Fossil

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.312 2008/05/12 12:39:56 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

/*
** CAPI3REF: Compile-Time Library Version Numbers {F10010}
**
** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in
** the sqlite3.h file specify the version of SQLite with which
** that header file is associated.
**
** The "version" of SQLite is a string of the form "X.Y.Z".
** The phrase "alpha" or "beta" might be appended after the Z.
** The X value is major version number always 3 in SQLite3.
** The X value only changes when  backwards compatibility is
** broken and we intend to never break
** backwards compatibility.  The Y value is the minor version
** number and only changes when
** there are major feature enhancements that are forwards compatible

**          evaluates to a string literal that is the SQLite version
**          with which the header file is associated.
**
** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer
**          with the value  (X*1000000 + Y*1000 + Z) where X, Y, and
**          Z are the major version, minor version, and release number.
*/
#define SQLITE_VERSION         "3.5.9"
#define SQLITE_VERSION_NUMBER  3005009

/*
** CAPI3REF: Run-Time Library Version Numbers {F10020}
** KEYWORDS: sqlite3_version
**
** These features provide the same information as the [SQLITE_VERSION]
** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated

int sqlite3_libversion_number(void);

/*
** CAPI3REF: Test To See If The Library Is Threadsafe {F10100}
**
** SQLite can be compiled with or without mutexes.  When
** the SQLITE_THREADSAFE C preprocessor macro is true, mutexes
** are enabled and SQLite is threadsafe.  When that macro is false,
** the mutexes are omitted.  Without the mutexes, it is not safe
** to use SQLite from more than one thread.
**
** There is a measurable performance penalty for enabling mutexes.
** So if speed is of utmost importance, it makes sense to disable
** the mutexes.  But for maximum safety, mutexes should be enabled.
** The default behavior is for mutexes to be enabled.

**          SQLite was compiled with its mutexes enabled or zero
**          if SQLite was compiled with mutexes disabled.
*/
int sqlite3_threadsafe(void);

/*
** CAPI3REF: Database Connection Handle {F12000}
** KEYWORDS: {database connection} {database connections}
**
** Each open SQLite database is represented by pointer to an instance of the
** opaque structure named "sqlite3".  It is useful to think of an sqlite3
** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
** [sqlite3_open_v2()] interfaces are its constructors
** and [sqlite3_close()] is its destructor.  There are many other interfaces
** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and

**          allocated using the equivalent of [sqlite3_mprintf()] and
**          *errmsg is made to point to that message.
**
** {F12134} The [sqlite3_exec()] routine does not change the value of
**          *errmsg if errmsg is NULL or if there are no errors.
**
** {F12137} The [sqlite3_exec()] function sets the error code and message
**          accessible via [sqlite3_errcode()], [sqlite3_errmsg()], and
**          [sqlite3_errmsg16()].
**
** LIMITATIONS:
**
** {U12141} The first parameter to [sqlite3_exec()] must be an valid and open
**          [database connection].
**
** {U12142} The database connection must not be closed while

**          a related primary result code as a prefix.
**
** {F10224} Primary result code names contain a single "_" character.
**
** {F10225} Extended result code names contain two or more "_" characters.
**
** {F10226} The numeric value of an extended result code contains the
**          numeric value of its corresponding primary result code in
**          its least significant 8 bits.
*/
#define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
#define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
#define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
#define SQLITE_IOERR_DELETE        (SQLITE_IOERR | (10<<8))
#define SQLITE_IOERR_BLOCKED       (SQLITE_IOERR | (11<<8))
#define SQLITE_IOERR_NOMEM         (SQLITE_IOERR | (12<<8))

/*
** CAPI3REF: Flags For File Open Operations {F10230}
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the xOpen method of the
** [sqlite3_vfs] object.
*/
#define SQLITE_OPEN_READONLY         0x00000001
#define SQLITE_OPEN_READWRITE        0x00000002
#define SQLITE_OPEN_CREATE           0x00000004

#define SQLITE_LOCK_PENDING       3
#define SQLITE_LOCK_EXCLUSIVE     4

/*
** CAPI3REF: Synchronization Type Flags {F10260}
**
** When SQLite invokes the xSync() method of an
** [sqlite3_io_methods] object it uses a combination of
** these integer values as the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 
** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 
** to use Mac OS-X style fullsync instead of fsync().
*/
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010

  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
};

/*
** CAPI3REF: OS Interface File Virtual Methods Object {F11120}
**
** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to
** an instance of this object.  This object defines the
** methods used to perform various operations against the open file.
**
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
*  The second choice is an
** OS-X style fullsync.  The SQLITE_SYNC_DATA flag may be ORed in to
** indicate that only the data of the file and not its inode needs to be

** CAPI3REF: Standard File Control Opcodes {F11310}
**
** These integer constants are opcodes for the xFileControl method
** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()]
** interface.
**
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
** into an integer that the pArg argument points to. This capability
** is used during testing and only needs to be supported when SQLITE_TEST
** is defined.
*/
#define SQLITE_FCNTL_LOCKSTATE        1

** versions of SQLite.  Additional fields may be appended to this
** object when the iVersion value is increased.
**
** The szOsFile field is the size of the subclassed [sqlite3_file]
** structure used by this VFS.  mxPathname is the maximum length of
** a pathname in this VFS.
**
** Registered sqlite3_vfs objects are kept on a linked list formed by
** the pNext pointer.  The [sqlite3_vfs_register()]
** and [sqlite3_vfs_unregister()] interfaces manage this list
** in a thread-safe way.  The [sqlite3_vfs_find()] interface
** searches the list.
**
** The pNext field is the only field in the sqlite3_vfs 
** structure that SQLite will ever modify.  SQLite will only access
** or modify this field while holding a particular static mutex.
** The application should never modify anything within the sqlite3_vfs
** object once the object has been registered.
**
** The zName field holds the name of the VFS module.  The name must
** be unique across all VFS modules.

** <li>  [SQLITE_OPEN_TRANSIENT_DB]
** <li>  [SQLITE_OPEN_SUBJOURNAL]
** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
** </ul> {END}
**
** The file I/O implementation can use the object type flags to
** changes the way it deals with files.  For example, an application
** that does not care about crash recovery or rollback might make
** the open of a journal file a no-op.  Writes to this journal would
** also be no-ops, and any attempt to read the journal would return 
** SQLITE_IOERR.  Or the implementation might recognize that a database 
** file will be doing page-aligned sector reads and writes in a random 
** order and set up its I/O subsystem accordingly.
** 
** SQLite might also add one of the following flags to the xOpen
** method:
** 
** <ul>
** <li> [SQLITE_OPEN_DELETEONCLOSE]
** <li> [SQLITE_OPEN_EXCLUSIVE]
** </ul>
** 
** {F11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
** deleted when it is closed.  {F11146} The [SQLITE_OPEN_DELETEONCLOSE]
** will be set for TEMP  databases, journals and for subjournals. 
** {F11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened
** for exclusive access.  This flag is set for all files except
** for the main database file. {END}
** 
** {F11148} At least szOsFile bytes of memory are allocated by SQLite 
** to hold the  [sqlite3_file] structure passed as the third 
** argument to xOpen.  {END}  The xOpen method does not have to
** allocate the structure; it should just fill it in.
** 
** {F11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 
** to test for the existance of a file,
** or [SQLITE_ACCESS_READWRITE] to test to see
** if a file is readable and writable, or [SQLITE_ACCESS_READ]
** to test to see if a file is at least readable.  {END} The file can be a 
** directory.
** 
** {F11150} SQLite will always allocate at least mxPathname+1 bytes for
** the output buffers for xGetTempname and xFullPathname. {F11151} The exact
** size of the output buffer is also passed as a parameter to both 
** methods. {END} If the output buffer is not large enough, SQLITE_CANTOPEN
** should be returned. As this is handled as a fatal error by SQLite,
** vfs implementations should endeavor to prevent this by setting 
** mxPathname to a sufficiently large value.
** 
** The xRandomness(), xSleep(), and xCurrentTime() interfaces
** are not strictly a part of the filesystem, but they are
** included in the VFS structure for completeness.
** The xRandomness() function attempts to return nBytes bytes
** of good-quality randomness into zOut.  The return value is
** the actual number of bytes of randomness obtained.  The
** xSleep() method causes the calling thread to sleep for at
** least the number of microseconds given.  The xCurrentTime()
** method returns a Julian Day Number for the current date and
** time.
*/
typedef struct sqlite3_vfs sqlite3_vfs;
struct sqlite3_vfs {
  int iVersion;            /* Structure version number */

};

/*
** CAPI3REF: Flags for the xAccess VFS method {F11190}
**
** {F11191} These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object. {END}  They determine
** what kind of permissions the xAccess method is
** looking for.  {F11192} With SQLITE_ACCESS_EXISTS, the xAccess method
** simply checks to see if the file exists. {F11193} With
** SQLITE_ACCESS_READWRITE, the xAccess method checks to see
** if the file is both readable and writable.  {F11194} With
** SQLITE_ACCESS_READ the xAccess method
** checks to see if the file is readable.
*/

** CAPI3REF: Last Insert Rowid {F12220}
**
** Each entry in an SQLite table has a unique 64-bit signed
** integer key called the "rowid". The rowid is always available
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
** names are not also used by explicitly declared columns. If
** the table has a column of type INTEGER PRIMARY KEY then that column
** is another alias for the rowid.
**
** This routine returns the rowid of the most recent
** successful INSERT into the database from the database connection
** shown in the first argument.  If no successful inserts
** have ever occurred on this database connection, zero is returned.
**
** If an INSERT occurs within a trigger, then the rowid of the

**
** {F12223} The [sqlite3_last_insert_rowid()] function returns
**          same value when called from the same trigger context
**          immediately before and after a ROLLBACK.
**
** LIMITATIONS:
**
** {U12232} If a separate thread does a new insert on the same
**          database connection while the [sqlite3_last_insert_rowid()]
**          function is running and thus changes the last insert rowid,
**          then the value returned by [sqlite3_last_insert_rowid()] is
**          unpredictable and might not equal either the old or the new
**          last insert rowid.
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified {F12240}
**
** This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the connection specified by the first parameter.  Only
** changes that are directly specified by the INSERT, UPDATE, or
** DELETE statement are counted.  Auxiliary changes caused by
** triggers are not counted. Use the [sqlite3_total_changes()] function
** to find the total number of changes including changes caused by triggers.
**
** A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of REPLACE constraint resolution,
** rollback, ABORT processing, DROP TABLE, or by any other
** mechanisms do not count as direct row changes.
**
** A "trigger context" is a scope of execution that begins and
** ends with the script of a trigger.  Most SQL statements are

** are counted as soon as the statement that makes them is completed 
** (when the statement handle is passed to [sqlite3_reset()] or 
** [sqlite3_finalize()]).
**
** SQLite implements the command "DELETE FROM table" without
** a WHERE clause by dropping and recreating the table.  (This is much
** faster than going
** through and deleting individual elements from the table.)  Because of
** this optimization, the change count for "DELETE FROM table" will be
** zero regardless of the number of elements that were originally in the
** table. To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
**
** See also the [sqlite3_changes()] interface.
**

**          [sqlite3_memory_highwater()] is true.  The value returned
**          by [sqlite3_memory_highwater(1)] is the highwater mark
**          prior to the reset.
*/
sqlite3_int64 sqlite3_memory_used(void);
sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

/*
** CAPI3REF: Pseudo-Random Number Generator {F17390}
**
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
** select random ROWIDs when inserting new records into a table that
** already uses the largest possible ROWID.  The PRNG is also used for
** the build-in random() and randomblob() SQL functions.  This interface allows
** appliations to access the same PRNG for other purposes.
**
** A call to this routine stores N bytes of randomness into buffer P.
**
** The first time this routine is invoked (either internally or by
** the application) the PRNG is seeded using randomness obtained
** from the xRandomness method of the default [sqlite3_vfs] object.
** On all subsequent invocations, the pseudo-randomness is generated
** internally and without recourse to the [sqlite3_vfs] xRandomness
** method.
**
** INVARIANTS:
**
** {F17392} The [sqlite3_randomness(N,P)] interface writes N bytes of
**          high-quality pseudo-randomness into buffer P.
*/
void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks {F12500}
**
** This routine registers a authorizer callback with a particular
** [database connection], supplied in the first argument.
** The authorizer callback is invoked as SQL statements are being compiled
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various
** points during the compilation process, as logic is being created
** to perform various actions, the authorizer callback is invoked to
** see if those actions are allowed.  The authorizer callback should
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
** specific action but allow the SQL statement to continue to be
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
** rejected with an error.   If the authorizer callback returns
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
** then [sqlite3_prepare_v2()] or equivalent call that triggered
** the authorizer will fail with an error message.
**
** When the callback returns [SQLITE_OK], that means the operation
** requested is ok.  When the callback returns [SQLITE_DENY], the
** [sqlite3_prepare_v2()] or equivalent call that triggered the
** authorizer will fail with an error message explaining that
** access is denied.  If the authorizer code is [SQLITE_READ]
** and the callback returns [SQLITE_IGNORE] then the
** [prepared statement] statement is constructed to substitute
** a NULL value in place of the table column that would have
** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
** return can be used to deny an untrusted user access to individual
** columns of a table.
**
** The first parameter to the authorizer callback is a copy of
** the third parameter to the sqlite3_set_authorizer() interface.
** The second parameter to the callback is an integer 
** [SQLITE_COPY | action code] that specifies the particular action
** to be authorized. The third through sixth
** parameters to the callback are zero-terminated strings that contain 
** additional details about the action to be authorized.
**
** An authorizer is used when [sqlite3_prepare | preparing]
** SQL statements from an untrusted
** source, to ensure that the SQL statements do not try to access data
** that they are not allowed to see, or that they do not try to
** execute malicious statements that damage the database.  For
** example, an application may allow a user to enter arbitrary
** SQL queries for evaluation by a database.  But the application does
** not want the user to be able to make arbitrary changes to the
** database.  An authorizer could then be put in place while the
** user-entered SQL is being [sqlite3_prepare | prepared] that
** disallows everything except [SELECT] statements.
**
** Applications that need to process SQL from untrusted sources
** might also consider lowering resource limits using [sqlite3_limit()]
** and limiting database size using the [max_page_count] [PRAGMA]
** in addition to using an authorizer.
**
** Only a single authorizer can be in place on a database connection
** at a time.  Each call to sqlite3_set_authorizer overrides the
** previous call.  Disable the authorizer by installing a NULL callback.
** The authorizer is disabled by default.
**
** Note that the authorizer callback is invoked only during 

** if the file is write protected.  In either case the database
** must already exist or an error is returned.  The third option
** opens the database for reading and writing and creates it if it does
** not already exist.
** The third options is behavior that is always used for [sqlite3_open()]
** and [sqlite3_open16()].
**
** If the 3rd parameter to [sqlite3_open_v2()] is not one of the
** combinations shown above then the behavior is undefined.
**
** If the filename is ":memory:", then an private
** in-memory database is created for the connection.  This in-memory
** database will vanish when the database connection is closed.  Future
** version of SQLite might make use of additional special filenames
** that begin with the ":" character.  It is recommended that 
** when a database filename really does begin with
** ":" that you prefix the filename with a pathname like "./" to

**
** {F12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()],
**          or [sqlite3_open_v2()] is ":memory:", then an private,
**          ephemeral, in-memory database is created for the connection.
**          <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required
**          in sqlite3_open_v2()?</todo>
**
** {F12719} If the filename is NULL or an empty string, then a private,
**          ephermeral on-disk database will be created.
**          <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required
**          in sqlite3_open_v2()?</todo>
**
** {F12721} The [database connection] created by 
**          [sqlite3_open_v2(F,D,G,V)] will use the
**          [sqlite3_vfs] object identified by the V parameter, or
**          the default [sqlite3_vfs] object is V is a NULL pointer.

** most recent API call succeeded, the return value from sqlite3_errcode()
** is undefined.
**
** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF8 or UTF16 respectively.
** Memory to hold the error message string is managed internally.
** The application does not need to worry with freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.
**
** INVARIANTS:
**
** {F12801} The [sqlite3_errcode(D)] interface returns the numeric
**          [SQLITE_OK | result code] or
**          [SQLITE_IOERR_READ | extended result code]
**          for the most recently failed interface call associated
**          with [database connection] D.




**
** {F12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]
**          interfaces return English-language text that describes
**          the error in the mostly recently failed interface call,
**          encoded as either UTF8 or UTF16 respectively.
**
** {F12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]
**          are valid until the next SQLite interface call.




**
** {F12808} Calls to API routines that do not return an error code
**          (example: [sqlite3_data_count()]) do not
**          change the error code or message returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**
** {F12809} Interfaces that are not associated with a specific

** </ol>
**
** Refer to documentation on individual methods above for additional
** information.
*/
typedef struct sqlite3_stmt sqlite3_stmt;

/*
** CAPI3REF: Run-time Limits {F12760}
**
** This interface allows the size of various constructs to be limited
** on a connection by connection basis.  The first parameter is the
** [database connection] whose limit is to be set or queried.  The
** second parameter is one of the [limit categories] that define a
** class of constructs to be size limited.  The third parameter is the
** new limit for that construct.  The function returns the old limit.
**
** If the new limit is a negative number, the limit is unchanged.
** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper
** bound set by a compile-time C-preprocess macro named SQLITE_MAX_XYZ.
** (The "_LIMIT_" in the name is changed to "_MAX_".)
** Attempts to increase a limit above its hard upper bound are
** silently truncated to the hard upper limit.
**
** Run time limits are intended for use in applications that manage
** both their own internal database and also databases that are controlled
** by untrusted external sources.  An example application might be a
** webbrowser that has its own databases for storing history and
** separate databases controlled by javascript applications downloaded
** off the internet.  The internal databases can be given the
** large, default limits.  Databases managed by external sources can
** be given much smaller limits designed to prevent a denial of service
** attach.  Developers might also want to use the [sqlite3_set_authorizer()]
** interface to further control untrusted SQL.  The size of the database
** created by an untrusted script can be contained using the
** [max_page_count] [PRAGMA].
**
** This interface is currently considered experimental and is subject
** to change or removal without prior notice.
**
** INVARIANTS:
**
** {F12762} A successful call to [sqlite3_limit(D,C,V)] where V is
**          positive changes the
**          limit on the size of construct C in [database connection] D
**          to the lessor of V and the hard upper bound on the size
**          of C that is set at compile-time.
**
** {F12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative
**          leaves the state of [database connection] D unchanged.
**
** {F12769} A successful call to [sqlite3_limit(D,C,V)] returns the
**          value of the limit on the size of construct C in
**          in [database connection] D as it was prior to the call.
*/
int sqlite3_limit(sqlite3*, int id, int newVal);

/*
** CAPI3REF: Run-Time Limit Categories {F12790}
** KEYWORDS: {limit category} {limit categories}
** 
** These constants define various aspects of a [database connection]
** that can be limited in size by calls to [sqlite3_limit()].
** The meanings of the various limits are as follows:
**
** <dl>
** <dt>SQLITE_LIMIT_LENGTH</dt>
** <dd>The maximum size of any
** string or blob or table row.<dd>
**
** <dt>SQLITE_LIMIT_SQL_LENGTH</dt>
** <dd>The maximum length of an SQL statement.</dd>
**
** <dt>SQLITE_LIMIT_COLUMN</dt>
** <dd>The maximum number of columns in a table definition or in the
** result set of a SELECT or the maximum number of columns in an index
** or in an ORDER BY or GROUP BY clause.</dd>
**
** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
** <dd>The maximum depth of the parse tree on any expression.</dd>
**
** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
** <dd>The maximum number of terms in a compound SELECT statement.</dd>
**
** <dt>SQLITE_LIMIT_VDBE_OP</dt>
** <dd>The maximum number of instructions in a virtual machine program
** used to implement an SQL statement.</dd>
**
** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
** <dd>The maximum number of arguments on a function.</dd>
**
** <dt>SQLITE_LIMIT_ATTACHED</dt>
** <dd>The maximum number of attached databases.</dd>
**
** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
** <dd>The maximum length of the pattern argument to the LIKE or
** GLOB operators.</dd>
**
** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
** <dd>The maximum number of variables in an SQL statement that can
** be bound.</dd>
** </dl>
*/
#define SQLITE_LIMIT_LENGTH                    0
#define SQLITE_LIMIT_SQL_LENGTH                1
#define SQLITE_LIMIT_COLUMN                    2
#define SQLITE_LIMIT_EXPR_DEPTH                3
#define SQLITE_LIMIT_COMPOUND_SELECT           4
#define SQLITE_LIMIT_VDBE_OP                   5
#define SQLITE_LIMIT_FUNCTION_ARG              6
#define SQLITE_LIMIT_ATTACHED                  7
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
#define SQLITE_LIMIT_VARIABLE_NUMBER           9

/*
** CAPI3REF: Compiling An SQL Statement {F13010}
**
** To execute an SQL query, it must first be compiled into a byte-code
** program using one of these routines. 
**
** The first argument "db" is an [database connection] 
** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()]
** or [sqlite3_open16()]. 
** The second argument "zSql" is the statement to be compiled, encoded
** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
** use UTF-16. {END}
**
** If the nByte argument is less
** than zero, then zSql is read up to the first zero terminator.
** If nByte is non-negative, then it is the maximum number of 
** bytes read from zSql.  When nByte is non-negative, the
** zSql string ends at either the first '\000' or '\u0000' character or 
** the nByte-th byte, whichever comes first. If the caller knows
** that the supplied string is nul-terminated, then there is a small
** performance advantage to be had by passing an nByte parameter that 
** is equal to the number of bytes in the input string <i>including</i> 
** the nul-terminator bytes.{END}
**
** *pzTail is made to point to the first byte past the end of the
** first SQL statement in zSql.  These routines only compiles the first
** statement in zSql, so *pzTail is left pointing to what remains
** uncompiled.
**
** *ppStmt is left pointing to a compiled [prepared statement] that can be
** executed using [sqlite3_step()].  Or if there is an error, *ppStmt is
** set to NULL.  If the input text contains no SQL (if the input
** is and empty string or a comment) then *ppStmt is set to NULL.
** {U13018} The calling procedure is responsible for deleting the
** compiled SQL statement
** using [sqlite3_finalize()] after it has finished with it.
**
** On success, [SQLITE_OK] is returned.  Otherwise an 

**          text in their zSql parameter as UTF-16 in the native byte order.
**
** {F13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]
**          and its variants is less than zero, then SQL text is
**          read from zSql is read up to the first zero terminator.
**
** {F13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]
**          and its variants is non-negative, then at most nBytes bytes
**          SQL text is read from zSql.
**
** {F13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants
**          if the zSql input text contains more than one SQL statement
**          and pzTail is not NULL, then *pzTail is made to point to the
**          first byte past the end of the first SQL statement in zSql.
**          <todo>What does *pzTail point to if there is one statement?</todo>
**
** {F13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)]
**          or one of its variants writes into *ppStmt a pointer to a new
**          [prepared statement] or a pointer to NULL
**          if zSql contains nothing other than whitespace or comments. 
**
** {F13019} The [sqlite3_prepare_v2()] interface and its variants return
**          [SQLITE_OK] or an appropriate [error code] upon failure.
**
** {F13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its
**          variants returns an error (any value other than [SQLITE_OK])
**          it first sets *ppStmt to NULL.
*/
int sqlite3_prepare(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */

** {F13103} The string returned by [sqlite3_sql(S)] is valid until the
**          [prepared statement] S is deleted using [sqlite3_finalize(S)].
*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF:  Dynamically Typed Value Object  {F15000}
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**
** SQLite uses the sqlite3_value object to represent all values
** that can be stored in a database table.
** SQLite uses dynamic typing for the values it stores.  
** Values stored in sqlite3_value objects can be
** be integers, floating point values, strings, BLOBs, or NULL.
**
** An sqlite3_value object may be either "protected" or "unprotected".
** Some interfaces require a protected sqlite3_value.  Other interfaces
** will accept either a protected or an unprotected sqlite3_value.
** Every interface that accepts sqlite3_value arguments specifies 
** whether or not it requires a protected sqlite3_value.
**
** The terms "protected" and "unprotected" refer to whether or not
** a mutex is held.  A internal mutex is held for a protected
** sqlite3_value object but no mutex is held for an unprotected
** sqlite3_value object.  If SQLite is compiled to be single-threaded
** (with SQLITE_THREADSAFE=0 and with [sqlite3_threadsafe()] returning 0)
** then there is no distinction between
** protected and unprotected sqlite3_value objects and they can be
** used interchangable.  However, for maximum code portability it
** is recommended that applications make the distinction between
** between protected and unprotected sqlite3_value objects even if
** they are single threaded.
**
** The sqlite3_value objects that are passed as parameters into the
** implementation of application-defined SQL functions are protected.
** The sqlite3_value object returned by
** [sqlite3_column_value()] is unprotected.
** Unprotected sqlite3_value objects may only be used with
** [sqlite3_result_value()] and [sqlite3_bind_value()].  All other
** interfaces that use sqlite3_value require protected sqlite3_value objects.
*/
typedef struct Mem sqlite3_value;

/*
** CAPI3REF:  SQL Function Context Object {F16001}
**
** The context in which an SQL function executes is stored in an

** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999).
**
** The third argument is the value to bind to the parameter.
**
** In those
** routines that have a fourth argument, its value is the number of bytes
** in the parameter.  To be clear: the value is the number of <u>bytes</u>
** in the value, not the number of characters. 

** If the fourth parameter is negative, the length of the string is
** number of bytes up to the first zero terminator.
**
** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
** string after SQLite has finished with it. If the fifth argument is
** the special value [SQLITE_STATIC], then SQLite assumes that the

**          [sqlite3_bind_text(S,N,V,L,D)], or
**          [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to
**          a function, SQLite invokes that function to destroy the
**          V value after it has finished using the V value.
**
** {F13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound
**          is a blob of L bytes, or a zero-length blob if L is negative.
**
** {F13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may
**          be either a [protected sqlite3_value] object or an
**          [unprotected sqlite3_value] object.
*/
int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
int sqlite3_bind_double(sqlite3_stmt*, int, double);
int sqlite3_bind_int(sqlite3_stmt*, int, int);
int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
int sqlite3_bind_null(sqlite3_stmt*, int);
int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));

int sqlite3_bind_parameter_count(sqlite3_stmt*);

/*
** CAPI3REF: Name Of A Host Parameter {F13620}
**
** This routine returns a pointer to the name of the n-th
** SQL parameter in a [prepared statement].
** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
** respectively.
** In other words, the initial ":" or "$" or "@" or "?"
** is included as part of the name.
** Parameters of the form "?" without a following integer have no name.
**
** The first host parameter has an index of 1, not 0.
**
** If the value n is out of range or if the n-th parameter is
** nameless, then NULL is returned.  The returned string is
** always in the UTF-8 encoding even if the named parameter was
** originally specified as UTF-16 in [sqlite3_prepare16()] or
** [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].
**
** INVARIANTS:
**
** {F13621} The [sqlite3_bind_parameter_name(S,N)] interface returns
**          a UTF-8 rendering of the name of the SQL parameter in
**          [prepared statement] S having index N, or
**          NULL if there is no SQL parameter with index N or if the
**          parameter with index N is an anonymous parameter "?".

*/
const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);

/*
** CAPI3REF: Index Of A Parameter With A Given Name {F13640}
**
** Return the index of an SQL parameter given its name.  The

** The details of the behavior of this sqlite3_step() interface depend
** on whether the statement was prepared using the newer "v2" interface
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
** new "v2" interface is recommended for new applications but the legacy
** interface will continue to be supported.
**
** In the legacy interface, the return value will be either [SQLITE_BUSY], 
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
** With the "v2" interface, any of the other [SQLITE_OK | result code]
** or [SQLITE_IOERR_READ | extended result code] might be returned as
** well.
**
** [SQLITE_BUSY] means that the database engine was unable to acquire the
** database locks it needs to do its job.  If the statement is a COMMIT

** even empty strings, are always zero terminated.  The return
** value from sqlite3_column_blob() for a zero-length blob is an arbitrary
** pointer, possibly even a NULL pointer.
**
** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
** but leaves the result in UTF-16 in native byte order instead of UTF-8.  
** The zero terminator is not included in this count.
**
** The object returned by [sqlite3_column_value()] is an
** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
** If the [unprotected sqlite3_value] object returned by
** [sqlite3_column_value()] is used in any other way, including calls
** to routines like 
** [sqlite3_value_int()], [sqlite3_value_text()], or [sqlite3_value_bytes()],
** then the behavior is undefined.
**
** These routines attempt to convert the value where appropriate.  For
** example, if the internal representation is FLOAT and a text result
** is requested, [sqlite3_snprintf()] is used internally to do the conversion
** automatically.  The following table details the conversions that
** are applied:
**

** {F13812} The [sqlite3_column_double(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a floating point value and
**          returns a copy of that value.
**
** {F13815} The [sqlite3_column_int(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a 64-bit signed integer and
**          returns the lower 32 bits of that integer.
**
** {F13818} The [sqlite3_column_int64(S,N)] interface converts the
**          Nth column in the current row of the result set for
**          [prepared statement] S into a 64-bit signed integer and
**          returns a copy of that integer.
**
** {F13821} The [sqlite3_column_text(S,N)] interface converts the

** {F13827} The [sqlite3_column_type(S,N)] interface returns
**          one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
**          [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
**          the Nth column in the current row of the result set for
**          [prepared statement] S.
**
** {F13830} The [sqlite3_column_value(S,N)] interface returns a
**          pointer to an [unprotected sqlite3_value] object for the
**          Nth column in the current row of the result set for
**          [prepared statement] S.
*/
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
double sqlite3_column_double(sqlite3_stmt*, int iCol);

** These two functions (collectively known as
** "function creation routines") are used to add SQL functions or aggregates
** or to redefine the behavior of existing SQL functions or aggregates.  The
** difference only between the two is that the second parameter, the
** name of the (scalar) function or aggregate, is encoded in UTF-8 for
** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
**
** The first parameter is the [database connection] to which the SQL
** function is to be added.  If a single
** program uses more than one [database connection] internally, then SQL
** functions must be added individually to each [database connection].

**
** The second parameter is the name of the SQL function to be created
** or redefined.
** The length of the name is limited to 255 bytes, exclusive of the 
** zero-terminator.  Note that the name length limit is in bytes, not
** characters.  Any attempt to create a function with a longer name
** will result in an SQLITE_ERROR error.

**
** {F16103} The [sqlite3_create_function16()] interface behaves exactly
**          like [sqlite3_create_function()] in every way except that it
**          interprets the zFunctionName argument as
**          zero-terminated UTF-16 native byte order instead of as a
**          zero-terminated UTF-8.
**
** {F16106} A successful invocation of
**          the [sqlite3_create_function(D,X,N,E,...)] interface registers
**          or replaces callback functions in [database connection] D
**          used to implement the SQL function named X with N parameters
**          and having a perferred text encoding of E.
**
** {F16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)]
**          replaces the P, F, S, and L values from any prior calls with
**          the same D, X, N, and E values.
**
** {F16112} The [sqlite3_create_function(D,X,...)] interface fails with
**          a return code of [SQLITE_ERROR] if the SQL function name X is
**          longer than 255 bytes exclusive of the zero terminator.
**
** {F16118} Either F must be NULL and S and L are non-NULL or else F
**          is non-NULL and S and L are NULL, otherwise
**          [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR].
**
** {F16121} The [sqlite3_create_function(D,...)] interface fails with an
**          error code of [SQLITE_BUSY] if there exist [prepared statements]
**          associated with the [database connection] D.
**
** {F16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an
**          error code of [SQLITE_ERROR] if parameter N (specifying the number
**          of arguments to the SQL function being registered) is less
**          than -1 or greater than 127.
**
** {F16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)]
**          interface causes callbacks to be invoked for the SQL function
**          named X when the number of arguments to the SQL function is
**          exactly N.
**
** {F16130} When N is -1, the [sqlite3_create_function(D,X,N,...)]
**          interface causes callbacks to be invoked for the SQL function
**          named X with any number of arguments.
**
** {F16133} When calls to [sqlite3_create_function(D,X,N,...)]
**          specify multiple implementations of the same function X
**          and when one implementation has N>=0 and the other has N=(-1)
**          the implementation with a non-zero N is preferred.
**
** {F16136} When calls to [sqlite3_create_function(D,X,N,E,...)]
**          specify multiple implementations of the same function X with
**          the same number of arguments N but with different
**          encodings E, then the implementation where E matches the
**          database encoding is preferred.
**
** {F16139} For an aggregate SQL function created using
**          [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finializer
**          function L will always be invoked exactly once if the
**          step function S is called one or more times.
**
** {F16142} When SQLite invokes either the xFunc or xStep function of
**          an application-defined SQL function or aggregate created
**          by [sqlite3_create_function()] or [sqlite3_create_function16()],
**          then the array of [sqlite3_value] objects passed as the
**          third parameter are always [protected sqlite3_value] objects.
*/
int sqlite3_create_function(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  void *pApp,

** this set of interface routines to access the parameter values on
** the function or aggregate.
**
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
** define callbacks that implement the SQL functions and aggregates.
** The 4th parameter to these callbacks is an array of pointers to
** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
** each parameter to the SQL function.  These routines are used to
** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.
**
** These routines work just like the corresponding 
** [sqlite3_column_blob | sqlite3_column_* routines] except that 
** these routines take a single [protected sqlite3_value] object pointer
** instead of an [sqlite3_stmt*] pointer and an integer column number.
**
** The sqlite3_value_text16() interface extracts a UTF16 string
** in the native byte-order of the host machine.  The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF16 strings as big-endian and little-endian respectively.
**
** The sqlite3_value_numeric_type() interface attempts to apply

** Please pay particular attention to the fact that the pointer that
** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
** or [sqlite3_value_text16()].  
**
** These routines must be called from the same thread as
** the SQL function that supplied the [sqlite3_value*] parameters.
**
**
** INVARIANTS:
**
** {F15103} The [sqlite3_value_blob(V)] interface converts the
**          [protected sqlite3_value] object V into a blob and then returns a
**          pointer to the converted value.
**
** {F15106} The [sqlite3_value_bytes(V)] interface returns the
**          number of bytes in the blob or string (exclusive of the
**          zero terminator on the string) that was returned by the
**          most recent call to [sqlite3_value_blob(V)] or
**          [sqlite3_value_text(V)].
**
** {F15109} The [sqlite3_value_bytes16(V)] interface returns the
**          number of bytes in the string (exclusive of the
**          zero terminator on the string) that was returned by the
**          most recent call to [sqlite3_value_text16(V)],
**          [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)].
**
** {F15112} The [sqlite3_value_double(V)] interface converts the
**          [protected sqlite3_value] object V into a floating point value and
**          returns a copy of that value.
**
** {F15115} The [sqlite3_value_int(V)] interface converts the
**          [protected sqlite3_value] object V into a 64-bit signed integer and
**          returns the lower 32 bits of that integer.
**
** {F15118} The [sqlite3_value_int64(V)] interface converts the
**          [protected sqlite3_value] object V into a 64-bit signed integer and
**          returns a copy of that integer.
**
** {F15121} The [sqlite3_value_text(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated UTF-8 
**          string and returns a pointer to that string.
**
** {F15124} The [sqlite3_value_text16(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated 2-byte
**          aligned UTF-16 native byte order
**          string and returns a pointer to that string.
**
** {F15127} The [sqlite3_value_text16be(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated 2-byte
**          aligned UTF-16 big-endian
**          string and returns a pointer to that string.
**
** {F15130} The [sqlite3_value_text16le(V)] interface converts the
**          [protected sqlite3_value] object V into a zero-terminated 2-byte
**          aligned UTF-16 little-endian
**          string and returns a pointer to that string.
**
** {F15133} The [sqlite3_value_type(V)] interface returns
**          one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
**          [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
**          the [sqlite3_value] object V.
**
** {F15136} The [sqlite3_value_numeric_type(V)] interface converts
**          the [protected sqlite3_value] object V into either an integer or
**          a floating point value if it can do so without loss of
**          information, and returns one of [SQLITE_NULL],
**          [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or
**          [SQLITE_BLOB] as appropriate for
**          the [protected sqlite3_value] object V after the conversion attempt.
*/
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtain Aggregate Function Context {F16210}
**
** The implementation of aggregate SQL functions use this routine to allocate
** a structure for storing their state.  
** The first time the sqlite3_aggregate_context() routine is
** is called for a particular aggregate, SQLite allocates nBytes of memory
** zeros that memory, and returns a pointer to it.
** On second and subsequent calls to sqlite3_aggregate_context()
** for the same aggregate function index, the same buffer is returned.
** The implementation
** of the aggregate can use the returned buffer to accumulate data.
**
** SQLite automatically frees the allocated buffer when the aggregate
** query concludes.
**
** The first parameter should be a copy of the 
** [sqlite3_context | SQL function context] that is the first
** parameter to the callback routine that implements the aggregate
** function.
**
** This routine must be called from the same thread in which
** the aggregate SQL function is running.
**
** INVARIANTS:
**
** {F16211} The first invocation of [sqlite3_aggregate_context(C,N)] for
**          a particular instance of an aggregate function (for a particular
**          context C) causes SQLite to allocation N bytes of memory,
**          zero that memory, and return a pointer to the allocationed
**          memory.
**
** {F16213} If a memory allocation error occurs during
**          [sqlite3_aggregate_context(C,N)] then the function returns 0.
**
** {F16215} Second and subsequent invocations of
**          [sqlite3_aggregate_context(C,N)] for the same context pointer C
**          ignore the N parameter and return a pointer to the same
**          block of memory returned by the first invocation.
**
** {F16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is
**          automatically freed on the next call to [sqlite3_reset()]
**          or [sqlite3_finalize()] for the [prepared statement] containing
**          the aggregate function associated with context C.
*/
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

/*
** CAPI3REF: User Data For Functions {F16240}
**
** The sqlite3_user_data() interface returns a copy of
** the pointer that was the pUserData parameter (the 5th parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function. {END}
**
** This routine must be called from the same thread in which
** the application-defined function is running.
**
** INVARIANTS:
**
** {F16243} The [sqlite3_user_data(C)] interface returns a copy of the
**          P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
**          or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
**          registered the SQL function associated with 
**          [sqlite3_context] C.
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Database Connection For Functions {F16250}
**
** The sqlite3_context_db_handle() interface returns a copy of
** the pointer to the [database connection] (the 1st parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function.
**
** INVARIANTS:
**
** {F16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the
**          D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
**          or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
**          registered the SQL function associated with 
**          [sqlite3_context] C.
*/
sqlite3 *sqlite3_context_db_handle(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data {F16270}
**
** The following two functions may be used by scalar SQL functions to
** associate meta-data with argument values. If the same value is passed to
** multiple invocations of the same SQL function during query execution, under
** some circumstances the associated meta-data may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** meta-data associated with the SQL value passed as the regular expression
** pattern.  The compiled regular expression can be reused on multiple
** invocations of the same function so that the original pattern string
** does not need to be recompiled on each invocation.
**

** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
** associated by the sqlite3_set_auxdata() function with the Nth argument
** value to the application-defined function.
** If no meta-data has been ever been set for the Nth
** argument of the function, or if the cooresponding function parameter
** has changed since the meta-data was set, then sqlite3_get_auxdata()
** returns a NULL pointer.
**
** The sqlite3_set_auxdata() interface saves the meta-data
** pointed to by its 3rd parameter as the meta-data for the N-th
** argument of the application-defined function.  Subsequent
** calls to sqlite3_get_auxdata() might return this data, if it has
** not been destroyed. 
** If it is not NULL, SQLite will invoke the destructor 
** function given by the 4th parameter to sqlite3_set_auxdata() on
** the meta-data when the corresponding function parameter changes
** or when the SQL statement completes, whichever comes first.
**
** SQLite is free to call the destructor and drop meta-data on
** any parameter of any function at any time.  The only guarantee
** is that the destructor will be called before the metadata is
** dropped.
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routines must be called from the same thread in which
** the SQL function is running.
**
** INVARIANTS:
**
** {F16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer
**          to metadata associated with the Nth parameter of the SQL function
**          whose context is C, or NULL if there is no metadata associated
**          with that parameter.
**
** {F16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata
**          pointer P to the Nth parameter of the SQL function with context
**          C.
**
** {F16276} SQLite will invoke the destructor D with a single argument
**          which is the metadata pointer P following a call to
**          [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold
**          the metadata.
**
** {F16277} SQLite ceases to hold metadata for an SQL function parameter
**          when the value of that parameter changes.
**
** {F16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor
**          is called for any prior metadata associated with the same function
**          context C and parameter N.
**
** {F16279} SQLite will call destructors for any metadata it is holding
**          in a particular [prepared statement] S when either
**          [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called.
*/
void *sqlite3_get_auxdata(sqlite3_context*, int N);
void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior {F10280}

** These functions work very much like the 
** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
** to bind values to host parameters in prepared statements.
** Refer to the
** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
** additional information.
**
** The sqlite3_result_blob() interface sets the result from
** an application defined function to be the BLOB whose content is pointed
** to by the second parameter and which is N bytes long where N is the
** third parameter. 
** The sqlite3_result_zeroblob() inerfaces set the result of
** the application defined function to be a BLOB containing all zero
** bytes and N bytes in size, where N is the value of the 2nd parameter.
**
** The sqlite3_result_double() interface sets the result from
** an application defined function to be a floating point value specified
** by its 2nd argument.
**
** The sqlite3_result_error() and sqlite3_result_error16() functions
** cause the implemented SQL function to throw an exception.
** SQLite uses the string pointed to by the
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
** as the text of an error message.  SQLite interprets the error
** message string from sqlite3_result_error() as UTF8. SQLite
** interprets the string from sqlite3_result_error16() as UTF16 in native
** byte order.  If the third parameter to sqlite3_result_error()
** or sqlite3_result_error16() is negative then SQLite takes as the error
** message all text up through the first zero character.
** If the third parameter to sqlite3_result_error() or
** sqlite3_result_error16() is non-negative then SQLite takes that many
** bytes (not characters) from the 2nd parameter as the error message.
** The sqlite3_result_error() and sqlite3_result_error16()
** routines make a copy private copy of the error message text before
** they return.  Hence, the calling function can deallocate or
** modify the text after they return without harm.
** The sqlite3_result_error_code() function changes the error code
** returned by SQLite as a result of an error in a function.  By default,
** the error code is SQLITE_ERROR.  A subsequent call to sqlite3_result_error()
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
**
** The sqlite3_result_toobig() interface causes SQLite
** to throw an error indicating that a string or BLOB is to long
** to represent.  The sqlite3_result_nomem() interface
** causes SQLite to throw an exception indicating that the a
** memory allocation failed.
**
** The sqlite3_result_int() interface sets the return value
** of the application-defined function to be the 32-bit signed integer
** value given in the 2nd argument.
** The sqlite3_result_int64() interface sets the return value
** of the application-defined function to be the 64-bit signed integer
** value given in the 2nd argument.
**
** The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** The sqlite3_result_text(), sqlite3_result_text16(), 
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
** set the return value of the application-defined function to be
** a text string which is represented as UTF-8, UTF-16 native byte order,
** UTF-16 little endian, or UTF-16 big endian, respectively.
** SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is negative, then SQLite takes result text from the 2nd parameter 
** through the first zero character.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is non-negative, then as many bytes (not characters) of the text
** pointed to by the 2nd parameter are taken as the application-defined
** function result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
** function as the destructor on the text or blob result when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_STATIC, then
** SQLite assumes that the text or blob result is constant space and
** does not copy the space or call a destructor when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
** then SQLite makes a copy of the result into space obtained from
** from [sqlite3_malloc()] before it returns.
**
** The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy the
** [unprotected sqlite3_value] object specified by the 2nd parameter.  The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
** A [protected sqlite3_value] object may always be used where an
** [unprotected sqlite3_value] object is required, so either
** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread 
** than the one containing the application-defined function that recieved
** the [sqlite3_context] pointer, the results are undefined.
**
** INVARIANTS:
**
** {F16403} The default return value from any SQL function is NULL.
**
** {F16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the
**          return value of function C to be a blob that is N bytes
**          in length and with content pointed to by V.
**
** {F16409} The [sqlite3_result_double(C,V)] interface changes the
**          return value of function C to be the floating point value V.
**
** {F16412} The [sqlite3_result_error(C,V,N)] interface changes the return
**          value of function C to be an exception with error code
**          [SQLITE_ERROR] and a UTF8 error message copied from V up to the
**          first zero byte or until N bytes are read if N is positive.
**
** {F16415} The [sqlite3_result_error16(C,V,N)] interface changes the return
**          value of function C to be an exception with error code
**          [SQLITE_ERROR] and a UTF16 native byte order error message
**          copied from V up to the first zero terminator or until N bytes
**          are read if N is positive.
**
** {F16418} The [sqlite3_result_error_toobig(C)] interface changes the return
**          value of the function C to be an exception with error code
**          [SQLITE_TOOBIG] and an appropriate error message.
**
** {F16421} The [sqlite3_result_error_nomem(C)] interface changes the return
**          value of the function C to be an exception with error code
**          [SQLITE_NOMEM] and an appropriate error message.
**
** {F16424} The [sqlite3_result_error_code(C,E)] interface changes the return
**          value of the function C to be an exception with error code E.
**          The error message text is unchanged.
**
** {F16427} The [sqlite3_result_int(C,V)] interface changes the
**          return value of function C to be the 32-bit integer value V.
**
** {F16430} The [sqlite3_result_int64(C,V)] interface changes the
**          return value of function C to be the 64-bit integer value V.
**
** {F16433} The [sqlite3_result_null(C)] interface changes the
**          return value of function C to be NULL.
**
** {F16436} The [sqlite3_result_text(C,V,N,D)] interface changes the
**          return value of function C to be the UTF8 string
**          V up to the first zero if N is negative
**          or the first N bytes of V if N is non-negative.
**
** {F16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the
**          return value of function C to be the UTF16 native byte order
**          string V up to the first zero if N is
**          negative or the first N bytes of V if N is non-negative.
**
** {F16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the
**          return value of function C to be the UTF16 big-endian
**          string V up to the first zero if N is
**          is negative or the first N bytes or V if N is non-negative.
**
** {F16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the
**          return value of function C to be the UTF16 little-endian
**          string V up to the first zero if N is
**          negative or the first N bytes of V if N is non-negative.
**
** {F16448} The [sqlite3_result_value(C,V)] interface changes the
**          return value of function C to be [unprotected sqlite3_value]
**          object V.
**
** {F16451} The [sqlite3_result_zeroblob(C,N)] interface changes the
**          return value of function C to be an N-byte blob of all zeros.
**
** {F16454} The [sqlite3_result_error()] and [sqlite3_result_error16()]
**          interfaces make a copy of their error message strings before
**          returning.
**
** {F16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
**          [sqlite3_result_text16be(C,V,N,D)], or
**          [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC]
**          then no destructor is ever called on the pointer V and SQLite
**          assumes that V is immutable.
**
** {F16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
**          [sqlite3_result_text16be(C,V,N,D)], or
**          [sqlite3_result_text16le(C,V,N,D)] is the constant
**          [SQLITE_TRANSIENT] then the interfaces makes a copy of the
**          content of V and retains the copy.
**
** {F16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
**          [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
**          [sqlite3_result_text16be(C,V,N,D)], or
**          [sqlite3_result_text16le(C,V,N,D)] is some value other than
**          the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then 
**          SQLite will invoke the destructor D with V as its only argument
**          when it has finished with the V value.
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
void sqlite3_result_error_code(sqlite3_context*, int);
void sqlite3_result_int(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
void sqlite3_result_null(sqlite3_context*);
void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);

/*
** CAPI3REF: Define New Collating Sequences {F16600}
**

** These functions are used to add new collation sequences to the
** [sqlite3*] handle specified as the first argument. 
**

** The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
** and a UTF-16 string for sqlite3_create_collation16(). In all cases
** the name is passed as the second function argument.
**

** The third argument may be one of the constants [SQLITE_UTF8],
** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
** routine expects to be passed pointers to strings encoded using UTF-8,
** UTF-16 little-endian or UTF-16 big-endian respectively. The
** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that
** the routine expects pointers to 16-bit word aligned strings
** of UTF16 in the native byte order of the host computer.
**

** A pointer to the user supplied routine must be passed as the fifth
** argument.  If it is NULL, this is the same as deleting the collation
** sequence (so that SQLite cannot call it anymore).
** Each time the application
** supplied function is invoked, it is passed a copy of the void* passed as
** the fourth argument to sqlite3_create_collation() or
** sqlite3_create_collation16() as its first parameter.
**

** The remaining arguments to the application-supplied routine are two strings,
** each represented by a (length, data) pair and encoded in the encoding
** that was passed as the third argument when the collation sequence was
** registered. {END} The application defined collation routine should
** return negative, zero or positive if
** the first string is less than, equal to, or greater than the second
** string. i.e. (STRING1 - STRING2).
**

** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
** excapt that it takes an extra argument which is a destructor for
** the collation.  The destructor is called when the collation is
** destroyed and is passed a copy of the fourth parameter void* pointer
** of the sqlite3_create_collation_v2().
** Collations are destroyed when
** they are overridden by later calls to the collation creation functions
** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
**
** INVARIANTS:
**
** {F16603} A successful call to the
**          [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface
**          registers function F as the comparison function used to
**          implement collation X on [database connection] B for
**          databases having encoding E.
**
** {F16604} SQLite understands the X parameter to
**          [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated
**          UTF-8 string in which case is ignored for ASCII characters and
**          is significant for non-ASCII characters.
**
** {F16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)]
**          with the same values for B, X, and E, override prior values
**          of P, F, and D.
**
** {F16609} The destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
**          is not NULL then it is called with argument P when the
**          collating function is dropped by SQLite.
**
** {F16612} A collating function is dropped when it is overloaded.
**
** {F16615} A collating function is dropped when the database connection
**          is closed using [sqlite3_close()].
**
** {F16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
**          is passed through as the first parameter to the comparison
**          function F for all subsequent invocations of F.
**
** {F16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly
**          the same as a call to [sqlite3_create_collation_v2()] with
**          the same parameters and a NULL destructor.
**
** {F16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)],
**          SQLite uses the comparison function F for all text comparison
**          operations on [database connection] B on text values that
**          use the collating sequence name X.
**
** {F16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same
**          as [sqlite3_create_collation(B,X,E,P,F)] except that the
**          collation name X is understood as UTF-16 in native byte order
**          instead of UTF-8.
**
** {F16630} When multiple comparison functions are available for the same
**          collating sequence, SQLite chooses the one whose text encoding
**          requires the least amount of conversion from the default
**          text encoding of the database.
*/
int sqlite3_create_collation(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)

  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
);

/*
** CAPI3REF: Collation Needed Callbacks {F16700}
**

** To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** database handle to be called whenever an undefined collation sequence is
** required.
**

** If the function is registered using the sqlite3_collation_needed() API,
** then it is passed the names of undefined collation sequences as strings
** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used, the names
** are passed as UTF-16 in machine native byte order. A call to either
** function replaces any existing callback.
**
** When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16().  The second argument is the database
** handle.  The third argument is one of [SQLITE_UTF8],
** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most
** desirable form of the collation sequence function required.
** The fourth parameter is the name of the
** required collation sequence.
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].
**
** INVARIANTS:
**
** {F16702} A successful call to [sqlite3_collation_needed(D,P,F)]
**          or [sqlite3_collation_needed16(D,P,F)] causes
**          the [database connection] D to invoke callback F with first
**          parameter P whenever it needs a comparison function for a
**          collating sequence that it does not know about.
**
** {F16704} Each successful call to [sqlite3_collation_needed()] or
**          [sqlite3_collation_needed16()] overrides the callback registered
**          on the same [database connection] by prior calls to either
**          interface.
**
** {F16706} The name of the requested collating function passed in the
**          4th parameter to the callback is in UTF-8 if the callback
**          was registered using [sqlite3_collation_needed()] and
**          is in UTF-16 native byte order if the callback was
**          registered using [sqlite3_collation_needed16()].
**
** 
*/
int sqlite3_collation_needed(
  sqlite3*, 
  void*, 
  void(*)(void*,sqlite3*,int eTextRep,const char*)
);
int sqlite3_collation_needed16(

  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** CAPI3REF:  Suspend Execution For A Short Time {F10530}
**
** The sqlite3_sleep() function
** causes the current thread to suspend execution
** for at least a number of milliseconds specified in its parameter.
**
** If the operating system does not support sleep requests with 
** millisecond time resolution, then the time will be rounded up to 
** the nearest second. The number of milliseconds of sleep actually 
** requested from the operating system is returned.
**
** SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.
**
** INVARIANTS:
**
** {F10533} The [sqlite3_sleep(M)] interface invokes the xSleep
**          method of the default [sqlite3_vfs|VFS] in order to
**          suspend execution of the current thread for at least
**          M milliseconds.
**
** {F10536} The [sqlite3_sleep(M)] interface returns the number of
**          milliseconds of sleep actually requested of the operating
**          system, which might be larger than the parameter M.
*/
int sqlite3_sleep(int);

/*
** CAPI3REF:  Name Of The Folder Holding Temporary Files {F10310}
**
** If this global variable is made to point to a string which is

** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically.  The only way to
** find out if SQLite automatically rolled back the transaction after
** an error is to use this function.
**
** INVARIANTS:
**
** {F12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or
**          zero if the [database connection] D is or is not in autocommit
**          mode, respectively.
**
** {F12932} Autocommit mode is on by default.
**
** {F12933} Autocommit mode is disabled by a successful [BEGIN] statement.
**
** {F12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK]

**          is undefined.
*/
int sqlite3_get_autocommit(sqlite3*);

/*
** CAPI3REF:  Find The Database Handle Of A Prepared Statement {F13120}
**
** The sqlite3_db_handle interface
** returns the [sqlite3*] database handle to which a
** [prepared statement] belongs.
** The database handle returned by sqlite3_db_handle
** is the same database handle that was
** the first argument to the [sqlite3_prepare_v2()] or its variants
** that was used to create the statement in the first place.
**
** INVARIANTS:
**
** {F13123} The [sqlite3_db_handle(S)] interface returns a pointer
**          to the [database connection] associated with
**          [prepared statement] S.
*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);


/*
** CAPI3REF: Commit And Rollback Notification Callbacks {F12950}
**
** The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The pArg argument is passed through
** to the callback.  If the callback on a commit hook function 
** returns non-zero, then the commit is converted into a rollback.
**
** If another function was previously registered, its
** pArg value is returned.  Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
**
** For the purposes of this API, a transaction is said to have been 
** rolled back if an explicit "ROLLBACK" statement is executed, or
** an error or constraint causes an implicit rollback to occur.
** The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.
** <todo> Check on this </todo>
**
** These are experimental interfaces and are subject to change.
**
** INVARIANTS:
**
** {F12951} The [sqlite3_commit_hook(D,F,P)] interface registers the
**          callback function F to be invoked with argument P whenever
**          a transaction commits on [database connection] D.
**
** {F12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P
**          argument from the previous call with the same 
**          [database connection ] D , or NULL on the first call
**          for a particular [database connection] D.
**
** {F12953} Each call to [sqlite3_commit_hook()] overwrites the callback
**          registered by prior calls.
**
** {F12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL
**          then the commit hook callback is cancelled and no callback
**          is invoked when a transaction commits.
**
** {F12955} If the commit callback returns non-zero then the commit is
**          converted into a rollback.
**
** {F12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the
**          callback function F to be invoked with argument P whenever
**          a transaction rolls back on [database connection] D.
**
** {F12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P
**          argument from the previous call with the same 
**          [database connection ] D , or NULL on the first call
**          for a particular [database connection] D.
**
** {F12963} Each call to [sqlite3_rollback_hook()] overwrites the callback
**          registered by prior calls.
**
** {F12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL
**          then the rollback hook callback is cancelled and no callback
**          is invoked when a transaction rolls back.
*/
void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

/*
** CAPI3REF: Data Change Notification Callbacks {F12970}
**
** The sqlite3_update_hook() interface
** registers a callback function with the database connection identified by the 
** first argument to be invoked whenever a row is updated, inserted or deleted.
** Any callback set by a previous call to this function for the same 
** database connection is overridden.
**
** The second argument is a pointer to the function to invoke when a 
** row is updated, inserted or deleted. 
** The first argument to the callback is
** a copy of the third argument to sqlite3_update_hook().
** The second callback 
** argument is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
** depending on the operation that caused the callback to be invoked.
** The third and 
** fourth arguments to the callback contain pointers to the database and 
** table name containing the affected row.
** The final callback parameter is 
** the rowid of the row.
** In the case of an update, this is the rowid after 
** the update takes place.
**
** The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).
**
** If another function was previously registered, its pArg value
** is returned.  Otherwise NULL is returned.
**
** INVARIANTS:
**
** {F12971} The [sqlite3_update_hook(D,F,P)] interface causes callback
**          function F to be invoked with first parameter P whenever
**          a table row is modified, inserted, or deleted on
**          [database connection] D.
**
** {F12973} The [sqlite3_update_hook(D,F,P)] interface returns the value
**          of P for the previous call on the same [database connection] D,
**          or NULL for the first call.
**
** {F12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)]
**          is NULL then the no update callbacks are made.
**
** {F12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls
**          to the same interface on the same [database connection] D.
**
** {F12979} The update hook callback is not invoked when internal system
**          tables such as sqlite_master and sqlite_sequence are modified.
**
** {F12981} The second parameter to the update callback 
**          is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
**          depending on the operation that caused the callback to be invoked.
**
** {F12983} The third and fourth arguments to the callback contain pointers
**          to zero-terminated UTF-8 strings which are the names of the
**          database and table that is being updated.

** {F12985} The final callback parameter is the rowid of the row after
**          the change occurs.
*/
void *sqlite3_update_hook(
  sqlite3*, 
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
  void*
);

/*
** CAPI3REF:  Enable Or Disable Shared Pager Cache {F10330}
**

** This routine enables or disables the sharing of the database cache
** and schema data structures between connections to the same database.

** Sharing is enabled if the argument is true and disabled if the argument
** is false.
**
** Cache sharing is enabled and disabled
** for an entire process. {END} This is a change as of SQLite version 3.5.0.
** In prior versions of SQLite, sharing was
** enabled or disabled for each thread separately.
**

** The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** Existing database connections continue use the sharing mode
** that was in effect at the time they were opened.
**
** Virtual tables cannot be used with a shared cache.   When shared
** cache is enabled, the [sqlite3_create_module()] API used to register
** virtual tables will always return an error.
**
** This routine returns [SQLITE_OK] if shared cache was
** enabled or disabled successfully.  An [error code]
** is returned otherwise.
**
** Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**
** INVARIANTS:
** 
** {F10331} A successful invocation of [sqlite3_enable_shared_cache(B)]
**          will enable or disable shared cache mode for any subsequently
**          created [database connection] in the same process.
**
** {F10336} When shared cache is enabled, the [sqlite3_create_module()]
**          interface will always return an error.
**
** {F10337} The [sqlite3_enable_shared_cache(B)] interface returns
**          [SQLITE_OK] if shared cache was enabled or disabled successfully.
**
** {F10339} Shared cache is disabled by default.
*/
int sqlite3_enable_shared_cache(int);

/*
** CAPI3REF:  Attempt To Free Heap Memory {F17340}
**
** The sqlite3_release_memory() interface attempts to
** free N bytes of heap memory by deallocating non-essential memory
** allocations held by the database labrary. {END}  Memory used
** to cache database pages to improve performance is an example of
** non-essential memory.  Sqlite3_release_memory() returns
** the number of bytes actually freed, which might be more or less
** than the amount requested.
**
** INVARIANTS:
**
** {F17341} The [sqlite3_release_memory(N)] interface attempts to
**          free N bytes of heap memory by deallocating non-essential
**          memory allocations held by the database labrary.
**
** {F16342} The [sqlite3_release_memory(N)] returns the number
**          of bytes actually freed, which might be more or less
**          than the amount requested.
*/
int sqlite3_release_memory(int);

/*
** CAPI3REF:  Impose A Limit On Heap Size {F17350}
**
** The sqlite3_soft_heap_limit() interface
** places a "soft" limit on the amount of heap memory that may be allocated
** by SQLite. If an internal allocation is requested 
** that would exceed the soft heap limit, [sqlite3_release_memory()] is
** invoked one or more times to free up some space before the allocation
** is made.
**
** The limit is called "soft", because if
** [sqlite3_release_memory()] cannot
** free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**

** A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.  
** But if the soft heap limit cannot honored, execution will
** continue without error or notification.  This is why the limit is 
** called a "soft" limit.  It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. In
** version 3.5.0 there is no mechanism for limiting the heap usage for
** individual threads.
**
** INVARIANTS:
**
** {F16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit
**          of N bytes on the amount of heap memory that may be allocated
**          using [sqlite3_malloc()] or [sqlite3_realloc()] at any point
**          in time.
**
** {F16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would
**          cause the total amount of allocated memory to exceed the
**          soft heap limit, then [sqlite3_release_memory()] is invoked
**          in an attempt to reduce the memory usage prior to proceeding
**          with the memory allocation attempt.
**
** {F16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger
**          attempts to reduce memory usage through the soft heap limit
**          mechanism continue even if the attempt to reduce memory
**          usage is unsuccessful.
**
** {F16354} A negative or zero value for N in a call to
**          [sqlite3_soft_heap_limit(N)] means that there is no soft
**          heap limit and [sqlite3_release_memory()] will only be
**          called when memory is completely exhausted.
**
** {F16355} The default value for the soft heap limit is zero.
**
** {F16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the
**          values set by all prior calls.
*/
void sqlite3_soft_heap_limit(int);

/*
** CAPI3REF:  Extract Metadata About A Column Of A Table {F12850}
**
** This routine

*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;

/*
** CAPI3REF: Virtual Table Object {F18000}
** KEYWORDS: sqlite3_module
**
** A module is a class of virtual tables.  Each module is defined
** by an instance of the following structure.  This structure consists
** mostly of methods for the module.
*/
struct sqlite3_module {
  int iVersion;
  int (*xCreate)(sqlite3*, void *pAux,

                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                       void **ppArg);

  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};

/*
** CAPI3REF: Virtual Table Indexing Information {F18100}
** KEYWORDS: sqlite3_index_info
**
** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the xBestIndex
** method of an sqlite3_module.  The fields under **Inputs** are the
** inputs to xBestIndex and are read-only.  xBestIndex inserts its
** results into the **Outputs** fields.
**
** The aConstraint[] array records WHERE clause constraints of the

#define SQLITE_INDEX_CONSTRAINT_GT    4
#define SQLITE_INDEX_CONSTRAINT_LE    8
#define SQLITE_INDEX_CONSTRAINT_LT    16
#define SQLITE_INDEX_CONSTRAINT_GE    32
#define SQLITE_INDEX_CONSTRAINT_MATCH 64

/*
** CAPI3REF: Register A Virtual Table Implementation {F18200}
**
** This routine is used to register a new module name with an SQLite
** connection.  Module names must be registered before creating new
** virtual tables on the module, or before using preexisting virtual
** tables of the module.
*/
int sqlite3_create_module(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *                     /* Client data for xCreate/xConnect */
);

/*
** CAPI3REF: Register A Virtual Table Implementation {F18210}
**
** This routine is identical to the sqlite3_create_module() method above,
** except that it allows a destructor function to be specified. It is
** even more experimental than the rest of the virtual tables API.
*/
int sqlite3_create_module_v2(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *,    /* Methods for the module */
  void *,                    /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*
** CAPI3REF: Virtual Table Instance Object {F18010}
** KEYWORDS: sqlite3_vtab
**
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  Each subclass will
** be tailored to the specific needs of the module implementation.   The
** purpose of this superclass is to define certain fields that are common
** to all module implementations.
**
** Virtual tables methods can set an error message by assigning a

struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* Used internally */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Virtual Table Cursor Object  {F18020}
** KEYWORDS: sqlite3_vtab_cursor
**
** Every module implementation uses a subclass of the following structure
** to describe cursors that point into the virtual table and are used
** to loop through the virtual table.  Cursors are created using the
** xOpen method of the module.  Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Declare The Schema Of A Virtual Table {F18280}
**
** The xCreate and xConnect methods of a module use the following API
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);

/*
** CAPI3REF: Overload A Function For A Virtual Table {F18300}
**
** Virtual tables can provide alternative implementations of functions
** using the xFindFunction method.  But global versions of those functions
** must exist in order to be overloaded.
**
** This API makes sure a global version of a function with a particular
** name and number of parameters exists.  If no such function exists
** before this API is called, a new function is created.  The implementation

**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB {F17800}
**
** An instance of this object represents an open BLOB on which
** incremental I/O can be preformed.
** Objects of this type are created by
** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
** can be used to read or write small subsections of the blob.
** The [sqlite3_blob_bytes()] interface returns the size of the
** blob in bytes.
*/
typedef struct sqlite3_blob sqlite3_blob;

/*
** CAPI3REF: Open A BLOB For Incremental I/O {F17810}
**
** This interfaces opens a handle to the blob located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words,  the same blob that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
** </pre> {END}
**
** If the flags parameter is non-zero, the blob is opened for 
** read and write access. If it is zero, the blob is opened for read 
** access.
**
** Note that the database name is not the filename that contains
** the database but rather the symbolic name of the database that
** is assigned when the database is connected using [ATTACH].
** For the main database file, the database name is "main".  For
** TEMP tables, the database name is "temp".
**
** On success, [SQLITE_OK] is returned and the new 
** [sqlite3_blob | blob handle] is written to *ppBlob. 
** Otherwise an error code is returned and 
** any value written to *ppBlob should not be used by the caller.
** This function sets the database-handle error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
** 
** INVARIANTS:
**
** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]
**          interface opens an [sqlite3_blob] object P on the blob
**          in column C of table T in database B on [database connection] D.
**
** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] starts
**          a new transaction on [database connection] D if that connection
**          is not already in a transaction.
**
** {F17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface opens the blob
**          for read and write access if and only if the F parameter
**          is non-zero.
**
** {F17819} The [sqlite3_blob_open()] interface returns [SQLITE_OK] on 
**          success and an appropriate [error code] on failure.
**
** {F17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
  int flags,
  sqlite3_blob **ppBlob
);

/*
** CAPI3REF:  Close A BLOB Handle {F17830}
**
** Close an open [sqlite3_blob | blob handle].
**
** Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in autocommit mode.
** If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit. {END}
** Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  {F17833} Any errors that occur during
** closing are reported as a non-zero return value.
**
** The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.
**
** INVARIANTS:
**
** {F17833} The [sqlite3_blob_close(P)] interface closes an
**          [sqlite3_blob] object P previously opened using
**          [sqlite3_blob_open()].
**
** {F17836} Closing an [sqlite3_blob] object using
**          [sqlite3_blob_close()] shall cause the current transaction to
**          commit if there are no other open [sqlite3_blob] objects
**          or [prepared statements] on the same [database connection] and
**          the [database connection] is in
**          [sqlite3_get_autocommit | autocommit mode].
**
** {F17839} The [sqlite3_blob_close(P)] interfaces closes the 
**          [sqlite3_blob] object P unconditionally, even if
**          [sqlite3_blob_close(P)] returns something other than [SQLITE_OK].
**          
*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF:  Return The Size Of An Open BLOB {F17840}
**
** Return the size in bytes of the blob accessible via the open 
** [sqlite3_blob] object in its only argument.
**
** INVARIANTS:
**
** {F17843} The [sqlite3_blob_bytes(P)] interface returns the size
**          in bytes of the BLOB that the [sqlite3_blob] object P
**          refers to.
*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF:  Read Data From A BLOB Incrementally {F17850}
**
** This function is used to read data from an open 
** [sqlite3_blob | blob-handle] into a caller supplied buffer.
** N bytes of data are copied into buffer
** Z from the open blob, starting at offset iOffset.
**
** If offset iOffset is less than N bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is read.  If N or iOffset is
** less than zero [SQLITE_ERROR] is returned and no data is read.
**
** On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17853} The [sqlite3_blob_read(P,Z,N,X)] interface reads N bytes
**          beginning at offset X from
**          the blob that [sqlite3_blob] object P refers to
**          and writes those N bytes into buffer Z.
**
** {F17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the blob
**          is less than N+X bytes, then the function returns [SQLITE_ERROR]
**          and nothing is read from the blob.
**
** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero
**          then the function returns [SQLITE_ERROR]
**          and nothing is read from the blob.
**
** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface returns [SQLITE_OK]
**          if N bytes where successfully read into buffer Z.
**
** {F17865} If the requested read could not be completed,
**          the [sqlite3_blob_read(P,Z,N,X)] interface returns an
**          appropriate [error code] or [extended error code].
**
** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error, where D is the
**          database handle that was used to open blob handle P.
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF:  Write Data Into A BLOB Incrementally {F17870}
**
** This function is used to write data into an open 
** [sqlite3_blob | blob-handle] from a user supplied buffer.
** n bytes of data are copied from the buffer
** pointed to by z into the open blob, starting at offset iOffset.
**
** If the [sqlite3_blob | blob-handle] passed as the first argument
** was not opened for writing (the flags parameter to [sqlite3_blob_open()]
*** was zero), this function returns [SQLITE_READONLY].
**
** This function may only modify the contents of the blob; it is
** not possible to increase the size of a blob using this API.
** If offset iOffset is less than n bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is written.  If n is
** less than zero [SQLITE_ERROR] is returned and no data is written.
**
** On success, SQLITE_OK is returned. Otherwise, an 
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17873} The [sqlite3_blob_write(P,Z,N,X)] interface writes N bytes
**          from buffer Z into
**          the blob that [sqlite3_blob] object P refers to
**          beginning at an offset of X into the blob.
**
** {F17875} The [sqlite3_blob_write(P,Z,N,X)] interface returns
**          [SQLITE_READONLY] if the [sqlite3_blob] object P was
**          [sqlite3_blob_open | opened] for reading only.
**
** {F17876} In [sqlite3_blob_write(P,Z,N,X)] if the size of the blob
**          is less than N+X bytes, then the function returns [SQLITE_ERROR]
**          and nothing is written into the blob.
**
** {F17879} In [sqlite3_blob_write(P,Z,N,X)] if X or N is less than zero
**          then the function returns [SQLITE_ERROR]
**          and nothing is written into the blob.
**
** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface returns [SQLITE_OK]
**          if N bytes where successfully written into blob.
**
** {F17885} If the requested write could not be completed,
**          the [sqlite3_blob_write(P,Z,N,X)] interface returns an
**          appropriate [error code] or [extended error code].
**
** {F17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
**          information approprate for that error.
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF:  Virtual File System Objects {F11200}
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system.  Most SQLite builds come with a
** single default VFS that is appropriate for the host computer.
** New VFSes can be registered and existing VFSes can be unregistered.
** The following interfaces are provided.
**
** The sqlite3_vfs_find() interface returns a pointer to 
** a VFS given its name.  Names are case sensitive.
** Names are zero-terminated UTF-8 strings.
** If there is no match, a NULL
** pointer is returned.  If zVfsName is NULL then the default 
** VFS is returned. 
**
** New VFSes are registered with sqlite3_vfs_register().
** Each new VFS becomes the default VFS if the makeDflt flag is set.
** The same VFS can be registered multiple times without injury.
** To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set.  If two different VFSes with the
** same name are registered, the behavior is undefined.  If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
** 
** Unregister a VFS with the sqlite3_vfs_unregister() interface.
** If the default VFS is unregistered, another VFS is chosen as
** the default.  The choice for the new VFS is arbitrary.
**
** INVARIANTS:
**
** {F11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the
**          registered [sqlite3_vfs] object whose name exactly matches
**          the zero-terminated UTF-8 string N, or it returns NULL if
**          there is no match.
**
** {F11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then
**          the function returns a pointer to the default [sqlite3_vfs]
**          object if there is one, or NULL if there is no default 
**          [sqlite3_vfs] object.
**
** {F11209} The [sqlite3_vfs_register(P,F)] interface registers the
**          well-formed [sqlite3_vfs] object P using the name given
**          by the zName field of the object.
**
** {F11212} Using the [sqlite3_vfs_register(P,F)] interface to register
**          the same [sqlite3_vfs] object multiple times is a harmless no-op.
**
** {F11215} The [sqlite3_vfs_register(P,F)] interface makes the
**          the [sqlite3_vfs] object P the default [sqlite3_vfs] object
**          if F is non-zero.
**
** {F11218} The [sqlite3_vfs_unregister(P)] interface unregisters the
**          [sqlite3_vfs] object P so that it is no longer returned by
**          subsequent calls to [sqlite3_vfs_find()].
*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);

/*
** CAPI3REF: Mutexes {F17000}

** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** </ul> {END}
**
** {F17015} The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END}
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

#define SQLITE_MUTEX_FAST             0
#define SQLITE_MUTEX_RECURSIVE        1
#define SQLITE_MUTEX_STATIC_MASTER    2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* sqlite3_release_memory() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */

/*
** CAPI3REF: Low-Level Control Of Database Files {F11300}
**
** {F11301} The [sqlite3_file_control()] interface makes a direct call to the
** xFileControl method for the [sqlite3_io_methods] object associated
** with a particular database identified by the second argument. {F11302} The

** Applications should not use any of these parameters or the
** [sqlite3_test_control()] interface.
*/
#define SQLITE_TESTCTRL_FAULT_CONFIG             1
#define SQLITE_TESTCTRL_FAULT_FAILURES           2
#define SQLITE_TESTCTRL_FAULT_BENIGN_FAILURES    3
#define SQLITE_TESTCTRL_FAULT_PENDING            4
#define SQLITE_TESTCTRL_PRNG_SAVE                5
#define SQLITE_TESTCTRL_PRNG_RESTORE             6
#define SQLITE_TESTCTRL_PRNG_RESET               7
#define SQLITE_TESTCTRL_BITVEC_TEST              8


/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT