Fossil

** State information for the tarball builder.
*/
static struct tarball_t {
  unsigned char *aHdr;      /* Space for building headers */
  char *zSpaces;            /* Spaces for padding */
  char *zPrevDir;           /* Name of directory for previous entry */
  int nPrevDirAlloc;        /* size of zPrevDir */
  char *pScratch;           /* scratch buffer used to build PAX data */
  int nScratchUsed;         /* part of buffer containing data */
  int nScratchAlloc;        /* size of buffer */
} tball;


/*
** field lengths of 'ustar' name and prefix fields.
*/
#define USTAR_NAME_LEN    100

  tball.aHdr = fossil_malloc(512+512);
  memset(tball.aHdr, 0, 512+512);
  tball.zSpaces = (char*)&tball.aHdr[512];
  /* zPrevDir init */
  tball.zPrevDir = NULL;
  tball.nPrevDirAlloc = 0;
  /* scratch buffer init */
  tball.pScratch = NULL;
  tball.nScratchUsed = 0;
  tball.nScratchAlloc = 0;

  memcpy(&tball.aHdr[108], "0000000", 8);  /* Owner ID */
  memcpy(&tball.aHdr[116], "0000000", 8);  /* Group ID */
  memcpy(&tball.aHdr[257], "ustar\00000", 8);  /* POSIX.1 format */
  memcpy(&tball.aHdr[265], "nobody", 7);   /* Owner name */
  memcpy(&tball.aHdr[297], "nobody", 7);   /* Group name */
  gzip_begin();
  db_multi_exec(
    "CREATE TEMP TABLE dir(name UNIQUE);"
  );
}


/*
** print to the scratch buffer
**
** used to build the Pax Interchange Format data, and create
** pseudo-file names for the header data.
**
** The buffer is grown automatically to accommodate the data.
*/
static int scratch_printf(
  const char *fmt,
  ...
){
  for(;;){
    int newSize, minSpace, n;
    /* calculate space in buffer */
    int space = tball.nScratchAlloc - tball.nScratchUsed;
    /* format the string */
    va_list vl;
    va_start(vl, fmt);
    n = vsnprintf(&tball.pScratch[tball.nScratchUsed], space, fmt, vl);
    assert(n >= 0);
    va_end(vl);
    /* if it fit we're done */
    if(n < space)
      return n;
    /* buffer too short: calculate reasonable new size */
    minSpace = tball.nScratchUsed+n+1;
    newSize = 2 * tball.nScratchAlloc;
    if(newSize < minSpace)
      newSize = minSpace;
    /* grow the buffer */
    tball.pScratch = fossil_realloc(tball.pScratch, newSize);
    tball.nScratchAlloc = newSize;
    /* loop to try again */
  }
}


/*
** verify that lla characters in 'zName' are in the
** ISO646 (=ASCII) character set.
*/
static int is_iso646_name(
  const char *zName,     /* file path */
  int nName              /* path length */
){
  int i;
  for(i = 0; i < nName; i++){
    unsigned char c = (unsigned char)zName[i];
    if(c > 0x7e)
      return 0;
  }
  return 1;
}


/*
**   copy string pSrc into pDst, truncating or padding with 0 if necessary

  /* only search if the string needs splitting */
  if(nName > USTAR_NAME_LEN){
    for(i = 1; i+1 < nName; i++)
      if(zName[i] == '/'){
        split = i+1;
        /* if the split position is within USTAR_NAME_LEN bytes from
         * the end we can quit */
        if(nName - split <= USTAR_NAME_LEN)
          break;
      }
  }
  return split;
}


/*
** attempt to split the file name path to meet 'ustar' header
** criteria.
*/
static int tar_split_path(
  const char *zName,     /* path */
  int nName,             /* path length */
  char *pName,           /* name field */
  char *pPrefix          /* prefix field */
){
  int split = find_split_pos(zName, nName);
  /* check whether both pieces fit */
  if(nName - split > USTAR_NAME_LEN || split > USTAR_PREFIX_LEN+1)
    return 0; /* no */


  /* extract name */
  padded_copy(pName, USTAR_NAME_LEN, &zName[split], nName - split);

  /* extract prefix */
  padded_copy(pPrefix, USTAR_PREFIX_LEN, zName, (split > 0 ? split - 1 : 0));

  char *pName,           /* name field */
  char *pPrefix,         /* prefix field */
  int bHeader            /* is this a 'x' type tar header? */
){
  int split;

  /* if this is a Pax Interchange header prepend "PaxHeader/"
   * so we can tell files apart from metadata */
  if(bHeader){
       int n;
       tball.nScratchUsed = 0;
       n = scratch_printf("PaxHeader/%*.*s", nName, nName, zName);
       zName = tball.pScratch;
       nName = n;
  }

  /* find the split position */
  split = find_split_pos(zName, nName);

  /* extract a name, truncate if needed */
  padded_copy(pName, USTAR_NAME_LEN, &zName[split], nName - split);

  int next10 = 1;
  int n;
  for(n = blen; n > 0; ){
    blen++; next10 *= 10;
    n /= 10;
  }
  /* adding the length extended the length field? */
  if(blen > next10)
    blen++;

  /* build the string */
  n = scratch_printf("%d %s=%*.*s\n", blen, zField, nValue, nValue, zValue);
  /* this _must_ be right */
  if(n != blen)
    fossil_fatal("internal error: PAX tar header has bad length");
  /* add length to scratch buffer */
  tball.nScratchUsed += blen;

}


/*
** set the header type, calculate the checksum and output
** the header
*/

  if( !is_iso646_name(zName, nName) ||
            !tar_split_path(zName, nName, tball.aHdr, &tball.aHdr[345]) ){
    int lastPage;
    /* add a file name for interoperability with older programs */
    approximate_split_path(zName, nName, tball.aHdr, &tball.aHdr[345], 1);

    /* generate the Pax Interchange path header */
    tball.nScratchUsed = 0;
    add_pax_header("path", zName, nName);

    /* set the header length, and write the header */
    sqlite3_snprintf(12, (char*)&tball.aHdr[124], "%011o", tball.nScratchUsed);

    cksum_and_write_header('x');

    /* write the Pax Interchange data */
    gzip_step(tball.pScratch, tball.nScratchUsed);
    lastPage = tball.nScratchUsed % 512;
    if( lastPage!=0 )
      gzip_step(tball.zSpaces, 512 - lastPage);


    /* generate an approximate path for the regular header */
    approximate_split_path(zName, nName, tball.aHdr, &tball.aHdr[345], 0);
  }
  /* set the size */
  sqlite3_snprintf(12, (char*)&tball.aHdr[124], "%011o", iSize);

  gzip_step(tball.zSpaces, 512);
  gzip_finish(pOut);
  fossil_free(tball.aHdr);
  tball.aHdr = 0;
  fossil_free(tball.zPrevDir);
  tball.zPrevDir = NULL;
  tball.nPrevDirAlloc = 0;
  fossil_free(tball.pScratch);
  tball.pScratch = NULL;
  tball.nScratchUsed = 0;
  tball.nScratchAlloc = 0;
}


/*
** COMMAND: test-tarball
**
** Generate a GZIP-compresssed tarball in the file given by the first argument