lib/libz/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 #include <unistd.h>
   9
  10 /* Local functions */
  11 local int gz_init OF((gz_statep));
  12 local int gz_comp OF((gz_statep, int));
  13 local int gz_zero OF((gz_statep, z_off64_t));
  14
  15 /* Initialize state for writing a gzip file.  Mark initialization by setting
  16    state->size to non-zero.  Return -1 on failure or 0 on success. */
  17 local int gz_init(state)
  18     gz_statep state;
  19 {
  20     int ret;
  21     z_streamp strm = &(state->strm);
  22
  23     /* allocate input and output buffers */
  24     state->in = malloc(state->want);
  25     state->out = malloc(state->want);
  26     if (state->in == NULL || state->out == NULL) {
  27         if (state->out != NULL)
  28             free(state->out);
  29         if (state->in != NULL)
  30             free(state->in);
  31         gz_error(state, Z_MEM_ERROR, "out of memory");
  32         return -1;
  33     }
  34
  35     /* allocate deflate memory, set up for gzip compression */
  36     strm->zalloc = Z_NULL;
  37     strm->zfree = Z_NULL;
  38     strm->opaque = Z_NULL;
  39     ret = deflateInit2(strm, state->level, Z_DEFLATED,
  40                        15 + 16, 8, state->strategy);
  41     if (ret != Z_OK) {
  42         free(state->in);
  43         gz_error(state, Z_MEM_ERROR, "out of memory");
  44         return -1;
  45     }
  46
  47     /* mark state as initialized */
  48     state->size = state->want;
  49
  50     /* initialize write buffer */
  51     strm->avail_out = state->size;
  52     strm->next_out = state->out;
  53     state->next = strm->next_out;
  54     return 0;
  55 }
  56
  57 /* Compress whatever is at avail_in and next_in and write to the output file.
  58    Return -1 if there is an error writing to the output file, otherwise 0.
  59    flush is assumed to be a valid deflate() flush value.  If flush is Z_FINISH,
  60    then the deflate() state is reset to start a new gzip stream. */
  61 local int gz_comp(state, flush)
  62     gz_statep state;
  63     int flush;
  64 {
  65     int ret, got;
  66     unsigned have;
  67     z_streamp strm = &(state->strm);
  68
  69     /* allocate memory if this is the first time through */
  70     if (state->size == 0 && gz_init(state) == -1)
  71         return -1;
  72
  73     /* run deflate() on provided input until it produces no more output */
  74     ret = Z_OK;
  75     do {
  76         /* write out current buffer contents if full, or if flushing, but if
  77            doing Z_FINISH then don't write until we get to Z_STREAM_END */
  78         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
  79             (flush != Z_FINISH || ret == Z_STREAM_END))) {
  80             have = (unsigned)(strm->next_out - state->next);
  81             if (have && ((got = write(state->fd, state->next, have)) < 0 ||
  82                          (unsigned)got != have)) {
  83                 gz_error(state, Z_ERRNO, zstrerror());
  84                 return -1;
  85             }
  86             if (strm->avail_out == 0) {
  87                 strm->avail_out = state->size;
  88                 strm->next_out = state->out;
  89             }
  90             state->next = strm->next_out;
  91         }
  92
  93         /* compress */
  94         have = strm->avail_out;
  95         ret = deflate(strm, flush);
  96         if (ret == Z_STREAM_ERROR) {
  97             gz_error(state, Z_STREAM_ERROR,
  98                       "internal error: deflate stream corrupt");
  99             return -1;
 100         }
 101         have -= strm->avail_out;
 102     } while (have);
 103
 104     /* if that completed a deflate stream, allow another to start */
 105     if (flush == Z_FINISH)
 106         deflateReset(strm);
 107
 108     /* all done, no errors */
 109     return 0;
 110 }
 111
 112 /* Compress len zeros to output.  Return -1 on error, 0 on success. */
 113 local int gz_zero(state, len)
 114     gz_statep state;
 115     z_off64_t len;
 116 {
 117     int first;
 118     unsigned n;
 119     z_streamp strm = &(state->strm);
 120
 121     /* consume whatever's left in the input buffer */
 122     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 123         return -1;
 124
 125     /* compress len zeros (len guaranteed > 0) */
 126     first = 1;
 127     while (len) {
 128         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
 129             (unsigned)len : state->size;
 130         if (first) {
 131             memset(state->in, 0, n);
 132             first = 0;
 133         }
 134         strm->avail_in = n;
 135         strm->next_in = state->in;
 136         state->pos += n;
 137         if (gz_comp(state, Z_NO_FLUSH) == -1)
 138             return -1;
 139         len -= n;
 140     }
 141     return 0;
 142 }
 143
 144 /* -- see zlib.h -- */
 145 int ZEXPORT gzwrite(file, buf, len)
 146     gzFile file;
 147     voidpc buf;
 148     unsigned len;
 149 {
 150     unsigned put = len;
 151     unsigned n;
 152     gz_statep state;
 153     z_streamp strm;
 154
 155     /* get internal structure */
 156     if (file == NULL)
 157         return 0;
 158     state = (gz_statep)file;
 159     strm = &(state->strm);
 160
 161     /* check that we're writing and that there's no error */
 162     if (state->mode != GZ_WRITE || state->err != Z_OK)
 163         return 0;
 164
 165     /* since an int is returned, make sure len fits in one, otherwise return
 166        with an error (this avoids the flaw in the interface) */
 167     if ((int)len < 0) {
 168         gz_error(state, Z_BUF_ERROR, "requested length does not fit in int");
 169         return 0;
 170     }
 171
 172     /* if len is zero, avoid unnecessary operations */
 173     if (len == 0)
 174         return 0;
 175
 176     /* allocate memory if this is the first time through */
 177     if (state->size == 0 && gz_init(state) == -1)
 178         return 0;
 179
 180     /* check for seek request */
 181     if (state->seek) {
 182         state->seek = 0;
 183         if (gz_zero(state, state->skip) == -1)
 184             return 0;
 185     }
 186
 187     /* for small len, copy to input buffer, otherwise compress directly */
 188     if (len < state->size) {
 189         /* copy to input buffer, compress when full */
 190         do {
 191             if (strm->avail_in == 0)
 192                 strm->next_in = state->in;
 193             n = state->size - strm->avail_in;
 194             if (n > len)
 195                 n = len;
 196             memcpy(strm->next_in + strm->avail_in, buf, n);
 197             strm->avail_in += n;
 198             state->pos += n;
 199             buf = (char *)buf + n;
 200             len -= n;
 201             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
 202                 return 0;
 203         } while (len);
 204     }
 205     else {
 206         /* consume whatever's left in the input buffer */
 207         if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 208             return 0;
 209
 210         /* directly compress user buffer to file */
 211         strm->avail_in = len;
 212         strm->next_in = (voidp)buf;
 213         state->pos += len;
 214         if (gz_comp(state, Z_NO_FLUSH) == -1)
 215             return 0;
 216     }
 217
 218     /* input was all buffered or compressed (put will fit in int) */
 219     return (int)put;
 220 }
 221
 222 /* -- see zlib.h -- */
 223 int ZEXPORT gzputc(file, c)
 224     gzFile file;
 225     int c;
 226 {
 227     unsigned char buf[1];
 228     gz_statep state;
 229     z_streamp strm;
 230
 231     /* get internal structure */
 232     if (file == NULL)
 233         return -1;
 234     state = (gz_statep)file;
 235     strm = &(state->strm);
 236
 237     /* check that we're writing and that there's no error */
 238     if (state->mode != GZ_WRITE || state->err != Z_OK)
 239         return -1;
 240
 241     /* check for seek request */
 242     if (state->seek) {
 243         state->seek = 0;
 244         if (gz_zero(state, state->skip) == -1)
 245             return -1;
 246     }
 247
 248     /* try writing to input buffer for speed (state->size == 0 if buffer not
 249        initialized) */
 250     if (strm->avail_in < state->size) {
 251         if (strm->avail_in == 0)
 252             strm->next_in = state->in;
 253         strm->next_in[strm->avail_in++] = c;
 254         state->pos++;
 255         return c;
 256     }
 257
 258     /* no room in buffer or not initialized, use gz_write() */
 259     buf[0] = c;
 260     if (gzwrite(file, buf, 1) != 1)
 261         return -1;
 262     return c;
 263 }
 264
 265 /* -- see zlib.h -- */
 266 int ZEXPORT gzputs(file, str)
 267     gzFile file;
 268     const char *str;
 269 {
 270     int ret;
 271     unsigned len;
 272
 273     /* write string */
 274     len = (unsigned)strlen(str);
 275     ret = gzwrite(file, str, len);
 276     return ret == 0 && len != 0 ? -1 : ret;
 277 }
 278
 279 #ifdef STDC
 280 #include <stdarg.h>
 281
 282 /* -- see zlib.h -- */
 283 int ZEXPORTVA gzprintf (gzFile file, const char *format, ...)
 284 {
 285     int size, len;
 286     gz_statep state;
 287     z_streamp strm;
 288     va_list va;
 289
 290     /* get internal structure */
 291     if (file == NULL)
 292         return -1;
 293     state = (gz_statep)file;
 294     strm = &(state->strm);
 295
 296     /* check that we're writing and that there's no error */
 297     if (state->mode != GZ_WRITE || state->err != Z_OK)
 298         return 0;
 299
 300     /* make sure we have some buffer space */
 301     if (state->size == 0 && gz_init(state) == -1)
 302         return 0;
 303
 304     /* check for seek request */
 305     if (state->seek) {
 306         state->seek = 0;
 307         if (gz_zero(state, state->skip) == -1)
 308             return 0;
 309     }
 310
 311     /* consume whatever's left in the input buffer */
 312     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 313         return 0;
 314
 315     /* do the printf() into the input buffer, put length in len */
 316     size = (int)(state->size);
 317     state->in[size - 1] = 0;
 318     va_start(va, format);
 319 #ifdef NO_vsnprintf
 320 #  ifdef HAS_vsprintf_void
 321     (void)vsprintf(state->in, format, va);
 322     va_end(va);
 323     for (len = 0; len < size; len++)
 324         if (state->in[len] == 0) break;
 325 #  else
 326     len = vsprintf(state->in, format, va);
 327     va_end(va);
 328 #  endif
 329 #else
 330 #  ifdef HAS_vsnprintf_void
 331     (void)vsnprintf(state->in, size, format, va);
 332     va_end(va);
 333     len = strlen(state->in);
 334 #  else
 335     len = vsnprintf((char *)(state->in), size, format, va);
 336     va_end(va);
 337 #  endif
 338 #endif
 339
 340     /* check that printf() results fit in buffer */
 341     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
 342         return 0;
 343
 344     /* update buffer and position, defer compression until needed */
 345     strm->avail_in = (unsigned)len;
 346     strm->next_in = state->in;
 347     state->pos += len;
 348     return len;
 349 }
 350
 351 #else /* !STDC */
 352
 353 /* -- see zlib.h -- */
 354 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 355                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
 356     gzFile file;
 357     const char *format;
 358     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 359         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
 360 {
 361     int size, len;
 362     gz_statep state;
 363     z_streamp strm;
 364
 365     /* get internal structure */
 366     if (file == NULL)
 367         return -1;
 368     state = (gz_statep)file;
 369     strm = &(state->strm);
 370
 371     /* check that we're writing and that there's no error */
 372     if (state->mode != GZ_WRITE || state->err != Z_OK)
 373         return 0;
 374
 375     /* make sure we have some buffer space */
 376     if (state->size == 0 && gz_init(state) == -1)
 377         return 0;
 378
 379     /* check for seek request */
 380     if (state->seek) {
 381         state->seek = 0;
 382         if (gz_zero(state, state->skip) == -1)
 383             return 0;
 384     }
 385
 386     /* consume whatever's left in the input buffer */
 387     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 388         return 0;
 389
 390     /* do the printf() into the input buffer, put length in len */
 391     size = (int)(state->size);
 392     state->in[size - 1] = 0;
 393 #ifdef NO_snprintf
 394 #  ifdef HAS_sprintf_void
 395     sprintf(state->in, format, a1, a2, a3, a4, a5, a6, a7, a8,
 396             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 397     for (len = 0; len < size; len++)
 398         if (state->in[len] == 0) break;
 399 #  else
 400     len = sprintf(state->in, format, a1, a2, a3, a4, a5, a6, a7, a8,
 401                 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 402 #  endif
 403 #else
 404 #  ifdef HAS_snprintf_void
 405     snprintf(state->in, size, format, a1, a2, a3, a4, a5, a6, a7, a8,
 406              a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 407     len = strlen(state->in);
 408 #  else
 409     len = snprintf(state->in, size, format, a1, a2, a3, a4, a5, a6, a7, a8,
 410                  a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 411 #  endif
 412 #endif
 413
 414     /* check that printf() results fit in buffer */
 415     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
 416         return 0;
 417
 418     /* update buffer and position, defer compression until needed */
 419     strm->avail_in = (unsigned)len;
 420     strm->next_in = state->in;
 421     state->pos += len;
 422     return len;
 423 }
 424
 425 #endif
 426
 427 /* -- see zlib.h -- */
 428 int ZEXPORT gzflush(file, flush)
 429     gzFile file;
 430     int flush;
 431 {
 432     gz_statep state;
 433
 434     /* get internal structure */
 435     if (file == NULL)
 436         return -1;
 437     state = (gz_statep)file;
 438
 439     /* check that we're writing and that there's no error */
 440     if (state->mode != GZ_WRITE || state->err != Z_OK)
 441         return Z_STREAM_ERROR;
 442
 443     /* check flush parameter */
 444     if (flush < 0 || flush > Z_FINISH)
 445         return Z_STREAM_ERROR;
 446
 447     /* check for seek request */
 448     if (state->seek) {
 449         state->seek = 0;
 450         if (gz_zero(state, state->skip) == -1)
 451             return -1;
 452     }
 453
 454     /* compress remaining data with requested flush */
 455     gz_comp(state, flush);
 456     return state->err;
 457 }
 458
 459 /* -- see zlib.h -- */
 460 int ZEXPORT gzsetparams(file, level, strategy)
 461     gzFile file;
 462     int level;
 463     int strategy;
 464 {
 465     gz_statep state;
 466     z_streamp strm;
 467
 468     /* get internal structure */
 469     if (file == NULL)
 470         return Z_STREAM_ERROR;
 471     state = (gz_statep)file;
 472     strm = &(state->strm);
 473
 474     /* check that we're writing and that there's no error */
 475     if (state->mode != GZ_WRITE || state->err != Z_OK)
 476         return Z_STREAM_ERROR;
 477
 478     /* if no change is requested, then do nothing */
 479     if (level == state->level && strategy == state->strategy)
 480         return Z_OK;
 481
 482     /* check for seek request */
 483     if (state->seek) {
 484         state->seek = 0;
 485         if (gz_zero(state, state->skip) == -1)
 486             return -1;
 487     }
 488
 489     /* change compression parameters for subsequent input */
 490     if (state->size) {
 491         /* flush previous input with previous parameters before changing */
 492         if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
 493             return state->err;
 494         deflateParams(strm, level, strategy);
 495     }
 496     state->level = level;
 497     state->strategy = strategy;
 498     return Z_OK;
 499 }
 500
 501 /* -- see zlib.h -- */
 502 int ZEXPORT gzclose_w(file)
 503     gzFile file;
 504 {
 505     int ret = 0;
 506     gz_statep state;
 507
 508     /* get internal structure */
 509     if (file == NULL)
 510         return Z_STREAM_ERROR;
 511     state = (gz_statep)file;
 512
 513     /* check that we're writing */
 514     if (state->mode != GZ_WRITE)
 515         return Z_STREAM_ERROR;
 516
 517     /* check for seek request */
 518     if (state->seek) {
 519         state->seek = 0;
 520         ret += gz_zero(state, state->skip);
 521     }
 522
 523     /* flush, free memory, and close file */
 524     ret += gz_comp(state, Z_FINISH);
 525     (void)deflateEnd(&(state->strm));
 526     free(state->out);
 527     free(state->in);
 528     gz_error(state, Z_OK, NULL);
 529     free(state->path);
 530     ret += close(state->fd);
 531     free(state);
 532     return ret ? Z_ERRNO : Z_OK;
 533 }