parser context */
................................................................................
  int i;                       /* Loop counter */
  int topOfLoop;               /* The top of the loop */
  int endOfLoop;               /* The end of the loop */
  int jZeroRows = -1;          /* Jump from here if number of rows is zero */
  int iDb;                     /* Index of database containing pTab */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regStat1 = iMem++;       /* The stat column of sqlite_stat1 */
#ifdef SQLITE_ENABLE_STAT3
  int regNumEq = regStat1;     /* Number of instances.  Same as regStat1 */
  int regNumLt = iMem++;       /* Number of keys less than regSample */
  int regNumDLt = iMem++;      /* Number of distinct keys less than regSample */
  int regSample = iMem++;      /* The next sample value */
  int regRowid = regSample;    /* Rowid of a sample */
  int regAccum = iMem++;       /* Register to hold Stat3Accum object */
  int regLoop = iMem++;        /* Loop counter */
  int regCount = iMem++;       /* Number of rows in the table or index */
  int regTemp1 = iMem++;       /* Intermediate register */
  int regTemp2 = iMem++;       /* Intermediate register */
  int once = 1;                /* One-time initialization */
  int shortJump = 0;           /* Instruction address */
  int iTabCur = pParse->nTab++; /* Table cursor */
#endif
  int regCol = iMem++;         /* Content of a column in analyzed table */
  int regRec = iMem++;         /* Register holding completed record */
  int regTemp = iMem++;        /* Temporary use register */
  int regNewRowid = iMem++;    /* Rowid for the inserted record */










  v = sqlite3GetVdbe(pParse);
  if( v==0 || NEVER(pTab==0) ){
    return;
  }
  if( pTab->tnum==0 ){
    /* Do not gather statistics on views or virtual tables */
................................................................................
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    int nCol;
    KeyInfo *pKey;
    int addrIfNot = 0;           /* address of OP_IfNot */
    int *aChngAddr;              /* Array of jump instruction addresses */

    if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
    VdbeNoopComment((v, "Begin analysis of %s", pIdx->zName));
    nCol = pIdx->nColumn;
    pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    if( iMem+1+(nCol*2)>pParse->nMem ){
      pParse->nMem = iMem+1+(nCol*2);
    }
    aChngAddr = sqlite3DbMallocRaw(db, sizeof(int)*pIdx->nColumn);
    if( aChngAddr==0 ) continue;

    /* Open a cursor to the index to be analyzed. */
    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
        (char *)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pIdx->zName));

    /* Populate the register containing the index name. */
    sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0);

#ifdef SQLITE_ENABLE_STAT3
    if( once ){

      once = 0;
      sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);





    }
    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regCount);
    sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_STAT3_SAMPLES, regTemp1);









    sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumEq);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumLt);
    sqlite3VdbeAddOp2(v, OP_Integer, -1, regNumDLt);
    sqlite3VdbeAddOp4(v, OP_Function, 1, regCount, regAccum,
                      (char*)&stat3InitFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 2);
#endif /* SQLITE_ENABLE_STAT3 */


    /* The block of memory cells initialized here is used as follows.
    **
    **    iMem:                
    **        The total number of rows in the table.
    **
    **    iMem+1 .. iMem+nCol: 
................................................................................
    }

    /* Start the analysis loop. This loop runs through all the entries in
    ** the index b-tree.  */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1);  /* Increment row counter */

    for(i=0; i<nCol; i++){
      CollSeq *pColl;
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol);
      if( i==0 ){































        /* Always record the very first row */
        addrIfNot = sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1);
      }
      assert( pIdx->azColl!=0 );
      assert( pIdx->azColl[i]!=0 );
      pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
      aChngAddr[i] = sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1,
                                      (char*)pColl, P4_COLLSEQ);
      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
      VdbeComment((v, "jump if column %d changed", i));
#ifdef SQLITE_ENABLE_STAT3
      if( i==0 ){
        sqlite3VdbeAddOp2(v, OP_AddImm, regNumEq, 1);
        VdbeComment((v, "incr repeat count"));
      }





#endif
    }
    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
    for(i=0; i<nCol; i++){
      sqlite3VdbeJumpHere(v, aChngAddr[i]);  /* Set jump dest for the OP_Ne */
      if( i==0 ){
        sqlite3VdbeJumpHere(v, addrIfNot);   /* Jump dest for OP_IfNot */
#ifdef SQLITE_ENABLE_STAT3
        sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
                          (char*)&stat3PushFuncdef, P4_FUNCDEF);
        sqlite3VdbeChangeP5(v, 5);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, pIdx->nColumn, regRowid);
        sqlite3VdbeAddOp3(v, OP_Add, regNumEq, regNumLt, regNumLt);
        sqlite3VdbeAddOp2(v, OP_AddImm, regNumDLt, 1);
        sqlite3VdbeAddOp2(v, OP_Integer, 1, regNumEq);
#endif        
      }

      sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1);
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1);
    }
    sqlite3DbFree(db, aChngAddr);

    /* Always jump here after updating the iMem+1...iMem+1+nCol counters */

    sqlite3VdbeResolveLabel(v, endOfLoop);

    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
#ifdef SQLITE_ENABLE_STAT3
    sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
                      (char*)&stat3PushFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 5);
    sqlite3VdbeAddOp2(v, OP_Integer, -1, regLoop);
    shortJump = 
    sqlite3VdbeAddOp2(v, OP_AddImm, regLoop, 1);
    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regTemp1,
                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 2);
    sqlite3VdbeAddOp1(v, OP_IsNull, regTemp1);
    sqlite3VdbeAddOp3(v, OP_NotExists, iTabCur, shortJump, regTemp1);
    sqlite3VdbeAddOp3(v, OP_Column, iTabCur, pIdx->aiColumn[0], regSample);
    sqlite3ColumnDefault(v, pTab, pIdx->aiColumn[0], regSample);
    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumEq,
                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 3);
    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumLt,
                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 4);
    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumDLt,
                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, 5);
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 6, regRec, "bbbbbb", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regNewRowid);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, shortJump);
    sqlite3VdbeJumpHere(v, shortJump+2);
#endif        

    /* Store the results in sqlite_stat1.
    **
    ** The result is a single row of the sqlite_stat1 table.  The first
    ** two columns are the names of the table and index.  The third column
    ** is a string composed of a list of integer statistics about the
    ** index.  The first integer in the list is the total number of entries
................................................................................
    **
    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regStat1);
    if( jZeroRows<0 ){
      jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
    }
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
      sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp);
      sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
    }
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
  }

  /* If the table has no indices, create a single sqlite_stat1 entry
  ** containing NULL as the index name and the row count as the content.
  */
  if( pTab->pIndex==0 ){
    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb);
    VdbeComment((v, "%s", pTab->zName));
    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat1);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1);
  }else{
    sqlite3VdbeJumpHere(v, jZeroRows);
    jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto);
  }
  sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
  sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
  sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
  sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
  sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
  if( pParse->nMem<regRec ) pParse->nMem = regRec;
  sqlite3VdbeJumpHere(v, jZeroRows);
}


/*
** Generate code that will cause the most recent index analysis to
** be loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
................................................................................
  Schema *pSchema = db->aDb[iDb].pSchema;    /* Schema of database iDb */
  HashElem *k;
  int iStatCur;
  int iMem;

  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 3;
  openStatTable(pParse, iDb, iStatCur, 0, 0);
  iMem = pParse->nMem+1;
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
    Table *pTab = (Table*)sqliteHashData(k);
    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem);
  }
................................................................................
  int iStatCur;

  assert( pTab!=0 );
  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 3;
  if( pOnlyIdx ){
    openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx");
  }else{
    openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl");
  }
  analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur, pParse->nMem+1);
  loadAnalysis(pParse, iDb);
................................................................................
** the table.
*/
static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
  analysisInfo *pInfo = (analysisInfo*)pData;
  Index *pIndex;
  Table *pTable;
  int i, c, n;
  tRowcnt v;
  const char *z;

  assert( argc==3 );
  UNUSED_PARAMETER2(NotUsed, argc);

  if( argv==0 || argv[0]==0 || argv[2]==0 ){
    return 0;
................................................................................
}

/*
** If the Index.aSample variable is not NULL, delete the aSample[] array
** and its contents.
*/
SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
#ifdef SQLITE_ENABLE_STAT3
  if( pIdx->aSample ){
    int j;
    for(j=0; j<pIdx->nSample; j++){
      IndexSample *p = &pIdx->aSample[j];
      if( p->eType==SQLITE_TEXT || p->eType==SQLITE_BLOB ){
        sqlite3_free(p->u.z);
      }
    }
    sqlite3_free(pIdx->aSample);
  }
  UNUSED_PARAMETER(db);
  pIdx->nSample = 0;
  pIdx->aSample = 0;
#else
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(pIdx);
#endif
}

#ifdef SQLITE_ENABLE_STAT3
/*
** Load content from the sqlite_stat3 table into the Index.aSample[]
** arrays of all indices.
*/
static int loadStat3(sqlite3 *db, const char *zDb){
  int rc;                       /* Result codes from subroutines */
  sqlite3_stmt *pStmt = 0;      /* An SQL statement being run */
  char *zSql;                   /* Text of the SQL statement */
  Index *pPrevIdx = 0;          /* Previous index in the loop */
  int idx = 0;                  /* slot in pIdx->aSample[] for next sample */
  int eType;                    /* Datatype of a sample */
  IndexSample *pSample;         /* A slot in pIdx->aSample[] */

  if( !sqlite3FindTable(db, "sqlite_stat3", zDb) ){
    return SQLITE_OK;
  }

  zSql = sqlite3MPrintf(db, 
      "SELECT idx,count(*) FROM %Q.sqlite_stat3"
      " GROUP BY idx", zDb);
  if( !zSql ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;

  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    char *zIndex;   /* Index name */
    Index *pIdx;    /* Pointer to the index object */
    int nSample;    /* Number of samples */

    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    nSample = sqlite3_column_int(pStmt, 1);
    if( nSample>255 ) continue;
    pIdx = sqlite3FindIndex(db, zIndex, zDb);
    if( pIdx==0 ) continue;
    assert( pIdx->nSample==0 );
    pIdx->nSample = (u8)nSample;
    pIdx->aSample = sqlite3MallocZero( nSample*sizeof(IndexSample) );
    pIdx->avgEq = pIdx->aiRowEst[1];
    if( pIdx->aSample==0 ){
      db->mallocFailed = 1;
      sqlite3_finalize(pStmt);
      return SQLITE_NOMEM;
    }
  }
  sqlite3_finalize(pStmt);

  zSql = sqlite3MPrintf(db, 
      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat3", zDb);
  if( !zSql ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;

  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    char *zIndex;   /* Index name */
    Index *pIdx;    /* Pointer to the index object */
    int i;          /* Loop counter */
    tRowcnt sumEq;  /* Sum of the nEq values */

    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    pIdx = sqlite3FindIndex(db, zIndex, zDb);
    if( pIdx==0 ) continue;
    if( pIdx==pPrevIdx ){
      idx++;
    }else{
      pPrevIdx = pIdx;
      idx = 0;
    }
    assert( idx<pIdx->nSample );
    pSample = &pIdx->aSample[idx];
    pSample->nEq = (tRowcnt)sqlite3_column_int64(pStmt, 1);
    pSample->nLt = (tRowcnt)sqlite3_column_int64(pStmt, 2);
    pSample->nDLt = (tRowcnt)sqlite3_column_int64(pStmt, 3);
    if( idx==pIdx->nSample-1 ){
      if( pSample->nDLt>0 ){
        for(i=0, sumEq=0; i<=idx-1; i++) sumEq += pIdx->aSample[i].nEq;
        pIdx->avgEq = (pSample->nLt - sumEq)/pSample->nDLt;
      }
      if( pIdx->avgEq<=0 ) pIdx->avgEq = 1;
    }
    eType = sqlite3_column_type(pStmt, 4);
    pSample->eType = (u8)eType;
    switch( eType ){
      case SQLITE_INTEGER: {
        pSample->u.i = sqlite3_column_int64(pStmt, 4);
        break;
      }
      case SQLITE_FLOAT: {
        pSample->u.r = sqlite3_column_double(pStmt, 4);
        break;
      }
      case SQLITE_NULL: {
        break;
      }
      default: assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); {
        const char *z = (const char *)(
              (eType==SQLITE_BLOB) ?
              sqlite3_column_blob(pStmt, 4):
              sqlite3_column_text(pStmt, 4)
           );
        int n = sqlite3_column_bytes(pStmt, 4);
        if( n>0xffff ) n = 0xffff;
        pSample->nByte = (u16)n;
        if( n < 1){
          pSample->u.z = 0;
        }else{
          pSample->u.z = sqlite3Malloc(n);
          if( pSample->u.z==0 ){
            db->mallocFailed = 1;
            sqlite3_finalize(pStmt);
            return SQLITE_NOMEM;
          }
          memcpy(pSample->u.z, z, n);
        }
      }
    }
  }
  return sqlite3_finalize(pStmt);
}
#endif /* SQLITE_ENABLE_STAT3 */

/*
** Load the content of the sqlite_stat1 and sqlite_stat3 tables. The
** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]
** arrays. The contents of sqlite_stat3 are used to populate the
** Index.aSample[] arrays.
**
** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR
** is returned. In this case, even if SQLITE_ENABLE_STAT3 was defined 
** during compilation and the sqlite_stat3 table is present, no data is 
** read from it.
**
** If SQLITE_ENABLE_STAT3 was defined during compilation and the 
** sqlite_stat3 table is not present in the database, SQLITE_ERROR is
** returned. However, in this case, data is read from the sqlite_stat1
** table (if it is present) before returning.
**
** If an OOM error occurs, this function always sets db->mallocFailed.
** This means if the caller does not care about other errors, the return
** code may be ignored.
*/
................................................................................
  assert( db->aDb[iDb].pBt!=0 );

  /* Clear any prior statistics */
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    sqlite3DefaultRowEst(pIdx);
#ifdef SQLITE_ENABLE_STAT3
    sqlite3DeleteIndexSamples(db, pIdx);
    pIdx->aSample = 0;
#endif
  }

  /* Check to make sure the sqlite_stat1 table exists */
  sInfo.db = db;
  sInfo.zDatabase = db->aDb[iDb].zName;
  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){
    return SQLITE_ERROR;
  }

  /* Load new statistics out of the sqlite_stat1 table */
  zSql = sqlite3MPrintf(db, 
      "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
    sqlite3DbFree(db, zSql);
  }


  /* Load the statistics from the sqlite_stat3 table. */
#ifdef SQLITE_ENABLE_STAT3



  if( rc==SQLITE_OK ){
    rc = loadStat3(db, sInfo.zDatabase);


































































  }
#endif

  if( rc==SQLITE_NOMEM ){
    db->mallocFailed = 1;
  }
  return rc;
................................................................................
  int noErr          /* Suppress error messages if VIEW already exists */
){
  Table *p;
  int n;
  const char *z;
  Token sEnd;
  DbFixer sFix;
  Token *pName;
  int iDb;
  sqlite3 *db = pParse->db;

  if( pParse->nVar>0 ){
    sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
    sqlite3SelectDelete(db, pSelect);
    return;
................................................................................
*/
static void sqlite3ClearStatTables(
  Parse *pParse,         /* The parsing context */
  int iDb,               /* The database number */
  const char *zType,     /* "idx" or "tbl" */
  const char *zName      /* Name of index or table */
){
  static const char *azStatTab[] = { 
    "sqlite_stat1",
    "sqlite_stat2",
    "sqlite_stat3",
  };
  int i;
  const char *zDbName = pParse->db->aDb[iDb].zName;
  for(i=0; i<ArraySize(azStatTab); i++){
    if( sqlite3FindTable(pParse->db, azStatTab[i], zDbName) ){
      sqlite3NestedParse(pParse,
        "DELETE FROM %Q.%s WHERE %s=%Q",
        zDbName, azStatTab[i], zType, zName
      );
    }
  }
}

/*
** Generate code to drop a table.
*/
SQLITE_PRIVATE void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, int isView){
  Vdbe *v;
  sqlite3 *db = pParse->db;
  Trigger *pTrigger;
  Db *pDb = &db->aDb[iDb];

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  sqlite3BeginWriteOperation(pParse, 1, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( IsVirtual(pTab) ){
    sqlite3VdbeAddOp0(v, OP_VBegin);
  }
#endif

  /* Drop all triggers associated with the table being dropped. Code
  ** is generated to remove entries from sqlite_master and/or
  ** sqlite_temp_master if required.
  */
  pTrigger = sqlite3TriggerList(pParse, pTab);
  while( pTrigger ){
    assert( pTrigger->pSchema==pTab->pSchema || 
        pTrigger->pSchema==db->aDb[1].pSchema );
    sqlite3DropTriggerPtr(pParse, pTrigger);
    pTrigger = pTrigger->pNext;
  }

#ifndef SQLITE_OMIT_AUTOINCREMENT
  /* Remove any entries of the sqlite_sequence table associated with
  ** the table being dropped. This is done before the table is dropped
  ** at the btree level, in case the sqlite_sequence table needs to
  ** move as a result of the drop (can happen in auto-vacuum mode).
  */
  if( pTab->tabFlags & TF_Autoincrement ){
    sqlite3NestedParse(pParse,
      "DELETE FROM %Q.sqlite_sequence WHERE name=%Q",
      pDb->zName, pTab->zName
    );
  }
#endif

  /* Drop all SQLITE_MASTER table and index entries that refer to the
  ** table. The program name loops through the master table and deletes
  ** every row that refers to a table of the same name as the one being
  ** dropped. Triggers are handled seperately because a trigger can be
  ** created in the temp database that refers to a table in another
  ** database.
  */
  sqlite3NestedParse(pParse, 
      "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
      pDb->zName, SCHEMA_TABLE(iDb), pTab->zName);
  if( !isView && !IsVirtual(pTab) ){
    destroyTable(pParse, pTab);
  }

  /* Remove the table entry from SQLite's internal schema and modify
  ** the schema cookie.
  */
  if( IsVirtual(pTab) ){
    sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);
  }
  sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
  sqlite3ChangeCookie(pParse, iDb);
  sqliteViewResetAll(db, iDb);

}

/*
** This routine is called to do the work of a DROP TABLE statement.
** pName is the name of the table to be dropped.
*/
SQLITE_PRIVATE void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
................................................................................
      goto exit_drop_table;
    }
    if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
      goto exit_drop_table;
    }
  }
#endif
  if( !pParse->nested && sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
    sqlite3ErrorMsg(pParse, "table %s may not be dropped", pTab->zName);
    goto exit_drop_table;
  }

#ifndef SQLITE_OMIT_VIEW
  /* Ensure DROP TABLE is not used on a view, and DROP VIEW is not used
  ** on a table.
................................................................................
#endif

  /* Generate code to remove the table from the master table
  ** on disk.
  */
  v = sqlite3GetVdbe(pParse);
  if( v ){


    sqlite3BeginWriteOperation(pParse, 1, iDb);






    sqlite3FkDropTable(pParse, pName, pTab);
    sqlite3CodeDropTable(pParse, pTab, iDb, isView);





































    sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);


  }












exit_drop_table:
  sqlite3SrcListDelete(db, pName);
}

/*
** This routine is called to create a new foreign key on the table
................................................................................
** the index already exists and must be cleared before being refilled and
** the root page number of the index is taken from pIndex->tnum.
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab++;     /* Btree cursor used for pTab */
  int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */

  int addr1;                     /* Address of top of loop */

  int tnum;                      /* Root page of index */
  Vdbe *v;                       /* Generate code into this virtual machine */
  KeyInfo *pKey;                 /* KeyInfo for index */
  int regIdxKey;                 /* Registers containing the index key */
  int regRecord;                 /* Register holding assemblied index record */
  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
................................................................................
  }
  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
                    (char *)pKey, P4_KEYINFO_HANDOFF);
  if( memRootPage>=0 ){
    sqlite3VdbeChangeP5(v, 1);
  }









  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);

  regRecord = sqlite3GetTempReg(pParse);
  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);





















  if( pIndex->onError!=OE_None ){
    const int regRowid = regIdxKey + pIndex->nColumn;
    const int j2 = sqlite3VdbeCurrentAddr(v) + 2;
    void * const pRegKey = SQLITE_INT_TO_PTR(regIdxKey);

    /* The registers accessed by the OP_IsUnique opcode were allocated
    ** using sqlite3GetTempRange() inside of the sqlite3GenerateIndexKey()
................................................................................
    ** we can be sure that no other temp registers have been allocated
    ** since sqlite3ReleaseTempRange() was called, it is safe to do so.
    */
    sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx, j2, regRowid, pRegKey, P4_INT32);
    sqlite3HaltConstraint(
        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC);
  }
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeJumpHere(v, addr1);

  sqlite3VdbeAddOp1(v, OP_Close, iTab);
  sqlite3VdbeAddOp1(v, OP_Close, iIdx);

}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
................................................................................
  /* 
  ** Allocate the index structure. 
  */
  nName = sqlite3Strlen30(zName);
  nCol = pList->nExpr;
  pIndex = sqlite3DbMallocZero(db, 
      sizeof(Index) +              /* Index structure  */
      sizeof(tRowcnt)*(nCol+1) +   /* Index.aiRowEst   */
      sizeof(int)*nCol +           /* Index.aiColumn   */

      sizeof(char *)*nCol +        /* Index.azColl     */
      sizeof(u8)*nCol +            /* Index.aSortOrder */
      nName + 1 +                  /* Index.zName      */
      nExtra                       /* Collation sequence names */
  );
  if( db->mallocFailed ){
    goto exit_create_index;
  }
  pIndex->aiRowEst = (tRowcnt*)(&pIndex[1]);
  pIndex->azColl = (char**)(&pIndex->aiRowEst[nCol+1]);
  pIndex->aiColumn = (int *)(&pIndex->azColl[nCol]);

  pIndex->aSortOrder = (u8 *)(&pIndex->aiColumn[nCol]);
  pIndex->zName = (char *)(&pIndex->aSortOrder[nCol]);
  zExtra = (char *)(&pIndex->zName[nName+1]);
  memcpy(pIndex->zName, zName, nName+1);
  pIndex->pTable = pTab;
  pIndex->nColumn = pList->nExpr;
  pIndex->onError = (u8)onError;
  pIndex->autoIndex = (u8)(pName==0);
................................................................................
**           aiRowEst[N]>=1
**
** Apart from that, we have little to go on besides intuition as to
** how aiRowEst[] should be initialized.  The numbers generated here
** are based on typical values found in actual indices.
*/
SQLITE_PRIVATE void sqlite3DefaultRowEst(Index *pIdx){
  tRowcnt *a = pIdx->aiRowEst;
  int i;
  tRowcnt n;
  assert( a!=0 );
  a[0] = pIdx->pTable->nRowEst;
  if( a[0]<10 ) a[0] = 10;
  n = 10;
  for(i=1; i<=pIdx->nColumn; i++){
    a[i] = n;
    if( n>5 ) n--;
................................................................................
**           A natural cross join B
**
** The operator is "natural cross join".  The A and B operands are stored
** in p->a[0] and p->a[1], respectively.  The parser initially stores the
** operator with A.  This routine shifts that operator over to B.
*/
SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList *p){
  if( p && p->a ){
    int i;

    for(i=p->nSrc-1; i>0; i--){
      p->a[i].jointype = p->a[i-1].jointype;
    }
    p->a[0].jointype = 0;
  }
}

................................................................................
** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
*/



/*
** Return the collating function associated with a function.
*/
static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
  return context->pColl;
}
................................................................................
    ** early.  */
    if( pParse->disableTriggers ){
      pTo = sqlite3FindTable(db, pFKey->zTo, zDb);
    }else{
      pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);
    }
    if( !pTo || locateFkeyIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){

      if( !isIgnoreErrors || db->mallocFailed ) return;
















      continue;
    }
    assert( pFKey->nCol==1 || (aiFree && pIdx) );

    if( aiFree ){
      aiCol = aiFree;
    }else{
................................................................................
#define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api = 0;
#define SQLITE_EXTENSION_INIT2(v)  sqlite3_api = v;

#endif /* _SQLITE3EXT_H_ */

/************** End of sqlite3ext.h ******************************************/
/************** Continuing where we left off in loadext.c ********************/


#ifndef SQLITE_OMIT_LOAD_EXTENSION

/*
** Some API routines are omitted when various features are
** excluded from a build of SQLite.  Substitute a NULL pointer
** for any missing APIs.
................................................................................
  Select *pSelect,       /* The whole SELECT statement */
  int regData            /* Register holding data to be sorted */
){
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);

  sqlite3ExprCacheClear(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1, 1);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord);





  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
  if( pSelect->iLimit ){
    int addr1, addr2;
    int iLimit;
    if( pSelect->iOffset ){
      iLimit = pSelect->iOffset+1;
................................................................................
  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, pseudoTab, regRow, nColumn);
    regRowid = 0;
  }else{
    regRowid = sqlite3GetTempReg(pParse);
  }










  addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak);
  codeOffset(v, p, addrContinue);
  sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr + 1, regRow);

  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      testcase( eDest==SRT_Table );
      testcase( eDest==SRT_EphemTab );
      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
................................................................................
  }
  sqlite3ReleaseTempReg(pParse, regRow);
  sqlite3ReleaseTempReg(pParse, regRowid);

  /* The bottom of the loop
  */
  sqlite3VdbeResolveLabel(v, addrContinue);



  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr);

  sqlite3VdbeResolveLabel(v, addrBreak);
  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
    sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0);
  }
}

/*
................................................................................
  }

  /* Set the limiter.
  */
  iEnd = sqlite3VdbeMakeLabel(v);
  p->nSelectRow = (double)LARGEST_INT64;
  computeLimitRegisters(pParse, p, iEnd);





  /* Open a virtual index to use for the distinct set.
  */
  if( p->selFlags & SF_Distinct ){
    KeyInfo *pKeyInfo;
    distinct = pParse->nTab++;
    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
................................................................................
      sqlite3VdbeChangeToNoop(v, addrSortIndex, 1);
      p->addrOpenEphm[2] = -1;
    }

    if( pWInfo->eDistinct ){
      VdbeOp *pOp;                /* No longer required OpenEphemeral instr. */
     
      assert( addrDistinctIndex>0 );
      pOp = sqlite3VdbeGetOp(v, addrDistinctIndex);

      assert( isDistinct );
      assert( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED 
           || pWInfo->eDistinct==WHERE_DISTINCT_UNIQUE 
      );
      distinct = -1;
................................................................................
    int iBMem;          /* First Mem address for previous GROUP BY */
    int iUseFlag;       /* Mem address holding flag indicating that at least
                        ** one row of the input to the aggregator has been
                        ** processed */
    int iAbortFlag;     /* Mem address which causes query abort if positive */
    int groupBySort;    /* Rows come from source in GROUP BY order */
    int addrEnd;        /* End of processing for this SELECT */



    /* Remove any and all aliases between the result set and the
    ** GROUP BY clause.
    */
    if( pGroupBy ){
      int k;                        /* Loop counter */
      struct ExprList_item *pItem;  /* For looping over expression in a list */
................................................................................
      int addrTopOfLoop;  /* Top of the input loop */
      int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
      int addrReset;      /* Subroutine for resetting the accumulator */
      int regReset;       /* Return address register for reset subroutine */

      /* If there is a GROUP BY clause we might need a sorting index to
      ** implement it.  Allocate that sorting index now.  If it turns out
      ** that we do not need it after all, the OpenEphemeral instruction
      ** will be converted into a Noop.  
      */
      sAggInfo.sortingIdx = pParse->nTab++;
      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
      addrSortingIdx = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, 
          sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
          0, (char*)pKeyInfo, P4_KEYINFO_HANDOFF);

      /* Initialize memory locations used by GROUP BY aggregate processing
      */
      iUseFlag = ++pParse->nMem;
      iAbortFlag = ++pParse->nMem;
................................................................................
              sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1);
            }
            j++;
          }
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);



        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
        sqlite3ExprCacheClear(pParse);
      }

      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
      ** Then compare the current GROUP BY terms against the GROUP BY terms
      ** from the previous row currently stored in a0, a1, a2...
      */
      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
      sqlite3ExprCacheClear(pParse);



      for(j=0; j<pGroupBy->nExpr; j++){
        if( groupBySort ){
          sqlite3VdbeAddOp3(v, OP_Column, sAggInfo.sortingIdx, j, iBMem+j);

        }else{
          sAggInfo.directMode = 1;
          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
        }
      }
      sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
                          (char*)pKeyInfo, P4_KEYINFO);
................................................................................
      updateAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
      VdbeComment((v, "indicate data in accumulator"));

      /* End of the loop
      */
      if( groupBySort ){
        sqlite3VdbeAddOp2(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop);
      }else{
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
      }

      /* Output the final row of result
      */
................................................................................
** This file contains the sqlite3_get_table() and sqlite3_free_table()
** interface routines.  These are just wrappers around the main
** interface routine of sqlite3_exec().
**
** These routines are in a separate files so that they will not be linked
** if they are not used.
*/



#ifndef SQLITE_OMIT_GET_TABLE

/*
** This structure is used to pass data from sqlite3_get_table() through
** to the callback function is uses to build the result.
*/
................................................................................
#define TERM_DYNAMIC    0x01   /* Need to call sqlite3ExprDelete(db, pExpr) */
#define TERM_VIRTUAL    0x02   /* Added by the optimizer.  Do not code */
#define TERM_CODED      0x04   /* This term is already coded */
#define TERM_COPIED     0x08   /* Has a child */
#define TERM_ORINFO     0x10   /* Need to free the WhereTerm.u.pOrInfo object */
#define TERM_ANDINFO    0x20   /* Need to free the WhereTerm.u.pAndInfo obj */
#define TERM_OR_OK      0x40   /* Used during OR-clause processing */
#ifdef SQLITE_ENABLE_STAT3
#  define TERM_VNULL    0x80   /* Manufactured x>NULL or x<=NULL term */
#else
#  define TERM_VNULL    0x00   /* Disabled if not using stat2 */
#endif

/*
** An instance of the following structure holds all information about a
................................................................................
      pTerm->nChild = 1;
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef SQLITE_ENABLE_STAT3
  /* When sqlite_stat2 histogram data is available an operator of the
  ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
  ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
  ** virtual term of that form.
  **
  ** Note that the virtual term must be tagged with TERM_VNULL.  This
  ** TERM_VNULL tag will suppress the not-null check at the beginning
................................................................................
      pNewTerm->iParent = idxTerm;
      pTerm = &pWC->a[idxTerm];
      pTerm->nChild = 1;
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_ENABLE_STAT */

  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
  ** an index for tables to the left of the join.
  */
  pTerm->prereqRight |= extraRight;
}

................................................................................
  /* Try to find a more efficient access pattern by using multiple indexes
  ** to optimize an OR expression within the WHERE clause. 
  */
  bestOrClauseIndex(pParse, pWC, pSrc, notReady, notValid, pOrderBy, pCost);
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef SQLITE_ENABLE_STAT3
/*

** Estimate the location of a particular key among all keys in an
** index.  Store the results in aStat as follows:





**
**    aStat[0]      Est. number of rows less than pVal
**    aStat[1]      Est. number of rows equal to pVal





**
** Return SQLITE_OK on success.





*/

static int whereKeyStats(
  Parse *pParse,              /* Database connection */
  Index *pIdx,                /* Index to consider domain of */
  sqlite3_value *pVal,        /* Value to consider */
  int roundUp,                /* Round up if true.  Round down if false */
  tRowcnt *aStat              /* OUT: stats written here */
){
  tRowcnt n;
  IndexSample *aSample;
  int i, eType;
  int isEq = 0;
  i64 v;
  double r, rS;

  assert( roundUp==0 || roundUp==1 );
  if( pVal==0 ) return SQLITE_ERROR;
  n = pIdx->aiRowEst[0];

  aSample = pIdx->aSample;
  i = 0;
  eType = sqlite3_value_type(pVal);

  if( eType==SQLITE_INTEGER ){
    v = sqlite3_value_int64(pVal);
    r = (i64)v;
    for(i=0; i<pIdx->nSample; i++){
      if( aSample[i].eType==SQLITE_NULL ) continue;
      if( aSample[i].eType>=SQLITE_TEXT ) break;
      if( aSample[i].eType==SQLITE_INTEGER ){
        if( aSample[i].u.i>=v ){
          isEq = aSample[i].u.i==v;
          break;
        }
      }else{
        assert( aSample[i].eType==SQLITE_FLOAT );
        if( aSample[i].u.r>=r ){
          isEq = aSample[i].u.r==r;
          break;
        }
      }
    }
  }else if( eType==SQLITE_FLOAT ){
    r = sqlite3_value_double(pVal);
    for(i=0; i<pIdx->nSample; i++){

      if( aSample[i].eType==SQLITE_NULL ) continue;
      if( aSample[i].eType>=SQLITE_TEXT ) break;
      if( aSample[i].eType==SQLITE_FLOAT ){

        rS = aSample[i].u.r;
      }else{
        rS = aSample[i].u.i;
      }
      if( rS>=r ){
        isEq = rS==r;
        break;
      }
    }
  }else if( eType==SQLITE_NULL ){
    i = 0;
    if( pIdx->nSample>=1 && aSample[0].eType==SQLITE_NULL ) isEq = 1;
  }else{
    assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
    for(i=0; i<pIdx->nSample; i++){

      if( aSample[i].eType==SQLITE_TEXT || aSample[i].eType==SQLITE_BLOB ){
        break;
      }
    }
    if( i<pIdx->nSample ){      

      sqlite3 *db = pParse->db;
      CollSeq *pColl;
      const u8 *z;





      if( eType==SQLITE_BLOB ){
        z = (const u8 *)sqlite3_value_blob(pVal);
        pColl = db->pDfltColl;
        assert( pColl->enc==SQLITE_UTF8 );
      }else{
        pColl = sqlite3GetCollSeq(db, SQLITE_UTF8, 0, *pIdx->azColl);
        if( pColl==0 ){
................................................................................
        z = (const u8 *)sqlite3ValueText(pVal, pColl->enc);
        if( !z ){
          return SQLITE_NOMEM;
        }
        assert( z && pColl && pColl->xCmp );
      }
      n = sqlite3ValueBytes(pVal, pColl->enc);
  
      for(; i<pIdx->nSample; i++){
        int c;
        int eSampletype = aSample[i].eType;
        if( eSampletype<eType ) continue;
        if( eSampletype!=eType ) break;
#ifndef SQLITE_OMIT_UTF16
        if( pColl->enc!=SQLITE_UTF8 ){
          int nSample;
          char *zSample = sqlite3Utf8to16(
              db, pColl->enc, aSample[i].u.z, aSample[i].nByte, &nSample
          );
          if( !zSample ){
................................................................................
          c = pColl->xCmp(pColl->pUser, nSample, zSample, n, z);
          sqlite3DbFree(db, zSample);
        }else
#endif
        {
          c = pColl->xCmp(pColl->pUser, aSample[i].nByte, aSample[i].u.z, n, z);
        }
        if( c>=0 ){
          if( c==0 ) isEq = 1;
          break;
        }
      }
    }


  }

  /* At this point, aSample[i] is the first sample that is greater than
  ** or equal to pVal.  Or if i==pIdx->nSample, then all samples are less
  ** than pVal.  If aSample[i]==pVal, then isEq==1.
  */
  if( isEq ){
    assert( i<pIdx->nSample );
    aStat[0] = aSample[i].nLt;
    aStat[1] = aSample[i].nEq;
  }else{
    tRowcnt iLower, iUpper, iGap;
    if( i==0 ){
      iLower = 0;
      iUpper = aSample[0].nLt;
    }else{
      iUpper = i>=pIdx->nSample ? n : aSample[i].nLt;
      iLower = aSample[i-1].nEq + aSample[i-1].nLt;
    }
    aStat[1] = pIdx->avgEq;
    if( iLower>=iUpper ){
      iGap = 0;
    }else{
      iGap = iUpper - iLower;
      if( iGap>=aStat[1]/2 ) iGap -= aStat[1]/2;
    }
    if( roundUp ){
      iGap = (iGap*2)/3;
    }else{
      iGap = iGap/3;
    }
    aStat[0] = iLower + iGap;
  }
  return SQLITE_OK;
}
#endif /* SQLITE_ENABLE_STAT3 */

/*
** If expression pExpr represents a literal value, set *pp to point to
** an sqlite3_value structure containing the same value, with affinity
** aff applied to it, before returning. It is the responsibility of the 
** caller to eventually release this structure by passing it to 
** sqlite3ValueFree().
................................................................................
** create an sqlite3_value structure containing this value, again with
** affinity aff applied to it, instead.
**
** If neither of the above apply, set *pp to NULL.
**
** If an error occurs, return an error code. Otherwise, SQLITE_OK.
*/
#ifdef SQLITE_ENABLE_STAT3
static int valueFromExpr(
  Parse *pParse, 
  Expr *pExpr, 
  u8 aff, 
  sqlite3_value **pp
){
  if( pExpr->op==TK_VARIABLE
................................................................................
** then nEq should be passed the value 1 (as the range restricted column,
** b, is the second left-most column of the index). Or, if the query is:
**
**   ... FROM t1 WHERE a > ? AND a < ? ...
**
** then nEq should be passed 0.
**
** The returned value is an integer divisor to reduce the estimated
** search space.  A return value of 1 means that range constraints are
** no help at all.  A return value of 2 means range constraints are
** expected to reduce the search space by half.  And so forth...


**
** In the absence of sqlite_stat3 ANALYZE data, each range inequality
** reduces the search space by a factor of 4.  Hence a single constraint (x>?)
** results in a return of 4 and a range constraint (x>? AND x<?) results
** in a return of 16.
*/
static int whereRangeScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  Index *p,            /* The index containing the range-compared column; "x" */
  int nEq,             /* index into p->aCol[] of the range-compared column */
  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
  double *pRangeDiv   /* OUT: Reduce search space by this divisor */
){
  int rc = SQLITE_OK;

#ifdef SQLITE_ENABLE_STAT3

  if( nEq==0 && p->nSample ){
    sqlite3_value *pRangeVal;


    tRowcnt iLower = 0;
    tRowcnt iUpper = p->aiRowEst[0];
    tRowcnt a[2];


    u8 aff = p->pTable->aCol[p->aiColumn[0]].affinity;

    if( pLower ){
      Expr *pExpr = pLower->pExpr->pRight;
      rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
      assert( pLower->eOperator==WO_GT || pLower->eOperator==WO_GE );
      if( rc==SQLITE_OK
       && whereKeyStats(pParse, p, pRangeVal, 0, a)==SQLITE_OK
      ){
        iLower = a[0];
        if( pLower->eOperator==WO_GT ) iLower += a[1];
      }
      sqlite3ValueFree(pRangeVal);
    }
    if( rc==SQLITE_OK && pUpper ){
      Expr *pExpr = pUpper->pExpr->pRight;
      rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
      assert( pUpper->eOperator==WO_LT || pUpper->eOperator==WO_LE );
      if( rc==SQLITE_OK
       && whereKeyStats(pParse, p, pRangeVal, 1, a)==SQLITE_OK
      ){
        iUpper = a[0];
        if( pUpper->eOperator==WO_LE ) iUpper += a[1];
      }
      sqlite3ValueFree(pRangeVal);
    }





    if( rc==SQLITE_OK ){
      if( iUpper<=iLower ){
        *pRangeDiv = (double)p->aiRowEst[0];


      }else{
        *pRangeDiv = (double)p->aiRowEst[0]/(double)(iUpper - iLower);



      }

      WHERETRACE(("range scan regions: %u..%u  div=%g\n",
                  (u32)iLower, (u32)iUpper, *pRangeDiv));
      return SQLITE_OK;
    }







  }





#else
  UNUSED_PARAMETER(pParse);
  UNUSED_PARAMETER(p);
  UNUSED_PARAMETER(nEq);
#endif
  assert( pLower || pUpper );
  *pRangeDiv = (double)1;

  if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ) *pRangeDiv *= (double)4;
  if( pUpper ) *pRangeDiv *= (double)4;
  return rc;
}

#ifdef SQLITE_ENABLE_STAT3
/*
** Estimate the number of rows that will be returned based on
** an equality constraint x=VALUE and where that VALUE occurs in
** the histogram data.  This only works when x is the left-most
** column of an index and sqlite_stat3 histogram data is available
** for that index.  When pExpr==NULL that means the constraint is
** "x IS NULL" instead of "x=VALUE".
**
** Write the estimated row count into *pnRow and return SQLITE_OK. 
** If unable to make an estimate, leave *pnRow unchanged and return
** non-zero.
**
................................................................................
static int whereEqualScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  Index *p,            /* The index whose left-most column is pTerm */
  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
  double *pnRow        /* Write the revised row estimate here */
){
  sqlite3_value *pRhs = 0;  /* VALUE on right-hand side of pTerm */

  u8 aff;                   /* Column affinity */
  int rc;                   /* Subfunction return code */
  tRowcnt a[2];             /* Statistics */


  assert( p->aSample!=0 );
  aff = p->pTable->aCol[p->aiColumn[0]].affinity;
  if( pExpr ){
    rc = valueFromExpr(pParse, pExpr, aff, &pRhs);
    if( rc ) goto whereEqualScanEst_cancel;
  }else{
    pRhs = sqlite3ValueNew(pParse->db);
  }
  if( pRhs==0 ) return SQLITE_NOTFOUND;
  rc = whereKeyStats(pParse, p, pRhs, 0, a);
  if( rc==SQLITE_OK ){


    WHERETRACE(("equality scan regions: %d\n", (int)a[1]));





    *pnRow = a[1];
  }

whereEqualScanEst_cancel:
  sqlite3ValueFree(pRhs);
  return rc;
}
#endif /* defined(SQLITE_ENABLE_STAT3) */

#ifdef SQLITE_ENABLE_STAT3
/*
** Estimate the number of rows that will be returned based on
** an IN constraint where the right-hand side of the IN operator
** is a list of values.  Example:
**
**        WHERE x IN (1,2,3,4)
**
................................................................................
*/
static int whereInScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  Index *p,            /* The index whose left-most column is pTerm */
  ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
  double *pnRow        /* Write the revised row estimate here */
){



  int rc = SQLITE_OK;         /* Subfunction return code */
  double nEst;                /* Number of rows for a single term */
  double nRowEst = (double)0; /* New estimate of the number of rows */



  int i;                      /* Loop counter */



  assert( p->aSample!=0 );



  for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
    nEst = p->aiRowEst[0];
    rc = whereEqualScanEst(pParse, p, pList->a[i].pExpr, &nEst);
    nRowEst += nEst;






  }











  if( rc==SQLITE_OK ){









    if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
    *pnRow = nRowEst;
    WHERETRACE(("IN row estimate: est=%g\n", nRowEst));

  }

  return rc;
}
#endif /* defined(SQLITE_ENABLE_STAT3) */


/*
** Find the best query plan for accessing a particular table.  Write the
** best query plan and its cost into the WhereCost object supplied as the
** last parameter.
**
................................................................................
){
  int iCur = pSrc->iCursor;   /* The cursor of the table to be accessed */
  Index *pProbe;              /* An index we are evaluating */
  Index *pIdx;                /* Copy of pProbe, or zero for IPK index */
  int eqTermMask;             /* Current mask of valid equality operators */
  int idxEqTermMask;          /* Index mask of valid equality operators */
  Index sPk;                  /* A fake index object for the primary key */
  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
  int wsFlagMask;             /* Allowed flags in pCost->plan.wsFlag */

  /* Initialize the cost to a worst-case value */
  memset(pCost, 0, sizeof(*pCost));
  pCost->rCost = SQLITE_BIG_DBL;

................................................................................
    eqTermMask = WO_EQ|WO_IN;
    pIdx = 0;
  }

  /* Loop over all indices looking for the best one to use
  */
  for(; pProbe; pIdx=pProbe=pProbe->pNext){
    const tRowcnt * const aiRowEst = pProbe->aiRowEst;
    double cost;                /* Cost of using pProbe */
    double nRow;                /* Estimated number of rows in result set */
    double log10N;              /* base-10 logarithm of nRow (inexact) */
    int rev;                    /* True to scan in reverse order */
    int wsFlags = 0;
    Bitmask used = 0;

................................................................................
    **
    **  bInEst:  
    **    Set to true if there was at least one "x IN (SELECT ...)" term used 
    **    in determining the value of nInMul.  Note that the RHS of the
    **    IN operator must be a SELECT, not a value list, for this variable
    **    to be true.
    **
    **  rangeDiv:
    **    An estimate of a divisor by which to reduce the search space due
    **    to inequality constraints.  In the absence of sqlite_stat3 ANALYZE


    **    data, a single inequality reduces the search space to 1/4rd its
    **    original size (rangeDiv==4).  Two inequalities reduce the search
    **    space to 1/16th of its original size (rangeDiv==16).


    **
    **  bSort:   
    **    Boolean. True if there is an ORDER BY clause that will require an 
    **    external sort (i.e. scanning the index being evaluated will not 
    **    correctly order records).
    **
    **  bLookup: 
................................................................................
    **
    **             SELECT a, b    FROM tbl WHERE a = 1;
    **             SELECT a, b, c FROM tbl WHERE a = 1;
    */
    int nEq;                      /* Number of == or IN terms matching index */
    int bInEst = 0;               /* True if "x IN (SELECT...)" seen */
    int nInMul = 1;               /* Number of distinct equalities to lookup */
    double rangeDiv = (double)1;  /* Estimated reduction in search space */
    int nBound = 0;               /* Number of range constraints seen */
    int bSort = !!pOrderBy;       /* True if external sort required */
    int bDist = !!pDistinct;      /* True if index cannot help with DISTINCT */
    int bLookup = 0;              /* True if not a covering index */
    WhereTerm *pTerm;             /* A single term of the WHERE clause */
#ifdef SQLITE_ENABLE_STAT3
    WhereTerm *pFirstTerm = 0;    /* First term matching the index */
#endif

    /* Determine the values of nEq and nInMul */
    for(nEq=0; nEq<pProbe->nColumn; nEq++){
      int j = pProbe->aiColumn[nEq];
      pTerm = findTerm(pWC, iCur, j, notReady, eqTermMask, pIdx);
................................................................................
        }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
          /* "x IN (value, value, ...)" */
          nInMul *= pExpr->x.pList->nExpr;
        }
      }else if( pTerm->eOperator & WO_ISNULL ){
        wsFlags |= WHERE_COLUMN_NULL;
      }
#ifdef SQLITE_ENABLE_STAT3
      if( nEq==0 && pProbe->aSample ) pFirstTerm = pTerm;
#endif
      used |= pTerm->prereqRight;
    }

    /* Determine the value of rangeDiv */
    if( nEq<pProbe->nColumn && pProbe->bUnordered==0 ){
      int j = pProbe->aiColumn[nEq];
      if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){
        WhereTerm *pTop = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pIdx);
        WhereTerm *pBtm = findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pIdx);
        whereRangeScanEst(pParse, pProbe, nEq, pBtm, pTop, &rangeDiv);
        if( pTop ){
          nBound = 1;
          wsFlags |= WHERE_TOP_LIMIT;
          used |= pTop->prereqRight;
        }
        if( pBtm ){
          nBound++;
................................................................................
    */
    nRow = (double)(aiRowEst[nEq] * nInMul);
    if( bInEst && nRow*2>aiRowEst[0] ){
      nRow = aiRowEst[0]/2;
      nInMul = (int)(nRow / aiRowEst[nEq]);
    }

#ifdef SQLITE_ENABLE_STAT3
    /* If the constraint is of the form x=VALUE or x IN (E1,E2,...)
    ** and we do not think that values of x are unique and if histogram
    ** data is available for column x, then it might be possible
    ** to get a better estimate on the number of rows based on
    ** VALUE and how common that value is according to the histogram.
    */
    if( nRow>(double)1 && nEq==1 && pFirstTerm!=0 && aiRowEst[1]>1 ){
................................................................................
        testcase( pFirstTerm->eOperator==WO_EQ );
        testcase( pFirstTerm->eOperator==WO_ISNULL );
        whereEqualScanEst(pParse, pProbe, pFirstTerm->pExpr->pRight, &nRow);
      }else if( pFirstTerm->eOperator==WO_IN && bInEst==0 ){
        whereInScanEst(pParse, pProbe, pFirstTerm->pExpr->x.pList, &nRow);
      }
    }
#endif /* SQLITE_ENABLE_STAT3 */

    /* Adjust the number of output rows and downward to reflect rows
    ** that are excluded by range constraints.
    */
    nRow = nRow/rangeDiv;
    if( nRow<1 ) nRow = 1;

    /* Experiments run on real SQLite databases show that the time needed
    ** to do a binary search to locate a row in a table or index is roughly
    ** log10(N) times the time to move from one row to the next row within
    ** a table or index.  The actual times can vary, with the size of
    ** records being an important factor.  Both moves and searches are
................................................................................
        }
      }
      if( nRow<2 ) nRow = 2;
    }


    WHERETRACE((
      "%s(%s): nEq=%d nInMul=%d rangeDiv=%d bSort=%d bLookup=%d wsFlags=0x%x\n"
      "         notReady=0x%llx log10N=%.1f nRow=%.1f cost=%.1f used=0x%llx\n",
      pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk"), 
      nEq, nInMul, (int)rangeDiv, bSort, bLookup, wsFlags,
      notReady, log10N, nRow, cost, used
    ));

    /* If this index is the best we have seen so far, then record this
    ** index and its cost in the pCost structure.
    */
    if( (!pIdx || wsFlags)
................................................................................
** The only modifications are the addition of a couple of NEVER()
** macros to disable tests that are needed in the case of a general
** LALR(1) grammar but which are always false in the
** specific grammar used by SQLite.
*/
/* First off, code is included that follows the "include" declaration
** in the input grammar file. */



/*
** Disable all error recovery processing in the parser push-down
** automaton.
*/
#define YYNOERRORRECOVERY 1
................................................................................
#else
  yyStackEntry yystack[YYSTACKDEPTH];  /* The parser's stack */
#endif
};
typedef struct yyParser yyParser;

#ifndef NDEBUG

static FILE *yyTraceFILE = 0;
static char *yyTracePrompt = 0;
#endif /* NDEBUG */

#ifndef NDEBUG
/* 
** Turn parser tracing on by giving a stream to which to write the trace
................................................................................
*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
*/


/*
** The charMap() macro maps alphabetic characters into their
** lower-case ASCII equivalent.  On ASCII machines, this is just
** an upper-to-lower case map.  On EBCDIC machines we also need
** to adjust the encoding.  Only alphabetic characters and underscores
** need to be translated.
................................................................................
    assert(sizeof(x)==8);
    assert(sizeof(x)==sizeof(y));
    memcpy(&y, &x, 8);
    assert( sqlite3IsNaN(y) );
  }
#endif
#endif











  return rc;
}

/*
** Undo the effects of sqlite3_initialize().  Must not be called while
** there are outstanding database connections or memory allocations or
................................................................................
/************** Continuing where we left off in fts3.c ***********************/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

#if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
# define SQLITE_CORE 1
#endif








#ifndef SQLITE_CORE 
  SQLITE_EXTENSION_INIT1
#endif

static int fts3EvalNext(Fts3Cursor *pCsr);
static int fts3EvalStart(Fts3Cursor *pCsr);
................................................................................
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)




typedef struct Fts3auxTable Fts3auxTable;
typedef struct Fts3auxCursor Fts3auxCursor;

struct Fts3auxTable {
  sqlite3_vtab base;              /* Base class used by SQLite core */
  Fts3Table *pFts3Tab;
................................................................................
#endif

/*
** Default span for NEAR operators.
*/
#define SQLITE_FTS3_DEFAULT_NEAR_PARAM 10




/*
** isNot:
**   This variable is used by function getNextNode(). When getNextNode() is
**   called, it sets ParseContext.isNot to true if the 'next node' is a 
**   FTSQUERY_PHRASE with a unary "-" attached to it. i.e. "mysql" in the
**   FTS3 query "sqlite -mysql". Otherwise, ParseContext.isNot is set to
................................................................................
/****************************************************************************
*****************************************************************************
** Everything after this point is just test code.
*/

#ifdef SQLITE_TEST



/*
** Function to query the hash-table of tokenizers (see README.tokenizers).
*/
static int queryTestTokenizer(
  sqlite3 *db, 
  const char *zName,  
................................................................................
**       (in which case SQLITE_CORE is not defined), or
**
**     * The FTS3 module is being built into the core of
**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)






/*
** Malloc and Free functions
*/
static void *fts3HashMalloc(int n){
  void *p = sqlite3_malloc(n);
................................................................................
**       (in which case SQLITE_CORE is not defined), or
**
**     * The FTS3 module is being built into the core of
**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)







/*
** Class derived from sqlite3_tokenizer
*/
typedef struct porter_tokenizer {
  sqlite3_tokenizer base;      /* Base class */
................................................................................
**       (in which case SQLITE_CORE is not defined), or
**
**     * The FTS3 module is being built into the core of
**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)




/*
** Implementation of the SQL scalar function for accessing the underlying 
** hash table. This function may be called as follows:
**
**   SELECT <function-name>(<key-name>);
**   SELECT <function-name>(<key-name>, <pointer>);
................................................................................
  sqlite3_free(zCopy);
  return rc;
}


#ifdef SQLITE_TEST




/*
** Implementation of a special SQL scalar function for testing tokenizers 
** designed to be used in concert with the Tcl testing framework. This
** function must be called with two arguments:
**
**   SELECT <function-name>(<key-name>, <input-string>);
................................................................................
**       (in which case SQLITE_CORE is not defined), or
**
**     * The FTS3 module is being built into the core of
**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)







typedef struct simple_tokenizer {
  sqlite3_tokenizer base;
  char delim[128];             /* flag ASCII delimiters */
} simple_tokenizer;

................................................................................
** tables. It also contains code to merge FTS3 b-tree segments. Some
** of the sub-routines used to merge segments are also used by the query 
** code in fts3.c.
*/

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)





/*
** When full-text index nodes are loaded from disk, the buffer that they
** are loaded into has the following number of bytes of padding at the end 
** of it. i.e. if a full-text index node is 900 bytes in size, then a buffer
** of 920 bytes is allocated for it.
**
................................................................................
**    May you share freely, never taking more than you give.
**
******************************************************************************
*/

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)




/*
** Characters that may appear in the second argument to matchinfo().
*/
#define FTS3_MATCHINFO_NPHRASE   'p'        /* 1 value */
#define FTS3_MATCHINFO_NCOL      'c'        /* 1 value */
#define FTS3_MATCHINFO_NDOC      'n'        /* 1 value */
................................................................................
#endif

#ifndef SQLITE_CORE
  SQLITE_EXTENSION_INIT1
#else
#endif




#ifndef SQLITE_AMALGAMATION
#include "sqlite3rtree.h"
typedef sqlite3_int64 i64;
typedef unsigned char u8;
typedef unsigned int u32;
#endif
................................................................................

/* Include ICU headers */
#include <unicode/utypes.h>
#include <unicode/uregex.h>
#include <unicode/ustring.h>
#include <unicode/ucol.h>



#ifndef SQLITE_CORE
  SQLITE_EXTENSION_INIT1
#else
#endif

/*
................................................................................
**
*************************************************************************
** This file implements a tokenizer for fts3 based on the ICU library.
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
#ifdef SQLITE_ENABLE_ICU




#include <unicode/ubrk.h>


#include <unicode/utf16.h>

typedef struct IcuTokenizer IcuTokenizer;
typedef struct IcuCursor IcuCursor;

struct IcuTokenizer {
  sqlite3_tokenizer base;

#endif

/*
** Exactly one of the following macros must be defined in order to
** specify which memory allocation subsystem to use.
**
**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
**     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
**
** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
** assert() macro is enabled, each call into the Win32 native heap subsystem
** will cause HeapValidate to be called.  If heap validation should fail, an
** assertion will be triggered.
**
** (Historical note:  There used to be several other options, but we've
** pared it down to just these two.)
**
** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
** the default.
*/
#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)>1
# error "At most one of the following compile-time configuration options\
 is allows: SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG"
#endif
#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)==0
# define SQLITE_SYSTEM_MALLOC 1
#endif

/*
** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
** sizes of memory allocations below this value where possible.
*/
................................................................................
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.7.8"
#define SQLITE_VERSION_NUMBER 3007008
#define SQLITE_SOURCE_ID      "2011-09-04 01:27:00 6b657ae75035eb10b0ad640998d3c9eadfdffa6e"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
................................................................................
** and that this object is only useful to a tiny minority of applications
** with specialized memory allocation requirements.  This object is
** also used during testing of SQLite in order to specify an alternative
** memory allocator that simulates memory out-of-memory conditions in
** order to verify that SQLite recovers gracefully from such
** conditions.
**
** The xMalloc, xRealloc, and xFree methods must work like the
** malloc(), realloc() and free() functions from the standard C library.



** ^SQLite guarantees that the second argument to
** xRealloc is always a value returned by a prior call to xRoundup.



**
** xSize should return the allocated size of a memory allocation
** previously obtained from xMalloc or xRealloc.  The allocated size
** is always at least as big as the requested size but may be larger.
**
** The xRoundup method returns what would be the allocated size of
** a memory allocation given a particular requested size.  Most memory
................................................................................
** WHERE clause might influence the choice of query plan for a statement,
** then the statement will be automatically recompiled, as if there had been 
** a schema change, on the first  [sqlite3_step()] call following any change
** to the [sqlite3_bind_text | bindings] of that [parameter]. 
** ^The specific value of WHERE-clause [parameter] might influence the 
** choice of query plan if the parameter is the left-hand side of a [LIKE]
** or [GLOB] operator or if the parameter is compared to an indexed column
** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled.
** the 
** </li>
** </ol>
*/
SQLITE_API int sqlite3_prepare(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
................................................................................
** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
** that can be stored in a u32 without loss of data.  The value
** is 0x00000000ffffffff.  But because of quirks of some compilers, we
** have to specify the value in the less intuitive manner shown:
*/
#define SQLITE_MAX_U32  ((((u64)1)<<32)-1)













/*
** Macros to determine whether the machine is big or little endian,
** evaluated at runtime.
*/
#ifdef SQLITE_AMALGAMATION
SQLITE_PRIVATE const int sqlite3one = 1;
#else
................................................................................
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
/* #include <stdio.h> */

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
** in the source file sqliteVdbe.c are allowed to see the insides
** of this structure.
*/
typedef struct Vdbe Vdbe;
................................................................................
    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
    CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
    Mem *pMem;             /* Used when p4type is P4_MEM */
    VTable *pVtab;         /* Used when p4type is P4_VTAB */
    KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
    int *ai;               /* Used when p4type is P4_INTARRAY */
    SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
    int (*xAdvance)(BtCursor *, int *);
  } p4;
#ifdef SQLITE_DEBUG
  char *zComment;          /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  int cnt;                 /* Number of times this instruction was executed */
  u64 cycles;              /* Total time spent executing this instruction */
................................................................................
#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
#define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
#define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
#define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */

/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
** is made.  That copy is freed when the Vdbe is finalized.  But if the
** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
** gets freed when the Vdbe is finalized so it still should be obtained
** from a single sqliteMalloc().  But no copy is made and the calling
** function should *not* try to free the KeyInfo.
................................................................................
#define OP_ReadCookie                          35
#define OP_SetCookie                           36
#define OP_VerifyCookie                        37
#define OP_OpenRead                            38
#define OP_OpenWrite                           39
#define OP_OpenAutoindex                       40
#define OP_OpenEphemeral                       41
#define OP_SorterOpen                          42
#define OP_OpenPseudo                          43
#define OP_Close                               44
#define OP_SeekLt                              45
#define OP_SeekLe                              46
#define OP_SeekGe                              47
#define OP_SeekGt                              48
#define OP_Seek                                49
#define OP_NotFound                            50
#define OP_Found                               51
#define OP_IsUnique                            52
#define OP_NotExists                           53
#define OP_Sequence                            54
#define OP_NewRowid                            55
#define OP_Insert                              56
#define OP_InsertInt                           57
#define OP_Delete                              58
#define OP_ResetCount                          59
#define OP_SorterCompare                       60
#define OP_SorterData                          61
#define OP_RowKey                              62
#define OP_RowData                             63
#define OP_Rowid                               64
#define OP_NullRow                             65
#define OP_Last                                66
#define OP_SorterSort                          67
#define OP_Sort                                70
#define OP_Rewind                              71
#define OP_SorterNext                          72
#define OP_Prev                                81
#define OP_Next                                92
#define OP_SorterInsert                        95
#define OP_IdxInsert                           96
#define OP_IdxDelete                           97
#define OP_IdxRowid                            98
#define OP_IdxLT                               99
#define OP_IdxGE                              100
#define OP_Destroy                            101
#define OP_Clear                              102
#define OP_CreateIndex                        103
#define OP_CreateTable                        104
#define OP_ParseSchema                        105
#define OP_LoadAnalysis                       106
#define OP_DropTable                          107
#define OP_DropIndex                          108
#define OP_DropTrigger                        109
#define OP_IntegrityCk                        110
#define OP_RowSetAdd                          111
#define OP_RowSetRead                         112
#define OP_RowSetTest                         113
#define OP_Program                            114
#define OP_Param                              115
#define OP_FkCounter                          116
#define OP_FkIfZero                           117
#define OP_MemMax                             118
#define OP_IfPos                              119
#define OP_IfNeg                              120
#define OP_IfZero                             121
#define OP_AggStep                            122
#define OP_AggFinal                           123
#define OP_Checkpoint                         124
#define OP_JournalMode                        125
#define OP_Vacuum                             126
#define OP_IncrVacuum                         127
#define OP_Expire                             128
#define OP_TableLock                          129
#define OP_VBegin                             131
#define OP_VCreate                            132
#define OP_VDestroy                           133
#define OP_VOpen                              134
#define OP_VFilter                            135
#define OP_VColumn                            136
#define OP_VNext                              137
#define OP_VRename                            138
#define OP_VUpdate                            139
#define OP_Pagecount                          140
#define OP_MaxPgcnt                           146
#define OP_Trace                              147
#define OP_Noop                               148
#define OP_Explain                            149






/* Properties such as "out2" or "jump" that are specified in
** comments following the "case" for each opcode in the vdbe.c
** are encoded into bitvectors as follows:
*/
#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */
................................................................................
#define OPFLG_OUT3            0x0040  /* out3:  P3 is an output */
#define OPFLG_INITIALIZER {\
/*   0 */ 0x00, 0x01, 0x05, 0x04, 0x04, 0x10, 0x00, 0x02,\
/*   8 */ 0x02, 0x02, 0x02, 0x02, 0x02, 0x00, 0x24, 0x24,\
/*  16 */ 0x00, 0x00, 0x00, 0x24, 0x04, 0x05, 0x04, 0x00,\
/*  24 */ 0x00, 0x01, 0x05, 0x05, 0x00, 0x00, 0x00, 0x02,\
/*  32 */ 0x00, 0x00, 0x00, 0x02, 0x10, 0x00, 0x00, 0x00,\
/*  40 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0x11, 0x11,\
/*  48 */ 0x11, 0x08, 0x11, 0x11, 0x11, 0x11, 0x02, 0x02,\
/*  56 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/*  64 */ 0x02, 0x00, 0x01, 0x01, 0x4c, 0x4c, 0x01, 0x01,\
/*  72 */ 0x01, 0x05, 0x05, 0x15, 0x15, 0x15, 0x15, 0x15,\
/*  80 */ 0x15, 0x01, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c,\
/*  88 */ 0x4c, 0x4c, 0x4c, 0x4c, 0x01, 0x24, 0x02, 0x08,\
/*  96 */ 0x08, 0x00, 0x02, 0x01, 0x01, 0x02, 0x00, 0x02,\
/* 104 */ 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0c,\
/* 112 */ 0x45, 0x15, 0x01, 0x02, 0x00, 0x01, 0x08, 0x05,\
/* 120 */ 0x05, 0x05, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01,\

/* 128 */ 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x01,\
/* 136 */ 0x00, 0x01, 0x00, 0x00, 0x02, 0x04, 0x04, 0x04,\
/* 144 */ 0x04, 0x04, 0x02, 0x00, 0x00, 0x00,}

/************** End of opcodes.h *********************************************/
/************** Continuing where we left off in vdbe.h ***********************/

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
................................................................................
SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*);
................................................................................
** Allowed values for the flags parameter to sqlite3PagerOpen().
**
** NOTE: These values must match the corresponding BTREE_ values in btree.h.
*/
#define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
#define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
#define PAGER_MEMORY        0x0004    /* In-memory database */
#define PAGER_SORTER        0x0020    /* Accumulator in external merge sort */

/*
** Valid values for the second argument to sqlite3PagerLockingMode().
*/
#define PAGER_LOCKINGMODE_QUERY      -1
#define PAGER_LOCKINGMODE_NORMAL      0
#define PAGER_LOCKINGMODE_EXCLUSIVE   1
................................................................................
struct Table {
  char *zName;         /* Name of the table or view */
  int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
  int nCol;            /* Number of columns in this table */
  Column *aCol;        /* Information about each column */
  Index *pIndex;       /* List of SQL indexes on this table. */
  int tnum;            /* Root BTree node for this table (see note above) */
  unsigned nRowEst;    /* Estimated rows in table - from sqlite_stat1 table */
  Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
  u16 nRef;            /* Number of pointers to this Table */
  u8 tabFlags;         /* Mask of TF_* values */
  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
  FKey *pFKey;         /* Linked list of all foreign keys in this table */
  char *zColAff;       /* String defining the affinity of each column */
#ifndef SQLITE_OMIT_CHECK
................................................................................
** algorithm to employ whenever an attempt is made to insert a non-unique
** element.
*/
struct Index {
  char *zName;     /* Name of this index */
  int nColumn;     /* Number of columns in the table used by this index */
  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
  unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
  Table *pTable;   /* The SQL table being indexed */
  int tnum;        /* Page containing root of this index in database file */
  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
  u8 bUnordered;   /* Use this index for == or IN queries only */

  char *zColAff;   /* String defining the affinity of each column */
  Index *pNext;    /* The next index associated with the same table */
  Schema *pSchema; /* Schema containing this index */
  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
  char **azColl;   /* Array of collation sequence names for index */


  IndexSample *aSample;    /* Array of SQLITE_INDEX_SAMPLES samples */

};

/*
** Each sample stored in the sqlite_stat2 table is represented in memory 
** using a structure of this type.
*/
struct IndexSample {
  union {
    char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
    double r;       /* Value if eType is SQLITE_FLOAT or SQLITE_INTEGER */

  } u;
  u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
  u8 nByte;         /* Size in byte of text or blob. */



};

/*
** Each token coming out of the lexer is an instance of
** this structure.  Tokens are also used as part of an expression.
**
** Note if Token.z==0 then Token.dyn and Token.n are undefined and
................................................................................
*/
struct AggInfo {
  u8 directMode;          /* Direct rendering mode means take data directly
                          ** from source tables rather than from accumulators */
  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
                          ** than the source table */
  int sortingIdx;         /* Cursor number of the sorting index */
  int sortingIdxPTab;     /* Cursor number of pseudo-table */
  ExprList *pGroupBy;     /* The group by clause */
  int nSortingColumn;     /* Number of columns in the sorting index */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    int iTable;              /* Cursor number of the source table */
    int iColumn;             /* Column number within the source table */
    int iSorterColumn;       /* Column number in the sorting index */
................................................................................
*/
#define SF_Distinct        0x0001  /* Output should be DISTINCT */
#define SF_Resolved        0x0002  /* Identifiers have been resolved */
#define SF_Aggregate       0x0004  /* Contains aggregate functions */
#define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
#define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
#define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
#define SF_UseSorter       0x0040  /* Sort using a sorter */


/*
** The results of a select can be distributed in several ways.  The
** "SRT" prefix means "SELECT Result Type".
*/
#define SRT_Union        1  /* Store result as keys in an index */
................................................................................
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);
#else
# define sqlite3ViewGetColumnNames(A,B) 0
#endif

SQLITE_PRIVATE void sqlite3DropTable(Parse*, SrcList*, int, int);

SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3*, Table*);
#ifndef SQLITE_OMIT_AUTOINCREMENT
SQLITE_PRIVATE   void sqlite3AutoincrementBegin(Parse *pParse);
SQLITE_PRIVATE   void sqlite3AutoincrementEnd(Parse *pParse);
#else
# define sqlite3AutoincrementBegin(X)
# define sqlite3AutoincrementEnd(X)
................................................................................
SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);
SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);
SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                        void(*)(void*));
SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);
SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);
SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
#ifdef SQLITE_ENABLE_STAT2
SQLITE_PRIVATE char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
#endif
SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION
SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];
SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
................................................................................
#endif
#ifdef SQLITE_ENABLE_RTREE
  "ENABLE_RTREE",
#endif
#ifdef SQLITE_ENABLE_STAT2
  "ENABLE_STAT2",
#endif



#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
  "ENABLE_UNLOCK_NOTIFY",
#endif
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  "ENABLE_UPDATE_DELETE_LIMIT",
#endif
#ifdef SQLITE_HAS_CODEC
................................................................................
#endif
#ifdef SQLITE_INT64_TYPE
  "INT64_TYPE",
#endif
#ifdef SQLITE_LOCK_TRACE
  "LOCK_TRACE",
#endif
#ifdef SQLITE_MAX_SCHEMA_RETRY
  "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),
#endif
#ifdef SQLITE_MEMDEBUG
  "MEMDEBUG",
#endif
#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
  "MIXED_ENDIAN_64BIT_FLOAT",
#endif
#ifdef SQLITE_NO_SYNC
................................................................................
  "OMIT_LOCALTIME",
#endif
#ifdef SQLITE_OMIT_LOOKASIDE
  "OMIT_LOOKASIDE",
#endif
#ifdef SQLITE_OMIT_MEMORYDB
  "OMIT_MEMORYDB",
#endif
#ifdef SQLITE_OMIT_MERGE_SORT
  "OMIT_MERGE_SORT",
#endif
#ifdef SQLITE_OMIT_OR_OPTIMIZATION
  "OMIT_OR_OPTIMIZATION",
#endif
#ifdef SQLITE_OMIT_PAGER_PRAGMAS
  "OMIT_PAGER_PRAGMAS",
#endif
................................................................................
  "OMIT_WAL",
#endif
#ifdef SQLITE_OMIT_WSD
  "OMIT_WSD",
#endif
#ifdef SQLITE_OMIT_XFER_OPT
  "OMIT_XFER_OPT",
#endif
#ifdef SQLITE_PAGECACHE_BLOCKALLOC
  "PAGECACHE_BLOCKALLOC",
#endif
#ifdef SQLITE_PERFORMANCE_TRACE
  "PERFORMANCE_TRACE",
#endif
#ifdef SQLITE_PROXY_DEBUG
  "PROXY_DEBUG",
#endif
................................................................................
typedef struct VdbeOp Op;

/*
** Boolean values
*/
typedef unsigned char Bool;

/* Opaque type used by code in vdbesort.c */
typedef struct VdbeSorter VdbeSorter;

/*
** A cursor is a pointer into a single BTree within a database file.
** The cursor can seek to a BTree entry with a particular key, or
** loop over all entries of the Btree.  You can also insert new BTree
** entries or retrieve the key or data from the entry that the cursor
** is currently pointing to.
** 
................................................................................
  Bool atFirst;         /* True if pointing to first entry */
  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
  Bool nullRow;         /* True if pointing to a row with no data */
  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
  Bool isTable;         /* True if a table requiring integer keys */
  Bool isIndex;         /* True if an index containing keys only - no data */
  Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
  Bool isSorter;        /* True if a new-style sorter */
  sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
  const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
  i64 seqCount;         /* Sequence counter */
  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
  VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */

  /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or 
  ** OP_IsUnique opcode on this cursor. */
  int seekResult;

  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to.  Only valid if cacheStatus matches
................................................................................
SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem*);
SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
SQLITE_PRIVATE void sqlite3VdbeMemReleaseExternal(Mem *p);
#define MemReleaseExt(X)  \
  if((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame)) \
    sqlite3VdbeMemReleaseExternal(X);
SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*);
SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);
SQLITE_PRIVATE void sqlite3VdbeMemStoreType(Mem *pMem);

#ifdef SQLITE_OMIT_MERGE_SORT
# define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
# define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
# define sqlite3VdbeSorterClose(Y,Z)
# define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
# define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
# define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
# define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK
#else
SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(VdbeCursor *, Mem *);
SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *);
SQLITE_PRIVATE int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *);
SQLITE_PRIVATE int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, Mem *);
SQLITE_PRIVATE int sqlite3VdbeSorterCompare(VdbeCursor *, Mem *, int *);
#endif

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
#else
# define sqlite3VdbeEnter(X)
# define sqlite3VdbeLeave(X)
................................................................................
**
**      Jean Meeus
**      Astronomical Algorithms, 2nd Edition, 1998
**      ISBM 0-943396-61-1
**      Willmann-Bell, Inc
**      Richmond, Virginia (USA)
*/
/* #include <stdlib.h> */
/* #include <assert.h> */
#include <time.h>

#ifndef SQLITE_OMIT_DATETIME_FUNCS


/*
** A structure for holding a single date and time.
................................................................................
#ifdef __GLIBC__
  extern int backtrace(void**,int);
  extern void backtrace_symbols_fd(void*const*,int,int);
#else
# define backtrace(A,B) 1
# define backtrace_symbols_fd(A,B,C)
#endif
/* #include <stdio.h> */

/*
** Each memory allocation looks like this:
**
**  ------------------------------------------------------------------------
**  | Title |  backtrace pointers |  MemBlockHdr |  allocation |  EndGuard |
**  ------------------------------------------------------------------------
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Memory allocation functions used throughout sqlite.
*/
/* #include <stdarg.h> */

/*
** Attempt to release up to n bytes of non-essential memory currently
** held by SQLite. An example of non-essential memory is memory used to
** cache database pages that are not currently in use.
*/
SQLITE_API int sqlite3_release_memory(int n){
................................................................................
**
**
** BOM or Byte Order Mark:
**     0xff 0xfe   little-endian utf-16 follows
**     0xfe 0xff   big-endian utf-16 follows
**
*/
/* #include <assert.h> */

#ifndef SQLITE_AMALGAMATION
/*
** The following constant value is used by the SQLITE_BIGENDIAN and
** SQLITE_LITTLEENDIAN macros.
*/
SQLITE_PRIVATE const int sqlite3one = 1;
................................................................................
** is set to the length of the returned string in bytes. The call should
** arrange to call sqlite3DbFree() on the returned pointer when it is
** no longer required.
** 
** If a malloc failure occurs, NULL is returned and the db.mallocFailed
** flag set.
*/
#ifdef SQLITE_ENABLE_STAT2
SQLITE_PRIVATE char *sqlite3Utf8to16(sqlite3 *db, u8 enc, char *z, int n, int *pnOut){
  Mem m;
  memset(&m, 0, sizeof(m));
  m.db = db;
  sqlite3VdbeMemSetStr(&m, z, n, SQLITE_UTF8, SQLITE_STATIC);
  if( sqlite3VdbeMemTranslate(&m, enc) ){
    assert( db->mallocFailed );
................................................................................
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
*/
/* #include <stdarg.h> */
#ifdef SQLITE_HAVE_ISNAN
# include <math.h>
#endif

/*
** Routine needed to support the testcase() macro.
*/
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the implementation of generic hash-tables
** used in SQLite.
*/
/* #include <assert.h> */

/* Turn bulk memory into a hash table object by initializing the
** fields of the Hash structure.
**
** "pNew" is a pointer to the hash table that is to be initialized.
*/
SQLITE_PRIVATE void sqlite3HashInit(Hash *pNew){
................................................................................
     /*  35 */ "ReadCookie",
     /*  36 */ "SetCookie",
     /*  37 */ "VerifyCookie",
     /*  38 */ "OpenRead",
     /*  39 */ "OpenWrite",
     /*  40 */ "OpenAutoindex",
     /*  41 */ "OpenEphemeral",
     /*  42 */ "SorterOpen",
     /*  43 */ "OpenPseudo",
     /*  44 */ "Close",
     /*  45 */ "SeekLt",
     /*  46 */ "SeekLe",
     /*  47 */ "SeekGe",
     /*  48 */ "SeekGt",
     /*  49 */ "Seek",
     /*  50 */ "NotFound",
     /*  51 */ "Found",
     /*  52 */ "IsUnique",
     /*  53 */ "NotExists",
     /*  54 */ "Sequence",
     /*  55 */ "NewRowid",
     /*  56 */ "Insert",
     /*  57 */ "InsertInt",
     /*  58 */ "Delete",
     /*  59 */ "ResetCount",
     /*  60 */ "SorterCompare",
     /*  61 */ "SorterData",
     /*  62 */ "RowKey",
     /*  63 */ "RowData",
     /*  64 */ "Rowid",
     /*  65 */ "NullRow",
     /*  66 */ "Last",
     /*  67 */ "SorterSort",
     /*  68 */ "Or",
     /*  69 */ "And",
     /*  70 */ "Sort",
     /*  71 */ "Rewind",
     /*  72 */ "SorterNext",
     /*  73 */ "IsNull",
     /*  74 */ "NotNull",
     /*  75 */ "Ne",
     /*  76 */ "Eq",
     /*  77 */ "Gt",
     /*  78 */ "Le",
     /*  79 */ "Lt",
     /*  80 */ "Ge",
     /*  81 */ "Prev",
     /*  82 */ "BitAnd",
     /*  83 */ "BitOr",
     /*  84 */ "ShiftLeft",
     /*  85 */ "ShiftRight",
     /*  86 */ "Add",
     /*  87 */ "Subtract",
     /*  88 */ "Multiply",
     /*  89 */ "Divide",
     /*  90 */ "Remainder",
     /*  91 */ "Concat",
     /*  92 */ "Next",
     /*  93 */ "BitNot",
     /*  94 */ "String8",
     /*  95 */ "SorterInsert",
     /*  96 */ "IdxInsert",
     /*  97 */ "IdxDelete",
     /*  98 */ "IdxRowid",
     /*  99 */ "IdxLT",
     /* 100 */ "IdxGE",
     /* 101 */ "Destroy",
     /* 102 */ "Clear",
     /* 103 */ "CreateIndex",
     /* 104 */ "CreateTable",
     /* 105 */ "ParseSchema",
     /* 106 */ "LoadAnalysis",
     /* 107 */ "DropTable",
     /* 108 */ "DropIndex",
     /* 109 */ "DropTrigger",
     /* 110 */ "IntegrityCk",
     /* 111 */ "RowSetAdd",
     /* 112 */ "RowSetRead",
     /* 113 */ "RowSetTest",
     /* 114 */ "Program",
     /* 115 */ "Param",
     /* 116 */ "FkCounter",
     /* 117 */ "FkIfZero",
     /* 118 */ "MemMax",
     /* 119 */ "IfPos",
     /* 120 */ "IfNeg",
     /* 121 */ "IfZero",
     /* 122 */ "AggStep",
     /* 123 */ "AggFinal",
     /* 124 */ "Checkpoint",
     /* 125 */ "JournalMode",
     /* 126 */ "Vacuum",
     /* 127 */ "IncrVacuum",
     /* 128 */ "Expire",
     /* 129 */ "TableLock",
     /* 130 */ "Real",
     /* 131 */ "VBegin",
     /* 132 */ "VCreate",
     /* 133 */ "VDestroy",
     /* 134 */ "VOpen",
     /* 135 */ "VFilter",
     /* 136 */ "VColumn",
     /* 137 */ "VNext",
     /* 138 */ "VRename",
     /* 139 */ "VUpdate",
     /* 140 */ "Pagecount",
     /* 141 */ "ToText",
     /* 142 */ "ToBlob",
     /* 143 */ "ToNumeric",
     /* 144 */ "ToInt",
     /* 145 */ "ToReal",
     /* 146 */ "MaxPgcnt",
     /* 147 */ "Trace",
     /* 148 */ "Noop",
     /* 149 */ "Explain",
  };
  return azName[i];
}
#endif

/************** End of opcodes.c *********************************************/
/************** Begin file os_os2.c ******************************************/
................................................................................
** macro to SQLITE_DEBUG and some older makefiles have not yet made the
** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
................................................................................
/*
** standard include files.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
/* #include <time.h> */
#include <sys/time.h>
#include <errno.h>
#ifndef SQLITE_OMIT_WAL
#include <sys/mman.h>
#endif

#if SQLITE_ENABLE_LOCKING_STYLE
................................................................................
#define SQLITE_FSFLAGS_IS_MSDOS     0x1

/*
** If we are to be thread-safe, include the pthreads header and define
** the SQLITE_UNIX_THREADS macro.
*/
#if SQLITE_THREADSAFE
/* # include <pthread.h> */
# define SQLITE_UNIX_THREADS 1
#endif

/*
** Default permissions when creating a new file
*/
#ifndef SQLITE_DEFAULT_FILE_PERMISSIONS
................................................................................

/*
** Allowed values for the unixFile.ctrlFlags bitmask:
*/
#define UNIXFILE_EXCL        0x01     /* Connections from one process only */
#define UNIXFILE_RDONLY      0x02     /* Connection is read only */
#define UNIXFILE_PERSIST_WAL 0x04     /* Persistent WAL mode */
#ifndef SQLITE_DISABLE_DIRSYNC
# define UNIXFILE_DIRSYNC    0x08     /* Directory sync needed */
#else
# define UNIXFILE_DIRSYNC    0x00
#endif

/*
** Include code that is common to all os_*.c files
*/
/************** Include os_common.h in the middle of os_unix.c ***************/
/************** Begin file os_common.h ***************************************/
/*
................................................................................
** macro to SQLITE_DEBUG and some older makefiles have not yet made the
** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
................................................................................
** to a non-zero value otherwise *pResOut is set to zero.  The return value
** is set to SQLITE_OK unless an I/O error occurs during lock checking.
*/
static int afpCheckReservedLock(sqlite3_file *id, int *pResOut){
  int rc = SQLITE_OK;
  int reserved = 0;
  unixFile *pFile = (unixFile*)id;
  afpLockingContext *context;
  
  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
  
  assert( pFile );
  context = (afpLockingContext *) pFile->lockingContext;
  if( context->reserved ){
    *pResOut = 1;
    return SQLITE_OK;
  }
  unixEnterMutex(); /* Because pFile->pInode is shared across threads */
  
  /* Check if a thread in this process holds such a lock */
................................................................................
    }
  }
  
  /* If control gets to this point, then actually go ahead and make
  ** operating system calls for the specified lock.
  */
  if( eFileLock==SHARED_LOCK ){
    int lrc1, lrc2, lrc1Errno = 0;
    long lk, mask;
    
    assert( pInode->nShared==0 );
    assert( pInode->eFileLock==0 );
        
    mask = (sizeof(long)==8) ? LARGEST_INT64 : 0x7fffffff;
    /* Now get the read-lock SHARED_LOCK */
................................................................................
#endif
  TIMER_START;
#if defined(USE_PREAD)
  do{ got = osPwrite(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
#elif defined(USE_PREAD64)
  do{ got = osPwrite64(id->h, pBuf, cnt, offset);}while( got<0 && errno==EINTR);
#else
  do{
    newOffset = lseek(id->h, offset, SEEK_SET);
    SimulateIOError( newOffset-- );
    if( newOffset!=offset ){
      if( newOffset == -1 ){
        ((unixFile*)id)->lastErrno = errno;
      }else{
        ((unixFile*)id)->lastErrno = 0;			
      }
      return -1;
    }
    got = osWrite(id->h, pBuf, cnt);
  }while( got<0 && errno==EINTR );
#endif
  TIMER_END;
  if( got<0 ){
    ((unixFile*)id)->lastErrno = errno;
  }

  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));
................................................................................
*/
SQLITE_API int sqlite3_sync_count = 0;
SQLITE_API int sqlite3_fullsync_count = 0;
#endif

/*
** We do not trust systems to provide a working fdatasync().  Some do.
** Others do no.  To be safe, we will stick with the (slightly slower)
** fsync(). If you know that your system does support fdatasync() correctly,
** then simply compile with -Dfdatasync=fdatasync
*/
#if !defined(fdatasync)
# define fdatasync fsync
#endif

/*
** Define HAVE_FULLFSYNC to 0 or 1 depending on whether or not
** the F_FULLFSYNC macro is defined.  F_FULLFSYNC is currently
** only available on Mac OS X.  But that could change.
................................................................................
    int dirfd;
    OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,
            HAVE_FULLFSYNC, isFullsync));
    rc = osOpenDirectory(pFile->zPath, &dirfd);
    if( rc==SQLITE_OK && dirfd>=0 ){
      full_fsync(dirfd, 0, 0);
      robust_close(pFile, dirfd, __LINE__);
    }else if( rc==SQLITE_CANTOPEN ){
      rc = SQLITE_OK;
    }
    pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;
  }
  return rc;
}

/*
................................................................................
** proxying locking division.
*/
static int proxyFileControl(sqlite3_file*,int,void*);
#endif

/* 
** This function is called to handle the SQLITE_FCNTL_SIZE_HINT 
** file-control operation.  Enlarge the database to nBytes in size
** (rounded up to the next chunk-size).  If the database is already
** nBytes or larger, this routine is a no-op.


*/
static int fcntlSizeHint(unixFile *pFile, i64 nByte){

  if( pFile->szChunk>0 ){
    i64 nSize;                    /* Required file size */

    struct stat buf;              /* Used to hold return values of fstat() */
   
    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;

    nSize = ((nByte+pFile->szChunk-1) / pFile->szChunk) * pFile->szChunk;





    if( nSize>(i64)buf.st_size ){

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
      /* The code below is handling the return value of osFallocate() 
      ** correctly. posix_fallocate() is defined to "returns zero on success, 
      ** or an error number on  failure". See the manpage for details. */
      int err;
................................................................................
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      int rc;
      SimulateIOErrorBenign(1);
      rc = fcntlSizeHint(pFile, *(i64 *)pArg);
      SimulateIOErrorBenign(0);
      return rc;
    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = (pFile->ctrlFlags & UNIXFILE_PERSIST_WAL)!=0;
      }else if( bPersist==0 ){
        pFile->ctrlFlags &= ~UNIXFILE_PERSIST_WAL;
................................................................................
** All other fields are read/write.  The unixShm.pFile->mutex must be held
** while accessing any read/write fields.
*/
struct unixShm {
  unixShmNode *pShmNode;     /* The underlying unixShmNode object */
  unixShm *pNext;            /* Next unixShm with the same unixShmNode */
  u8 hasMutex;               /* True if holding the unixShmNode mutex */
  u8 id;                     /* Id of this connection within its unixShmNode */
  u16 sharedMask;            /* Mask of shared locks held */
  u16 exclMask;              /* Mask of exclusive locks held */



};

/*
** Constants used for locking
*/
#define UNIX_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)         /* first lock byte */
#define UNIX_SHM_DMS    (UNIX_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
................................................................................
  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
  int isCreate     = (flags & SQLITE_OPEN_CREATE);
  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
  int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
#if SQLITE_ENABLE_LOCKING_STYLE
  int isAutoProxy  = (flags & SQLITE_OPEN_AUTOPROXY);
#endif
#if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
  struct statfs fsInfo;
#endif

  /* If creating a master or main-file journal, this function will open
  ** a file-descriptor on the directory too. The first time unixSync()
  ** is called the directory file descriptor will be fsync()ed and close()d.
  */
  int syncDir = (isCreate && (
        eType==SQLITE_OPEN_MASTER_JOURNAL 
................................................................................
  osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
#endif

  noLock = eType!=SQLITE_OPEN_MAIN_DB;

  
#if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE

  if( fstatfs(fd, &fsInfo) == -1 ){
    ((unixFile*)pFile)->lastErrno = errno;
    robust_close(p, fd, __LINE__);
    return SQLITE_IOERR_ACCESS;
  }
  if (0 == strncmp("msdos", fsInfo.f_fstypename, 5)) {
    ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;
................................................................................
    int useProxy = 0;

    /* SQLITE_FORCE_PROXY_LOCKING==1 means force always use proxy, 0 means 
    ** never use proxy, NULL means use proxy for non-local files only.  */
    if( envforce!=NULL ){
      useProxy = atoi(envforce)>0;
    }else{

      if( statfs(zPath, &fsInfo) == -1 ){
        /* In theory, the close(fd) call is sub-optimal. If the file opened
        ** with fd is a database file, and there are other connections open
        ** on that file that are currently holding advisory locks on it,
        ** then the call to close() will cancel those locks. In practice,
        ** we're assuming that statfs() doesn't fail very often. At least
        ** not while other file descriptors opened by the same process on
................................................................................
#else
      if( fsync(fd) )
#endif
      {
        rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
      }
      robust_close(0, fd, __LINE__);
    }else if( rc==SQLITE_CANTOPEN ){
      rc = SQLITE_OK;
    }
  }
#endif
  return rc;
}

/*
................................................................................
      int err = errno;
      if( pError ){
        *pError = err;
      }
      return SQLITE_IOERR;
    }
  }
#else
  UNUSED_PARAMETER(pError);
#endif
#ifdef SQLITE_TEST
  /* simulate multiple hosts by creating unique hostid file paths */
  if( sqlite3_hostid_num != 0){
    pHostID[0] = (char)(pHostID[0] + (char)(sqlite3_hostid_num & 0xFF));
  }
#endif
................................................................................
static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
  proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 
  unixFile *conchFile = pCtx->conchFile;
  int rc = SQLITE_OK;
  int nTries = 0;
  struct timespec conchModTime;
  
  memset(&conchModTime, 0, sizeof(conchModTime));
  do {
    rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
    nTries ++;
    if( rc==SQLITE_BUSY ){
      /* If the lock failed (busy):
       * 1st try: get the mod time of the conch, wait 0.5s and try again. 
       * 2nd try: fail if the mod time changed or host id is different, wait 
................................................................................
        }
      }
      conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, SHARED_LOCK);
      
    end_takeconch:
      OSTRACE(("TRANSPROXY: CLOSE  %d\n", pFile->h));
      if( rc==SQLITE_OK && pFile->openFlags ){
        int fd;
        if( pFile->h>=0 ){
          robust_close(pFile, pFile->h, __LINE__);
        }
        pFile->h = -1;
        fd = robust_open(pCtx->dbPath, pFile->openFlags,
                      SQLITE_DEFAULT_FILE_PERMISSIONS);
        OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
        if( fd>=0 ){
          pFile->h = fd;
        }else{
          rc=SQLITE_CANTOPEN_BKPT; /* SQLITE_BUSY? proxyTakeConch called
           during locking */
................................................................................
** macro to SQLITE_DEBUG and some older makefiles have not yet made the
** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
................................................................................
  HANDLE hMutex;          /* Mutex used to control access to shared lock */  
  HANDLE hShared;         /* Shared memory segment used for locking */
  winceLock local;        /* Locks obtained by this instance of winFile */
  winceLock *shared;      /* Global shared lock memory for the file  */
#endif
};

/*
 * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the
 * various Win32 API heap functions instead of our own.
 */
#ifdef SQLITE_WIN32_MALLOC
/*
 * The initial size of the Win32-specific heap.  This value may be zero.
 */
#ifndef SQLITE_WIN32_HEAP_INIT_SIZE
#  define SQLITE_WIN32_HEAP_INIT_SIZE ((SQLITE_DEFAULT_CACHE_SIZE) * \
                                       (SQLITE_DEFAULT_PAGE_SIZE) + 4194304)
#endif

/*
 * The maximum size of the Win32-specific heap.  This value may be zero.
 */
#ifndef SQLITE_WIN32_HEAP_MAX_SIZE
#  define SQLITE_WIN32_HEAP_MAX_SIZE  (0)
#endif

/*
 * The extra flags to use in calls to the Win32 heap APIs.  This value may be
 * zero for the default behavior.
 */
#ifndef SQLITE_WIN32_HEAP_FLAGS
#  define SQLITE_WIN32_HEAP_FLAGS     (0)
#endif

/*
** The winMemData structure stores information required by the Win32-specific
** sqlite3_mem_methods implementation.
*/
typedef struct winMemData winMemData;
struct winMemData {
#ifndef NDEBUG
  u32 magic;    /* Magic number to detect structure corruption. */
#endif
  HANDLE hHeap; /* The handle to our heap. */
  BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */
};

#ifndef NDEBUG
#define WINMEM_MAGIC     0x42b2830b
#endif

static struct winMemData win_mem_data = {
#ifndef NDEBUG
  WINMEM_MAGIC,
#endif
  NULL, FALSE
};

#ifndef NDEBUG
#define winMemAssertMagic() assert( win_mem_data.magic==WINMEM_MAGIC )
#else
#define winMemAssertMagic()
#endif

#define winMemGetHeap() win_mem_data.hHeap

static void *winMemMalloc(int nBytes);
static void winMemFree(void *pPrior);
static void *winMemRealloc(void *pPrior, int nBytes);
static int winMemSize(void *p);
static int winMemRoundup(int n);
static int winMemInit(void *pAppData);
static void winMemShutdown(void *pAppData);

SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetWin32(void);
#endif /* SQLITE_WIN32_MALLOC */

/*
** Forward prototypes.
*/
static int getSectorSize(
    sqlite3_vfs *pVfs,
    const char *zRelative     /* UTF-8 file name */
................................................................................
      GetVersionEx(&sInfo);
      sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return sqlite3_os_type==2;
  }
#endif /* SQLITE_OS_WINCE */

#ifdef SQLITE_WIN32_MALLOC
/*
** Allocate nBytes of memory.
*/
static void *winMemMalloc(int nBytes){
  HANDLE hHeap;
  void *p;

  winMemAssertMagic();
  hHeap = winMemGetHeap();
  assert( hHeap!=0 );
  assert( hHeap!=INVALID_HANDLE_VALUE );
#ifdef SQLITE_WIN32_MALLOC_VALIDATE
  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
  assert( nBytes>=0 );
  p = HeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
  if( !p ){
    sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%d), heap=%p",
        nBytes, GetLastError(), (void*)hHeap);
  }
  return p;
}

/*
** Free memory.
*/
static void winMemFree(void *pPrior){
  HANDLE hHeap;

  winMemAssertMagic();
  hHeap = winMemGetHeap();
  assert( hHeap!=0 );
  assert( hHeap!=INVALID_HANDLE_VALUE );
#ifdef SQLITE_WIN32_MALLOC_VALIDATE
  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
#endif
  if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
  if( !HeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
    sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%d), heap=%p",
        pPrior, GetLastError(), (void*)hHeap);
  }
}

/*
** Change the size of an existing memory allocation
*/
static void *winMemRealloc(void *pPrior, int nBytes){
  HANDLE hHeap;
  void *p;

  winMemAssertMagic();
  hHeap = winMemGetHeap();
  assert( hHeap!=0 );
  assert( hHeap!=INVALID_HANDLE_VALUE );
#ifdef SQLITE_WIN32_MALLOC_VALIDATE
  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
#endif
  assert( nBytes>=0 );
  if( !pPrior ){
    p = HeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
  }else{
    p = HeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
  }
  if( !p ){
    sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%d), heap=%p",
        pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, GetLastError(),
        (void*)hHeap);
  }
  return p;
}

/*
** Return the size of an outstanding allocation, in bytes.
*/
static int winMemSize(void *p){
  HANDLE hHeap;
  SIZE_T n;

  winMemAssertMagic();
  hHeap = winMemGetHeap();
  assert( hHeap!=0 );
  assert( hHeap!=INVALID_HANDLE_VALUE );
#ifdef SQLITE_WIN32_MALLOC_VALIDATE
  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
  if( !p ) return 0;
  n = HeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
  if( n==(SIZE_T)-1 ){
    sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%d), heap=%p",
        p, GetLastError(), (void*)hHeap);
    return 0;
  }
  return (int)n;
}

/*
** Round up a request size to the next valid allocation size.
*/
static int winMemRoundup(int n){
  return n;
}

/*
** Initialize this module.
*/
static int winMemInit(void *pAppData){
  winMemData *pWinMemData = (winMemData *)pAppData;

  if( !pWinMemData ) return SQLITE_ERROR;
  assert( pWinMemData->magic==WINMEM_MAGIC );
  if( !pWinMemData->hHeap ){
    pWinMemData->hHeap = HeapCreate(SQLITE_WIN32_HEAP_FLAGS,
                                    SQLITE_WIN32_HEAP_INIT_SIZE,
                                    SQLITE_WIN32_HEAP_MAX_SIZE);
    if( !pWinMemData->hHeap ){
      sqlite3_log(SQLITE_NOMEM,
          "failed to HeapCreate (%d), flags=%u, initSize=%u, maxSize=%u",
          GetLastError(), SQLITE_WIN32_HEAP_FLAGS, SQLITE_WIN32_HEAP_INIT_SIZE,
          SQLITE_WIN32_HEAP_MAX_SIZE);
      return SQLITE_NOMEM;
    }
    pWinMemData->bOwned = TRUE;
  }
  assert( pWinMemData->hHeap!=0 );
  assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
#ifdef SQLITE_WIN32_MALLOC_VALIDATE
  assert( HeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
  return SQLITE_OK;
}

/*
** Deinitialize this module.
*/
static void winMemShutdown(void *pAppData){
  winMemData *pWinMemData = (winMemData *)pAppData;

  if( !pWinMemData ) return;
  if( pWinMemData->hHeap ){
    assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
#ifdef SQLITE_WIN32_MALLOC_VALIDATE
    assert( HeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
    if( pWinMemData->bOwned ){
      if( !HeapDestroy(pWinMemData->hHeap) ){
        sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%d), heap=%p",
            GetLastError(), (void*)pWinMemData->hHeap);
      }
      pWinMemData->bOwned = FALSE;
    }
    pWinMemData->hHeap = NULL;
  }
}

/*
** Populate the low-level memory allocation function pointers in
** sqlite3GlobalConfig.m with pointers to the routines in this file. The
** arguments specify the block of memory to manage.
**
** This routine is only called by sqlite3_config(), and therefore
** is not required to be threadsafe (it is not).
*/
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetWin32(void){
  static const sqlite3_mem_methods winMemMethods = {
    winMemMalloc,
    winMemFree,
    winMemRealloc,
    winMemSize,
    winMemRoundup,
    winMemInit,
    winMemShutdown,
    &win_mem_data
  };
  return &winMemMethods;
}

SQLITE_PRIVATE void sqlite3MemSetDefault(void){
  sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetWin32());
}
#endif /* SQLITE_WIN32_MALLOC */

/*
** Convert a UTF-8 string to microsoft unicode (UTF-16?). 
**
** Space to hold the returned string is obtained from malloc.
*/
static WCHAR *utf8ToUnicode(const char *zFilename){
  int nChar;
................................................................................
/*************************************************************************
** This section contains code for WinCE only.
*/
/*
** WindowsCE does not have a localtime() function.  So create a
** substitute.
*/
/* #include <time.h> */
struct tm *__cdecl localtime(const time_t *t)
{
  static struct tm y;
  FILETIME uTm, lTm;
  SYSTEMTIME pTm;
  sqlite3_int64 t64;
  t64 = *t;
................................................................................
  SimulateIOError(return SQLITE_IOERR_TRUNCATE);

  /* If the user has configured a chunk-size for this file, truncate the
  ** file so that it consists of an integer number of chunks (i.e. the
  ** actual file size after the operation may be larger than the requested
  ** size).
  */
  if( pFile->szChunk>0 ){
    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
  }

  /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
  if( seekWinFile(pFile, nByte) ){
    rc = winLogError(SQLITE_IOERR_TRUNCATE, "winTruncate1", pFile->zPath);
  }else if( 0==SetEndOfFile(pFile->h) ){
................................................................................
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      if( pFile->szChunk>0 ){
        sqlite3_int64 oldSz;
        int rc = winFileSize(id, &oldSz);
        if( rc==SQLITE_OK ){
          sqlite3_int64 newSz = *(sqlite3_int64*)pArg;
          if( newSz>oldSz ){
            SimulateIOErrorBenign(1);
            rc = winTruncate(id, newSz);
            SimulateIOErrorBenign(0);
          }
        }
        return rc;
      }
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = pFile->bPersistWal;
      }else{
................................................................................


typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;
typedef struct PGroup PGroup;

typedef struct PGroupBlock PGroupBlock;
typedef struct PGroupBlockList PGroupBlockList;

/* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
** of one or more PCaches that are able to recycle each others unpinned
** pages when they are under memory pressure.  A PGroup is an instance of
** the following object.
**
** This page cache implementation works in one of two modes:
**
................................................................................
struct PGroup {
  sqlite3_mutex *mutex;          /* MUTEX_STATIC_LRU or NULL */
  int nMaxPage;                  /* Sum of nMax for purgeable caches */
  int nMinPage;                  /* Sum of nMin for purgeable caches */
  int mxPinned;                  /* nMaxpage + 10 - nMinPage */
  int nCurrentPage;              /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;   /* LRU list of unpinned pages */
#ifdef SQLITE_PAGECACHE_BLOCKALLOC
  int isBusy;                    /* Do not run ReleaseMemory() if true */
  PGroupBlockList *pBlockList;   /* List of block-lists for this group */
#endif
};

/*
** If SQLITE_PAGECACHE_BLOCKALLOC is defined when the library is built,
** each PGroup structure has a linked list of the the following starting
** at PGroup.pBlockList. There is one entry for each distinct page-size 
** currently used by members of the PGroup (i.e. 1024 bytes, 4096 bytes
** etc.). Variable PGroupBlockList.nByte is set to the actual allocation
** size requested by each pcache, which is the database page-size plus
** the various header structures used by the pcache, pager and btree layers.
** Usually around (pgsz+200) bytes.
**
** This size (pgsz+200) bytes is not allocated efficiently by some
** implementations of malloc. In particular, some implementations are only
** able to allocate blocks of memory chunks of 2^N bytes, where N is some
** integer value. Since the page-size is a power of 2, this means we
** end up wasting (pgsz-200) bytes in each allocation.
**
** If SQLITE_PAGECACHE_BLOCKALLOC is defined, the (pgsz+200) byte blocks
** are not allocated directly. Instead, blocks of roughly M*(pgsz+200) bytes 
** are requested from malloc allocator. After a block is returned,
** sqlite3MallocSize() is used to determine how many (pgsz+200) byte
** allocations can fit in the space returned by malloc(). This value may
** be more than M.
**
** The blocks are stored in a doubly-linked list. Variable PGroupBlock.nEntry
** contains the number of allocations that will fit in the aData[] space.
** nEntry is limited to the number of bits in bitmask mUsed. If a slot
** within aData is in use, the corresponding bit in mUsed is set. Thus
** when (mUsed+1==(1 << nEntry)) the block is completely full.
**
** Each time a slot within a block is freed, the block is moved to the start
** of the linked-list. And if a block becomes completely full, then it is
** moved to the end of the list. As a result, when searching for a free
** slot, only the first block in the list need be examined. If it is full,
** then it is guaranteed that all blocks are full.
*/
struct PGroupBlockList {
  int nByte;                     /* Size of each allocation in bytes */
  PGroupBlock *pFirst;           /* First PGroupBlock in list */
  PGroupBlock *pLast;            /* Last PGroupBlock in list */
  PGroupBlockList *pNext;        /* Next block-list attached to group */
};

struct PGroupBlock {
  Bitmask mUsed;                 /* Mask of used slots */
  int nEntry;                    /* Maximum number of allocations in aData[] */
  u8 *aData;                     /* Pointer to data block */
  PGroupBlock *pNext;            /* Next PGroupBlock in list */
  PGroupBlock *pPrev;            /* Previous PGroupBlock in list */
  PGroupBlockList *pList;        /* Owner list */
};

/* Minimum value for PGroupBlock.nEntry */
#define PAGECACHE_BLOCKALLOC_MINENTRY 15

/* Each page cache is an instance of the following object.  Every
** open database file (including each in-memory database and each
** temporary or transient database) has a single page cache which
** is an instance of this object.
**
** Pointers to structures of this type are cast and returned as 
** opaque sqlite3_pcache* handles.
................................................................................
** a pointer to a block of szPage bytes of data and the return value is
** a pointer to the associated PgHdr1 structure.
**
**   assert( PGHDR1_TO_PAGE(PAGE_TO_PGHDR1(pCache, X))==X );
*/
#define PGHDR1_TO_PAGE(p)    (void*)(((char*)p) - p->pCache->szPage)
#define PAGE_TO_PGHDR1(c, p) (PgHdr1*)(((char*)p) + c->szPage)

/*
** Blocks used by the SQLITE_PAGECACHE_BLOCKALLOC blocks to store/retrieve 
** a PGroupBlock pointer based on a pointer to a page buffer. 
*/
#define PAGE_SET_BLOCKPTR(pCache, pPg, pBlock) \
  ( *(PGroupBlock **)&(((u8*)pPg)[sizeof(PgHdr1) + pCache->szPage]) = pBlock )

#define PAGE_GET_BLOCKPTR(pCache, pPg) \
  ( *(PGroupBlock **)&(((u8*)pPg)[sizeof(PgHdr1) + pCache->szPage]) )


/*
** Macros to enter and leave the PCache LRU mutex.
*/
#define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
#define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)

................................................................................
    iSize = sqlite3MallocSize(p);
    sqlite3MemdebugSetType(p, MEMTYPE_PCACHE);
    return iSize;
  }
}
#endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */

#ifdef SQLITE_PAGECACHE_BLOCKALLOC
/*
** The block pBlock belongs to list pList but is not currently linked in.
** Insert it into the start of the list.
*/
static void addBlockToList(PGroupBlockList *pList, PGroupBlock *pBlock){
  pBlock->pPrev = 0;
  pBlock->pNext = pList->pFirst;
  pList->pFirst = pBlock;
  if( pBlock->pNext ){
    pBlock->pNext->pPrev = pBlock;
  }else{
    assert( pList->pLast==0 );
    pList->pLast = pBlock;
  }
}

/*
** If there are no blocks in the list headed by pList, remove pList
** from the pGroup->pBlockList list and free it with sqlite3_free().
*/
static void freeListIfEmpty(PGroup *pGroup, PGroupBlockList *pList){
  assert( sqlite3_mutex_held(pGroup->mutex) );
  if( pList->pFirst==0 ){
    PGroupBlockList **pp;
    for(pp=&pGroup->pBlockList; *pp!=pList; pp=&(*pp)->pNext);
    *pp = (*pp)->pNext;
    sqlite3_free(pList);
  }
}
#endif /* SQLITE_PAGECACHE_BLOCKALLOC */

/*
** Allocate a new page object initially associated with cache pCache.
*/
static PgHdr1 *pcache1AllocPage(PCache1 *pCache){
  int nByte = sizeof(PgHdr1) + pCache->szPage;
  void *pPg = 0;
  PgHdr1 *p;

#ifdef SQLITE_PAGECACHE_BLOCKALLOC
  PGroup *pGroup = pCache->pGroup;
  PGroupBlockList *pList;
  PGroupBlock *pBlock;
  int i;

  nByte += sizeof(PGroupBlockList *);
  nByte = ROUND8(nByte);

  for(pList=pGroup->pBlockList; pList; pList=pList->pNext){
    if( pList->nByte==nByte ) break;
  }
  if( pList==0 ){
    PGroupBlockList *pNew;
    assert( pGroup->isBusy==0 );
    assert( sqlite3_mutex_held(pGroup->mutex) );
    pGroup->isBusy = 1;  /* Disable sqlite3PcacheReleaseMemory() */
    pNew = (PGroupBlockList *)sqlite3MallocZero(sizeof(PGroupBlockList));
    pGroup->isBusy = 0;  /* Reenable sqlite3PcacheReleaseMemory() */
    if( pNew==0 ){
      /* malloc() failure. Return early. */
      return 0;
    }
#ifdef SQLITE_DEBUG
    for(pList=pGroup->pBlockList; pList; pList=pList->pNext){
      assert( pList->nByte!=nByte );
    }
#endif
    pNew->nByte = nByte;
    pNew->pNext = pGroup->pBlockList;
    pGroup->pBlockList = pNew;
    pList = pNew;
  }

  pBlock = pList->pFirst;
  if( pBlock==0 || pBlock->mUsed==(((Bitmask)1<<pBlock->nEntry)-1) ){
    int sz;

    /* Allocate a new block. Try to allocate enough space for the PGroupBlock
    ** structure and MINENTRY allocations of nByte bytes each. If the 
    ** allocator returns more memory than requested, then more than MINENTRY 
    ** allocations may fit in it. */
    assert( sqlite3_mutex_held(pGroup->mutex) );
    pcache1LeaveMutex(pCache->pGroup);
    sz = sizeof(PGroupBlock) + PAGECACHE_BLOCKALLOC_MINENTRY * nByte;
    pBlock = (PGroupBlock *)sqlite3Malloc(sz);
    pcache1EnterMutex(pCache->pGroup);

    if( !pBlock ){
      freeListIfEmpty(pGroup, pList);
      return 0;
    }
    pBlock->nEntry = (sqlite3MallocSize(pBlock) - sizeof(PGroupBlock)) / nByte;
    if( pBlock->nEntry>=BMS ){
      pBlock->nEntry = BMS-1;
    }
    pBlock->pList = pList;
    pBlock->mUsed = 0;
    pBlock->aData = (u8 *)&pBlock[1];
    addBlockToList(pList, pBlock);

    sz = sqlite3MallocSize(pBlock);
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);
    sqlite3_mutex_leave(pcache1.mutex);
  }

  for(i=0; pPg==0 && ALWAYS(i<pBlock->nEntry); i++){
    if( 0==(pBlock->mUsed & ((Bitmask)1<<i)) ){
      pBlock->mUsed |= ((Bitmask)1<<i);
      pPg = (void *)&pBlock->aData[pList->nByte * i];
    }
  }
  assert( pPg );
  PAGE_SET_BLOCKPTR(pCache, pPg, pBlock);

  /* If the block is now full, shift it to the end of the list */
  if( pBlock->mUsed==(((Bitmask)1<<pBlock->nEntry)-1) && pList->pLast!=pBlock ){
    assert( pList->pFirst==pBlock );
    assert( pBlock->pPrev==0 );
    assert( pList->pLast->pNext==0 );
    pList->pFirst = pBlock->pNext;
    pList->pFirst->pPrev = 0;
    pBlock->pPrev = pList->pLast;
    pBlock->pNext = 0;
    pList->pLast->pNext = pBlock;
    pList->pLast = pBlock;
  }
  p = PAGE_TO_PGHDR1(pCache, pPg);
  if( pCache->bPurgeable ){
    pCache->pGroup->nCurrentPage++;
  }
#else
  /* The group mutex must be released before pcache1Alloc() is called. This
  ** is because it may call sqlite3_release_memory(), which assumes that 
  ** this mutex is not held. */
  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
  pcache1LeaveMutex(pCache->pGroup);
  pPg = pcache1Alloc(nByte);
  pcache1EnterMutex(pCache->pGroup);
  if( pPg ){
    p = PAGE_TO_PGHDR1(pCache, pPg);
    if( pCache->bPurgeable ){
      pCache->pGroup->nCurrentPage++;
    }
  }else{
    p = 0;
  }
#endif
  return p;
}

/*
** Free a page object allocated by pcache1AllocPage().
**
** The pointer is allowed to be NULL, which is prudent.  But it turns out
** that the current implementation happens to never call this routine
** with a NULL pointer, so we mark the NULL test with ALWAYS().
*/
static void pcache1FreePage(PgHdr1 *p){
  if( ALWAYS(p) ){
    PCache1 *pCache = p->pCache;
    void *pPg = PGHDR1_TO_PAGE(p);

#ifdef SQLITE_PAGECACHE_BLOCKALLOC
    PGroupBlock *pBlock = PAGE_GET_BLOCKPTR(pCache, pPg);
    PGroupBlockList *pList = pBlock->pList;
    int i = ((u8 *)pPg - pBlock->aData) / pList->nByte;

    assert( pPg==(void *)&pBlock->aData[i*pList->nByte] );
    assert( pBlock->mUsed & ((Bitmask)1<<i) );
    pBlock->mUsed &= ~((Bitmask)1<<i);

    /* Remove the block from the list. If it is completely empty, free it.
    ** Or if it is not completely empty, re-insert it at the start of the
    ** list. */
    if( pList->pFirst==pBlock ){
      pList->pFirst = pBlock->pNext;
      if( pList->pFirst ) pList->pFirst->pPrev = 0;
    }else{
      pBlock->pPrev->pNext = pBlock->pNext;
    }
    if( pList->pLast==pBlock ){
      pList->pLast = pBlock->pPrev;
      if( pList->pLast ) pList->pLast->pNext = 0;
    }else{
      pBlock->pNext->pPrev = pBlock->pPrev;
    }

    if( pBlock->mUsed==0 ){
      PGroup *pGroup = p->pCache->pGroup;

      int sz = sqlite3MallocSize(pBlock);
      sqlite3_mutex_enter(pcache1.mutex);
      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -sz);
      sqlite3_mutex_leave(pcache1.mutex);
      freeListIfEmpty(pGroup, pList);
      sqlite3_free(pBlock);
    }else{
      addBlockToList(pList, pBlock);
    }
#else
    assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );
    pcache1Free(pPg);
#endif
    if( pCache->bPurgeable ){
      pCache->pGroup->nCurrentPage--;
    }

  }
}

/*
** Malloc function used by SQLite to obtain space from the buffer configured
** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer
** exists, this function falls back to sqlite3Malloc().
................................................................................
  }

  /* Step 5. If a usable page buffer has still not been found, 
  ** attempt to allocate a new one. 
  */
  if( !pPage ){
    if( createFlag==1 ) sqlite3BeginBenignMalloc();

    pPage = pcache1AllocPage(pCache);

    if( createFlag==1 ) sqlite3EndBenignMalloc();
  }

  if( pPage ){
    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
................................................................................
**
** nReq is the number of bytes of memory required. Once this much has
** been released, the function returns. The return value is the total number 
** of bytes of memory released.
*/
SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int nReq){
  int nFree = 0;
#ifdef SQLITE_PAGECACHE_BLOCKALLOC
  if( pcache1.grp.isBusy ) return 0;
#endif
  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  assert( sqlite3_mutex_notheld(pcache1.mutex) );
  if( pcache1.pStart==0 ){
    PgHdr1 *p;
    pcache1EnterMutex(&pcache1.grp);
    while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
      nFree += pcache1MemSize(PGHDR1_TO_PAGE(p));
................................................................................
  u8 noSync;                  /* Do not sync the journal if true */
  u8 fullSync;                /* Do extra syncs of the journal for robustness */
  u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
  u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
  u8 tempFile;                /* zFilename is a temporary file */
  u8 readOnly;                /* True for a read-only database */
  u8 memDb;                   /* True to inhibit all file I/O */
  u8 hasSeenStress;           /* pagerStress() called one or more times */

  /**************************************************************************
  ** The following block contains those class members that change during
  ** routine opertion.  Class members not in this block are either fixed
  ** when the pager is first created or else only change when there is a
  ** significant mode change (such as changing the page_size, locking_mode,
  ** or the journal_mode).  From another view, these class members describe
................................................................................
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager){
  u8 *pTmp = (u8 *)pPager->pTmpSpace;

  assert( assert_pager_state(pPager) );
  disable_simulated_io_errors();
  sqlite3BeginBenignMalloc();
  /* pPager->errCode = 0; */
  pPager->exclusiveMode = 0;
#ifndef SQLITE_OMIT_WAL
  sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags, pPager->pageSize, pTmp);
  pPager->pWal = 0;
................................................................................
  ** Spilling is also prohibited when in an error state since that could
  ** lead to database corruption.   In the current implementaton it 
  ** is impossible for sqlite3PCacheFetch() to be called with createFlag==1
  ** while in the error state, hence it is impossible for this routine to
  ** be called in the error state.  Nevertheless, we include a NEVER()
  ** test for the error state as a safeguard against future changes.
  */
  pPager->hasSeenStress = 1;
  if( NEVER(pPager->errCode) ) return SQLITE_OK;
  if( pPager->doNotSpill ) return SQLITE_OK;
  if( pPager->doNotSyncSpill && (pPg->flags & PGHDR_NEED_SYNC)!=0 ){
    return SQLITE_OK;
  }

  pPg->pDirty = 0;
................................................................................
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
      u8 *pCell = findCell(pPage, i);
      if( eType==PTRMAP_OVERFLOW1 ){
        CellInfo info;
        btreeParseCellPtr(pPage, pCell, &info);
        if( info.iOverflow
         && pCell+info.iOverflow+3<=pPage->aData+pPage->maskPage
         && iFrom==get4byte(&pCell[info.iOverflow])
        ){
          put4byte(&pCell[info.iOverflow], iTo);
          break;

        }
      }else{
        if( get4byte(pCell)==iFrom ){
          put4byte(pCell, iTo);
          break;
        }
      }
................................................................................
  assert( wrFlag==0 || p->inTrans==TRANS_WRITE );
  assert( pBt->pPage1 && pBt->pPage1->aData );

  if( NEVER(wrFlag && pBt->readOnly) ){
    return SQLITE_READONLY;
  }
  if( iTable==1 && btreePagecount(pBt)==0 ){
    assert( wrFlag==0 );
    iTable = 0;
  }

  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables and link the cursor into the BtShared list.  */
  pCur->pgnoRoot = (Pgno)iTable;
  pCur->iPage = -1;
  pCur->pKeyInfo = pKeyInfo;
................................................................................

  if( pCur->iPage>=0 ){
    int i;
    for(i=1; i<=pCur->iPage; i++){
      releasePage(pCur->apPage[i]);
    }
    pCur->iPage = 0;
  }else if( pCur->pgnoRoot==0 ){
    pCur->eState = CURSOR_INVALID;
    return SQLITE_OK;
  }else{
    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]);
    if( rc!=SQLITE_OK ){
      pCur->eState = CURSOR_INVALID;
      return rc;
    }
    pCur->iPage = 0;
................................................................................
  int rc;

  assert( cursorHoldsMutex(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  rc = moveToRoot(pCur);
  if( rc==SQLITE_OK ){
    if( pCur->eState==CURSOR_INVALID ){
      assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
      assert( pCur->apPage[pCur->iPage]->nCell>0 );
      *pRes = 0;
      rc = moveToLeftmost(pCur);
    }
  }
................................................................................
#endif
    return SQLITE_OK;
  }

  rc = moveToRoot(pCur);
  if( rc==SQLITE_OK ){
    if( CURSOR_INVALID==pCur->eState ){
      assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
      assert( pCur->eState==CURSOR_VALID );
      *pRes = 0;
      rc = moveToRightmost(pCur);
      pCur->atLast = rc==SQLITE_OK ?1:0;
    }
................................................................................
    }
  }

  rc = moveToRoot(pCur);
  if( rc ){
    return rc;
  }
  assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage] );
  assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->isInit );
  assert( pCur->eState==CURSOR_INVALID || pCur->apPage[pCur->iPage]->nCell>0 );
  if( pCur->eState==CURSOR_INVALID ){
    *pRes = -1;
    assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
    return SQLITE_OK;
  }
  assert( pCur->apPage[0]->intKey || pIdxKey );
  for(;;){
    int lwr, upr, idx;
    Pgno chldPg;
    MemPage *pPage = pCur->apPage[pCur->iPage];
................................................................................
  u32 ovflPageSize;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  btreeParseCellPtr(pPage, pCell, &info);
  if( info.iOverflow==0 ){
    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
  }
  if( pCell+info.iOverflow+3 > pPage->aData+pPage->maskPage ){
    return SQLITE_CORRUPT;  /* Cell extends past end of page */
  }
  ovflPgno = get4byte(&pCell[info.iOverflow]);
  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( ovflPgno==0 || nOvfl>0 );
  while( nOvfl-- ){
    Pgno iNext = 0;
................................................................................
** SQLITE_OK is returned if the operation is successfully executed. 
** Otherwise, if an error is encountered (i.e. an IO error or database
** corruption) an SQLite error code is returned.
*/
SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){
  i64 nEntry = 0;                      /* Value to return in *pnEntry */
  int rc;                              /* Return code */

  if( pCur->pgnoRoot==0 ){
    *pnEntry = 0;
    return SQLITE_OK;
  }
  rc = moveToRoot(pCur);

  /* Unless an error occurs, the following loop runs one iteration for each
  ** page in the B-Tree structure (not including overflow pages). 
  */
  while( rc==SQLITE_OK ){
    int iIdx;                          /* Index of child node in parent */
................................................................................
** "write version" (single byte at byte offset 19) fields in the database
** header to iVersion.
*/
SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
  BtShared *pBt = pBtree->pBt;
  int rc;                         /* Return code */
 

  assert( iVersion==1 || iVersion==2 );

  /* If setting the version fields to 1, do not automatically open the
  ** WAL connection, even if the version fields are currently set to 2.
  */
  pBt->doNotUseWAL = (u8)(iVersion==1);

................................................................................
    }
  
    /* Update the schema version field in the destination database. This
    ** is to make sure that the schema-version really does change in
    ** the case where the source and destination databases have the
    ** same schema version.
    */
    if( rc==SQLITE_DONE ){
      rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1);
      if( rc==SQLITE_OK ){


        if( p->pDestDb ){
          sqlite3ResetInternalSchema(p->pDestDb, -1);
        }
        if( destMode==PAGER_JOURNALMODE_WAL ){
          rc = sqlite3BtreeSetVersion(p->pDest, 2);
        }
      }
      if( rc==SQLITE_OK ){
        int nDestTruncate;
        /* Set nDestTruncate to the final number of pages in the destination
        ** database. The complication here is that the destination page
        ** size may be different to the source page size. 
        **
        ** If the source page size is smaller than the destination page size, 
        ** round up. In this case the call to sqlite3OsTruncate() below will
        ** fix the size of the file. However it is important to call
        ** sqlite3PagerTruncateImage() here so that any pages in the 
        ** destination file that lie beyond the nDestTruncate page mark are
        ** journalled by PagerCommitPhaseOne() before they are destroyed
        ** by the file truncation.
        */
        assert( pgszSrc==sqlite3BtreeGetPageSize(p->pSrc) );
        assert( pgszDest==sqlite3BtreeGetPageSize(p->pDest) );
        if( pgszSrc<pgszDest ){
          int ratio = pgszDest/pgszSrc;
          nDestTruncate = (nSrcPage+ratio-1)/ratio;
          if( nDestTruncate==(int)PENDING_BYTE_PAGE(p->pDest->pBt) ){
            nDestTruncate--;
          }
        }else{
          nDestTruncate = nSrcPage * (pgszSrc/pgszDest);
        }
        sqlite3PagerTruncateImage(pDestPager, nDestTruncate);

        if( pgszSrc<pgszDest ){
          /* If the source page-size is smaller than the destination page-size,
          ** two extra things may need to happen:
          **
          **   * The destination may need to be truncated, and
          **
          **   * Data stored on the pages immediately following the 
          **     pending-byte page in the source database may need to be
          **     copied into the destination database.
          */
          const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
          sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
          i64 iOff;
          i64 iEnd;

          assert( pFile );
          assert( (i64)nDestTruncate*(i64)pgszDest >= iSize || (
                nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1)
             && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
          ));

          /* This call ensures that all data required to recreate the original
          ** database has been stored in the journal for pDestPager and the
          ** journal synced to disk. So at this point we may safely modify
          ** the database file in any way, knowing that if a power failure
          ** occurs, the original database will be reconstructed from the 
          ** journal file.  */
          rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);

          /* Write the extra pages and truncate the database file as required */
          iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
          for(
            iOff=PENDING_BYTE+pgszSrc; 
            rc==SQLITE_OK && iOff<iEnd; 
            iOff+=pgszSrc
          ){
            PgHdr *pSrcPg = 0;
            const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
            rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
            if( rc==SQLITE_OK ){
              u8 *zData = sqlite3PagerGetData(pSrcPg);
              rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
            }
            sqlite3PagerUnref(pSrcPg);
          }
          if( rc==SQLITE_OK ){
            rc = backupTruncateFile(pFile, iSize);
          }

          /* Sync the database file to disk. */
          if( rc==SQLITE_OK ){
            rc = sqlite3PagerSync(pDestPager);
          }
        }else{
          rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
        }
    
        /* Finish committing the transaction to the destination database. */
        if( SQLITE_OK==rc
         && SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest, 0))
        ){
          rc = SQLITE_DONE;
        }
      }
    }
  
    /* If bCloseTrans is true, then this function opened a read transaction
    ** on the source database. Close the read transaction here. There is
    ** no need to check the return values of the btree methods here, as
    ** "committing" a read-only transaction cannot fail.
................................................................................
/*
** If the memory cell contains a string value that must be freed by
** invoking an external callback, free it now. Calling this function
** does not free any Mem.zMalloc buffer.
*/
SQLITE_PRIVATE void sqlite3VdbeMemReleaseExternal(Mem *p){
  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );





  if( p->flags&MEM_Agg ){
    sqlite3VdbeMemFinalize(p, p->u.pDef);
    assert( (p->flags & MEM_Agg)==0 );
    sqlite3VdbeMemRelease(p);
  }else if( p->flags&MEM_Dyn && p->xDel ){
    assert( (p->flags&MEM_RowSet)==0 );
    p->xDel((void *)p->z);
    p->xDel = 0;
  }else if( p->flags&MEM_RowSet ){
    sqlite3RowSetClear(p->u.pRowSet);
  }else if( p->flags&MEM_Frame ){
    sqlite3VdbeMemSetNull(p);

  }
}

/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.type==SQLITE_TEXT).
*/
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p){
  MemReleaseExt(p);
  sqlite3DbFree(p->db, p->zMalloc);
  p->z = 0;
  p->zMalloc = 0;
  p->xDel = 0;
}

/*
................................................................................
** Make an shallow copy of pFrom into pTo.  Prior contents of
** pTo are freed.  The pFrom->z field is not duplicated.  If
** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
** and flags gets srcType (either MEM_Ephem or MEM_Static).
*/
SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
  assert( (pFrom->flags & MEM_RowSet)==0 );
  MemReleaseExt(pTo);
  memcpy(pTo, pFrom, MEMCELLSIZE);
  pTo->xDel = 0;
  if( (pFrom->flags&MEM_Static)==0 ){
    pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
    assert( srcType==MEM_Ephem || srcType==MEM_Static );
    pTo->flags |= srcType;
  }
................................................................................
** Make a full copy of pFrom into pTo.  Prior contents of pTo are
** freed before the copy is made.
*/
SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
  int rc = SQLITE_OK;

  assert( (pFrom->flags & MEM_RowSet)==0 );
  MemReleaseExt(pTo);
  memcpy(pTo, pFrom, MEMCELLSIZE);
  pTo->flags &= ~MEM_Dyn;

  if( pTo->flags&(MEM_Str|MEM_Blob) ){
    if( 0==(pFrom->flags&MEM_Static) ){
      pTo->flags |= MEM_Ephem;
      rc = sqlite3VdbeMemMakeWriteable(pTo);
................................................................................

  if( !pExpr ){
    *ppVal = 0;
    return SQLITE_OK;
  }
  op = pExpr->op;

  /* op can only be TK_REGISTER if we have compiled with SQLITE_ENABLE_STAT2.
  ** The ifdef here is to enable us to achieve 100% branch test coverage even
  ** when SQLITE_ENABLE_STAT2 is omitted.
  */
#ifdef SQLITE_ENABLE_STAT2
  if( op==TK_REGISTER ) op = pExpr->op2;
#else
  if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
#endif

  /* Handle negative integers in a single step.  This is needed in the
  ** case when the value is -9223372036854775808.
................................................................................
    }else if( opcode==OP_VFilter ){
      int n;
      assert( p->nOp - i >= 3 );
      assert( pOp[-1].opcode==OP_Integer );
      n = pOp[-1].p1;
      if( n>nMaxArgs ) nMaxArgs = n;
#endif
    }else if( opcode==OP_Next || opcode==OP_SorterNext ){
      pOp->p4.xAdvance = sqlite3BtreeNext;
      pOp->p4type = P4_ADVANCE;
    }else if( opcode==OP_Prev ){
      pOp->p4.xAdvance = sqlite3BtreePrevious;
      pOp->p4type = P4_ADVANCE;
    }

    if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
      assert( -1-pOp->p2<p->nLabel );
      pOp->p2 = aLabel[-1-pOp->p2];
    }
  }
................................................................................

/*
** Change the value of the P1 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqlite3VdbeAddOpList but we want to make a
** few minor changes to the program.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){
  assert( p!=0 );
  if( ((u32)p->nOp)>addr ){

    p->aOp[addr].p1 = val;
  }
}

/*
** Change the value of the P2 operand for a specific instruction.
** This routine is useful for setting a jump destination.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){
  assert( p!=0 );
  if( ((u32)p->nOp)>addr ){

    p->aOp[addr].p2 = val;
  }
}

/*
** Change the value of the P3 operand for a specific instruction.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){
  assert( p!=0 );
  if( ((u32)p->nOp)>addr ){

    p->aOp[addr].p3 = val;
  }
}

/*
** Change the value of the P5 operand for the most recently
** added operation.
................................................................................
}

/*
** Change the P2 operand of instruction addr so that it points to
** the address of the next instruction to be coded.
*/
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
  assert( addr>=0 );
  sqlite3VdbeChangeP2(p, addr, p->nOp);
}


/*
** If the input FuncDef structure is ephemeral, then free it.  If
** the FuncDef is not ephermal, then do nothing.
*/
................................................................................
    case P4_INTARRAY: {
      sqlite3_snprintf(nTemp, zTemp, "intarray");
      break;
    }
    case P4_SUBPROGRAM: {
      sqlite3_snprintf(nTemp, zTemp, "program");
      break;
    }
    case P4_ADVANCE: {
      zTemp[0] = 0;
      break;
    }
    default: {
      zP4 = pOp->p4.z;
      if( zP4==0 ){
        zP4 = zTemp;
        zTemp[0] = 0;
      }
................................................................................
** Close a VDBE cursor and release all the resources that cursor 
** happens to hold.
*/
SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
  if( pCx==0 ){
    return;
  }
  sqlite3VdbeSorterClose(p->db, pCx);
  if( pCx->pBt ){
    sqlite3BtreeClose(pCx->pBt);
    /* The pCx->pCursor will be close automatically, if it exists, by
    ** the call above. */
  }else if( pCx->pCursor ){
    sqlite3BtreeCloseCursor(pCx->pCursor);
  }
................................................................................

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)

/* Return true if the cursor was opened using the OP_OpenSorter opcode. */
#ifdef SQLITE_OMIT_MERGE_SORT
# define isSorter(x) 0
#else
# define isSorter(x) ((x)->pSorter!=0)
#endif

/*
** Argument pMem points at a register that will be passed to a
** user-defined function or returned to the user as the result of a query.
** This routine sets the pMem->type variable used by the sqlite3_value_*() 
** routines.
*/
SQLITE_PRIVATE void sqlite3VdbeMemStoreType(Mem *pMem){
................................................................................
      Mem sMem;          /* For storing the record being decoded */
      u8 *zIdx;          /* Index into header */
      u8 *zEndHdr;       /* Pointer to first byte after the header */
      u32 offset;        /* Offset into the data */
      u32 szField;       /* Number of bytes in the content of a field */
      int szHdr;         /* Size of the header size field at start of record */
      int avail;         /* Number of bytes of available data */
      u32 t;             /* A type code from the record header */
      Mem *pReg;         /* PseudoTable input register */
    } am;
    struct OP_Affinity_stack_vars {
      const char *zAffinity;   /* The affinity to be applied */
      char cAff;               /* A single character of affinity */
    } an;
    struct OP_MakeRecord_stack_vars {
................................................................................
      Btree *pX;
      VdbeCursor *pCur;
      Db *pDb;
    } aw;
    struct OP_OpenEphemeral_stack_vars {
      VdbeCursor *pCx;
    } ax;
    struct OP_SorterOpen_stack_vars {
      VdbeCursor *pCx;
    } ay;
    struct OP_OpenPseudo_stack_vars {
      VdbeCursor *pCx;
    } az;
    struct OP_SeekGt_stack_vars {
      int res;
      int oc;
      VdbeCursor *pC;
      UnpackedRecord r;
      int nField;
      i64 iKey;      /* The rowid we are to seek to */
    } ba;
    struct OP_Seek_stack_vars {
      VdbeCursor *pC;
    } bb;
    struct OP_Found_stack_vars {
      int alreadyExists;
      VdbeCursor *pC;
      int res;
      UnpackedRecord *pIdxKey;
      UnpackedRecord r;
      char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
    } bc;
    struct OP_IsUnique_stack_vars {
      u16 ii;
      VdbeCursor *pCx;
      BtCursor *pCrsr;
      u16 nField;
      Mem *aMx;
      UnpackedRecord r;                  /* B-Tree index search key */
      i64 R;                             /* Rowid stored in register P3 */
    } bd;
    struct OP_NotExists_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
      u64 iKey;
    } be;
    struct OP_NewRowid_stack_vars {
      i64 v;                 /* The new rowid */
      VdbeCursor *pC;        /* Cursor of table to get the new rowid */
      int res;               /* Result of an sqlite3BtreeLast() */
      int cnt;               /* Counter to limit the number of searches */
      Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */
      VdbeFrame *pFrame;     /* Root frame of VDBE */
    } bf;
    struct OP_InsertInt_stack_vars {
      Mem *pData;       /* MEM cell holding data for the record to be inserted */
      Mem *pKey;        /* MEM cell holding key  for the record */
      i64 iKey;         /* The integer ROWID or key for the record to be inserted */
      VdbeCursor *pC;   /* Cursor to table into which insert is written */
      int nZero;        /* Number of zero-bytes to append */
      int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
      const char *zDb;  /* database name - used by the update hook */
      const char *zTbl; /* Table name - used by the opdate hook */
      int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
    } bg;
    struct OP_Delete_stack_vars {
      i64 iKey;
      VdbeCursor *pC;
    } bh;
    struct OP_SorterCompare_stack_vars {
      VdbeCursor *pC;
      int res;
    } bi;
    struct OP_SorterData_stack_vars {
      VdbeCursor *pC;
    } bj;
    struct OP_RowData_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      u32 n;
      i64 n64;
    } bk;
    struct OP_Rowid_stack_vars {
      VdbeCursor *pC;
      i64 v;
      sqlite3_vtab *pVtab;
      const sqlite3_module *pModule;
    } bl;
    struct OP_NullRow_stack_vars {
      VdbeCursor *pC;
    } bm;
    struct OP_Last_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
    } bn;
    struct OP_Rewind_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
    } bo;
    struct OP_Next_stack_vars {
      VdbeCursor *pC;

      int res;
    } bp;
    struct OP_IdxInsert_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int nKey;
      const char *zKey;
    } bq;
    struct OP_IdxDelete_stack_vars {
      VdbeCursor *pC;
      BtCursor *pCrsr;
      int res;
      UnpackedRecord r;
    } br;
    struct OP_IdxRowid_stack_vars {
      BtCursor *pCrsr;
      VdbeCursor *pC;
      i64 rowid;
    } bs;
    struct OP_IdxGE_stack_vars {
      VdbeCursor *pC;
      int res;
      UnpackedRecord r;
    } bt;
    struct OP_Destroy_stack_vars {
      int iMoved;
      int iCnt;
      Vdbe *pVdbe;
      int iDb;
    } bu;
    struct OP_Clear_stack_vars {
      int nChange;
    } bv;
    struct OP_CreateTable_stack_vars {
      int pgno;
      int flags;
      Db *pDb;
    } bw;
    struct OP_ParseSchema_stack_vars {
      int iDb;
      const char *zMaster;
      char *zSql;
      InitData initData;
    } bx;
    struct OP_IntegrityCk_stack_vars {
      int nRoot;      /* Number of tables to check.  (Number of root pages.) */
      int *aRoot;     /* Array of rootpage numbers for tables to be checked */
      int j;          /* Loop counter */
      int nErr;       /* Number of errors reported */
      char *z;        /* Text of the error report */
      Mem *pnErr;     /* Register keeping track of errors remaining */
    } by;
    struct OP_RowSetRead_stack_vars {
      i64 val;
    } bz;
    struct OP_RowSetTest_stack_vars {
      int iSet;
      int exists;
    } ca;
    struct OP_Program_stack_vars {
      int nMem;               /* Number of memory registers for sub-program */
      int nByte;              /* Bytes of runtime space required for sub-program */
      Mem *pRt;               /* Register to allocate runtime space */
      Mem *pMem;              /* Used to iterate through memory cells */
      Mem *pEnd;              /* Last memory cell in new array */
      VdbeFrame *pFrame;      /* New vdbe frame to execute in */
      SubProgram *pProgram;   /* Sub-program to execute */
      void *t;                /* Token identifying trigger */
    } cb;
    struct OP_Param_stack_vars {
      VdbeFrame *pFrame;
      Mem *pIn;
    } cc;
    struct OP_MemMax_stack_vars {
      Mem *pIn1;
      VdbeFrame *pFrame;
    } cd;
    struct OP_AggStep_stack_vars {
      int n;
      int i;
      Mem *pMem;
      Mem *pRec;
      sqlite3_context ctx;
      sqlite3_value **apVal;
    } ce;
    struct OP_AggFinal_stack_vars {
      Mem *pMem;
    } cf;
    struct OP_Checkpoint_stack_vars {
      int i;                          /* Loop counter */
      int aRes[3];                    /* Results */
      Mem *pMem;                      /* Write results here */
    } cg;
    struct OP_JournalMode_stack_vars {
      Btree *pBt;                     /* Btree to change journal mode of */
      Pager *pPager;                  /* Pager associated with pBt */
      int eNew;                       /* New journal mode */
      int eOld;                       /* The old journal mode */
      const char *zFilename;          /* Name of database file for pPager */
    } ch;
    struct OP_IncrVacuum_stack_vars {
      Btree *pBt;
    } ci;
    struct OP_VBegin_stack_vars {
      VTable *pVTab;
    } cj;
    struct OP_VOpen_stack_vars {
      VdbeCursor *pCur;
      sqlite3_vtab_cursor *pVtabCursor;
      sqlite3_vtab *pVtab;
      sqlite3_module *pModule;
    } ck;
    struct OP_VFilter_stack_vars {
      int nArg;
      int iQuery;
      const sqlite3_module *pModule;
      Mem *pQuery;
      Mem *pArgc;
      sqlite3_vtab_cursor *pVtabCursor;
      sqlite3_vtab *pVtab;
      VdbeCursor *pCur;
      int res;
      int i;
      Mem **apArg;
    } cl;
    struct OP_VColumn_stack_vars {
      sqlite3_vtab *pVtab;
      const sqlite3_module *pModule;
      Mem *pDest;
      sqlite3_context sContext;
    } cm;
    struct OP_VNext_stack_vars {
      sqlite3_vtab *pVtab;
      const sqlite3_module *pModule;
      int res;
      VdbeCursor *pCur;
    } cn;
    struct OP_VRename_stack_vars {
      sqlite3_vtab *pVtab;
      Mem *pName;
    } co;
    struct OP_VUpdate_stack_vars {
      sqlite3_vtab *pVtab;
      sqlite3_module *pModule;
      int nArg;
      int i;
      sqlite_int64 rowid;
      Mem **apArg;
      Mem *pX;
    } cp;
    struct OP_Trace_stack_vars {
      char *zTrace;
      char *z;
    } cq;
  } u;
  /* End automatically generated code
  ********************************************************************/

  assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
  sqlite3VdbeEnter(p);
  if( p->rc==SQLITE_NOMEM ){
................................................................................
    */
    assert( pOp->opflags==sqlite3OpcodeProperty[pOp->opcode] );
    if( pOp->opflags & OPFLG_OUT2_PRERELEASE ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=p->nMem );
      pOut = &aMem[pOp->p2];
      memAboutToChange(p, pOut);
      MemReleaseExt(pOut);
      pOut->flags = MEM_Int;
    }

    /* Sanity checking on other operands */
#ifdef SQLITE_DEBUG
    if( (pOp->opflags & OPFLG_IN1)!=0 ){
      assert( pOp->p1>0 );
................................................................................
  Mem sMem;          /* For storing the record being decoded */
  u8 *zIdx;          /* Index into header */
  u8 *zEndHdr;       /* Pointer to first byte after the header */
  u32 offset;        /* Offset into the data */
  u32 szField;       /* Number of bytes in the content of a field */
  int szHdr;         /* Size of the header size field at start of record */
  int avail;         /* Number of bytes of available data */
  u32 t;             /* A type code from the record header */
  Mem *pReg;         /* PseudoTable input register */
#endif /* local variables moved into u.am */


  u.am.p1 = pOp->p1;
  u.am.p2 = pOp->p2;
  u.am.pC = 0;
  memset(&u.am.sMem, 0, sizeof(u.am.sMem));
  assert( u.am.p1<p->nCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.am.pDest = &aMem[pOp->p3];
  memAboutToChange(p, u.am.pDest);

  u.am.zRec = 0;

  /* This block sets the variable u.am.payloadSize to be the total number of
  ** bytes in the record.
  **
  ** u.am.zRec is set to be the complete text of the record if it is available.
  ** The complete record text is always available for pseudo-tables
................................................................................
      assert( (u.am.payloadSize64 & SQLITE_MAX_U32)==(u64)u.am.payloadSize64 );
      u.am.payloadSize = (u32)u.am.payloadSize64;
    }else{
      assert( sqlite3BtreeCursorIsValid(u.am.pCrsr) );
      rc = sqlite3BtreeDataSize(u.am.pCrsr, &u.am.payloadSize);
      assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
    }
  }else if( ALWAYS(u.am.pC->pseudoTableReg>0) ){
    u.am.pReg = &aMem[u.am.pC->pseudoTableReg];
    assert( u.am.pReg->flags & MEM_Blob );
    assert( memIsValid(u.am.pReg) );
    u.am.payloadSize = u.am.pReg->n;
    u.am.zRec = u.am.pReg->z;
    u.am.pC->cacheStatus = (pOp->p5&OPFLAG_CLEARCACHE) ? CACHE_STALE : p->cacheCtr;
    assert( u.am.payloadSize==0 || u.am.zRec!=0 );
  }else{
    /* Consider the row to be NULL */
    u.am.payloadSize = 0;
  }

  /* If u.am.payloadSize is 0, then just store a NULL.  This can happen because of
  ** nullRow or because of a corrupt database. */
  if( u.am.payloadSize==0 ){

    MemSetTypeFlag(u.am.pDest, MEM_Null);
    goto op_column_out;
  }
  assert( db->aLimit[SQLITE_LIMIT_LENGTH]>=0 );
  if( u.am.payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
    goto too_big;
  }

................................................................................
    ** arrays.  u.am.aType[u.am.i] will contain the type integer for the u.am.i-th
    ** column and u.am.aOffset[u.am.i] will contain the u.am.offset from the beginning
    ** of the record to the start of the data for the u.am.i-th column
    */
    for(u.am.i=0; u.am.i<u.am.nField; u.am.i++){
      if( u.am.zIdx<u.am.zEndHdr ){
        u.am.aOffset[u.am.i] = u.am.offset;
        if( u.am.zIdx[0]<0x80 ){
          u.am.t = u.am.zIdx[0];
          u.am.zIdx++;
        }else{
          u.am.zIdx += sqlite3GetVarint32(u.am.zIdx, &u.am.t);
        }
        u.am.aType[u.am.i] = u.am.t;
        u.am.szField = sqlite3VdbeSerialTypeLen(u.am.t);
        u.am.offset += u.am.szField;
        if( u.am.offset<u.am.szField ){  /* True if u.am.offset overflows */
          u.am.zIdx = &u.am.zEndHdr[1];  /* Forces SQLITE_CORRUPT return below */
          break;
        }
      }else{
        /* If u.am.i is less that u.am.nField, then there are less fields in this
................................................................................
  ** then there are not enough fields in the record to satisfy the
  ** request.  In this case, set the value NULL or to P4 if P4 is
  ** a pointer to a Mem object.
  */
  if( u.am.aOffset[u.am.p2] ){
    assert( rc==SQLITE_OK );
    if( u.am.zRec ){
      MemReleaseExt(u.am.pDest);
      sqlite3VdbeSerialGet((u8 *)&u.am.zRec[u.am.aOffset[u.am.p2]], u.am.aType[u.am.p2], u.am.pDest);
    }else{
      u.am.len = sqlite3VdbeSerialTypeLen(u.am.aType[u.am.p2]);
      sqlite3VdbeMemMove(&u.am.sMem, u.am.pDest);
      rc = sqlite3VdbeMemFromBtree(u.am.pCrsr, u.am.aOffset[u.am.p2], u.am.len, u.am.pC->isIndex, &u.am.sMem);
      if( rc!=SQLITE_OK ){
        goto op_column_out;
................................................................................
      sqlite3VdbeSerialGet((u8*)u.am.zData, u.am.aType[u.am.p2], u.am.pDest);
    }
    u.am.pDest->enc = encoding;
  }else{
    if( pOp->p4type==P4_MEM ){
      sqlite3VdbeMemShallowCopy(u.am.pDest, pOp->p4.pMem, MEM_Static);
    }else{
      MemSetTypeFlag(u.am.pDest, MEM_Null);
    }
  }

  /* If we dynamically allocated space to hold the data (in the
  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
  ** dynamically allocated space over to the u.am.pDest structure.
  ** This prevents a memory copy.
................................................................................
case OP_Count: {         /* out2-prerelease */
#if 0  /* local variables moved into u.ap */
  i64 nEntry;
  BtCursor *pCrsr;
#endif /* local variables moved into u.ap */

  u.ap.pCrsr = p->apCsr[pOp->p1]->pCursor;
  if( ALWAYS(u.ap.pCrsr) ){
    rc = sqlite3BtreeCount(u.ap.pCrsr, &u.ap.nEntry);
  }else{
    u.ap.nEntry = 0;
  }
  pOut->u.i = u.ap.nEntry;
  break;
}
................................................................................
  u.aw.pCur = allocateCursor(p, pOp->p1, u.aw.nField, u.aw.iDb, 1);
  if( u.aw.pCur==0 ) goto no_mem;
  u.aw.pCur->nullRow = 1;
  u.aw.pCur->isOrdered = 1;
  rc = sqlite3BtreeCursor(u.aw.pX, u.aw.p2, u.aw.wrFlag, u.aw.pKeyInfo, u.aw.pCur->pCursor);
  u.aw.pCur->pKeyInfo = u.aw.pKeyInfo;

  /* Since it performs no memory allocation or IO, the only value that
  ** sqlite3BtreeCursor() may return is SQLITE_OK. */



  assert( rc==SQLITE_OK );




  /* Set the VdbeCursor.isTable and isIndex variables. Previous versions of
  ** SQLite used to check if the root-page flags were sane at this point
  ** and report database corruption if they were not, but this check has
  ** since moved into the btree layer.  */
  u.aw.pCur->isTable = pOp->p4type!=P4_KEYINFO;
  u.aw.pCur->isIndex = !u.aw.pCur->isTable;
  break;
}

/* Opcode: OpenEphemeral P1 P2 * P4 P5
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if 
** the main database is read-only.  The ephemeral
** table is deleted automatically when the cursor is closed.
**
** P2 is the number of columns in the ephemeral table.
................................................................................
** that defines the format of keys in the index.
**
** This opcode was once called OpenTemp.  But that created
** confusion because the term "temp table", might refer either
** to a TEMP table at the SQL level, or to a table opened by
** this opcode.  Then this opcode was call OpenVirtual.  But
** that created confusion with the whole virtual-table idea.
**
** The P5 parameter can be a mask of the BTREE_* flags defined
** in btree.h.  These flags control aspects of the operation of
** the btree.  The BTREE_OMIT_JOURNAL and BTREE_SINGLE flags are
** added automatically.
*/
/* Opcode: OpenAutoindex P1 P2 * P4 *
**
** This opcode works the same as OP_OpenEphemeral.  It has a
** different name to distinguish its use.  Tables created using
** by this opcode will be used for automatically created transient
** indices in joins.
................................................................................
      u.ax.pCx->isTable = 1;
    }
  }
  u.ax.pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  u.ax.pCx->isIndex = !u.ax.pCx->isTable;
  break;
}

/* Opcode: OpenSorter P1 P2 * P4 *
**
** This opcode works like OP_OpenEphemeral except that it opens
** a transient index that is specifically designed to sort large
** tables using an external merge-sort algorithm.
*/
case OP_SorterOpen: {
#if 0  /* local variables moved into u.ay */
  VdbeCursor *pCx;
#endif /* local variables moved into u.ay */
#ifndef SQLITE_OMIT_MERGE_SORT
  u.ay.pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
  if( u.ay.pCx==0 ) goto no_mem;
  u.ay.pCx->pKeyInfo = pOp->p4.pKeyInfo;
  u.ay.pCx->pKeyInfo->enc = ENC(p->db);
  u.ay.pCx->isSorter = 1;
  rc = sqlite3VdbeSorterInit(db, u.ay.pCx);
#else
  pOp->opcode = OP_OpenEphemeral;
  pc--;
#endif
  break;
}

/* Opcode: OpenPseudo P1 P2 P3 * *
**
** Open a new cursor that points to a fake table that contains a single
** row of data.  The content of that one row in the content of memory
** register P2.  In other words, cursor P1 becomes an alias for the 
** MEM_Blob content contained in register P2.
................................................................................
** individual columns using the OP_Column opcode.  The OP_Column opcode
** is the only cursor opcode that works with a pseudo-table.
**
** P3 is the number of fields in the records that will be stored by
** the pseudo-table.
*/
case OP_OpenPseudo: {
#if 0  /* local variables moved into u.az */
  VdbeCursor *pCx;
#endif /* local variables moved into u.az */

  assert( pOp->p1>=0 );
  u.az.pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
  if( u.az.pCx==0 ) goto no_mem;
  u.az.pCx->nullRow = 1;
  u.az.pCx->pseudoTableReg = pOp->p2;
  u.az.pCx->isTable = 1;
  u.az.pCx->isIndex = 0;
  break;
}

/* Opcode: Close P1 * * * *
**
** Close a cursor previously opened as P1.  If P1 is not
** currently open, this instruction is a no-op.
................................................................................
**
** See also: Found, NotFound, Distinct, SeekGt, SeekGe, SeekLt
*/
case OP_SeekLt:         /* jump, in3 */
case OP_SeekLe:         /* jump, in3 */
case OP_SeekGe:         /* jump, in3 */
case OP_SeekGt: {       /* jump, in3 */
#if 0  /* local variables moved into u.ba */
  int res;
  int oc;
  VdbeCursor *pC;
  UnpackedRecord r;
  int nField;
  i64 iKey;      /* The rowid we are to seek to */
#endif /* local variables moved into u.ba */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p2!=0 );
  u.ba.pC = p->apCsr[pOp->p1];
  assert( u.ba.pC!=0 );
  assert( u.ba.pC->pseudoTableReg==0 );
  assert( OP_SeekLe == OP_SeekLt+1 );
  assert( OP_SeekGe == OP_SeekLt+2 );
  assert( OP_SeekGt == OP_SeekLt+3 );
  assert( u.ba.pC->isOrdered );
  if( ALWAYS(u.ba.pC->pCursor!=0) ){
    u.ba.oc = pOp->opcode;
    u.ba.pC->nullRow = 0;
    if( u.ba.pC->isTable ){
      /* The input value in P3 might be of any type: integer, real, string,
      ** blob, or NULL.  But it needs to be an integer before we can do
      ** the seek, so covert it. */
      pIn3 = &aMem[pOp->p3];
      applyNumericAffinity(pIn3);
      u.ba.iKey = sqlite3VdbeIntValue(pIn3);
      u.ba.pC->rowidIsValid = 0;

      /* If the P3 value could not be converted into an integer without
      ** loss of information, then special processing is required... */
      if( (pIn3->flags & MEM_Int)==0 ){
        if( (pIn3->flags & MEM_Real)==0 ){
          /* If the P3 value cannot be converted into any kind of a number,
          ** then the seek is not possible, so jump to P2 */
................................................................................
          pc = pOp->p2 - 1;
          break;
        }
        /* If we reach this point, then the P3 value must be a floating
        ** point number. */
        assert( (pIn3->flags & MEM_Real)!=0 );

        if( u.ba.iKey==SMALLEST_INT64 && (pIn3->r<(double)u.ba.iKey || pIn3->r>0) ){
          /* The P3 value is too large in magnitude to be expressed as an
          ** integer. */
          u.ba.res = 1;
          if( pIn3->r<0 ){
            if( u.ba.oc>=OP_SeekGe ){  assert( u.ba.oc==OP_SeekGe || u.ba.oc==OP_SeekGt );
              rc = sqlite3BtreeFirst(u.ba.pC->pCursor, &u.ba.res);
              if( rc!=SQLITE_OK ) goto abort_due_to_error;
            }
          }else{
            if( u.ba.oc<=OP_SeekLe ){  assert( u.ba.oc==OP_SeekLt || u.ba.oc==OP_SeekLe );
              rc = sqlite3BtreeLast(u.ba.pC->pCursor, &u.ba.res);
              if( rc!=SQLITE_OK ) goto abort_due_to_error;
            }
          }
          if( u.ba.res ){
            pc = pOp->p2 - 1;
          }
          break;
        }else if( u.ba.oc==OP_SeekLt || u.ba.oc==OP_SeekGe ){
          /* Use the ceiling() function to convert real->int */
          if( pIn3->r > (double)u.ba.iKey ) u.ba.iKey++;
        }else{
          /* Use the floor() function to convert real->int */
          assert( u.ba.oc==OP_SeekLe || u.ba.oc==OP_SeekGt );
          if( pIn3->r < (double)u.ba.iKey ) u.ba.iKey--;
        }
      }
      rc = sqlite3BtreeMovetoUnpacked(u.ba.pC->pCursor, 0, (u64)u.ba.iKey, 0, &u.ba.res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      if( u.ba.res==0 ){
        u.ba.pC->rowidIsValid = 1;
        u.ba.pC->lastRowid = u.ba.iKey;
      }
    }else{
      u.ba.nField = pOp->p4.i;
      assert( pOp->p4type==P4_INT32 );
      assert( u.ba.nField>0 );
      u.ba.r.pKeyInfo = u.ba.pC->pKeyInfo;
      u.ba.r.nField = (u16)u.ba.nField;

      /* The next line of code computes as follows, only faster:
      **   if( u.ba.oc==OP_SeekGt || u.ba.oc==OP_SeekLe ){
      **     u.ba.r.flags = UNPACKED_INCRKEY;
      **   }else{
      **     u.ba.r.flags = 0;
      **   }
      */
      u.ba.r.flags = (u16)(UNPACKED_INCRKEY * (1 & (u.ba.oc - OP_SeekLt)));
      assert( u.ba.oc!=OP_SeekGt || u.ba.r.flags==UNPACKED_INCRKEY );
      assert( u.ba.oc!=OP_SeekLe || u.ba.r.flags==UNPACKED_INCRKEY );
      assert( u.ba.oc!=OP_SeekGe || u.ba.r.flags==0 );
      assert( u.ba.oc!=OP_SeekLt || u.ba.r.flags==0 );

      u.ba.r.aMem = &aMem[pOp->p3];
#ifdef SQLITE_DEBUG
      { int i; for(i=0; i<u.ba.r.nField; i++) assert( memIsValid(&u.ba.r.aMem[i]) ); }
#endif
      ExpandBlob(u.ba.r.aMem);
      rc = sqlite3BtreeMovetoUnpacked(u.ba.pC->pCursor, &u.ba.r, 0, 0, &u.ba.res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      u.ba.pC->rowidIsValid = 0;
    }
    u.ba.pC->deferredMoveto = 0;
    u.ba.pC->cacheStatus = CACHE_STALE;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
    if( u.ba.oc>=OP_SeekGe ){  assert( u.ba.oc==OP_SeekGe || u.ba.oc==OP_SeekGt );
      if( u.ba.res<0 || (u.ba.res==0 && u.ba.oc==OP_SeekGt) ){
        rc = sqlite3BtreeNext(u.ba.pC->pCursor, &u.ba.res);
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
        u.ba.pC->rowidIsValid = 0;
      }else{
        u.ba.res = 0;
      }
    }else{
      assert( u.ba.oc==OP_SeekLt || u.ba.oc==OP_SeekLe );
      if( u.ba.res>0 || (u.ba.res==0 && u.ba.oc==OP_SeekLt) ){
        rc = sqlite3BtreePrevious(u.ba.pC->pCursor, &u.ba.res);
        if( rc!=SQLITE_OK ) goto abort_due_to_error;
        u.ba.pC->rowidIsValid = 0;
      }else{
        /* u.ba.res might be negative because the table is empty.  Check to
        ** see if this is the case.
        */
        u.ba.res = sqlite3BtreeEof(u.ba.pC->pCursor);
      }
    }
    assert( pOp->p2>0 );
    if( u.ba.res ){
      pc = pOp->p2 - 1;
    }
  }else{
    /* This happens when attempting to open the sqlite3_master table
    ** for read access returns SQLITE_EMPTY. In this case always
    ** take the jump (since there are no records in the table).
    */
................................................................................
** for P1 to move so that it points to the rowid given by P2.
**
** This is actually a deferred seek.  Nothing actually happens until
** the cursor is used to read a record.  That way, if no reads
** occur, no unnecessary I/O happens.
*/
case OP_Seek: {    /* in2 */
#if 0  /* local variables moved into u.bb */
  VdbeCursor *pC;
#endif /* local variables moved into u.bb */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bb.pC = p->apCsr[pOp->p1];
  assert( u.bb.pC!=0 );
  if( ALWAYS(u.bb.pC->pCursor!=0) ){
    assert( u.bb.pC->isTable );
    u.bb.pC->nullRow = 0;
    pIn2 = &aMem[pOp->p2];
    u.bb.pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
    u.bb.pC->rowidIsValid = 0;
    u.bb.pC->deferredMoveto = 1;
  }
  break;
}
  

/* Opcode: Found P1 P2 P3 P4 *
**
................................................................................
** falls through to the next instruction and P1 is left pointing at the
** matching entry.
**
** See also: Found, NotExists, IsUnique
*/
case OP_NotFound:       /* jump, in3 */
case OP_Found: {        /* jump, in3 */
#if 0  /* local variables moved into u.bc */
  int alreadyExists;
  VdbeCursor *pC;
  int res;
  UnpackedRecord *pIdxKey;
  UnpackedRecord r;
  char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
#endif /* local variables moved into u.bc */

#ifdef SQLITE_TEST
  sqlite3_found_count++;
#endif

  u.bc.alreadyExists = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p4type==P4_INT32 );
  u.bc.pC = p->apCsr[pOp->p1];
  assert( u.bc.pC!=0 );
  pIn3 = &aMem[pOp->p3];
  if( ALWAYS(u.bc.pC->pCursor!=0) ){

    assert( u.bc.pC->isTable==0 );
    if( pOp->p4.i>0 ){
      u.bc.r.pKeyInfo = u.bc.pC->pKeyInfo;
      u.bc.r.nField = (u16)pOp->p4.i;
      u.bc.r.aMem = pIn3;
#ifdef SQLITE_DEBUG
      { int i; for(i=0; i<u.bc.r.nField; i++) assert( memIsValid(&u.bc.r.aMem[i]) ); }
#endif
      u.bc.r.flags = UNPACKED_PREFIX_MATCH;
      u.bc.pIdxKey = &u.bc.r;
    }else{
      assert( pIn3->flags & MEM_Blob );
      assert( (pIn3->flags & MEM_Zero)==0 );  /* zeroblobs already expanded */
      u.bc.pIdxKey = sqlite3VdbeRecordUnpack(u.bc.pC->pKeyInfo, pIn3->n, pIn3->z,
                                        u.bc.aTempRec, sizeof(u.bc.aTempRec));
      if( u.bc.pIdxKey==0 ){
        goto no_mem;
      }
      u.bc.pIdxKey->flags |= UNPACKED_PREFIX_MATCH;
    }
    rc = sqlite3BtreeMovetoUnpacked(u.bc.pC->pCursor, u.bc.pIdxKey, 0, 0, &u.bc.res);
    if( pOp->p4.i==0 ){
      sqlite3VdbeDeleteUnpackedRecord(u.bc.pIdxKey);
    }
    if( rc!=SQLITE_OK ){
      break;
    }
    u.bc.alreadyExists = (u.bc.res==0);
    u.bc.pC->deferredMoveto = 0;
    u.bc.pC->cacheStatus = CACHE_STALE;
  }
  if( pOp->opcode==OP_Found ){
    if( u.bc.alreadyExists ) pc = pOp->p2 - 1;
  }else{
    if( !u.bc.alreadyExists ) pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: IsUnique P1 P2 P3 P4 *
**
** Cursor P1 is open on an index b-tree - that is to say, a btree which
................................................................................
** to instruction P2. Otherwise, the rowid of the conflicting index
** entry is copied to register P3 and control falls through to the next
** instruction.
**
** See also: NotFound, NotExists, Found
*/
case OP_IsUnique: {        /* jump, in3 */
#if 0  /* local variables moved into u.bd */
  u16 ii;
  VdbeCursor *pCx;
  BtCursor *pCrsr;
  u16 nField;
  Mem *aMx;
  UnpackedRecord r;                  /* B-Tree index search key */
  i64 R;                             /* Rowid stored in register P3 */
#endif /* local variables moved into u.bd */

  pIn3 = &aMem[pOp->p3];
  u.bd.aMx = &aMem[pOp->p4.i];
  /* Assert that the values of parameters P1 and P4 are in range. */
  assert( pOp->p4type==P4_INT32 );
  assert( pOp->p4.i>0 && pOp->p4.i<=p->nMem );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  /* Find the index cursor. */
  u.bd.pCx = p->apCsr[pOp->p1];
  assert( u.bd.pCx->deferredMoveto==0 );
  u.bd.pCx->seekResult = 0;
  u.bd.pCx->cacheStatus = CACHE_STALE;
  u.bd.pCrsr = u.bd.pCx->pCursor;

  /* If any of the values are NULL, take the jump. */
  u.bd.nField = u.bd.pCx->pKeyInfo->nField;
  for(u.bd.ii=0; u.bd.ii<u.bd.nField; u.bd.ii++){
    if( u.bd.aMx[u.bd.ii].flags & MEM_Null ){
      pc = pOp->p2 - 1;
      u.bd.pCrsr = 0;
      break;
    }
  }
  assert( (u.bd.aMx[u.bd.nField].flags & MEM_Null)==0 );

  if( u.bd.pCrsr!=0 ){
    /* Populate the index search key. */
    u.bd.r.pKeyInfo = u.bd.pCx->pKeyInfo;
    u.bd.r.nField = u.bd.nField + 1;
    u.bd.r.flags = UNPACKED_PREFIX_SEARCH;
    u.bd.r.aMem = u.bd.aMx;
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<u.bd.r.nField; i++) assert( memIsValid(&u.bd.r.aMem[i]) ); }
#endif

    /* Extract the value of u.bd.R from register P3. */
    sqlite3VdbeMemIntegerify(pIn3);
    u.bd.R = pIn3->u.i;

    /* Search the B-Tree index. If no conflicting record is found, jump
    ** to P2. Otherwise, copy the rowid of the conflicting record to
    ** register P3 and fall through to the next instruction.  */
    rc = sqlite3BtreeMovetoUnpacked(u.bd.pCrsr, &u.bd.r, 0, 0, &u.bd.pCx->seekResult);
    if( (u.bd.r.flags & UNPACKED_PREFIX_SEARCH) || u.bd.r.rowid==u.bd.R ){
      pc = pOp->p2 - 1;
    }else{
      pIn3->u.i = u.bd.r.rowid;
    }
  }
  break;
}

/* Opcode: NotExists P1 P2 P3 * *
**
................................................................................
** operation assumes the key is an integer and that P1 is a table whereas
** NotFound assumes key is a blob constructed from MakeRecord and
** P1 is an index.
**
** See also: Found, NotFound, IsUnique
*/
case OP_NotExists: {        /* jump, in3 */
#if 0  /* local variables moved into u.be */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  u64 iKey;
#endif /* local variables moved into u.be */

  pIn3 = &aMem[pOp->p3];
  assert( pIn3->flags & MEM_Int );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.be.pC = p->apCsr[pOp->p1];
  assert( u.be.pC!=0 );
  assert( u.be.pC->isTable );
  assert( u.be.pC->pseudoTableReg==0 );
  u.be.pCrsr = u.be.pC->pCursor;
  if( ALWAYS(u.be.pCrsr!=0) ){
    u.be.res = 0;
    u.be.iKey = pIn3->u.i;
    rc = sqlite3BtreeMovetoUnpacked(u.be.pCrsr, 0, u.be.iKey, 0, &u.be.res);
    u.be.pC->lastRowid = pIn3->u.i;
    u.be.pC->rowidIsValid = u.be.res==0 ?1:0;
    u.be.pC->nullRow = 0;
    u.be.pC->cacheStatus = CACHE_STALE;
    u.be.pC->deferredMoveto = 0;
    if( u.be.res!=0 ){
      pc = pOp->p2 - 1;
      assert( u.be.pC->rowidIsValid==0 );
    }
    u.be.pC->seekResult = u.be.res;
  }else{
    /* This happens when an attempt to open a read cursor on the
    ** sqlite_master table returns SQLITE_EMPTY.
    */
    pc = pOp->p2 - 1;
    assert( u.be.pC->rowidIsValid==0 );
    u.be.pC->seekResult = 0;
  }
  break;
}

/* Opcode: Sequence P1 P2 * * *
**
** Find the next available sequence number for cursor P1.
................................................................................
** the largest previously generated record number. No new record numbers are
** allowed to be less than this value. When this value reaches its maximum, 
** an SQLITE_FULL error is generated. The P3 register is updated with the '
** generated record number. This P3 mechanism is used to help implement the
** AUTOINCREMENT feature.
*/
case OP_NewRowid: {           /* out2-prerelease */
#if 0  /* local variables moved into u.bf */
  i64 v;                 /* The new rowid */
  VdbeCursor *pC;        /* Cursor of table to get the new rowid */
  int res;               /* Result of an sqlite3BtreeLast() */
  int cnt;               /* Counter to limit the number of searches */
  Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */
  VdbeFrame *pFrame;     /* Root frame of VDBE */
#endif /* local variables moved into u.bf */

  u.bf.v = 0;
  u.bf.res = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bf.pC = p->apCsr[pOp->p1];
  assert( u.bf.pC!=0 );
  if( NEVER(u.bf.pC->pCursor==0) ){
    /* The zero initialization above is all that is needed */
  }else{
    /* The next rowid or record number (different terms for the same
    ** thing) is obtained in a two-step algorithm.
    **
    ** First we attempt to find the largest existing rowid and add one
    ** to that.  But if the largest existing rowid is already the maximum
................................................................................
    ** probabilistic algorithm
    **
    ** The second algorithm is to select a rowid at random and see if
    ** it already exists in the table.  If it does not exist, we have
    ** succeeded.  If the random rowid does exist, we select a new one
    ** and try again, up to 100 times.
    */
    assert( u.bf.pC->isTable );

#ifdef SQLITE_32BIT_ROWID
#   define MAX_ROWID 0x7fffffff
#else
    /* Some compilers complain about constants of the form 0x7fffffffffffffff.
    ** Others complain about 0x7ffffffffffffffffLL.  The following macro seems
    ** to provide the constant while making all compilers happy.
    */
#   define MAX_ROWID  (i64)( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
#endif

    if( !u.bf.pC->useRandomRowid ){
      u.bf.v = sqlite3BtreeGetCachedRowid(u.bf.pC->pCursor);
      if( u.bf.v==0 ){
        rc = sqlite3BtreeLast(u.bf.pC->pCursor, &u.bf.res);
        if( rc!=SQLITE_OK ){
          goto abort_due_to_error;
        }
        if( u.bf.res ){
          u.bf.v = 1;   /* IMP: R-61914-48074 */
        }else{
          assert( sqlite3BtreeCursorIsValid(u.bf.pC->pCursor) );
          rc = sqlite3BtreeKeySize(u.bf.pC->pCursor, &u.bf.v);
          assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
          if( u.bf.v==MAX_ROWID ){
            u.bf.pC->useRandomRowid = 1;
          }else{
            u.bf.v++;   /* IMP: R-29538-34987 */
          }
        }
      }

#ifndef SQLITE_OMIT_AUTOINCREMENT
      if( pOp->p3 ){
        /* Assert that P3 is a valid memory cell. */
        assert( pOp->p3>0 );
        if( p->pFrame ){
          for(u.bf.pFrame=p->pFrame; u.bf.pFrame->pParent; u.bf.pFrame=u.bf.pFrame->pParent);
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=u.bf.pFrame->nMem );
          u.bf.pMem = &u.bf.pFrame->aMem[pOp->p3];
        }else{
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=p->nMem );
          u.bf.pMem = &aMem[pOp->p3];
          memAboutToChange(p, u.bf.pMem);
        }
        assert( memIsValid(u.bf.pMem) );

        REGISTER_TRACE(pOp->p3, u.bf.pMem);
        sqlite3VdbeMemIntegerify(u.bf.pMem);
        assert( (u.bf.pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
        if( u.bf.pMem->u.i==MAX_ROWID || u.bf.pC->useRandomRowid ){
          rc = SQLITE_FULL;   /* IMP: R-12275-61338 */
          goto abort_due_to_error;
        }
        if( u.bf.v<u.bf.pMem->u.i+1 ){
          u.bf.v = u.bf.pMem->u.i + 1;
        }
        u.bf.pMem->u.i = u.bf.v;
      }
#endif

      sqlite3BtreeSetCachedRowid(u.bf.pC->pCursor, u.bf.v<MAX_ROWID ? u.bf.v+1 : 0);
    }
    if( u.bf.pC->useRandomRowid ){
      /* IMPLEMENTATION-OF: R-07677-41881 If the largest ROWID is equal to the
      ** largest possible integer (9223372036854775807) then the database
      ** engine starts picking positive candidate ROWIDs at random until
      ** it finds one that is not previously used. */
      assert( pOp->p3==0 );  /* We cannot be in random rowid mode if this is
                             ** an AUTOINCREMENT table. */
      /* on the first attempt, simply do one more than previous */
      u.bf.v = lastRowid;
      u.bf.v &= (MAX_ROWID>>1); /* ensure doesn't go negative */
      u.bf.v++; /* ensure non-zero */
      u.bf.cnt = 0;
      while(   ((rc = sqlite3BtreeMovetoUnpacked(u.bf.pC->pCursor, 0, (u64)u.bf.v,
                                                 0, &u.bf.res))==SQLITE_OK)
            && (u.bf.res==0)
            && (++u.bf.cnt<100)){
        /* collision - try another random rowid */
        sqlite3_randomness(sizeof(u.bf.v), &u.bf.v);
        if( u.bf.cnt<5 ){
          /* try "small" random rowids for the initial attempts */
          u.bf.v &= 0xffffff;
        }else{
          u.bf.v &= (MAX_ROWID>>1); /* ensure doesn't go negative */
        }
        u.bf.v++; /* ensure non-zero */
      }
      if( rc==SQLITE_OK && u.bf.res==0 ){
        rc = SQLITE_FULL;   /* IMP: R-38219-53002 */
        goto abort_due_to_error;
      }
      assert( u.bf.v>0 );  /* EV: R-40812-03570 */
    }
    u.bf.pC->rowidIsValid = 0;
    u.bf.pC->deferredMoveto = 0;
    u.bf.pC->cacheStatus = CACHE_STALE;
  }
  pOut->u.i = u.bf.v;
  break;
}

/* Opcode: Insert P1 P2 P3 P4 P5
**
** Write an entry into the table of cursor P1.  A new entry is
** created if it doesn't already exist or the data for an existing
................................................................................
/* Opcode: InsertInt P1 P2 P3 P4 P5
**
** This works exactly like OP_Insert except that the key is the
** integer value P3, not the value of the integer stored in register P3.
*/
case OP_Insert: 
case OP_InsertInt: {
#if 0  /* local variables moved into u.bg */
  Mem *pData;       /* MEM cell holding data for the record to be inserted */
  Mem *pKey;        /* MEM cell holding key  for the record */
  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
  VdbeCursor *pC;   /* Cursor to table into which insert is written */
  int nZero;        /* Number of zero-bytes to append */
  int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
  const char *zDb;  /* database name - used by the update hook */
  const char *zTbl; /* Table name - used by the opdate hook */
  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
#endif /* local variables moved into u.bg */

  u.bg.pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(u.bg.pData) );
  u.bg.pC = p->apCsr[pOp->p1];
  assert( u.bg.pC!=0 );
  assert( u.bg.pC->pCursor!=0 );
  assert( u.bg.pC->pseudoTableReg==0 );
  assert( u.bg.pC->isTable );
  REGISTER_TRACE(pOp->p2, u.bg.pData);

  if( pOp->opcode==OP_Insert ){
    u.bg.pKey = &aMem[pOp->p3];
    assert( u.bg.pKey->flags & MEM_Int );
    assert( memIsValid(u.bg.pKey) );
    REGISTER_TRACE(pOp->p3, u.bg.pKey);
    u.bg.iKey = u.bg.pKey->u.i;
  }else{
    assert( pOp->opcode==OP_InsertInt );
    u.bg.iKey = pOp->p3;
  }

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = u.bg.iKey;
  if( u.bg.pData->flags & MEM_Null ){
    u.bg.pData->z = 0;
    u.bg.pData->n = 0;
  }else{
    assert( u.bg.pData->flags & (MEM_Blob|MEM_Str) );
  }
  u.bg.seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? u.bg.pC->seekResult : 0);
  if( u.bg.pData->flags & MEM_Zero ){
    u.bg.nZero = u.bg.pData->u.nZero;
  }else{
    u.bg.nZero = 0;
  }
  sqlite3BtreeSetCachedRowid(u.bg.pC->pCursor, 0);
  rc = sqlite3BtreeInsert(u.bg.pC->pCursor, 0, u.bg.iKey,
                          u.bg.pData->z, u.bg.pData->n, u.bg.nZero,
                          pOp->p5 & OPFLAG_APPEND, u.bg.seekResult
  );
  u.bg.pC->rowidIsValid = 0;
  u.bg.pC->deferredMoveto = 0;
  u.bg.pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
    u.bg.zDb = db->aDb[u.bg.pC->iDb].zName;
    u.bg.zTbl = pOp->p4.z;
    u.bg.op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
    assert( u.bg.pC->isTable );
    db->xUpdateCallback(db->pUpdateArg, u.bg.op, u.bg.zDb, u.bg.zTbl, u.bg.iKey);
    assert( u.bg.pC->iDb>=0 );
  }
  break;
}

/* Opcode: Delete P1 P2 * P4 *
**
** Delete the record at which the P1 cursor is currently pointing.
................................................................................
**
** If P4 is not NULL, then it is the name of the table that P1 is
** pointing to.  The update hook will be invoked, if it exists.
** If P4 is not NULL then the P1 cursor must have been positioned
** using OP_NotFound prior to invoking this opcode.
*/
case OP_Delete: {
#if 0  /* local variables moved into u.bh */
  i64 iKey;
  VdbeCursor *pC;
#endif /* local variables moved into u.bh */

  u.bh.iKey = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bh.pC = p->apCsr[pOp->p1];
  assert( u.bh.pC!=0 );
  assert( u.bh.pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */

  /* If the update-hook will be invoked, set u.bh.iKey to the rowid of the
  ** row being deleted.
  */
  if( db->xUpdateCallback && pOp->p4.z ){
    assert( u.bh.pC->isTable );
    assert( u.bh.pC->rowidIsValid );  /* lastRowid set by previous OP_NotFound */
    u.bh.iKey = u.bh.pC->lastRowid;
  }

  /* The OP_Delete opcode always follows an OP_NotExists or OP_Last or
  ** OP_Column on the same table without any intervening operations that
  ** might move or invalidate the cursor.  Hence cursor u.bh.pC is always pointing
  ** to the row to be deleted and the sqlite3VdbeCursorMoveto() operation
  ** below is always a no-op and cannot fail.  We will run it anyhow, though,
  ** to guard against future changes to the code generator.
  **/
  assert( u.bh.pC->deferredMoveto==0 );
  rc = sqlite3VdbeCursorMoveto(u.bh.pC);
  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  sqlite3BtreeSetCachedRowid(u.bh.pC->pCursor, 0);
  rc = sqlite3BtreeDelete(u.bh.pC->pCursor);
  u.bh.pC->cacheStatus = CACHE_STALE;

  /* Invoke the update-hook if required. */
  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
    const char *zDb = db->aDb[u.bh.pC->iDb].zName;
    const char *zTbl = pOp->p4.z;
    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, u.bh.iKey);
    assert( u.bh.pC->iDb>=0 );
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
/* Opcode: ResetCount * * * * *
**
** The value of the change counter is copied to the database handle
................................................................................
** This is used by trigger programs.
*/
case OP_ResetCount: {
  sqlite3VdbeSetChanges(db, p->nChange);
  p->nChange = 0;
  break;
}

/* Opcode: SorterCompare P1 P2 P3
**
** P1 is a sorter cursor. This instruction compares the record blob in 
** register P3 with the entry that the sorter cursor currently points to.
** If, excluding the rowid fields at the end, the two records are a match,
** fall through to the next instruction. Otherwise, jump to instruction P2.
*/
case OP_SorterCompare: {
#if 0  /* local variables moved into u.bi */
  VdbeCursor *pC;
  int res;
#endif /* local variables moved into u.bi */

  u.bi.pC = p->apCsr[pOp->p1];
  assert( isSorter(u.bi.pC) );
  pIn3 = &aMem[pOp->p3];
  rc = sqlite3VdbeSorterCompare(u.bi.pC, pIn3, &u.bi.res);
  if( u.bi.res ){
    pc = pOp->p2-1;
  }
  break;
};

/* Opcode: SorterData P1 P2 * * *
**
** Write into register P2 the current sorter data for sorter cursor P1.
*/
case OP_SorterData: {
#if 0  /* local variables moved into u.bj */
  VdbeCursor *pC;
#endif /* local variables moved into u.bj */
#ifndef SQLITE_OMIT_MERGE_SORT
  pOut = &aMem[pOp->p2];
  u.bj.pC = p->apCsr[pOp->p1];
  assert( u.bj.pC->isSorter );
  rc = sqlite3VdbeSorterRowkey(u.bj.pC, pOut);
#else
  pOp->opcode = OP_RowKey;
  pc--;
#endif
  break;
}

/* Opcode: RowData P1 P2 * * *
**
** Write into register P2 the complete row data for cursor P1.
** There is no interpretation of the data.  
** It is just copied onto the P2 register exactly as 
** it is found in the database file.
................................................................................
** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/
case OP_RowKey:
case OP_RowData: {
#if 0  /* local variables moved into u.bk */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  u32 n;
  i64 n64;
#endif /* local variables moved into u.bk */

  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bk.pC = p->apCsr[pOp->p1];
  assert( u.bk.pC->isSorter==0 );
  assert( u.bk.pC->isTable || pOp->opcode!=OP_RowData );
  assert( u.bk.pC->isIndex || pOp->opcode==OP_RowData );
  assert( u.bk.pC!=0 );
  assert( u.bk.pC->nullRow==0 );
  assert( u.bk.pC->pseudoTableReg==0 );
  assert( !u.bk.pC->isSorter );
  assert( u.bk.pC->pCursor!=0 );
  u.bk.pCrsr = u.bk.pC->pCursor;
  assert( sqlite3BtreeCursorIsValid(u.bk.pCrsr) );

  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
  ** the cursor.  Hence the following sqlite3VdbeCursorMoveto() call is always
  ** a no-op and can never fail.  But we leave it in place as a safety.
  */
  assert( u.bk.pC->deferredMoveto==0 );
  rc = sqlite3VdbeCursorMoveto(u.bk.pC);
  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  if( u.bk.pC->isIndex ){
    assert( !u.bk.pC->isTable );
    rc = sqlite3BtreeKeySize(u.bk.pCrsr, &u.bk.n64);
    assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
    if( u.bk.n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    u.bk.n = (u32)u.bk.n64;
  }else{
    rc = sqlite3BtreeDataSize(u.bk.pCrsr, &u.bk.n);
    assert( rc==SQLITE_OK );    /* DataSize() cannot fail */
    if( u.bk.n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
  }
  if( sqlite3VdbeMemGrow(pOut, u.bk.n, 0) ){
    goto no_mem;
  }
  pOut->n = u.bk.n;
  MemSetTypeFlag(pOut, MEM_Blob);
  if( u.bk.pC->isIndex ){
    rc = sqlite3BtreeKey(u.bk.pCrsr, 0, u.bk.n, pOut->z);
  }else{
    rc = sqlite3BtreeData(u.bk.pCrsr, 0, u.bk.n, pOut->z);
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Rowid P1 P2 * * *
................................................................................
** P1 is currently point to.
**
** P1 can be either an ordinary table or a virtual table.  There used to
** be a separate OP_VRowid opcode for use with virtual tables, but this
** one opcode now works for both table types.
*/
case OP_Rowid: {                 /* out2-prerelease */
#if 0  /* local variables moved into u.bl */
  VdbeCursor *pC;
  i64 v;
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
#endif /* local variables moved into u.bl */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bl.pC = p->apCsr[pOp->p1];
  assert( u.bl.pC!=0 );
  assert( u.bl.pC->pseudoTableReg==0 );
  if( u.bl.pC->nullRow ){
    pOut->flags = MEM_Null;
    break;
  }else if( u.bl.pC->deferredMoveto ){
    u.bl.v = u.bl.pC->movetoTarget;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  }else if( u.bl.pC->pVtabCursor ){
    u.bl.pVtab = u.bl.pC->pVtabCursor->pVtab;
    u.bl.pModule = u.bl.pVtab->pModule;
    assert( u.bl.pModule->xRowid );
    rc = u.bl.pModule->xRowid(u.bl.pC->pVtabCursor, &u.bl.v);
    importVtabErrMsg(p, u.bl.pVtab);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  }else{
    assert( u.bl.pC->pCursor!=0 );
    rc = sqlite3VdbeCursorMoveto(u.bl.pC);
    if( rc ) goto abort_due_to_error;
    if( u.bl.pC->rowidIsValid ){
      u.bl.v = u.bl.pC->lastRowid;
    }else{
      rc = sqlite3BtreeKeySize(u.bl.pC->pCursor, &u.bl.v);
      assert( rc==SQLITE_OK );  /* Always so because of CursorMoveto() above */
    }
  }
  pOut->u.i = u.bl.v;
  break;
}

/* Opcode: NullRow P1 * * * *
**
** Move the cursor P1 to a null row.  Any OP_Column operations
** that occur while the cursor is on the null row will always
** write a NULL.
*/
case OP_NullRow: {
#if 0  /* local variables moved into u.bm */
  VdbeCursor *pC;
#endif /* local variables moved into u.bm */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bm.pC = p->apCsr[pOp->p1];
  assert( u.bm.pC!=0 );
  u.bm.pC->nullRow = 1;
  u.bm.pC->rowidIsValid = 0;
  assert( u.bm.pC->pCursor || u.bm.pC->pVtabCursor );
  if( u.bm.pC->pCursor ){
    sqlite3BtreeClearCursor(u.bm.pC->pCursor);
  }
  break;
}

/* Opcode: Last P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Last: {        /* jump */
#if 0  /* local variables moved into u.bn */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
#endif /* local variables moved into u.bn */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bn.pC = p->apCsr[pOp->p1];
  assert( u.bn.pC!=0 );
  u.bn.pCrsr = u.bn.pC->pCursor;
  if( NEVER(u.bn.pCrsr==0) ){
    u.bn.res = 1;
  }else{
    rc = sqlite3BtreeLast(u.bn.pCrsr, &u.bn.res);
  }
  u.bn.pC->nullRow = (u8)u.bn.res;
  u.bn.pC->deferredMoveto = 0;
  u.bn.pC->rowidIsValid = 0;
  u.bn.pC->cacheStatus = CACHE_STALE;
  if( pOp->p2>0 && u.bn.res ){
    pc = pOp->p2 - 1;
  }
  break;
}


/* Opcode: Sort P1 P2 * * *
................................................................................
** Sorting is accomplished by writing records into a sorting index,
** then rewinding that index and playing it back from beginning to
** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
** rewinding so that the global variable will be incremented and
** regression tests can determine whether or not the optimizer is
** correctly optimizing out sorts.
*/
case OP_SorterSort:    /* jump */
#ifdef SQLITE_OMIT_MERGE_SORT
  pOp->opcode = OP_Sort;
#endif
case OP_Sort: {        /* jump */
#ifdef SQLITE_TEST
  sqlite3_sort_count++;
  sqlite3_search_count--;
#endif
  p->aCounter[SQLITE_STMTSTATUS_SORT-1]++;
  /* Fall through into OP_Rewind */
................................................................................
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Rewind: {        /* jump */
#if 0  /* local variables moved into u.bo */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
#endif /* local variables moved into u.bo */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bo.pC = p->apCsr[pOp->p1];
  assert( u.bo.pC!=0 );
  assert( u.bo.pC->isSorter==(pOp->opcode==OP_SorterSort) );
  u.bo.res = 1;

  if( isSorter(u.bo.pC) ){
    rc = sqlite3VdbeSorterRewind(db, u.bo.pC, &u.bo.res);
  }else{
    u.bo.pCrsr = u.bo.pC->pCursor;
    assert( u.bo.pCrsr );
    rc = sqlite3BtreeFirst(u.bo.pCrsr, &u.bo.res);
    u.bo.pC->atFirst = u.bo.res==0 ?1:0;
    u.bo.pC->deferredMoveto = 0;
    u.bo.pC->cacheStatus = CACHE_STALE;
    u.bo.pC->rowidIsValid = 0;
  }
  u.bo.pC->nullRow = (u8)u.bo.res;
  assert( pOp->p2>0 && pOp->p2<p->nOp );
  if( u.bo.res ){
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: Next P1 P2 * P4 P5
**
** Advance cursor P1 so that it points to the next key/data pair in its
** table or index.  If there are no more key/value pairs then fall through
** to the following instruction.  But if the cursor advance was successful,
** jump immediately to P2.
**
** The P1 cursor must be for a real table, not a pseudo-table.
**
** P4 is always of type P4_ADVANCE. The function pointer points to
** sqlite3BtreeNext().
**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
**
** See also: Prev
*/
/* Opcode: Prev P1 P2 * * P5
................................................................................
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index.  If there is no previous key/value pairs then fall through
** to the following instruction.  But if the cursor backup was successful,
** jump immediately to P2.
**
** The P1 cursor must be for a real table, not a pseudo-table.
**
** P4 is always of type P4_ADVANCE. The function pointer points to
** sqlite3BtreePrevious().
**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
*/
case OP_SorterNext:    /* jump */
#ifdef SQLITE_OMIT_MERGE_SORT
  pOp->opcode = OP_Next;
#endif
case OP_Prev:          /* jump */
case OP_Next: {        /* jump */
#if 0  /* local variables moved into u.bp */
  VdbeCursor *pC;

  int res;
#endif /* local variables moved into u.bp */

  CHECK_FOR_INTERRUPT;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p5<=ArraySize(p->aCounter) );
  u.bp.pC = p->apCsr[pOp->p1];
  if( u.bp.pC==0 ){
    break;  /* See ticket #2273 */
  }
  assert( u.bp.pC->isSorter==(pOp->opcode==OP_SorterNext) );
  if( isSorter(u.bp.pC) ){
    assert( pOp->opcode==OP_SorterNext );
    rc = sqlite3VdbeSorterNext(db, u.bp.pC, &u.bp.res);
  }else{
    u.bp.res = 1;
    assert( u.bp.pC->deferredMoveto==0 );
    assert( u.bp.pC->pCursor );
    assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
    assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
    rc = pOp->p4.xAdvance(u.bp.pC->pCursor, &u.bp.res);
  }
  u.bp.pC->nullRow = (u8)u.bp.res;
  u.bp.pC->cacheStatus = CACHE_STALE;
  if( u.bp.res==0 ){
    pc = pOp->p2 - 1;
    if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
  }
  u.bp.pC->rowidIsValid = 0;
  break;
}

/* Opcode: IdxInsert P1 P2 P3 * P5
**
** Register P2 holds an SQL index key made using the
** MakeRecord instructions.  This opcode writes that key
................................................................................
**
** P3 is a flag that provides a hint to the b-tree layer that this
** insert is likely to be an append.
**
** This instruction only works for indices.  The equivalent instruction
** for tables is OP_Insert.
*/
case OP_SorterInsert:       /* in2 */
#ifdef SQLITE_OMIT_MERGE_SORT
  pOp->opcode = OP_IdxInsert;
#endif
case OP_IdxInsert: {        /* in2 */
#if 0  /* local variables moved into u.bq */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int nKey;
  const char *zKey;
#endif /* local variables moved into u.bq */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bq.pC = p->apCsr[pOp->p1];
  assert( u.bq.pC!=0 );
  assert( u.bq.pC->isSorter==(pOp->opcode==OP_SorterInsert) );
  pIn2 = &aMem[pOp->p2];
  assert( pIn2->flags & MEM_Blob );
  u.bq.pCrsr = u.bq.pC->pCursor;
  if( ALWAYS(u.bq.pCrsr!=0) ){
    assert( u.bq.pC->isTable==0 );
    rc = ExpandBlob(pIn2);
    if( rc==SQLITE_OK ){
      if( isSorter(u.bq.pC) ){
        rc = sqlite3VdbeSorterWrite(db, u.bq.pC, pIn2);
      }else{
        u.bq.nKey = pIn2->n;
        u.bq.zKey = pIn2->z;

        rc = sqlite3BtreeInsert(u.bq.pCrsr, u.bq.zKey, u.bq.nKey, "", 0, 0, pOp->p3,
            ((pOp->p5 & OPFLAG_USESEEKRESULT) ? u.bq.pC->seekResult : 0)
            );
        assert( u.bq.pC->deferredMoveto==0 );
        u.bq.pC->cacheStatus = CACHE_STALE;
      }
    }
  }
  break;
}

/* Opcode: IdxDelete P1 P2 P3 * *
**
** The content of P3 registers starting at register P2 form
** an unpacked index key. This opcode removes that entry from the 
** index opened by cursor P1.
*/
case OP_IdxDelete: {
#if 0  /* local variables moved into u.br */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  UnpackedRecord r;
#endif /* local variables moved into u.br */

  assert( pOp->p3>0 );
  assert( pOp->p2>0 && pOp->p2+pOp->p3<=p->nMem+1 );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.br.pC = p->apCsr[pOp->p1];
  assert( u.br.pC!=0 );
  u.br.pCrsr = u.br.pC->pCursor;
  if( ALWAYS(u.br.pCrsr!=0) ){
    u.br.r.pKeyInfo = u.br.pC->pKeyInfo;
    u.br.r.nField = (u16)pOp->p3;
    u.br.r.flags = 0;
    u.br.r.aMem = &aMem[pOp->p2];
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<u.br.r.nField; i++) assert( memIsValid(&u.br.r.aMem[i]) ); }
#endif
    rc = sqlite3BtreeMovetoUnpacked(u.br.pCrsr, &u.br.r, 0, 0, &u.br.res);
    if( rc==SQLITE_OK && u.br.res==0 ){
      rc = sqlite3BtreeDelete(u.br.pCrsr);
    }
    assert( u.br.pC->deferredMoveto==0 );
    u.br.pC->cacheStatus = CACHE_STALE;
  }
  break;
}

/* Opcode: IdxRowid P1 P2 * * *
**
** Write into register P2 an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1.  This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeRecord.
*/
case OP_IdxRowid: {              /* out2-prerelease */
#if 0  /* local variables moved into u.bs */
  BtCursor *pCrsr;
  VdbeCursor *pC;
  i64 rowid;
#endif /* local variables moved into u.bs */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bs.pC = p->apCsr[pOp->p1];
  assert( u.bs.pC!=0 );
  u.bs.pCrsr = u.bs.pC->pCursor;
  pOut->flags = MEM_Null;
  if( ALWAYS(u.bs.pCrsr!=0) ){
    rc = sqlite3VdbeCursorMoveto(u.bs.pC);
    if( NEVER(rc) ) goto abort_due_to_error;
    assert( u.bs.pC->deferredMoveto==0 );
    assert( u.bs.pC->isTable==0 );
    if( !u.bs.pC->nullRow ){
      rc = sqlite3VdbeIdxRowid(db, u.bs.pCrsr, &u.bs.rowid);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pOut->u.i = u.bs.rowid;
      pOut->flags = MEM_Int;
    }
  }
  break;
}

/* Opcode: IdxGE P1 P2 P3 P4 P5
................................................................................
** Otherwise fall through to the next instruction.
**
** If P5 is non-zero then the key value is increased by an epsilon prior 
** to the comparison.  This makes the opcode work like IdxLE.
*/
case OP_IdxLT:          /* jump */
case OP_IdxGE: {        /* jump */
#if 0  /* local variables moved into u.bt */
  VdbeCursor *pC;
  int res;
  UnpackedRecord r;
#endif /* local variables moved into u.bt */

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  u.bt.pC = p->apCsr[pOp->p1];
  assert( u.bt.pC!=0 );
  assert( u.bt.pC->isOrdered );
  if( ALWAYS(u.bt.pC->pCursor!=0) ){
    assert( u.bt.pC->deferredMoveto==0 );
    assert( pOp->p5==0 || pOp->p5==1 );
    assert( pOp->p4type==P4_INT32 );
    u.bt.r.pKeyInfo = u.bt.pC->pKeyInfo;
    u.bt.r.nField = (u16)pOp->p4.i;
    if( pOp->p5 ){
      u.bt.r.flags = UNPACKED_INCRKEY | UNPACKED_IGNORE_ROWID;
    }else{
      u.bt.r.flags = UNPACKED_IGNORE_ROWID;
    }
    u.bt.r.aMem = &aMem[pOp->p3];
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<u.bt.r.nField; i++) assert( memIsValid(&u.bt.r.aMem[i]) ); }
#endif
    rc = sqlite3VdbeIdxKeyCompare(u.bt.pC, &u.bt.r, &u.bt.res);
    if( pOp->opcode==OP_IdxLT ){
      u.bt.res = -u.bt.res;
    }else{
      assert( pOp->opcode==OP_IdxGE );
      u.bt.res++;
    }
    if( u.bt.res>0 ){
      pc = pOp->p2 - 1 ;
    }
  }
  break;
}

/* Opcode: Destroy P1 P2 P3 * *
................................................................................
** movement was required (because the table being dropped was already 
** the last one in the database) then a zero is stored in register P2.
** If AUTOVACUUM is disabled then a zero is stored in register P2.
**
** See also: Clear
*/
case OP_Destroy: {     /* out2-prerelease */
#if 0  /* local variables moved into u.bu */
  int iMoved;
  int iCnt;
  Vdbe *pVdbe;
  int iDb;
#endif /* local variables moved into u.bu */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  u.bu.iCnt = 0;
  for(u.bu.pVdbe=db->pVdbe; u.bu.pVdbe; u.bu.pVdbe = u.bu.pVdbe->pNext){
    if( u.bu.pVdbe->magic==VDBE_MAGIC_RUN && u.bu.pVdbe->inVtabMethod<2 && u.bu.pVdbe->pc>=0 ){
      u.bu.iCnt++;
    }
  }
#else
  u.bu.iCnt = db->activeVdbeCnt;
#endif
  pOut->flags = MEM_Null;
  if( u.bu.iCnt>1 ){
    rc = SQLITE_LOCKED;
    p->errorAction = OE_Abort;
  }else{
    u.bu.iDb = pOp->p3;
    assert( u.bu.iCnt==1 );
    assert( (p->btreeMask & (((yDbMask)1)<<u.bu.iDb))!=0 );
    rc = sqlite3BtreeDropTable(db->aDb[u.bu.iDb].pBt, pOp->p1, &u.bu.iMoved);
    pOut->flags = MEM_Int;
    pOut->u.i = u.bu.iMoved;
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( rc==SQLITE_OK && u.bu.iMoved!=0 ){
      sqlite3RootPageMoved(db, u.bu.iDb, u.bu.iMoved, pOp->p1);
      /* All OP_Destroy operations occur on the same btree */
      assert( resetSchemaOnFault==0 || resetSchemaOnFault==u.bu.iDb+1 );
      resetSchemaOnFault = u.bu.iDb+1;
    }
#endif
  }
  break;
}

/* Opcode: Clear P1 P2 P3
................................................................................
** count is incremented by the number of rows in the table being cleared. 
** If P3 is greater than zero, then the value stored in register P3 is
** also incremented by the number of rows in the table being cleared.
**
** See also: Destroy
*/
case OP_Clear: {
#if 0  /* local variables moved into u.bv */
  int nChange;
#endif /* local variables moved into u.bv */

  u.bv.nChange = 0;
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p2))!=0 );
  rc = sqlite3BtreeClearTable(
      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &u.bv.nChange : 0)
  );
  if( pOp->p3 ){
    p->nChange += u.bv.nChange;
    if( pOp->p3>0 ){
      assert( memIsValid(&aMem[pOp->p3]) );
      memAboutToChange(p, &aMem[pOp->p3]);
      aMem[pOp->p3].u.i += u.bv.nChange;
    }
  }
  break;
}

/* Opcode: CreateTable P1 P2 * * *
**
................................................................................
** P1>1.  Write the root page number of the new table into
** register P2.
**
** See documentation on OP_CreateTable for additional information.
*/
case OP_CreateIndex:            /* out2-prerelease */
case OP_CreateTable: {          /* out2-prerelease */
#if 0  /* local variables moved into u.bw */
  int pgno;
  int flags;
  Db *pDb;
#endif /* local variables moved into u.bw */

  u.bw.pgno = 0;
  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
  u.bw.pDb = &db->aDb[pOp->p1];
  assert( u.bw.pDb->pBt!=0 );
  if( pOp->opcode==OP_CreateTable ){
    /* u.bw.flags = BTREE_INTKEY; */
    u.bw.flags = BTREE_INTKEY;
  }else{
    u.bw.flags = BTREE_BLOBKEY;
  }
  rc = sqlite3BtreeCreateTable(u.bw.pDb->pBt, &u.bw.pgno, u.bw.flags);
  pOut->u.i = u.bw.pgno;
  break;
}

/* Opcode: ParseSchema P1 * * P4 *
**
** Read and parse all entries from the SQLITE_MASTER table of database P1
** that match the WHERE clause P4. 
**
** This opcode invokes the parser to create a new virtual machine,
** then runs the new virtual machine.  It is thus a re-entrant opcode.
*/
case OP_ParseSchema: {
#if 0  /* local variables moved into u.bx */
  int iDb;
  const char *zMaster;
  char *zSql;
  InitData initData;
#endif /* local variables moved into u.bx */

  /* Any prepared statement that invokes this opcode will hold mutexes
  ** on every btree.  This is a prerequisite for invoking
  ** sqlite3InitCallback().
  */
#ifdef SQLITE_DEBUG
  for(u.bx.iDb=0; u.bx.iDb<db->nDb; u.bx.iDb++){
    assert( u.bx.iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[u.bx.iDb].pBt) );
  }
#endif

  u.bx.iDb = pOp->p1;
  assert( u.bx.iDb>=0 && u.bx.iDb<db->nDb );
  assert( DbHasProperty(db, u.bx.iDb, DB_SchemaLoaded) );
  /* Used to be a conditional */ {
    u.bx.zMaster = SCHEMA_TABLE(u.bx.iDb);
    u.bx.initData.db = db;
    u.bx.initData.iDb = pOp->p1;
    u.bx.initData.pzErrMsg = &p->zErrMsg;
    u.bx.zSql = sqlite3MPrintf(db,
       "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
       db->aDb[u.bx.iDb].zName, u.bx.zMaster, pOp->p4.z);
    if( u.bx.zSql==0 ){
      rc = SQLITE_NOMEM;
    }else{
      assert( db->init.busy==0 );
      db->init.busy = 1;
      u.bx.initData.rc = SQLITE_OK;
      assert( !db->mallocFailed );
      rc = sqlite3_exec(db, u.bx.zSql, sqlite3InitCallback, &u.bx.initData, 0);
      if( rc==SQLITE_OK ) rc = u.bx.initData.rc;
      sqlite3DbFree(db, u.bx.zSql);
      db->init.busy = 0;
    }
  }
  if( rc==SQLITE_NOMEM ){
    goto no_mem;
  }
  break;
................................................................................
**
** If P5 is not zero, the check is done on the auxiliary database
** file, not the main database file.
**
** This opcode is used to implement the integrity_check pragma.
*/
case OP_IntegrityCk: {
#if 0  /* local variables moved into u.by */
  int nRoot;      /* Number of tables to check.  (Number of root pages.) */
  int *aRoot;     /* Array of rootpage numbers for tables to be checked */
  int j;          /* Loop counter */
  int nErr;       /* Number of errors reported */
  char *z;        /* Text of the error report */
  Mem *pnErr;     /* Register keeping track of errors remaining */
#endif /* local variables moved into u.by */

  u.by.nRoot = pOp->p2;
  assert( u.by.nRoot>0 );
  u.by.aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(u.by.nRoot+1) );
  if( u.by.aRoot==0 ) goto no_mem;
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.by.pnErr = &aMem[pOp->p3];
  assert( (u.by.pnErr->flags & MEM_Int)!=0 );
  assert( (u.by.pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &aMem[pOp->p1];
  for(u.by.j=0; u.by.j<u.by.nRoot; u.by.j++){
    u.by.aRoot[u.by.j] = (int)sqlite3VdbeIntValue(&pIn1[u.by.j]);
  }
  u.by.aRoot[u.by.j] = 0;
  assert( pOp->p5<db->nDb );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p5))!=0 );
  u.by.z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, u.by.aRoot, u.by.nRoot,
                                 (int)u.by.pnErr->u.i, &u.by.nErr);
  sqlite3DbFree(db, u.by.aRoot);
  u.by.pnErr->u.i -= u.by.nErr;
  sqlite3VdbeMemSetNull(pIn1);
  if( u.by.nErr==0 ){
    assert( u.by.z==0 );
  }else if( u.by.z==0 ){
    goto no_mem;
  }else{
    sqlite3VdbeMemSetStr(pIn1, u.by.z, -1, SQLITE_UTF8, sqlite3_free);
  }
  UPDATE_MAX_BLOBSIZE(pIn1);
  sqlite3VdbeChangeEncoding(pIn1, encoding);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

................................................................................
/* Opcode: RowSetRead P1 P2 P3 * *
**
** Extract the smallest value from boolean index P1 and put that value into
** register P3.  Or, if boolean index P1 is initially empty, leave P3
** unchanged and jump to instruction P2.
*/
case OP_RowSetRead: {       /* jump, in1, out3 */
#if 0  /* local variables moved into u.bz */
  i64 val;
#endif /* local variables moved into u.bz */
  CHECK_FOR_INTERRUPT;
  pIn1 = &aMem[pOp->p1];
  if( (pIn1->flags & MEM_RowSet)==0
   || sqlite3RowSetNext(pIn1->u.pRowSet, &u.bz.val)==0
  ){
    /* The boolean index is empty */
    sqlite3VdbeMemSetNull(pIn1);
    pc = pOp->p2 - 1;
  }else{
    /* A value was pulled from the index */
    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], u.bz.val);
  }
  break;
}

/* Opcode: RowSetTest P1 P2 P3 P4
**
** Register P3 is assumed to hold a 64-bit integer value. If register P1
................................................................................
** (b) when P4==-1 there is no need to insert the value, as it will
** never be tested for, and (c) when a value that is part of set X is
** inserted, there is no need to search to see if the same value was
** previously inserted as part of set X (only if it was previously
** inserted as part of some other set).
*/
case OP_RowSetTest: {                     /* jump, in1, in3 */
#if 0  /* local variables moved into u.ca */
  int iSet;
  int exists;
#endif /* local variables moved into u.ca */

  pIn1 = &aMem[pOp->p1];
  pIn3 = &aMem[pOp->p3];
  u.ca.iSet = pOp->p4.i;
  assert( pIn3->flags&MEM_Int );

  /* If there is anything other than a rowset object in memory cell P1,
  ** delete it now and initialize P1 with an empty rowset
  */
  if( (pIn1->flags & MEM_RowSet)==0 ){
    sqlite3VdbeMemSetRowSet(pIn1);
    if( (pIn1->flags & MEM_RowSet)==0 ) goto no_mem;
  }

  assert( pOp->p4type==P4_INT32 );
  assert( u.ca.iSet==-1 || u.ca.iSet>=0 );
  if( u.ca.iSet ){
    u.ca.exists = sqlite3RowSetTest(pIn1->u.pRowSet,
                               (u8)(u.ca.iSet>=0 ? u.ca.iSet & 0xf : 0xff),
                               pIn3->u.i);
    if( u.ca.exists ){
      pc = pOp->p2 - 1;
      break;
    }
  }
  if( u.ca.iSet>=0 ){
    sqlite3RowSetInsert(pIn1->u.pRowSet, pIn3->u.i);
  }
  break;
}


#ifndef SQLITE_OMIT_TRIGGER
................................................................................
** exception using the RAISE() function. Register P3 contains the address 
** of a memory cell in this (the parent) VM that is used to allocate the 
** memory required by the sub-vdbe at runtime.
**
** P4 is a pointer to the VM containing the trigger program.
*/
case OP_Program: {        /* jump */
#if 0  /* local variables moved into u.cb */
  int nMem;               /* Number of memory registers for sub-program */
  int nByte;              /* Bytes of runtime space required for sub-program */
  Mem *pRt;               /* Register to allocate runtime space */
  Mem *pMem;              /* Used to iterate through memory cells */
  Mem *pEnd;              /* Last memory cell in new array */
  VdbeFrame *pFrame;      /* New vdbe frame to execute in */
  SubProgram *pProgram;   /* Sub-program to execute */
  void *t;                /* Token identifying trigger */
#endif /* local variables moved into u.cb */

  u.cb.pProgram = pOp->p4.pProgram;
  u.cb.pRt = &aMem[pOp->p3];
  assert( memIsValid(u.cb.pRt) );
  assert( u.cb.pProgram->nOp>0 );

  /* If the p5 flag is clear, then recursive invocation of triggers is
  ** disabled for backwards compatibility (p5 is set if this sub-program
  ** is really a trigger, not a foreign key action, and the flag set
  ** and cleared by the "PRAGMA recursive_triggers" command is clear).
  **
  ** It is recursive invocation of triggers, at the SQL level, that is
  ** disabled. In some cases a single trigger may generate more than one
  ** SubProgram (if the trigger may be executed with more than one different
  ** ON CONFLICT algorithm). SubProgram structures associated with a
  ** single trigger all have the same value for the SubProgram.token
  ** variable.  */
  if( pOp->p5 ){
    u.cb.t = u.cb.pProgram->token;
    for(u.cb.pFrame=p->pFrame; u.cb.pFrame && u.cb.pFrame->token!=u.cb.t; u.cb.pFrame=u.cb.pFrame->pParent);
    if( u.cb.pFrame ) break;
  }

  if( p->nFrame>=db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
    rc = SQLITE_ERROR;
    sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
    break;
  }

  /* Register u.cb.pRt is used to store the memory required to save the state
  ** of the current program, and the memory required at runtime to execute
  ** the trigger program. If this trigger has been fired before, then u.cb.pRt
  ** is already allocated. Otherwise, it must be initialized.  */
  if( (u.cb.pRt->flags&MEM_Frame)==0 ){
    /* SubProgram.nMem is set to the number of memory cells used by the
    ** program stored in SubProgram.aOp. As well as these, one memory
    ** cell is required for each cursor used by the program. Set local
    ** variable u.cb.nMem (and later, VdbeFrame.nChildMem) to this value.
    */
    u.cb.nMem = u.cb.pProgram->nMem + u.cb.pProgram->nCsr;
    u.cb.nByte = ROUND8(sizeof(VdbeFrame))
              + u.cb.nMem * sizeof(Mem)
              + u.cb.pProgram->nCsr * sizeof(VdbeCursor *);
    u.cb.pFrame = sqlite3DbMallocZero(db, u.cb.nByte);
    if( !u.cb.pFrame ){
      goto no_mem;
    }
    sqlite3VdbeMemRelease(u.cb.pRt);
    u.cb.pRt->flags = MEM_Frame;
    u.cb.pRt->u.pFrame = u.cb.pFrame;

    u.cb.pFrame->v = p;
    u.cb.pFrame->nChildMem = u.cb.nMem;
    u.cb.pFrame->nChildCsr = u.cb.pProgram->nCsr;
    u.cb.pFrame->pc = pc;
    u.cb.pFrame->aMem = p->aMem;
    u.cb.pFrame->nMem = p->nMem;
    u.cb.pFrame->apCsr = p->apCsr;
    u.cb.pFrame->nCursor = p->nCursor;
    u.cb.pFrame->aOp = p->aOp;
    u.cb.pFrame->nOp = p->nOp;
    u.cb.pFrame->token = u.cb.pProgram->token;

    u.cb.pEnd = &VdbeFrameMem(u.cb.pFrame)[u.cb.pFrame->nChildMem];
    for(u.cb.pMem=VdbeFrameMem(u.cb.pFrame); u.cb.pMem!=u.cb.pEnd; u.cb.pMem++){
      u.cb.pMem->flags = MEM_Null;
      u.cb.pMem->db = db;
    }
  }else{
    u.cb.pFrame = u.cb.pRt->u.pFrame;
    assert( u.cb.pProgram->nMem+u.cb.pProgram->nCsr==u.cb.pFrame->nChildMem );
    assert( u.cb.pProgram->nCsr==u.cb.pFrame->nChildCsr );
    assert( pc==u.cb.pFrame->pc );
  }

  p->nFrame++;
  u.cb.pFrame->pParent = p->pFrame;
  u.cb.pFrame->lastRowid = lastRowid;
  u.cb.pFrame->nChange = p->nChange;
  p->nChange = 0;
  p->pFrame = u.cb.pFrame;
  p->aMem = aMem = &VdbeFrameMem(u.cb.pFrame)[-1];
  p->nMem = u.cb.pFrame->nChildMem;
  p->nCursor = (u16)u.cb.pFrame->nChildCsr;
  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
  p->aOp = aOp = u.cb.pProgram->aOp;
  p->nOp = u.cb.pProgram->nOp;
  pc = -1;

  break;
}

/* Opcode: Param P1 P2 * * *
**
................................................................................
** and old.* values.
**
** The address of the cell in the parent frame is determined by adding
** the value of the P1 argument to the value of the P1 argument to the
** calling OP_Program instruction.
*/
case OP_Param: {           /* out2-prerelease */
#if 0  /* local variables moved into u.cc */
  VdbeFrame *pFrame;
  Mem *pIn;
#endif /* local variables moved into u.cc */
  u.cc.pFrame = p->pFrame;
  u.cc.pIn = &u.cc.pFrame->aMem[pOp->p1 + u.cc.pFrame->aOp[u.cc.pFrame->pc].p1];
  sqlite3VdbeMemShallowCopy(pOut, u.cc.pIn, MEM_Ephem);
  break;
}

#endif /* #ifndef SQLITE_OMIT_TRIGGER */

#ifndef SQLITE_OMIT_FOREIGN_KEY
/* Opcode: FkCounter P1 P2 * * *
................................................................................
** within a sub-program). Set the value of register P1 to the maximum of 
** its current value and the value in register P2.
**
** This instruction throws an error if the memory cell is not initially
** an integer.
*/
case OP_MemMax: {        /* in2 */
#if 0  /* local variables moved into u.cd */
  Mem *pIn1;
  VdbeFrame *pFrame;
#endif /* local variables moved into u.cd */
  if( p->pFrame ){
    for(u.cd.pFrame=p->pFrame; u.cd.pFrame->pParent; u.cd.pFrame=u.cd.pFrame->pParent);
    u.cd.pIn1 = &u.cd.pFrame->aMem[pOp->p1];
  }else{
    u.cd.pIn1 = &aMem[pOp->p1];
  }
  assert( memIsValid(u.cd.pIn1) );
  sqlite3VdbeMemIntegerify(u.cd.pIn1);
  pIn2 = &aMem[pOp->p2];
  sqlite3VdbeMemIntegerify(pIn2);
  if( u.cd.pIn1->u.i<pIn2->u.i){
    u.cd.pIn1->u.i = pIn2->u.i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: IfPos P1 P2 * * *
**
................................................................................
** structure that specifies the function.  Use register
** P3 as the accumulator.
**
** The P5 arguments are taken from register P2 and its
** successors.
*/
case OP_AggStep: {
#if 0  /* local variables moved into u.ce */
  int n;
  int i;
  Mem *pMem;
  Mem *pRec;
  sqlite3_context ctx;
  sqlite3_value **apVal;
#endif /* local variables moved into u.ce */

  u.ce.n = pOp->p5;
  assert( u.ce.n>=0 );
  u.ce.pRec = &aMem[pOp->p2];
  u.ce.apVal = p->apArg;
  assert( u.ce.apVal || u.ce.n==0 );
  for(u.ce.i=0; u.ce.i<u.ce.n; u.ce.i++, u.ce.pRec++){
    assert( memIsValid(u.ce.pRec) );
    u.ce.apVal[u.ce.i] = u.ce.pRec;
    memAboutToChange(p, u.ce.pRec);
    sqlite3VdbeMemStoreType(u.ce.pRec);
  }
  u.ce.ctx.pFunc = pOp->p4.pFunc;
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.ce.ctx.pMem = u.ce.pMem = &aMem[pOp->p3];
  u.ce.pMem->n++;
  u.ce.ctx.s.flags = MEM_Null;
  u.ce.ctx.s.z = 0;
  u.ce.ctx.s.zMalloc = 0;
  u.ce.ctx.s.xDel = 0;
  u.ce.ctx.s.db = db;
  u.ce.ctx.isError = 0;
  u.ce.ctx.pColl = 0;
  if( u.ce.ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p4type==P4_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    u.ce.ctx.pColl = pOp[-1].p4.pColl;
  }
  (u.ce.ctx.pFunc->xStep)(&u.ce.ctx, u.ce.n, u.ce.apVal); /* IMP: R-24505-23230 */
  if( u.ce.ctx.isError ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&u.ce.ctx.s));
    rc = u.ce.ctx.isError;
  }

  sqlite3VdbeMemRelease(&u.ce.ctx.s);

  break;
}

/* Opcode: AggFinal P1 P2 * P4 *
**
** Execute the finalizer function for an aggregate.  P1 is
................................................................................
** P4 is a pointer to the FuncDef for this function.  The P2
** argument is not used by this opcode.  It is only there to disambiguate
** functions that can take varying numbers of arguments.  The
** P4 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {
#if 0  /* local variables moved into u.cf */
  Mem *pMem;
#endif /* local variables moved into u.cf */
  assert( pOp->p1>0 && pOp->p1<=p->nMem );
  u.cf.pMem = &aMem[pOp->p1];
  assert( (u.cf.pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(u.cf.pMem, pOp->p4.pFunc);
  if( rc ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(u.cf.pMem));
  }
  sqlite3VdbeChangeEncoding(u.cf.pMem, encoding);
  UPDATE_MAX_BLOBSIZE(u.cf.pMem);
  if( sqlite3VdbeMemTooBig(u.cf.pMem) ){
    goto too_big;
  }
  break;
}

#ifndef SQLITE_OMIT_WAL
/* Opcode: Checkpoint P1 P2 P3 * *
................................................................................
** SQLITE_BUSY or not, respectively.  Write the number of pages in the
** WAL after the checkpoint into mem[P3+1] and the number of pages
** in the WAL that have been checkpointed after the checkpoint
** completes into mem[P3+2].  However on an error, mem[P3+1] and
** mem[P3+2] are initialized to -1.
*/
case OP_Checkpoint: {
#if 0  /* local variables moved into u.cg */
  int i;                          /* Loop counter */
  int aRes[3];                    /* Results */
  Mem *pMem;                      /* Write results here */
#endif /* local variables moved into u.cg */

  u.cg.aRes[0] = 0;
  u.cg.aRes[1] = u.cg.aRes[2] = -1;
  assert( pOp->p2==SQLITE_CHECKPOINT_PASSIVE
       || pOp->p2==SQLITE_CHECKPOINT_FULL
       || pOp->p2==SQLITE_CHECKPOINT_RESTART
  );
  rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &u.cg.aRes[1], &u.cg.aRes[2]);
  if( rc==SQLITE_BUSY ){
    rc = SQLITE_OK;
    u.cg.aRes[0] = 1;
  }
  for(u.cg.i=0, u.cg.pMem = &aMem[pOp->p3]; u.cg.i<3; u.cg.i++, u.cg.pMem++){
    sqlite3VdbeMemSetInt64(u.cg.pMem, (i64)u.cg.aRes[u.cg.i]);
  }
  break;
};  
#endif

#ifndef SQLITE_OMIT_PRAGMA
/* Opcode: JournalMode P1 P2 P3 * P5
................................................................................
** operation. No IO is required.
**
** If changing into or out of WAL mode the procedure is more complicated.
**
** Write a string containing the final journal-mode to register P2.
*/
case OP_JournalMode: {    /* out2-prerelease */
#if 0  /* local variables moved into u.ch */
  Btree *pBt;                     /* Btree to change journal mode of */
  Pager *pPager;                  /* Pager associated with pBt */
  int eNew;                       /* New journal mode */
  int eOld;                       /* The old journal mode */
  const char *zFilename;          /* Name of database file for pPager */
#endif /* local variables moved into u.ch */

  u.ch.eNew = pOp->p3;
  assert( u.ch.eNew==PAGER_JOURNALMODE_DELETE
       || u.ch.eNew==PAGER_JOURNALMODE_TRUNCATE
       || u.ch.eNew==PAGER_JOURNALMODE_PERSIST
       || u.ch.eNew==PAGER_JOURNALMODE_OFF
       || u.ch.eNew==PAGER_JOURNALMODE_MEMORY
       || u.ch.eNew==PAGER_JOURNALMODE_WAL
       || u.ch.eNew==PAGER_JOURNALMODE_QUERY
  );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );

  u.ch.pBt = db->aDb[pOp->p1].pBt;
  u.ch.pPager = sqlite3BtreePager(u.ch.pBt);
  u.ch.eOld = sqlite3PagerGetJournalMode(u.ch.pPager);
  if( u.ch.eNew==PAGER_JOURNALMODE_QUERY ) u.ch.eNew = u.ch.eOld;
  if( !sqlite3PagerOkToChangeJournalMode(u.ch.pPager) ) u.ch.eNew = u.ch.eOld;

#ifndef SQLITE_OMIT_WAL
  u.ch.zFilename = sqlite3PagerFilename(u.ch.pPager);

  /* Do not allow a transition to journal_mode=WAL for a database
  ** in temporary storage or if the VFS does not support shared memory
  */
  if( u.ch.eNew==PAGER_JOURNALMODE_WAL
   && (u.ch.zFilename[0]==0                         /* Temp file */
       || !sqlite3PagerWalSupported(u.ch.pPager))   /* No shared-memory support */
  ){
    u.ch.eNew = u.ch.eOld;
  }

  if( (u.ch.eNew!=u.ch.eOld)
   && (u.ch.eOld==PAGER_JOURNALMODE_WAL || u.ch.eNew==PAGER_JOURNALMODE_WAL)
  ){
    if( !db->autoCommit || db->activeVdbeCnt>1 ){
      rc = SQLITE_ERROR;
      sqlite3SetString(&p->zErrMsg, db,
          "cannot change %s wal mode from within a transaction",
          (u.ch.eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
      );
      break;
    }else{

      if( u.ch.eOld==PAGER_JOURNALMODE_WAL ){
        /* If leaving WAL mode, close the log file. If successful, the call
        ** to PagerCloseWal() checkpoints and deletes the write-ahead-log
        ** file. An EXCLUSIVE lock may still be held on the database file
        ** after a successful return.
        */
        rc = sqlite3PagerCloseWal(u.ch.pPager);
        if( rc==SQLITE_OK ){
          sqlite3PagerSetJournalMode(u.ch.pPager, u.ch.eNew);
        }
      }else if( u.ch.eOld==PAGER_JOURNALMODE_MEMORY ){
        /* Cannot transition directly from MEMORY to WAL.  Use mode OFF
        ** as an intermediate */
        sqlite3PagerSetJournalMode(u.ch.pPager, PAGER_JOURNALMODE_OFF);
      }

      /* Open a transaction on the database file. Regardless of the journal
      ** mode, this transaction always uses a rollback journal.
      */
      assert( sqlite3BtreeIsInTrans(u.ch.pBt)==0 );
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeSetVersion(u.ch.pBt, (u.ch.eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
      }
    }
  }
#endif /* ifndef SQLITE_OMIT_WAL */

  if( rc ){
    u.ch.eNew = u.ch.eOld;
  }
  u.ch.eNew = sqlite3PagerSetJournalMode(u.ch.pPager, u.ch.eNew);

  pOut = &aMem[pOp->p2];
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = (char *)sqlite3JournalModename(u.ch.eNew);
  pOut->n = sqlite3Strlen30(pOut->z);
  pOut->enc = SQLITE_UTF8;
  sqlite3VdbeChangeEncoding(pOut, encoding);
  break;
};
#endif /* SQLITE_OMIT_PRAGMA */

................................................................................
/* Opcode: IncrVacuum P1 P2 * * *
**
** Perform a single step of the incremental vacuum procedure on
** the P1 database. If the vacuum has finished, jump to instruction
** P2. Otherwise, fall through to the next instruction.
*/
case OP_IncrVacuum: {        /* jump */
#if 0  /* local variables moved into u.ci */
  Btree *pBt;
#endif /* local variables moved into u.ci */

  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
  u.ci.pBt = db->aDb[pOp->p1].pBt;
  rc = sqlite3BtreeIncrVacuum(u.ci.pBt);
  if( rc==SQLITE_DONE ){
    pc = pOp->p2 - 1;
    rc = SQLITE_OK;
  }
  break;
}
#endif
................................................................................
** xBegin method for that table.
**
** Also, whether or not P4 is set, check that this is not being called from
** within a callback to a virtual table xSync() method. If it is, the error
** code will be set to SQLITE_LOCKED.
*/
case OP_VBegin: {
#if 0  /* local variables moved into u.cj */
  VTable *pVTab;
#endif /* local variables moved into u.cj */
  u.cj.pVTab = pOp->p4.pVtab;
  rc = sqlite3VtabBegin(db, u.cj.pVTab);
  if( u.cj.pVTab ) importVtabErrMsg(p, u.cj.pVTab->pVtab);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VCreate P1 * * P4 *
**
................................................................................
/* Opcode: VOpen P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number.  This opcode opens a cursor to the virtual
** table and stores that cursor in P1.
*/
case OP_VOpen: {
#if 0  /* local variables moved into u.ck */
  VdbeCursor *pCur;
  sqlite3_vtab_cursor *pVtabCursor;
  sqlite3_vtab *pVtab;
  sqlite3_module *pModule;
#endif /* local variables moved into u.ck */

  u.ck.pCur = 0;
  u.ck.pVtabCursor = 0;
  u.ck.pVtab = pOp->p4.pVtab->pVtab;
  u.ck.pModule = (sqlite3_module *)u.ck.pVtab->pModule;
  assert(u.ck.pVtab && u.ck.pModule);
  rc = u.ck.pModule->xOpen(u.ck.pVtab, &u.ck.pVtabCursor);
  importVtabErrMsg(p, u.ck.pVtab);
  if( SQLITE_OK==rc ){
    /* Initialize sqlite3_vtab_cursor base class */
    u.ck.pVtabCursor->pVtab = u.ck.pVtab;

    /* Initialise vdbe cursor object */
    u.ck.pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
    if( u.ck.pCur ){
      u.ck.pCur->pVtabCursor = u.ck.pVtabCursor;
      u.ck.pCur->pModule = u.ck.pVtabCursor->pVtab->pModule;
    }else{
      db->mallocFailed = 1;
      u.ck.pModule->xClose(u.ck.pVtabCursor);
    }
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
** xFilter method. Registers P3+2..P3+1+argc are the argc
** additional parameters which are passed to
** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
**
** A jump is made to P2 if the result set after filtering would be empty.
*/
case OP_VFilter: {   /* jump */
#if 0  /* local variables moved into u.cl */
  int nArg;
  int iQuery;
  const sqlite3_module *pModule;
  Mem *pQuery;
  Mem *pArgc;
  sqlite3_vtab_cursor *pVtabCursor;
  sqlite3_vtab *pVtab;
  VdbeCursor *pCur;
  int res;
  int i;
  Mem **apArg;
#endif /* local variables moved into u.cl */

  u.cl.pQuery = &aMem[pOp->p3];
  u.cl.pArgc = &u.cl.pQuery[1];
  u.cl.pCur = p->apCsr[pOp->p1];
  assert( memIsValid(u.cl.pQuery) );
  REGISTER_TRACE(pOp->p3, u.cl.pQuery);
  assert( u.cl.pCur->pVtabCursor );
  u.cl.pVtabCursor = u.cl.pCur->pVtabCursor;
  u.cl.pVtab = u.cl.pVtabCursor->pVtab;
  u.cl.pModule = u.cl.pVtab->pModule;

  /* Grab the index number and argc parameters */
  assert( (u.cl.pQuery->flags&MEM_Int)!=0 && u.cl.pArgc->flags==MEM_Int );
  u.cl.nArg = (int)u.cl.pArgc->u.i;
  u.cl.iQuery = (int)u.cl.pQuery->u.i;

  /* Invoke the xFilter method */
  {
    u.cl.res = 0;
    u.cl.apArg = p->apArg;
    for(u.cl.i = 0; u.cl.i<u.cl.nArg; u.cl.i++){
      u.cl.apArg[u.cl.i] = &u.cl.pArgc[u.cl.i+1];
      sqlite3VdbeMemStoreType(u.cl.apArg[u.cl.i]);
    }

    p->inVtabMethod = 1;
    rc = u.cl.pModule->xFilter(u.cl.pVtabCursor, u.cl.iQuery, pOp->p4.z, u.cl.nArg, u.cl.apArg);
    p->inVtabMethod = 0;
    importVtabErrMsg(p, u.cl.pVtab);
    if( rc==SQLITE_OK ){
      u.cl.res = u.cl.pModule->xEof(u.cl.pVtabCursor);
    }

    if( u.cl.res ){
      pc = pOp->p2 - 1;
    }
  }
  u.cl.pCur->nullRow = 0;

  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VColumn P1 P2 P3 * *
**
** Store the value of the P2-th column of
** the row of the virtual-table that the 
** P1 cursor is pointing to into register P3.
*/
case OP_VColumn: {
#if 0  /* local variables moved into u.cm */
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  Mem *pDest;
  sqlite3_context sContext;
#endif /* local variables moved into u.cm */

  VdbeCursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->pVtabCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  u.cm.pDest = &aMem[pOp->p3];
  memAboutToChange(p, u.cm.pDest);
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(u.cm.pDest);
    break;
  }
  u.cm.pVtab = pCur->pVtabCursor->pVtab;
  u.cm.pModule = u.cm.pVtab->pModule;
  assert( u.cm.pModule->xColumn );
  memset(&u.cm.sContext, 0, sizeof(u.cm.sContext));

  /* The output cell may already have a buffer allocated. Move
  ** the current contents to u.cm.sContext.s so in case the user-function
  ** can use the already allocated buffer instead of allocating a
  ** new one.
  */
  sqlite3VdbeMemMove(&u.cm.sContext.s, u.cm.pDest);
  MemSetTypeFlag(&u.cm.sContext.s, MEM_Null);

  rc = u.cm.pModule->xColumn(pCur->pVtabCursor, &u.cm.sContext, pOp->p2);
  importVtabErrMsg(p, u.cm.pVtab);
  if( u.cm.sContext.isError ){
    rc = u.cm.sContext.isError;
  }

  /* Copy the result of the function to the P3 register. We
  ** do this regardless of whether or not an error occurred to ensure any
  ** dynamic allocation in u.cm.sContext.s (a Mem struct) is  released.
  */
  sqlite3VdbeChangeEncoding(&u.cm.sContext.s, encoding);
  sqlite3VdbeMemMove(u.cm.pDest, &u.cm.sContext.s);
  REGISTER_TRACE(pOp->p3, u.cm.pDest);
  UPDATE_MAX_BLOBSIZE(u.cm.pDest);

  if( sqlite3VdbeMemTooBig(u.cm.pDest) ){
    goto too_big;
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
/* Opcode: VNext P1 P2 * * *
**
** Advance virtual table P1 to the next row in its result set and
** jump to instruction P2.  Or, if the virtual table has reached
** the end of its result set, then fall through to the next instruction.
*/
case OP_VNext: {   /* jump */
#if 0  /* local variables moved into u.cn */
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  int res;
  VdbeCursor *pCur;
#endif /* local variables moved into u.cn */

  u.cn.res = 0;
  u.cn.pCur = p->apCsr[pOp->p1];
  assert( u.cn.pCur->pVtabCursor );
  if( u.cn.pCur->nullRow ){
    break;
  }
  u.cn.pVtab = u.cn.pCur->pVtabCursor->pVtab;
  u.cn.pModule = u.cn.pVtab->pModule;
  assert( u.cn.pModule->xNext );

  /* Invoke the xNext() method of the module. There is no way for the
  ** underlying implementation to return an error if one occurs during
  ** xNext(). Instead, if an error occurs, true is returned (indicating that
  ** data is available) and the error code returned when xColumn or
  ** some other method is next invoked on the save virtual table cursor.
  */
  p->inVtabMethod = 1;
  rc = u.cn.pModule->xNext(u.cn.pCur->pVtabCursor);
  p->inVtabMethod = 0;
  importVtabErrMsg(p, u.cn.pVtab);
  if( rc==SQLITE_OK ){
    u.cn.res = u.cn.pModule->xEof(u.cn.pCur->pVtabCursor);
  }

  if( !u.cn.res ){
    /* If there is data, jump to P2 */
    pc = pOp->p2 - 1;
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

................................................................................
/* Opcode: VRename P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xRename method. The value
** in register P1 is passed as the zName argument to the xRename method.
*/
case OP_VRename: {
#if 0  /* local variables moved into u.co */
  sqlite3_vtab *pVtab;
  Mem *pName;
#endif /* local variables moved into u.co */

  u.co.pVtab = pOp->p4.pVtab->pVtab;
  u.co.pName = &aMem[pOp->p1];
  assert( u.co.pVtab->pModule->xRename );
  assert( memIsValid(u.co.pName) );
  REGISTER_TRACE(pOp->p1, u.co.pName);
  assert( u.co.pName->flags & MEM_Str );
  rc = u.co.pVtab->pModule->xRename(u.co.pVtab, u.co.pName->z);
  importVtabErrMsg(p, u.co.pVtab);
  p->expired = 0;

  break;
}
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
................................................................................
** a row to delete.
**
** P1 is a boolean flag. If it is set to true and the xUpdate call
** is successful, then the value returned by sqlite3_last_insert_rowid() 
** is set to the value of the rowid for the row just inserted.
*/
case OP_VUpdate: {
#if 0  /* local variables moved into u.cp */
  sqlite3_vtab *pVtab;
  sqlite3_module *pModule;
  int nArg;
  int i;
  sqlite_int64 rowid;
  Mem **apArg;
  Mem *pX;
#endif /* local variables moved into u.cp */

  assert( pOp->p2==1        || pOp->p5==OE_Fail   || pOp->p5==OE_Rollback
       || pOp->p5==OE_Abort || pOp->p5==OE_Ignore || pOp->p5==OE_Replace
  );
  u.cp.pVtab = pOp->p4.pVtab->pVtab;
  u.cp.pModule = (sqlite3_module *)u.cp.pVtab->pModule;
  u.cp.nArg = pOp->p2;
  assert( pOp->p4type==P4_VTAB );
  if( ALWAYS(u.cp.pModule->xUpdate) ){
    u8 vtabOnConflict = db->vtabOnConflict;
    u.cp.apArg = p->apArg;
    u.cp.pX = &aMem[pOp->p3];
    for(u.cp.i=0; u.cp.i<u.cp.nArg; u.cp.i++){
      assert( memIsValid(u.cp.pX) );
      memAboutToChange(p, u.cp.pX);
      sqlite3VdbeMemStoreType(u.cp.pX);
      u.cp.apArg[u.cp.i] = u.cp.pX;
      u.cp.pX++;
    }
    db->vtabOnConflict = pOp->p5;
    rc = u.cp.pModule->xUpdate(u.cp.pVtab, u.cp.nArg, u.cp.apArg, &u.cp.rowid);
    db->vtabOnConflict = vtabOnConflict;
    importVtabErrMsg(p, u.cp.pVtab);
    if( rc==SQLITE_OK && pOp->p1 ){
      assert( u.cp.nArg>1 && u.cp.apArg[0] && (u.cp.apArg[0]->flags&MEM_Null) );
      db->lastRowid = lastRowid = u.cp.rowid;
    }
    if( rc==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
      if( pOp->p5==OE_Ignore ){
        rc = SQLITE_OK;
      }else{
        p->errorAction = ((pOp->p5==OE_Replace) ? OE_Abort : pOp->p5);
      }
................................................................................
#ifndef SQLITE_OMIT_TRACE
/* Opcode: Trace * * * P4 *
**
** If tracing is enabled (by the sqlite3_trace()) interface, then
** the UTF-8 string contained in P4 is emitted on the trace callback.
*/
case OP_Trace: {
#if 0  /* local variables moved into u.cq */
  char *zTrace;
  char *z;
#endif /* local variables moved into u.cq */

  if( db->xTrace && (u.cq.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0 ){
    u.cq.z = sqlite3VdbeExpandSql(p, u.cq.zTrace);
    db->xTrace(db->pTraceArg, u.cq.z);
    sqlite3DbFree(db, u.cq.z);
  }
#ifdef SQLITE_DEBUG
  if( (db->flags & SQLITE_SqlTrace)!=0
   && (u.cq.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){
    sqlite3DebugPrintf("SQL-trace: %s\n", u.cq.zTrace);
  }
#endif /* SQLITE_DEBUG */
  break;
}
#endif


................................................................................
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

#endif /* #ifndef SQLITE_OMIT_INCRBLOB */

/************** End of vdbeblob.c ********************************************/
/************** Begin file vdbesort.c ****************************************/
/*
** 2011 July 9
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code for the VdbeSorter object, used in concert with
** a VdbeCursor to sort large numbers of keys (as may be required, for
** example, by CREATE INDEX statements on tables too large to fit in main
** memory).
*/


#ifndef SQLITE_OMIT_MERGE_SORT

typedef struct VdbeSorterIter VdbeSorterIter;
typedef struct SorterRecord SorterRecord;

/*
** NOTES ON DATA STRUCTURE USED FOR N-WAY MERGES:
**
** As keys are added to the sorter, they are written to disk in a series
** of sorted packed-memory-arrays (PMAs). The size of each PMA is roughly
** the same as the cache-size allowed for temporary databases. In order
** to allow the caller to extract keys from the sorter in sorted order,
** all PMAs currently stored on disk must be merged together. This comment
** describes the data structure used to do so. The structure supports 
** merging any number of arrays in a single pass with no redundant comparison 
** operations.
**
** The aIter[] array contains an iterator for each of the PMAs being merged.
** An aIter[] iterator either points to a valid key or else is at EOF. For 
** the purposes of the paragraphs below, we assume that the array is actually 
** N elements in size, where N is the smallest power of 2 greater to or equal 
** to the number of iterators being merged. The extra aIter[] elements are 
** treated as if they are empty (always at EOF).
**
** The aTree[] array is also N elements in size. The value of N is stored in
** the VdbeSorter.nTree variable.
**
** The final (N/2) elements of aTree[] contain the results of comparing
** pairs of iterator keys together. Element i contains the result of 
** comparing aIter[2*i-N] and aIter[2*i-N+1]. Whichever key is smaller, the
** aTree element is set to the index of it. 
**
** For the purposes of this comparison, EOF is considered greater than any
** other key value. If the keys are equal (only possible with two EOF
** values), it doesn't matter which index is stored.
**
** The (N/4) elements of aTree[] that preceed the final (N/2) described 
** above contains the index of the smallest of each block of 4 iterators.
** And so on. So that aTree[1] contains the index of the iterator that 
** currently points to the smallest key value. aTree[0] is unused.
**
** Example:
**
**     aIter[0] -> Banana
**     aIter[1] -> Feijoa
**     aIter[2] -> Elderberry
**     aIter[3] -> Currant
**     aIter[4] -> Grapefruit
**     aIter[5] -> Apple
**     aIter[6] -> Durian
**     aIter[7] -> EOF
**
**     aTree[] = { X, 5   0, 5    0, 3, 5, 6 }
**
** The current element is "Apple" (the value of the key indicated by 
** iterator 5). When the Next() operation is invoked, iterator 5 will
** be advanced to the next key in its segment. Say the next key is
** "Eggplant":
**
**     aIter[5] -> Eggplant
**
** The contents of aTree[] are updated first by comparing the new iterator
** 5 key to the current key of iterator 4 (still "Grapefruit"). The iterator
** 5 value is still smaller, so aTree[6] is set to 5. And so on up the tree.
** The value of iterator 6 - "Durian" - is now smaller than that of iterator
** 5, so aTree[3] is set to 6. Key 0 is smaller than key 6 (Banana<Durian),
** so the value written into element 1 of the array is 0. As follows:
**
**     aTree[] = { X, 0   0, 6    0, 3, 5, 6 }
**
** In other words, each time we advance to the next sorter element, log2(N)
** key comparison operations are required, where N is the number of segments
** being merged (rounded up to the next power of 2).
*/
struct VdbeSorter {
  int nInMemory;                  /* Current size of pRecord list as PMA */
  int nTree;                      /* Used size of aTree/aIter (power of 2) */
  VdbeSorterIter *aIter;          /* Array of iterators to merge */
  int *aTree;                     /* Current state of incremental merge */
  i64 iWriteOff;                  /* Current write offset within file pTemp1 */
  i64 iReadOff;                   /* Current read offset within file pTemp1 */
  sqlite3_file *pTemp1;           /* PMA file 1 */
  int nPMA;                       /* Number of PMAs stored in pTemp1 */
  SorterRecord *pRecord;          /* Head of in-memory record list */
  int mnPmaSize;                  /* Minimum PMA size, in bytes */
  int mxPmaSize;                  /* Maximum PMA size, in bytes.  0==no limit */
  char *aSpace;                   /* Space for UnpackRecord() */
  int nSpace;                     /* Size of aSpace in bytes */
};

/*
** The following type is an iterator for a PMA. It caches the current key in 
** variables nKey/aKey. If the iterator is at EOF, pFile==0.
*/
struct VdbeSorterIter {
  i64 iReadOff;                   /* Current read offset */
  i64 iEof;                       /* 1 byte past EOF for this iterator */
  sqlite3_file *pFile;            /* File iterator is reading from */
  int nAlloc;                     /* Bytes of space at aAlloc */
  u8 *aAlloc;                     /* Allocated space */
  int nKey;                       /* Number of bytes in key */
  u8 *aKey;                       /* Pointer to current key */
};

/*
** A structure to store a single record. All in-memory records are connected
** together into a linked list headed at VdbeSorter.pRecord using the 
** SorterRecord.pNext pointer.
*/
struct SorterRecord {
  void *pVal;
  int nVal;
  SorterRecord *pNext;
};

/* Minimum allowable value for the VdbeSorter.nWorking variable */
#define SORTER_MIN_WORKING 10

/* Maximum number of segments to merge in a single pass. */
#define SORTER_MAX_MERGE_COUNT 16

/*
** Free all memory belonging to the VdbeSorterIter object passed as the second
** argument. All structure fields are set to zero before returning.
*/
static void vdbeSorterIterZero(sqlite3 *db, VdbeSorterIter *pIter){
  sqlite3DbFree(db, pIter->aAlloc);
  memset(pIter, 0, sizeof(VdbeSorterIter));
}

/*
** Advance iterator pIter to the next key in its PMA. Return SQLITE_OK if
** no error occurs, or an SQLite error code if one does.
*/
static int vdbeSorterIterNext(
  sqlite3 *db,                    /* Database handle (for sqlite3DbMalloc() ) */
  VdbeSorterIter *pIter           /* Iterator to advance */
){
  int rc;                         /* Return Code */
  int nRead;                      /* Number of bytes read */
  int nRec = 0;                   /* Size of record in bytes */
  int iOff = 0;                   /* Size of serialized size varint in bytes */

  nRead = pIter->iEof - pIter->iReadOff;
  if( nRead>5 ) nRead = 5;
  if( nRead<=0 ){
    /* This is an EOF condition */
    vdbeSorterIterZero(db, pIter);
    return SQLITE_OK;
  }

  rc = sqlite3OsRead(pIter->pFile, pIter->aAlloc, nRead, pIter->iReadOff);
  if( rc==SQLITE_OK ){
    iOff = getVarint32(pIter->aAlloc, nRec);
    if( (iOff+nRec)>nRead ){
      int nRead2;                   /* Number of extra bytes to read */
      if( (iOff+nRec)>pIter->nAlloc ){
        int nNew = pIter->nAlloc*2;
        while( (iOff+nRec)>nNew ) nNew = nNew*2;
        pIter->aAlloc = sqlite3DbReallocOrFree(db, pIter->aAlloc, nNew);
        if( !pIter->aAlloc ) return SQLITE_NOMEM;
        pIter->nAlloc = nNew;
      }
  
      nRead2 = iOff + nRec - nRead;
      rc = sqlite3OsRead(
          pIter->pFile, &pIter->aAlloc[nRead], nRead2, pIter->iReadOff+nRead
      );
    }
  }

  assert( rc!=SQLITE_OK || nRec>0 );
  pIter->iReadOff += iOff+nRec;
  pIter->nKey = nRec;
  pIter->aKey = &pIter->aAlloc[iOff];
  return rc;
}

/*
** Write a single varint, value iVal, to file-descriptor pFile. Return
** SQLITE_OK if successful, or an SQLite error code if some error occurs.
**
** The value of *piOffset when this function is called is used as the byte
** offset in file pFile to write to. Before returning, *piOffset is 
** incremented by the number of bytes written.
*/
static int vdbeSorterWriteVarint(
  sqlite3_file *pFile,            /* File to write to */
  i64 iVal,                       /* Value to write as a varint */
  i64 *piOffset                   /* IN/OUT: Write offset in file pFile */
){
  u8 aVarint[9];                  /* Buffer large enough for a varint */
  int nVarint;                    /* Number of used bytes in varint */
  int rc;                         /* Result of write() call */

  nVarint = sqlite3PutVarint(aVarint, iVal);
  rc = sqlite3OsWrite(pFile, aVarint, nVarint, *piOffset);
  *piOffset += nVarint;

  return rc;
}

/*
** Read a single varint from file-descriptor pFile. Return SQLITE_OK if
** successful, or an SQLite error code if some error occurs.
**
** The value of *piOffset when this function is called is used as the
** byte offset in file pFile from whence to read the varint. If successful
** (i.e. if no IO error occurs), then *piOffset is set to the offset of
** the first byte past the end of the varint before returning. *piVal is
** set to the integer value read. If an error occurs, the final values of
** both *piOffset and *piVal are undefined.
*/
static int vdbeSorterReadVarint(
  sqlite3_file *pFile,            /* File to read from */
  i64 *piOffset,                  /* IN/OUT: Read offset in pFile */
  i64 *piVal                      /* OUT: Value read from file */
){
  u8 aVarint[9];                  /* Buffer large enough for a varint */
  i64 iOff = *piOffset;           /* Offset in file to read from */
  int rc;                         /* Return code */

  rc = sqlite3OsRead(pFile, aVarint, 9, iOff);
  if( rc==SQLITE_OK ){
    *piOffset += getVarint(aVarint, (u64 *)piVal);
  }

  return rc;
}

/*
** Initialize iterator pIter to scan through the PMA stored in file pFile
** starting at offset iStart and ending at offset iEof-1. This function 
** leaves the iterator pointing to the first key in the PMA (or EOF if the 
** PMA is empty).
*/
static int vdbeSorterIterInit(
  sqlite3 *db,                    /* Database handle */
  VdbeSorter *pSorter,            /* Sorter object */
  i64 iStart,                     /* Start offset in pFile */
  VdbeSorterIter *pIter,          /* Iterator to populate */
  i64 *pnByte                     /* IN/OUT: Increment this value by PMA size */
){
  int rc;

  assert( pSorter->iWriteOff>iStart );
  assert( pIter->aAlloc==0 );
  pIter->pFile = pSorter->pTemp1;
  pIter->iReadOff = iStart;
  pIter->nAlloc = 128;
  pIter->aAlloc = (u8 *)sqlite3DbMallocRaw(db, pIter->nAlloc);
  if( !pIter->aAlloc ){
    rc = SQLITE_NOMEM;
  }else{
    i64 nByte;                         /* Total size of PMA in bytes */
    rc = vdbeSorterReadVarint(pSorter->pTemp1, &pIter->iReadOff, &nByte);
    *pnByte += nByte;
    pIter->iEof = pIter->iReadOff + nByte;
  }
  if( rc==SQLITE_OK ){
    rc = vdbeSorterIterNext(db, pIter);
  }
  return rc;
}


/*
** Compare key1 (buffer pKey1, size nKey1 bytes) with key2 (buffer pKey2, 
** size nKey2 bytes).  Argument pKeyInfo supplies the collation functions
** used by the comparison. If an error occurs, return an SQLite error code.
** Otherwise, return SQLITE_OK and set *pRes to a negative, zero or positive
** value, depending on whether key1 is smaller, equal to or larger than key2.
**
** If the bOmitRowid argument is non-zero, assume both keys end in a rowid
** field. For the purposes of the comparison, ignore it. Also, if bOmitRowid
** is true and key1 contains even a single NULL value, it is considered to
** be less than key2. Even if key2 also contains NULL values.
**
** If pKey2 is passed a NULL pointer, then it is assumed that the pCsr->aSpace
** has been allocated and contains an unpacked record that is used as key2.
*/
static int vdbeSorterCompare(
  VdbeCursor *pCsr,               /* Cursor object (for pKeyInfo) */
  int bOmitRowid,                 /* Ignore rowid field at end of keys */
  void *pKey1, int nKey1,         /* Left side of comparison */
  void *pKey2, int nKey2,         /* Right side of comparison */
  int *pRes                       /* OUT: Result of comparison */
){
  KeyInfo *pKeyInfo = pCsr->pKeyInfo;
  VdbeSorter *pSorter = pCsr->pSorter;
  char *aSpace = pSorter->aSpace;
  int nSpace = pSorter->nSpace;
  UnpackedRecord *r2;
  int i;

  if( aSpace==0 ){
    nSpace = ROUND8(sizeof(UnpackedRecord))+(pKeyInfo->nField+1)*sizeof(Mem);
    aSpace = (char *)sqlite3Malloc(nSpace);
    if( aSpace==0 ) return SQLITE_NOMEM;
    pSorter->aSpace = aSpace;
    pSorter->nSpace = nSpace;
  }

  if( pKey2 ){
    /* This call cannot fail. As the memory is already allocated. */
    r2 = sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, aSpace, nSpace);
    assert( r2 && (r2->flags & UNPACKED_NEED_FREE)==0 );
    assert( r2==(UnpackedRecord*)aSpace );
  }else{
    r2 = (UnpackedRecord *)aSpace;
    assert( !bOmitRowid );
  }

  if( bOmitRowid ){
    for(i=0; i<r2->nField-1; i++){
      if( r2->aMem[i].flags & MEM_Null ){
        *pRes = -1;
        return SQLITE_OK;
      }
    }
    r2->flags |= UNPACKED_PREFIX_MATCH;
    r2->nField--;
    assert( r2->nField>0 );
  }

  *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
  return SQLITE_OK;
}

/*
** This function is called to compare two iterator keys when merging 
** multiple b-tree segments. Parameter iOut is the index of the aTree[] 
** value to recalculate.
*/
static int vdbeSorterDoCompare(VdbeCursor *pCsr, int iOut){
  VdbeSorter *pSorter = pCsr->pSorter;
  int i1;
  int i2;
  int iRes;
  VdbeSorterIter *p1;
  VdbeSorterIter *p2;

  assert( iOut<pSorter->nTree && iOut>0 );

  if( iOut>=(pSorter->nTree/2) ){
    i1 = (iOut - pSorter->nTree/2) * 2;
    i2 = i1 + 1;
  }else{
    i1 = pSorter->aTree[iOut*2];
    i2 = pSorter->aTree[iOut*2+1];
  }

  p1 = &pSorter->aIter[i1];
  p2 = &pSorter->aIter[i2];

  if( p1->pFile==0 ){
    iRes = i2;
  }else if( p2->pFile==0 ){
    iRes = i1;
  }else{
    int res;
    int rc;
    assert( pCsr->pSorter->aSpace!=0 );  /* allocated in vdbeSorterMerge() */
    rc = vdbeSorterCompare(
        pCsr, 0, p1->aKey, p1->nKey, p2->aKey, p2->nKey, &res
    );
    /* The vdbeSorterCompare() call cannot fail since pCsr->pSorter->aSpace
    ** has already been allocated. */
    assert( rc==SQLITE_OK );

    if( res<=0 ){
      iRes = i1;
    }else{
      iRes = i2;
    }
  }

  pSorter->aTree[iOut] = iRes;
  return SQLITE_OK;
}

/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){
  int pgsz;                       /* Page size of main database */
  int mxCache;                    /* Cache size */
  VdbeSorter *pSorter;            /* The new sorter */

  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
  pCsr->pSorter = pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));
  if( pSorter==0 ){
    return SQLITE_NOMEM;
  }

  if( !sqlite3TempInMemory(db) ){
    pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
    pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
    mxCache = db->aDb[0].pSchema->cache_size;
    if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
    pSorter->mxPmaSize = mxCache * pgsz;
  }

  return SQLITE_OK;
}

/*
** Free the list of sorted records starting at pRecord.
*/
static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){
  SorterRecord *p;
  SorterRecord *pNext;
  for(p=pRecord; p; p=pNext){
    pNext = p->pNext;
    sqlite3DbFree(db, p);
  }
}

/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
  VdbeSorter *pSorter = pCsr->pSorter;
  if( pSorter ){
    if( pSorter->aIter ){
      int i;
      for(i=0; i<pSorter->nTree; i++){
        vdbeSorterIterZero(db, &pSorter->aIter[i]);
      }
      sqlite3DbFree(db, pSorter->aIter);
    }
    if( pSorter->pTemp1 ){
      sqlite3OsCloseFree(pSorter->pTemp1);
    }
    vdbeSorterRecordFree(db, pSorter->pRecord);
    sqlite3_free(pSorter->aSpace);
    sqlite3DbFree(db, pSorter);
    pCsr->pSorter = 0;
  }
}

/*
** Allocate space for a file-handle and open a temporary file. If successful,
** set *ppFile to point to the malloc'd file-handle and return SQLITE_OK.
** Otherwise, set *ppFile to 0 and return an SQLite error code.
*/
static int vdbeSorterOpenTempFile(sqlite3 *db, sqlite3_file **ppFile){
  int dummy;
  return sqlite3OsOpenMalloc(db->pVfs, 0, ppFile,
      SQLITE_OPEN_TEMP_JOURNAL |
      SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &dummy
  );
}

/*
** Attemp to merge the two sorted lists p1 and p2 into a single list. If no
** error occurs set *ppOut to the head of the new list and return SQLITE_OK.
*/
static int vdbeSorterMerge(
  sqlite3 *db,                    /* Database handle */
  VdbeCursor *pCsr,               /* For pKeyInfo */
  SorterRecord *p1,               /* First list to merge */
  SorterRecord *p2,               /* Second list to merge */
  SorterRecord **ppOut            /* OUT: Head of merged list */
){
  int rc = SQLITE_OK;
  SorterRecord *pFinal = 0;
  SorterRecord **pp = &pFinal;
  void *pVal2 = p2 ? p2->pVal : 0;

  while( p1 && p2 ){
    int res;
    rc = vdbeSorterCompare(pCsr, 0, p1->pVal, p1->nVal, pVal2, p2->nVal, &res);
    if( rc!=SQLITE_OK ){
      *pp = 0;
      vdbeSorterRecordFree(db, p1);
      vdbeSorterRecordFree(db, p2);
      vdbeSorterRecordFree(db, pFinal);
      *ppOut = 0;
      return rc;
    }
    if( res<=0 ){
      *pp = p1;
      pp = &p1->pNext;
      p1 = p1->pNext;
      pVal2 = 0;
    }else{
      *pp = p2;
       pp = &p2->pNext;
      p2 = p2->pNext;
      if( p2==0 ) break;
      pVal2 = p2->pVal;
    }
  }
  *pp = p1 ? p1 : p2;

  *ppOut = pFinal;
  return SQLITE_OK;
}

/*
** Sort the linked list of records headed at pCsr->pRecord. Return SQLITE_OK
** if successful, or an SQLite error code (i.e. SQLITE_NOMEM) if an error
** occurs.
*/
static int vdbeSorterSort(sqlite3 *db, VdbeCursor *pCsr){
  int rc = SQLITE_OK;
  int i;
  SorterRecord **aSlot;
  SorterRecord *p;
  VdbeSorter *pSorter = pCsr->pSorter;

  aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *));
  if( !aSlot ){
    return SQLITE_NOMEM;
  }

  p = pSorter->pRecord;
  while( p ){
    SorterRecord *pNext = p->pNext;
    p->pNext = 0;
    for(i=0; rc==SQLITE_OK && aSlot[i]; i++){
      rc = vdbeSorterMerge(db, pCsr, p, aSlot[i], &p);
      aSlot[i] = 0;
    }
    if( rc!=SQLITE_OK ){
      vdbeSorterRecordFree(db, pNext);
      break;
    }
    aSlot[i] = p;
    p = pNext;
  }

  p = 0;
  for(i=0; i<64; i++){
    if( rc==SQLITE_OK ){
      rc = vdbeSorterMerge(db, pCsr, p, aSlot[i], &p);
    }else{
      vdbeSorterRecordFree(db, aSlot[i]);
    }
  }
  pSorter->pRecord = p;

  sqlite3_free(aSlot);
  return rc;
}


/*
** Write the current contents of the in-memory linked-list to a PMA. Return
** SQLITE_OK if successful, or an SQLite error code otherwise.
**
** The format of a PMA is:
**
**     * A varint. This varint contains the total number of bytes of content
**       in the PMA (not including the varint itself).
**
**     * One or more records packed end-to-end in order of ascending keys. 
**       Each record consists of a varint followed by a blob of data (the 
**       key). The varint is the number of bytes in the blob of data.
*/
static int vdbeSorterListToPMA(sqlite3 *db, VdbeCursor *pCsr){
  int rc = SQLITE_OK;             /* Return code */
  VdbeSorter *pSorter = pCsr->pSorter;

  if( pSorter->nInMemory==0 ){
    assert( pSorter->pRecord==0 );
    return rc;
  }

  rc = vdbeSorterSort(db, pCsr);

  /* If the first temporary PMA file has not been opened, open it now. */
  if( rc==SQLITE_OK && pSorter->pTemp1==0 ){
    rc = vdbeSorterOpenTempFile(db, &pSorter->pTemp1);
    assert( rc!=SQLITE_OK || pSorter->pTemp1 );
    assert( pSorter->iWriteOff==0 );
    assert( pSorter->nPMA==0 );
  }

  if( rc==SQLITE_OK ){
    i64 iOff = pSorter->iWriteOff;
    SorterRecord *p;
    SorterRecord *pNext = 0;
    static const char eightZeros[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };

    pSorter->nPMA++;
    rc = vdbeSorterWriteVarint(pSorter->pTemp1, pSorter->nInMemory, &iOff);
    for(p=pSorter->pRecord; rc==SQLITE_OK && p; p=pNext){
      pNext = p->pNext;
      rc = vdbeSorterWriteVarint(pSorter->pTemp1, p->nVal, &iOff);

      if( rc==SQLITE_OK ){
        rc = sqlite3OsWrite(pSorter->pTemp1, p->pVal, p->nVal, iOff);
        iOff += p->nVal;
      }

      sqlite3DbFree(db, p);
    }

    /* This assert verifies that unless an error has occurred, the size of 
    ** the PMA on disk is the same as the expected size stored in
    ** pSorter->nInMemory. */ 
    assert( rc!=SQLITE_OK || pSorter->nInMemory==(
          iOff-pSorter->iWriteOff-sqlite3VarintLen(pSorter->nInMemory)
    ));

    pSorter->iWriteOff = iOff;
    if( rc==SQLITE_OK ){
      /* Terminate each file with 8 extra bytes so that from any offset
      ** in the file we can always read 9 bytes without a SHORT_READ error */
      rc = sqlite3OsWrite(pSorter->pTemp1, eightZeros, 8, iOff);
    }
    pSorter->pRecord = p;
  }

  return rc;
}

/*
** Add a record to the sorter.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
  sqlite3 *db,                    /* Database handle */
  VdbeCursor *pCsr,               /* Sorter cursor */
  Mem *pVal                       /* Memory cell containing record */
){
  VdbeSorter *pSorter = pCsr->pSorter;
  int rc = SQLITE_OK;             /* Return Code */
  SorterRecord *pNew;             /* New list element */

  assert( pSorter );
  pSorter->nInMemory += sqlite3VarintLen(pVal->n) + pVal->n;

  pNew = (SorterRecord *)sqlite3DbMallocRaw(db, pVal->n + sizeof(SorterRecord));
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    pNew->pVal = (void *)&pNew[1];
    memcpy(pNew->pVal, pVal->z, pVal->n);
    pNew->nVal = pVal->n;
    pNew->pNext = pSorter->pRecord;
    pSorter->pRecord = pNew;
  }

  /* See if the contents of the sorter should now be written out. They
  ** are written out when either of the following are true:
  **
  **   * The total memory allocated for the in-memory list is greater 
  **     than (page-size * cache-size), or
  **
  **   * The total memory allocated for the in-memory list is greater 
  **     than (page-size * 10) and sqlite3HeapNearlyFull() returns true.
  */
  if( rc==SQLITE_OK && pSorter->mxPmaSize>0 && (
        (pSorter->nInMemory>pSorter->mxPmaSize)
     || (pSorter->nInMemory>pSorter->mnPmaSize && sqlite3HeapNearlyFull())
  )){
    rc = vdbeSorterListToPMA(db, pCsr);
    pSorter->nInMemory = 0;
  }

  return rc;
}

/*
** Helper function for sqlite3VdbeSorterRewind(). 
*/
static int vdbeSorterInitMerge(
  sqlite3 *db,                    /* Database handle */
  VdbeCursor *pCsr,               /* Cursor handle for this sorter */
  i64 *pnByte                     /* Sum of bytes in all opened PMAs */
){
  VdbeSorter *pSorter = pCsr->pSorter;
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Used to iterator through aIter[] */
  i64 nByte = 0;                  /* Total bytes in all opened PMAs */

  /* Initialize the iterators. */
  for(i=0; i<SORTER_MAX_MERGE_COUNT; i++){
    VdbeSorterIter *pIter = &pSorter->aIter[i];
    rc = vdbeSorterIterInit(db, pSorter, pSorter->iReadOff, pIter, &nByte);
    pSorter->iReadOff = pIter->iEof;
    assert( rc!=SQLITE_OK || pSorter->iReadOff<=pSorter->iWriteOff );
    if( rc!=SQLITE_OK || pSorter->iReadOff>=pSorter->iWriteOff ) break;
  }

  /* Initialize the aTree[] array. */
  for(i=pSorter->nTree-1; rc==SQLITE_OK && i>0; i--){
    rc = vdbeSorterDoCompare(pCsr, i);
  }

  *pnByte = nByte;
  return rc;
}

/*
** Once the sorter has been populated, this function is called to prepare
** for iterating through its contents in sorted order.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterRewind(sqlite3 *db, VdbeCursor *pCsr, int *pbEof){
  VdbeSorter *pSorter = pCsr->pSorter;
  int rc;                         /* Return code */
  sqlite3_file *pTemp2 = 0;       /* Second temp file to use */
  i64 iWrite2 = 0;                /* Write offset for pTemp2 */
  int nIter;                      /* Number of iterators used */
  int nByte;                      /* Bytes of space required for aIter/aTree */
  int N = 2;                      /* Power of 2 >= nIter */

  assert( pSorter );

  /* If no data has been written to disk, then do not do so now. Instead,
  ** sort the VdbeSorter.pRecord list. The vdbe layer will read data directly
  ** from the in-memory list.  */
  if( pSorter->nPMA==0 ){
    *pbEof = !pSorter->pRecord;
    assert( pSorter->aTree==0 );
    return vdbeSorterSort(db, pCsr);
  }

  /* Write the current b-tree to a PMA. Close the b-tree cursor. */
  rc = vdbeSorterListToPMA(db, pCsr);
  if( rc!=SQLITE_OK ) return rc;

  /* Allocate space for aIter[] and aTree[]. */
  nIter = pSorter->nPMA;
  if( nIter>SORTER_MAX_MERGE_COUNT ) nIter = SORTER_MAX_MERGE_COUNT;
  assert( nIter>0 );
  while( N<nIter ) N += N;
  nByte = N * (sizeof(int) + sizeof(VdbeSorterIter));
  pSorter->aIter = (VdbeSorterIter *)sqlite3DbMallocZero(db, nByte);
  if( !pSorter->aIter ) return SQLITE_NOMEM;
  pSorter->aTree = (int *)&pSorter->aIter[N];
  pSorter->nTree = N;

  do {
    int iNew;                     /* Index of new, merged, PMA */

    for(iNew=0; 
        rc==SQLITE_OK && iNew*SORTER_MAX_MERGE_COUNT<pSorter->nPMA; 
        iNew++
    ){
      i64 nWrite;                 /* Number of bytes in new PMA */

      /* If there are SORTER_MAX_MERGE_COUNT or less PMAs in file pTemp1,
      ** initialize an iterator for each of them and break out of the loop.
      ** These iterators will be incrementally merged as the VDBE layer calls
      ** sqlite3VdbeSorterNext().
      **
      ** Otherwise, if pTemp1 contains more than SORTER_MAX_MERGE_COUNT PMAs,
      ** initialize interators for SORTER_MAX_MERGE_COUNT of them. These PMAs
      ** are merged into a single PMA that is written to file pTemp2.
      */
      rc = vdbeSorterInitMerge(db, pCsr, &nWrite);
      assert( rc!=SQLITE_OK || pSorter->aIter[ pSorter->aTree[1] ].pFile );
      if( rc!=SQLITE_OK || pSorter->nPMA<=SORTER_MAX_MERGE_COUNT ){
        break;
      }

      /* Open the second temp file, if it is not already open. */
      if( pTemp2==0 ){
        assert( iWrite2==0 );
        rc = vdbeSorterOpenTempFile(db, &pTemp2);
      }

      if( rc==SQLITE_OK ){
        rc = vdbeSorterWriteVarint(pTemp2, nWrite, &iWrite2);
      }

      if( rc==SQLITE_OK ){
        int bEof = 0;
        while( rc==SQLITE_OK && bEof==0 ){
          int nToWrite;
          VdbeSorterIter *pIter = &pSorter->aIter[ pSorter->aTree[1] ];
          assert( pIter->pFile );
          nToWrite = pIter->nKey + sqlite3VarintLen(pIter->nKey);
          rc = sqlite3OsWrite(pTemp2, pIter->aAlloc, nToWrite, iWrite2);
          iWrite2 += nToWrite;
          if( rc==SQLITE_OK ){
            rc = sqlite3VdbeSorterNext(db, pCsr, &bEof);
          }
        }
      }
    }

    if( pSorter->nPMA<=SORTER_MAX_MERGE_COUNT ){
      break;
    }else{
      sqlite3_file *pTmp = pSorter->pTemp1;
      pSorter->nPMA = iNew;
      pSorter->pTemp1 = pTemp2;
      pTemp2 = pTmp;
      pSorter->iWriteOff = iWrite2;
      pSorter->iReadOff = 0;
      iWrite2 = 0;
    }
  }while( rc==SQLITE_OK );

  if( pTemp2 ){
    sqlite3OsCloseFree(pTemp2);
  }
  *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
  return rc;
}

/*
** Advance to the next element in the sorter.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, VdbeCursor *pCsr, int *pbEof){
  VdbeSorter *pSorter = pCsr->pSorter;
  int rc;                         /* Return code */

  if( pSorter->aTree ){
    int iPrev = pSorter->aTree[1];/* Index of iterator to advance */
    int i;                        /* Index of aTree[] to recalculate */

    rc = vdbeSorterIterNext(db, &pSorter->aIter[iPrev]);
    for(i=(pSorter->nTree+iPrev)/2; rc==SQLITE_OK && i>0; i=i/2){
      rc = vdbeSorterDoCompare(pCsr, i);
    }

    *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
  }else{
    SorterRecord *pFree = pSorter->pRecord;
    pSorter->pRecord = pFree->pNext;
    pFree->pNext = 0;
    vdbeSorterRecordFree(db, pFree);
    *pbEof = !pSorter->pRecord;
    rc = SQLITE_OK;
  }
  return rc;
}

/*
** Return a pointer to a buffer owned by the sorter that contains the 
** current key.
*/
static void *vdbeSorterRowkey(
  VdbeSorter *pSorter,            /* Sorter object */
  int *pnKey                      /* OUT: Size of current key in bytes */
){
  void *pKey;
  if( pSorter->aTree ){
    VdbeSorterIter *pIter;
    pIter = &pSorter->aIter[ pSorter->aTree[1] ];
    *pnKey = pIter->nKey;
    pKey = pIter->aKey;
  }else{
    *pnKey = pSorter->pRecord->nVal;
    pKey = pSorter->pRecord->pVal;
  }
  return pKey;
}

/*
** Copy the current sorter key into the memory cell pOut.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(VdbeCursor *pCsr, Mem *pOut){
  VdbeSorter *pSorter = pCsr->pSorter;
  void *pKey; int nKey;           /* Sorter key to copy into pOut */

  pKey = vdbeSorterRowkey(pSorter, &nKey);
  if( sqlite3VdbeMemGrow(pOut, nKey, 0) ){
    return SQLITE_NOMEM;
  }
  pOut->n = nKey;
  MemSetTypeFlag(pOut, MEM_Blob);
  memcpy(pOut->z, pKey, nKey);

  return SQLITE_OK;
}

/*
** Compare the key in memory cell pVal with the key that the sorter cursor
** passed as the first argument currently points to. For the purposes of
** the comparison, ignore the rowid field at the end of each record.
**
** If an error occurs, return an SQLite error code (i.e. SQLITE_NOMEM).
** Otherwise, set *pRes to a negative, zero or positive value if the
** key in pVal is smaller than, equal to or larger than the current sorter
** key.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
  VdbeCursor *pCsr,               /* Sorter cursor */
  Mem *pVal,                      /* Value to compare to current sorter key */
  int *pRes                       /* OUT: Result of comparison */
){
  int rc;
  VdbeSorter *pSorter = pCsr->pSorter;
  void *pKey; int nKey;           /* Sorter key to compare pVal with */

  pKey = vdbeSorterRowkey(pSorter, &nKey);
  rc = vdbeSorterCompare(pCsr, 1, pVal->z, pVal->n, pKey, nKey, pRes);
  assert( rc!=SQLITE_OK || pVal->db->mallocFailed || (*pRes)<=0 );
  return rc;
}

#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */

/************** End of vdbesort.c ********************************************/
/************** Begin file journal.c *****************************************/
/*
** 2007 August 22
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
................................................................................
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for walking the parser tree for
** an SQL statement.
*/
/* #include <stdlib.h> */
/* #include <string.h> */


/*
** Walk an expression tree.  Invoke the callback once for each node
** of the expression, while decending.  (In other words, the callback
** is invoked before visiting children.)
**
................................................................................
**
*************************************************************************
**
** This file contains routines used for walking the parser tree and
** resolve all identifiers by associating them with a particular
** table and column.
*/
/* #include <stdlib.h> */
/* #include <string.h> */

/*
** Turn the pExpr expression into an alias for the iCol-th column of the
** result set in pEList.
**
** If the result set column is a simple column reference, then this routine
** makes an exact copy.  But for any other kind of expression, this
................................................................................
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        inReg = pCol->iMem;
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                              pCol->iSorterColumn, target);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){
................................................................................
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.


























































































*/
#ifndef SQLITE_OMIT_ANALYZE

/*
** This routine generates code that opens the sqlite_stat1 table for
** writing with cursor iStatCur. If the library was built with the
** SQLITE_ENABLE_STAT2 macro defined, then the sqlite_stat2 table is
................................................................................
  const char *zWhereType  /* Either "tbl" or "idx" */
){
  static const struct {
    const char *zName;
    const char *zCols;
  } aTable[] = {
    { "sqlite_stat1", "tbl,idx,stat" },
#ifdef SQLITE_ENABLE_STAT2




    { "sqlite_stat2", "tbl,idx,sampleno,sample" },


#endif
  };

  int aRoot[] = {0, 0};
  u8 aCreateTbl[] = {0, 0};

  int i;
................................................................................
  Db *pDb;
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];












  for(i=0; i<ArraySize(aTable); i++){
    const char *zTab = aTable[i].zName;
    Table *pStat;
    if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){
      /* The sqlite_stat[12] table does not exist. Create it. Note that a 
      ** side-effect of the CREATE TABLE statement is to leave the rootpage 
      ** of the new table in register pParse->regRoot. This is important 
................................................................................
      }else{
        /* The sqlite_stat[12] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  /* Open the sqlite_stat[12] tables for writing. */
  for(i=0; i<ArraySize(aTable); i++){
    sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb);
    sqlite3VdbeChangeP4(v, -1, (char *)3, P4_INT32);
    sqlite3VdbeChangeP5(v, aCreateTbl[i]);
  }
}






























































































































































































































/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
  Parse *pParse,   /* Parser context */
................................................................................
  int i;                       /* Loop counter */
  int topOfLoop;               /* The top of the loop */
  int endOfLoop;               /* The end of the loop */
  int jZeroRows = -1;          /* Jump from here if number of rows is zero */
  int iDb;                     /* Index of database containing pTab */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regSampleno = iMem++;    /* Register containing next sample number */















  int regCol = iMem++;         /* Content of a column analyzed table */
  int regRec = iMem++;         /* Register holding completed record */
  int regTemp = iMem++;        /* Temporary use register */
  int regRowid = iMem++;       /* Rowid for the inserted record */

#ifdef SQLITE_ENABLE_STAT2
  int addr = 0;                /* Instruction address */
  int regTemp2 = iMem++;       /* Temporary use register */
  int regSamplerecno = iMem++; /* Index of next sample to record */
  int regRecno = iMem++;       /* Current sample index */
  int regLast = iMem++;        /* Index of last sample to record */
  int regFirst = iMem++;       /* Index of first sample to record */
#endif

  v = sqlite3GetVdbe(pParse);
  if( v==0 || NEVER(pTab==0) ){
    return;
  }
  if( pTab->tnum==0 ){
    /* Do not gather statistics on views or virtual tables */
................................................................................
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    int nCol;
    KeyInfo *pKey;



    if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;

    nCol = pIdx->nColumn;
    pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    if( iMem+1+(nCol*2)>pParse->nMem ){
      pParse->nMem = iMem+1+(nCol*2);
    }



    /* Open a cursor to the index to be analyzed. */
    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
        (char *)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pIdx->zName));

    /* Populate the register containing the index name. */
    sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0);

#ifdef SQLITE_ENABLE_STAT2


    /* If this iteration of the loop is generating code to analyze the
    ** first index in the pTab->pIndex list, then register regLast has
    ** not been populated. In this case populate it now.  */
    if( pTab->pIndex==pIdx ){
      sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regSamplerecno);
      sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2-1, regTemp);
      sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2, regTemp2);

      sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regLast);
      sqlite3VdbeAddOp2(v, OP_Null, 0, regFirst);
      addr = sqlite3VdbeAddOp3(v, OP_Lt, regSamplerecno, 0, regLast);
      sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regFirst);
      sqlite3VdbeAddOp3(v, OP_Multiply, regLast, regTemp, regLast);
      sqlite3VdbeAddOp2(v, OP_AddImm, regLast, SQLITE_INDEX_SAMPLES*2-2);
      sqlite3VdbeAddOp3(v, OP_Divide,  regTemp2, regLast, regLast);
      sqlite3VdbeJumpHere(v, addr);
    }

    /* Zero the regSampleno and regRecno registers. */
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regSampleno);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRecno);
    sqlite3VdbeAddOp2(v, OP_Copy, regFirst, regSamplerecno);




#endif

    /* The block of memory cells initialized here is used as follows.
    **
    **    iMem:                
    **        The total number of rows in the table.
    **
    **    iMem+1 .. iMem+nCol: 
................................................................................
    }

    /* Start the analysis loop. This loop runs through all the entries in
    ** the index b-tree.  */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1);

    for(i=0; i<nCol; i++){
      CollSeq *pColl;
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol);
      if( i==0 ){
#ifdef SQLITE_ENABLE_STAT2
        /* Check if the record that cursor iIdxCur points to contains a
        ** value that should be stored in the sqlite_stat2 table. If so,
        ** store it.  */
        int ne = sqlite3VdbeAddOp3(v, OP_Ne, regRecno, 0, regSamplerecno);
        assert( regTabname+1==regIdxname 
             && regTabname+2==regSampleno
             && regTabname+3==regCol
        );
        sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
        sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 4, regRec, "aaab", 0);
        sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regRowid);
        sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regRowid);

        /* Calculate new values for regSamplerecno and regSampleno.
        **
        **   sampleno = sampleno + 1
        **   samplerecno = samplerecno+(remaining records)/(remaining samples)
        */
        sqlite3VdbeAddOp2(v, OP_AddImm, regSampleno, 1);
        sqlite3VdbeAddOp3(v, OP_Subtract, regRecno, regLast, regTemp);
        sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
        sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regTemp2);
        sqlite3VdbeAddOp3(v, OP_Subtract, regSampleno, regTemp2, regTemp2);
        sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regTemp, regTemp);
        sqlite3VdbeAddOp3(v, OP_Add, regSamplerecno, regTemp, regSamplerecno);

        sqlite3VdbeJumpHere(v, ne);
        sqlite3VdbeAddOp2(v, OP_AddImm, regRecno, 1);
#endif

        /* Always record the very first row */
        sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1);
      }
      assert( pIdx->azColl!=0 );
      assert( pIdx->azColl[i]!=0 );
      pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
      sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1,
                       (char*)pColl, P4_COLLSEQ);
      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);





    }
    if( db->mallocFailed ){
      /* If a malloc failure has occurred, then the result of the expression 
      ** passed as the second argument to the call to sqlite3VdbeJumpHere() 
      ** below may be negative. Which causes an assert() to fail (or an
      ** out-of-bounds write if SQLITE_DEBUG is not defined).  */
      return;
    }
    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
    for(i=0; i<nCol; i++){
      int addr2 = sqlite3VdbeCurrentAddr(v) - (nCol*2);
      if( i==0 ){
        sqlite3VdbeJumpHere(v, addr2-1);  /* Set jump dest for the OP_IfNot */









      }
      sqlite3VdbeJumpHere(v, addr2);      /* Set jump dest for the OP_Ne */
      sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1);
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1);
    }



    /* End of the analysis loop. */
    sqlite3VdbeResolveLabel(v, endOfLoop);

    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);






























    /* Store the results in sqlite_stat1.
    **
    ** The result is a single row of the sqlite_stat1 table.  The first
    ** two columns are the names of the table and index.  The third column
    ** is a string composed of a list of integer statistics about the
    ** index.  The first integer in the list is the total number of entries
................................................................................
    **
    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regSampleno);
    if( jZeroRows<0 ){
      jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
    }
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
      sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp);
      sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno);
    }
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
  }

  /* If the table has no indices, create a single sqlite_stat1 entry
  ** containing NULL as the index name and the row count as the content.
  */
  if( pTab->pIndex==0 ){
    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb);
    VdbeComment((v, "%s", pTab->zName));
    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regSampleno);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regSampleno);
  }else{
    sqlite3VdbeJumpHere(v, jZeroRows);
    jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto);
  }
  sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
  sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
  sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
  sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
  sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
  if( pParse->nMem<regRec ) pParse->nMem = regRec;
  sqlite3VdbeJumpHere(v, jZeroRows);
}


/*
** Generate code that will cause the most recent index analysis to
** be loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
................................................................................
  Schema *pSchema = db->aDb[iDb].pSchema;    /* Schema of database iDb */
  HashElem *k;
  int iStatCur;
  int iMem;

  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 2;
  openStatTable(pParse, iDb, iStatCur, 0, 0);
  iMem = pParse->nMem+1;
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
    Table *pTab = (Table*)sqliteHashData(k);
    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem);
  }
................................................................................
  int iStatCur;

  assert( pTab!=0 );
  assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  sqlite3BeginWriteOperation(pParse, 0, iDb);
  iStatCur = pParse->nTab;
  pParse->nTab += 2;
  if( pOnlyIdx ){
    openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx");
  }else{
    openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl");
  }
  analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur, pParse->nMem+1);
  loadAnalysis(pParse, iDb);
................................................................................
** the table.
*/
static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
  analysisInfo *pInfo = (analysisInfo*)pData;
  Index *pIndex;
  Table *pTable;
  int i, c, n;
  unsigned int v;
  const char *z;

  assert( argc==3 );
  UNUSED_PARAMETER2(NotUsed, argc);

  if( argv==0 || argv[0]==0 || argv[2]==0 ){
    return 0;
................................................................................
}

/*
** If the Index.aSample variable is not NULL, delete the aSample[] array
** and its contents.
*/
SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
#ifdef SQLITE_ENABLE_STAT2
  if( pIdx->aSample ){
    int j;
    for(j=0; j<SQLITE_INDEX_SAMPLES; j++){
      IndexSample *p = &pIdx->aSample[j];
      if( p->eType==SQLITE_TEXT || p->eType==SQLITE_BLOB ){
        sqlite3DbFree(db, p->u.z);
      }
    }
    sqlite3DbFree(db, pIdx->aSample);
  }



#else
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(pIdx);
#endif
}


/*
































































































































** Load the content of the sqlite_stat1 and sqlite_stat2 tables. The
** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]
** arrays. The contents of sqlite_stat2 are used to populate the
** Index.aSample[] arrays.
**
** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR
** is returned. In this case, even if SQLITE_ENABLE_STAT2 was defined 
** during compilation and the sqlite_stat2 table is present, no data is 
** read from it.
**
** If SQLITE_ENABLE_STAT2 was defined during compilation and the 
** sqlite_stat2 table is not present in the database, SQLITE_ERROR is
** returned. However, in this case, data is read from the sqlite_stat1
** table (if it is present) before returning.
**
** If an OOM error occurs, this function always sets db->mallocFailed.
** This means if the caller does not care about other errors, the return
** code may be ignored.
*/
................................................................................
  assert( db->aDb[iDb].pBt!=0 );

  /* Clear any prior statistics */
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    sqlite3DefaultRowEst(pIdx);

    sqlite3DeleteIndexSamples(db, pIdx);
    pIdx->aSample = 0;

  }

  /* Check to make sure the sqlite_stat1 table exists */
  sInfo.db = db;
  sInfo.zDatabase = db->aDb[iDb].zName;
  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){
    return SQLITE_ERROR;
  }

  /* Load new statistics out of the sqlite_stat1 table */
  zSql = sqlite3MPrintf(db, 
      "SELECT tbl, idx, stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
    sqlite3DbFree(db, zSql);
  }


  /* Load the statistics from the sqlite_stat2 table. */
#ifdef SQLITE_ENABLE_STAT2
  if( rc==SQLITE_OK && !sqlite3FindTable(db, "sqlite_stat2", sInfo.zDatabase) ){
    rc = SQLITE_ERROR;
  }
  if( rc==SQLITE_OK ){

    sqlite3_stmt *pStmt = 0;

    zSql = sqlite3MPrintf(db, 
        "SELECT idx,sampleno,sample FROM %Q.sqlite_stat2", sInfo.zDatabase);
    if( !zSql ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
      sqlite3DbFree(db, zSql);
    }

    if( rc==SQLITE_OK ){
      while( sqlite3_step(pStmt)==SQLITE_ROW ){
        char *zIndex;   /* Index name */
        Index *pIdx;    /* Pointer to the index object */

        zIndex = (char *)sqlite3_column_text(pStmt, 0);
        pIdx = zIndex ? sqlite3FindIndex(db, zIndex, sInfo.zDatabase) : 0;
        if( pIdx ){
          int iSample = sqlite3_column_int(pStmt, 1);
          if( iSample<SQLITE_INDEX_SAMPLES && iSample>=0 ){
            int eType = sqlite3_column_type(pStmt, 2);

            if( pIdx->aSample==0 ){
              static const int sz = sizeof(IndexSample)*SQLITE_INDEX_SAMPLES;
              pIdx->aSample = (IndexSample *)sqlite3DbMallocRaw(0, sz);
              if( pIdx->aSample==0 ){
                db->mallocFailed = 1;
                break;
              }
	      memset(pIdx->aSample, 0, sz);
            }

            assert( pIdx->aSample );
            {
              IndexSample *pSample = &pIdx->aSample[iSample];
              pSample->eType = (u8)eType;
              if( eType