zlib/gzwrite.c

   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 }