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      1 /* gzwrite.c -- zlib functions for writing gzip files
      2  * Copyright (C) 2004, 2005, 2010 Mark Adler
      3  * For conditions of distribution and use, see copyright notice in zlib.h
      4  */
      5 
      6 #include "gzguts.h"
      7 
      8 /* Local functions */
      9 local int gz_init OF((gz_statep));
     10 local int gz_comp OF((gz_statep, int));
     11 local int gz_zero OF((gz_statep, z_off64_t));
     12 
     13 /* Initialize state for writing a gzip file.  Mark initialization by setting
     14    state->size to non-zero.  Return -1 on failure or 0 on success. */
     15 local int gz_init(state)
     16     gz_statep state;
     17 {
     18     int ret;
     19     z_streamp strm = &(state->strm);
     20 
     21     /* allocate input and output buffers */
     22     state->in = malloc(state->want);
     23     state->out = malloc(state->want);
     24     if (state->in == NULL || state->out == NULL) {
     25         if (state->out != NULL)
     26             free(state->out);
     27         if (state->in != NULL)
     28             free(state->in);
     29         gz_error(state, Z_MEM_ERROR, "out of memory");
     30         return -1;
     31     }
     32 
     33     /* allocate deflate memory, set up for gzip compression */
     34     strm->zalloc = Z_NULL;
     35     strm->zfree = Z_NULL;
     36     strm->opaque = Z_NULL;
     37     ret = deflateInit2(strm, state->level, Z_DEFLATED,
     38                        15 + 16, 8, state->strategy);
     39     if (ret != Z_OK) {
     40         free(state->in);
     41         gz_error(state, Z_MEM_ERROR, "out of memory");
     42         return -1;
     43     }
     44 
     45     /* mark state as initialized */
     46     state->size = state->want;
     47 
     48     /* initialize write buffer */
     49     strm->avail_out = state->size;
     50     strm->next_out = state->out;
     51     state->next = strm->next_out;
     52     return 0;
     53 }
     54 
     55 /* Compress whatever is at avail_in and next_in and write to the output file.
     56    Return -1 if there is an error writing to the output file, otherwise 0.
     57    flush is assumed to be a valid deflate() flush value.  If flush is Z_FINISH,
     58    then the deflate() state is reset to start a new gzip stream. */
     59 local int gz_comp(state, flush)
     60     gz_statep state;
     61     int flush;
     62 {
     63     int ret, got;
     64     unsigned have;
     65     z_streamp strm = &(state->strm);
     66 
     67     /* allocate memory if this is the first time through */
     68     if (state->size == 0 && gz_init(state) == -1)
     69         return -1;
     70 
     71     /* run deflate() on provided input until it produces no more output */
     72     ret = Z_OK;
     73     do {
     74         /* write out current buffer contents if full, or if flushing, but if
     75            doing Z_FINISH then don't write until we get to Z_STREAM_END */
     76         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
     77             (flush != Z_FINISH || ret == Z_STREAM_END))) {
     78             have = (unsigned)(strm->next_out - state->next);
     79             if (have && ((got = write(state->fd, state->next, have)) < 0 ||
     80                          (unsigned)got != have)) {
     81                 gz_error(state, Z_ERRNO, zstrerror());
     82                 return -1;
     83             }
     84             if (strm->avail_out == 0) {
     85                 strm->avail_out = state->size;
     86                 strm->next_out = state->out;
     87             }
     88             state->next = strm->next_out;
     89         }
     90 
     91         /* compress */
     92         have = strm->avail_out;
     93         ret = deflate(strm, flush);
     94         if (ret == Z_STREAM_ERROR) {
     95             gz_error(state, Z_STREAM_ERROR,
     96                       "internal error: deflate stream corrupt");
     97             return -1;
     98         }
     99         have -= strm->avail_out;
    100     } while (have);
    101 
    102     /* if that completed a deflate stream, allow another to start */
    103     if (flush == Z_FINISH)
    104         deflateReset(strm);
    105 
    106     /* all done, no errors */
    107     return 0;
    108 }
    109 
    110 /* Compress len zeros to output.  Return -1 on error, 0 on success. */
    111 local int gz_zero(state, len)
    112     gz_statep state;
    113     z_off64_t len;
    114 {
    115     int first;
    116     unsigned n;
    117     z_streamp strm = &(state->strm);
    118 
    119     /* consume whatever's left in the input buffer */
    120     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    121         return -1;
    122 
    123     /* compress len zeros (len guaranteed > 0) */
    124     first = 1;
    125     while (len) {
    126         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
    127             (unsigned)len : state->size;
    128         if (first) {
    129             memset(state->in, 0, n);
    130             first = 0;
    131         }
    132         strm->avail_in = n;
    133         strm->next_in = state->in;
    134         state->pos += n;
    135         if (gz_comp(state, Z_NO_FLUSH) == -1)
    136             return -1;
    137         len -= n;
    138     }
    139     return 0;
    140 }
    141 
    142 /* -- see zlib.h -- */
    143 int ZEXPORT gzwrite(file, buf, len)
    144     gzFile file;
    145     voidpc buf;
    146     unsigned len;
    147 {
    148     unsigned put = len;
    149     unsigned n;
    150     gz_statep state;
    151     z_streamp strm;
    152 
    153     /* get internal structure */
    154     if (file == NULL)
    155         return 0;
    156     state = (gz_statep)file;
    157     strm = &(state->strm);
    158 
    159     /* check that we're writing and that there's no error */
    160     if (state->mode != GZ_WRITE || state->err != Z_OK)
    161         return 0;
    162 
    163     /* since an int is returned, make sure len fits in one, otherwise return
    164        with an error (this avoids the flaw in the interface) */
    165     if ((int)len < 0) {
    166         gz_error(state, Z_BUF_ERROR, "requested length does not fit in int");
    167         return 0;
    168     }
    169 
    170     /* if len is zero, avoid unnecessary operations */
    171     if (len == 0)
    172         return 0;
    173 
    174     /* allocate memory if this is the first time through */
    175     if (state->size == 0 && gz_init(state) == -1)
    176         return 0;
    177 
    178     /* check for seek request */
    179     if (state->seek) {
    180         state->seek = 0;
    181         if (gz_zero(state, state->skip) == -1)
    182             return 0;
    183     }
    184 
    185     /* for small len, copy to input buffer, otherwise compress directly */
    186     if (len < state->size) {
    187         /* copy to input buffer, compress when full */
    188         do {
    189             if (strm->avail_in == 0)
    190                 strm->next_in = state->in;
    191             n = state->size - strm->avail_in;
    192             if (n > len)
    193                 n = len;
    194             memcpy(strm->next_in + strm->avail_in, buf, n);
    195             strm->avail_in += n;
    196             state->pos += n;
    197             buf = (char *)buf + n;
    198             len -= n;
    199             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
    200                 return 0;
    201         } while (len);
    202     }
    203     else {
    204         /* consume whatever's left in the input buffer */
    205         if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    206             return 0;
    207 
    208         /* directly compress user buffer to file */
    209         strm->avail_in = len;
    210         strm->next_in = (voidp)buf;
    211         state->pos += len;
    212         if (gz_comp(state, Z_NO_FLUSH) == -1)
    213             return 0;
    214     }
    215 
    216     /* input was all buffered or compressed (put will fit in int) */
    217     return (int)put;
    218 }
    219 
    220 /* -- see zlib.h -- */
    221 int ZEXPORT gzputc(file, c)
    222     gzFile file;
    223     int c;
    224 {
    225     unsigned char buf[1];
    226     gz_statep state;
    227     z_streamp strm;
    228 
    229     /* get internal structure */
    230     if (file == NULL)
    231         return -1;
    232     state = (gz_statep)file;
    233     strm = &(state->strm);
    234 
    235     /* check that we're writing and that there's no error */
    236     if (state->mode != GZ_WRITE || state->err != Z_OK)
    237         return -1;
    238 
    239     /* check for seek request */
    240     if (state->seek) {
    241         state->seek = 0;
    242         if (gz_zero(state, state->skip) == -1)
    243             return -1;
    244     }
    245 
    246     /* try writing to input buffer for speed (state->size == 0 if buffer not
    247        initialized) */
    248     if (strm->avail_in < state->size) {
    249         if (strm->avail_in == 0)
    250             strm->next_in = state->in;
    251         strm->next_in[strm->avail_in++] = c;
    252         state->pos++;
    253         return c;
    254     }
    255 
    256     /* no room in buffer or not initialized, use gz_write() */
    257     buf[0] = c;
    258     if (gzwrite(file, buf, 1) != 1)
    259         return -1;
    260     return c;
    261 }
    262 
    263 /* -- see zlib.h -- */
    264 int ZEXPORT gzputs(file, str)
    265     gzFile file;
    266     const char *str;
    267 {
    268     int ret;
    269     unsigned len;
    270 
    271     /* write string */
    272     len = (unsigned)strlen(str);
    273     ret = gzwrite(file, str, len);
    274     return ret == 0 && len != 0 ? -1 : ret;
    275 }
    276 
    277 #ifdef STDC
    278 #include <stdarg.h>
    279 
    280 /* -- see zlib.h -- */
    281 int ZEXPORTVA gzprintf (gzFile file, const char *format, ...)
    282 {
    283     int size, len;
    284     gz_statep state;
    285     z_streamp strm;
    286     va_list va;
    287 
    288     /* get internal structure */
    289     if (file == NULL)
    290         return -1;
    291     state = (gz_statep)file;
    292     strm = &(state->strm);
    293 
    294     /* check that we're writing and that there's no error */
    295     if (state->mode != GZ_WRITE || state->err != Z_OK)
    296         return 0;
    297 
    298     /* make sure we have some buffer space */
    299     if (state->size == 0 && gz_init(state) == -1)
    300         return 0;
    301 
    302     /* check for seek request */
    303     if (state->seek) {
    304         state->seek = 0;
    305         if (gz_zero(state, state->skip) == -1)
    306             return 0;
    307     }
    308 
    309     /* consume whatever's left in the input buffer */
    310     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    311         return 0;
    312 
    313     /* do the printf() into the input buffer, put length in len */
    314     size = (int)(state->size);
    315     state->in[size - 1] = 0;
    316     va_start(va, format);
    317 #ifdef NO_vsnprintf
    318 #  ifdef HAS_vsprintf_void
    319     (void)vsprintf(state->in, format, va);
    320     va_end(va);
    321     for (len = 0; len < size; len++)
    322         if (state->in[len] == 0) break;
    323 #  else
    324     len = vsprintf(state->in, format, va);
    325     va_end(va);
    326 #  endif
    327 #else
    328 #  ifdef HAS_vsnprintf_void
    329     (void)vsnprintf(state->in, size, format, va);
    330     va_end(va);
    331     len = strlen(state->in);
    332 #  else
    333     len = vsnprintf((char *)(state->in), size, format, va);
    334     va_end(va);
    335 #  endif
    336 #endif
    337 
    338     /* check that printf() results fit in buffer */
    339     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
    340         return 0;
    341 
    342     /* update buffer and position, defer compression until needed */
    343     strm->avail_in = (unsigned)len;
    344     strm->next_in = state->in;
    345     state->pos += len;
    346     return len;
    347 }
    348 
    349 #else /* !STDC */
    350 
    351 /* -- see zlib.h -- */
    352 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
    353                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
    354     gzFile file;
    355     const char *format;
    356     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
    357         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
    358 {
    359     int size, len;
    360     gz_statep state;
    361     z_streamp strm;
    362 
    363     /* get internal structure */
    364     if (file == NULL)
    365         return -1;
    366     state = (gz_statep)file;
    367     strm = &(state->strm);
    368 
    369     /* check that we're writing and that there's no error */
    370     if (state->mode != GZ_WRITE || state->err != Z_OK)
    371         return 0;
    372 
    373     /* make sure we have some buffer space */
    374     if (state->size == 0 && gz_init(state) == -1)
    375         return 0;
    376 
    377     /* check for seek request */
    378     if (state->seek) {
    379         state->seek = 0;
    380         if (gz_zero(state, state->skip) == -1)
    381             return 0;
    382     }
    383 
    384     /* consume whatever's left in the input buffer */
    385     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    386         return 0;
    387 
    388     /* do the printf() into the input buffer, put length in len */
    389     size = (int)(state->size);
    390     state->in[size - 1] = 0;
    391 #ifdef NO_snprintf
    392 #  ifdef HAS_sprintf_void
    393     sprintf(state->in, format, a1, a2, a3, a4, a5, a6, a7, a8,
    394             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    395     for (len = 0; len < size; len++)
    396         if (state->in[len] == 0) break;
    397 #  else
    398     len = sprintf(state->in, format, a1, a2, a3, a4, a5, a6, a7, a8,
    399                 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    400 #  endif
    401 #else
    402 #  ifdef HAS_snprintf_void
    403     snprintf(state->in, size, format, a1, a2, a3, a4, a5, a6, a7, a8,
    404              a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    405     len = strlen(state->in);
    406 #  else
    407     len = snprintf(state->in, size, format, a1, a2, a3, a4, a5, a6, a7, a8,
    408                  a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    409 #  endif
    410 #endif
    411 
    412     /* check that printf() results fit in buffer */
    413     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
    414         return 0;
    415 
    416     /* update buffer and position, defer compression until needed */
    417     strm->avail_in = (unsigned)len;
    418     strm->next_in = state->in;
    419     state->pos += len;
    420     return len;
    421 }
    422 
    423 #endif
    424 
    425 /* -- see zlib.h -- */
    426 int ZEXPORT gzflush(file, flush)
    427     gzFile file;
    428     int flush;
    429 {
    430     gz_statep state;
    431 
    432     /* get internal structure */
    433     if (file == NULL)
    434         return -1;
    435     state = (gz_statep)file;
    436 
    437     /* check that we're writing and that there's no error */
    438     if (state->mode != GZ_WRITE || state->err != Z_OK)
    439         return Z_STREAM_ERROR;
    440 
    441     /* check flush parameter */
    442     if (flush < 0 || flush > Z_FINISH)
    443         return Z_STREAM_ERROR;
    444 
    445     /* check for seek request */
    446     if (state->seek) {
    447         state->seek = 0;
    448         if (gz_zero(state, state->skip) == -1)
    449             return -1;
    450     }
    451 
    452     /* compress remaining data with requested flush */
    453     gz_comp(state, flush);
    454     return state->err;
    455 }
    456 
    457 /* -- see zlib.h -- */
    458 int ZEXPORT gzsetparams(file, level, strategy)
    459     gzFile file;
    460     int level;
    461     int strategy;
    462 {
    463     gz_statep state;
    464     z_streamp strm;
    465 
    466     /* get internal structure */
    467     if (file == NULL)
    468         return Z_STREAM_ERROR;
    469     state = (gz_statep)file;
    470     strm = &(state->strm);
    471 
    472     /* check that we're writing and that there's no error */
    473     if (state->mode != GZ_WRITE || state->err != Z_OK)
    474         return Z_STREAM_ERROR;
    475 
    476     /* if no change is requested, then do nothing */
    477     if (level == state->level && strategy == state->strategy)
    478         return Z_OK;
    479 
    480     /* check for seek request */
    481     if (state->seek) {
    482         state->seek = 0;
    483         if (gz_zero(state, state->skip) == -1)
    484             return -1;
    485     }
    486 
    487     /* change compression parameters for subsequent input */
    488     if (state->size) {
    489         /* flush previous input with previous parameters before changing */
    490         if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
    491             return state->err;
    492         deflateParams(strm, level, strategy);
    493     }
    494     state->level = level;
    495     state->strategy = strategy;
    496     return Z_OK;
    497 }
    498 
    499 /* -- see zlib.h -- */
    500 int ZEXPORT gzclose_w(file)
    501     gzFile file;
    502 {
    503     int ret = 0;
    504     gz_statep state;
    505 
    506     /* get internal structure */
    507     if (file == NULL)
    508         return Z_STREAM_ERROR;
    509     state = (gz_statep)file;
    510 
    511     /* check that we're writing */
    512     if (state->mode != GZ_WRITE)
    513         return Z_STREAM_ERROR;
    514 
    515     /* check for seek request */
    516     if (state->seek) {
    517         state->seek = 0;
    518         ret += gz_zero(state, state->skip);
    519     }
    520 
    521     /* flush, free memory, and close file */
    522     ret += gz_comp(state, Z_FINISH);
    523     (void)deflateEnd(&(state->strm));
    524     free(state->out);
    525     free(state->in);
    526     gz_error(state, Z_OK, NULL);
    527     free(state->path);
    528     ret += close(state->fd);
    529     free(state);
    530     return ret ? Z_ERRNO : Z_OK;
    531 }
    532