zlib/gzwrite.c

   1 /* gzwrite.c -- zlib functions for writing gzip files
   2  * Copyright (C) 2004, 2005, 2010, 2011, 2012 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 buffer */
  22     state->in = malloc(state->want);
  23     if (state->in == NULL) {
  24         gz_error(state, Z_MEM_ERROR, "out of memory");
  25         return -1;
  26     }
  27
  28     /* only need output buffer and deflate state if compressing */
  29     if (!state->direct) {
  30         /* allocate output buffer */
  31         state->out = malloc(state->want);
  32         if (state->out == NULL) {
  33             free(state->in);
  34             gz_error(state, Z_MEM_ERROR, "out of memory");
  35             return -1;
  36         }
  37
  38         /* allocate deflate memory, set up for gzip compression */
  39         strm->zalloc = Z_NULL;
  40         strm->zfree = Z_NULL;
  41         strm->opaque = Z_NULL;
  42         ret = deflateInit2(strm, state->level, Z_DEFLATED,
  43                            MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
  44         if (ret != Z_OK) {
  45             free(state->out);
  46             free(state->in);
  47             gz_error(state, Z_MEM_ERROR, "out of memory");
  48             return -1;
  49         }
  50     }
  51
  52     /* mark state as initialized */
  53     state->size = state->want;
  54
  55     /* initialize write buffer if compressing */
  56     if (!state->direct) {
  57         strm->avail_out = state->size;
  58         strm->next_out = state->out;
  59         state->x.next = strm->next_out;
  60     }
  61     return 0;
  62 }
  63
  64 /* Compress whatever is at avail_in and next_in and write to the output file.
  65    Return -1 if there is an error writing to the output file, otherwise 0.
  66    flush is assumed to be a valid deflate() flush value.  If flush is Z_FINISH,
  67    then the deflate() state is reset to start a new gzip stream.  If gz->direct
  68    is true, then simply write to the output file without compressing, and
  69    ignore flush. */
  70 local int gz_comp(state, flush)
  71     gz_statep state;
  72     int flush;
  73 {
  74     int ret, got;
  75     unsigned have;
  76     z_streamp strm = &(state->strm);
  77
  78     /* allocate memory if this is the first time through */
  79     if (state->size == 0 && gz_init(state) == -1)
  80         return -1;
  81
  82     /* write directly if requested */
  83     if (state->direct) {
  84         got = write(state->fd, strm->next_in, strm->avail_in);
  85         if (got < 0 || (unsigned)got != strm->avail_in) {
  86             gz_error(state, Z_ERRNO, zstrerror());
  87             return -1;
  88         }
  89         strm->avail_in = 0;
  90         return 0;
  91     }
  92
  93     /* run deflate() on provided input until it produces no more output */
  94     ret = Z_OK;
  95     do {
  96         /* write out current buffer contents if full, or if flushing, but if
  97            doing Z_FINISH then don't write until we get to Z_STREAM_END */
  98         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
  99             (flush != Z_FINISH || ret == Z_STREAM_END))) {
 100             have = (unsigned)(strm->next_out - state->x.next);
 101             if (have && ((got = write(state->fd, state->x.next, have)) < 0 ||
 102                          (unsigned)got != have)) {
 103                 gz_error(state, Z_ERRNO, zstrerror());
 104                 return -1;
 105             }
 106             if (strm->avail_out == 0) {
 107                 strm->avail_out = state->size;
 108                 strm->next_out = state->out;
 109             }
 110             state->x.next = strm->next_out;
 111         }
 112
 113         /* compress */
 114         have = strm->avail_out;
 115         ret = deflate(strm, flush);
 116         if (ret == Z_STREAM_ERROR) {
 117             gz_error(state, Z_STREAM_ERROR,
 118                       "internal error: deflate stream corrupt");
 119             return -1;
 120         }
 121         have -= strm->avail_out;
 122     } while (have);
 123
 124     /* if that completed a deflate stream, allow another to start */
 125     if (flush == Z_FINISH)
 126         deflateReset(strm);
 127
 128     /* all done, no errors */
 129     return 0;
 130 }
 131
 132 /* Compress len zeros to output.  Return -1 on error, 0 on success. */
 133 local int gz_zero(state, len)
 134     gz_statep state;
 135     z_off64_t len;
 136 {
 137     int first;
 138     unsigned n;
 139     z_streamp strm = &(state->strm);
 140
 141     /* consume whatever's left in the input buffer */
 142     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 143         return -1;
 144
 145     /* compress len zeros (len guaranteed > 0) */
 146     first = 1;
 147     while (len) {
 148         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
 149             (unsigned)len : state->size;
 150         if (first) {
 151             memset(state->in, 0, n);
 152             first = 0;
 153         }
 154         strm->avail_in = n;
 155         strm->next_in = state->in;
 156         state->x.pos += n;
 157         if (gz_comp(state, Z_NO_FLUSH) == -1)
 158             return -1;
 159         len -= n;
 160     }
 161     return 0;
 162 }
 163
 164 /* -- see zlib.h -- */
 165 int ZEXPORT gzwrite(file, buf, len)
 166     gzFile file;
 167     voidpc buf;
 168     unsigned len;
 169 {
 170     unsigned put = len;
 171     unsigned n;
 172     gz_statep state;
 173     z_streamp strm;
 174
 175     /* get internal structure */
 176     if (file == NULL)
 177         return 0;
 178     state = (gz_statep)file;
 179     strm = &(state->strm);
 180
 181     /* check that we're writing and that there's no error */
 182     if (state->mode != GZ_WRITE || state->err != Z_OK)
 183         return 0;
 184
 185     /* since an int is returned, make sure len fits in one, otherwise return
 186        with an error (this avoids the flaw in the interface) */
 187     if ((int)len < 0) {
 188         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
 189         return 0;
 190     }
 191
 192     /* if len is zero, avoid unnecessary operations */
 193     if (len == 0)
 194         return 0;
 195
 196     /* allocate memory if this is the first time through */
 197     if (state->size == 0 && gz_init(state) == -1)
 198         return 0;
 199
 200     /* check for seek request */
 201     if (state->seek) {
 202         state->seek = 0;
 203         if (gz_zero(state, state->skip) == -1)
 204             return 0;
 205     }
 206
 207     /* for small len, copy to input buffer, otherwise compress directly */
 208     if (len < state->size) {
 209         /* copy to input buffer, compress when full */
 210         do {
 211             if (strm->avail_in == 0)
 212                 strm->next_in = state->in;
 213             n = state->size - strm->avail_in;
 214             if (n > len)
 215                 n = len;
 216             memcpy(strm->next_in + strm->avail_in, buf, n);
 217             strm->avail_in += n;
 218             state->x.pos += n;
 219             buf = (char *)buf + n;
 220             len -= n;
 221             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
 222                 return 0;
 223         } while (len);
 224     }
 225     else {
 226         /* consume whatever's left in the input buffer */
 227         if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 228             return 0;
 229
 230         /* directly compress user buffer to file */
 231         strm->avail_in = len;
 232         strm->next_in = (voidp)buf;
 233         state->x.pos += len;
 234         if (gz_comp(state, Z_NO_FLUSH) == -1)
 235             return 0;
 236     }
 237
 238     /* input was all buffered or compressed (put will fit in int) */
 239     return (int)put;
 240 }
 241
 242 /* -- see zlib.h -- */
 243 int ZEXPORT gzputc(file, c)
 244     gzFile file;
 245     int c;
 246 {
 247     unsigned char buf[1];
 248     gz_statep state;
 249     z_streamp strm;
 250
 251     /* get internal structure */
 252     if (file == NULL)
 253         return -1;
 254     state = (gz_statep)file;
 255     strm = &(state->strm);
 256
 257     /* check that we're writing and that there's no error */
 258     if (state->mode != GZ_WRITE || state->err != Z_OK)
 259         return -1;
 260
 261     /* check for seek request */
 262     if (state->seek) {
 263         state->seek = 0;
 264         if (gz_zero(state, state->skip) == -1)
 265             return -1;
 266     }
 267
 268     /* try writing to input buffer for speed (state->size == 0 if buffer not
 269        initialized) */
 270     if (strm->avail_in < state->size) {
 271         if (strm->avail_in == 0)
 272             strm->next_in = state->in;
 273         strm->next_in[strm->avail_in++] = c;
 274         state->x.pos++;
 275         return c & 0xff;
 276     }
 277
 278     /* no room in buffer or not initialized, use gz_write() */
 279     buf[0] = c;
 280     if (gzwrite(file, buf, 1) != 1)
 281         return -1;
 282     return c & 0xff;
 283 }
 284
 285 /* -- see zlib.h -- */
 286 int ZEXPORT gzputs(file, str)
 287     gzFile file;
 288     const char *str;
 289 {
 290     int ret;
 291     unsigned len;
 292
 293     /* write string */
 294     len = (unsigned)strlen(str);
 295     ret = gzwrite(file, str, len);
 296     return ret == 0 && len != 0 ? -1 : ret;
 297 }
 298
 299 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
 300 #include <stdarg.h>
 301
 302 /* -- see zlib.h -- */
 303 int ZEXPORTVA gzprintf (gzFile file, const char *format, ...)
 304 {
 305     int size, len;
 306     gz_statep state;
 307     z_streamp strm;
 308     va_list va;
 309
 310     /* get internal structure */
 311     if (file == NULL)
 312         return -1;
 313     state = (gz_statep)file;
 314     strm = &(state->strm);
 315
 316     /* check that we're writing and that there's no error */
 317     if (state->mode != GZ_WRITE || state->err != Z_OK)
 318         return 0;
 319
 320     /* make sure we have some buffer space */
 321     if (state->size == 0 && gz_init(state) == -1)
 322         return 0;
 323
 324     /* check for seek request */
 325     if (state->seek) {
 326         state->seek = 0;
 327         if (gz_zero(state, state->skip) == -1)
 328             return 0;
 329     }
 330
 331     /* consume whatever's left in the input buffer */
 332     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 333         return 0;
 334
 335     /* do the printf() into the input buffer, put length in len */
 336     size = (int)(state->size);
 337     state->in[size - 1] = 0;
 338     va_start(va, format);
 339 #ifdef NO_vsnprintf
 340 #  ifdef HAS_vsprintf_void
 341     (void)vsprintf((char *)(state->in), format, va);
 342     va_end(va);
 343     for (len = 0; len < size; len++)
 344         if (state->in[len] == 0) break;
 345 #  else
 346     len = vsprintf((char *)(state->in), format, va);
 347     va_end(va);
 348 #  endif
 349 #else
 350 #  ifdef HAS_vsnprintf_void
 351     (void)vsnprintf((char *)(state->in), size, format, va);
 352     va_end(va);
 353     len = strlen((char *)(state->in));
 354 #  else
 355     len = vsnprintf((char *)(state->in), size, format, va);
 356     va_end(va);
 357 #  endif
 358 #endif
 359
 360     /* check that printf() results fit in buffer */
 361     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
 362         return 0;
 363
 364     /* update buffer and position, defer compression until needed */
 365     strm->avail_in = (unsigned)len;
 366     strm->next_in = state->in;
 367     state->x.pos += len;
 368     return len;
 369 }
 370
 371 #else /* !STDC && !Z_HAVE_STDARG_H */
 372
 373 /* -- see zlib.h -- */
 374 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 375                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
 376     gzFile file;
 377     const char *format;
 378     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 379         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
 380 {
 381     int size, len;
 382     gz_statep state;
 383     z_streamp strm;
 384
 385     /* get internal structure */
 386     if (file == NULL)
 387         return -1;
 388     state = (gz_statep)file;
 389     strm = &(state->strm);
 390
 391     /* check that can really pass pointer in ints */
 392     if (sizeof(int) != sizeof(void *))
 393         return 0;
 394
 395     /* check that we're writing and that there's no error */
 396     if (state->mode != GZ_WRITE || state->err != Z_OK)
 397         return 0;
 398
 399     /* make sure we have some buffer space */
 400     if (state->size == 0 && gz_init(state) == -1)
 401         return 0;
 402
 403     /* check for seek request */
 404     if (state->seek) {
 405         state->seek = 0;
 406         if (gz_zero(state, state->skip) == -1)
 407             return 0;
 408     }
 409
 410     /* consume whatever's left in the input buffer */
 411     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 412         return 0;
 413
 414     /* do the printf() into the input buffer, put length in len */
 415     size = (int)(state->size);
 416     state->in[size - 1] = 0;
 417 #ifdef NO_snprintf
 418 #  ifdef HAS_sprintf_void
 419     sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
 420             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 421     for (len = 0; len < size; len++)
 422         if (state->in[len] == 0) break;
 423 #  else
 424     len = sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
 425                   a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 426 #  endif
 427 #else
 428 #  ifdef HAS_snprintf_void
 429     snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6, a7, a8,
 430              a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 431     len = strlen((char *)(state->in));
 432 #  else
 433     len = snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6,
 434                    a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18,
 435                    a19, a20);
 436 #  endif
 437 #endif
 438
 439     /* check that printf() results fit in buffer */
 440     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
 441         return 0;
 442
 443     /* update buffer and position, defer compression until needed */
 444     strm->avail_in = (unsigned)len;
 445     strm->next_in = state->in;
 446     state->x.pos += len;
 447     return len;
 448 }
 449
 450 #endif
 451
 452 /* -- see zlib.h -- */
 453 int ZEXPORT gzflush(file, flush)
 454     gzFile file;
 455     int flush;
 456 {
 457     gz_statep state;
 458
 459     /* get internal structure */
 460     if (file == NULL)
 461         return -1;
 462     state = (gz_statep)file;
 463
 464     /* check that we're writing and that there's no error */
 465     if (state->mode != GZ_WRITE || state->err != Z_OK)
 466         return Z_STREAM_ERROR;
 467
 468     /* check flush parameter */
 469     if (flush < 0 || flush > Z_FINISH)
 470         return Z_STREAM_ERROR;
 471
 472     /* check for seek request */
 473     if (state->seek) {
 474         state->seek = 0;
 475         if (gz_zero(state, state->skip) == -1)
 476             return -1;
 477     }
 478
 479     /* compress remaining data with requested flush */
 480     gz_comp(state, flush);
 481     return state->err;
 482 }
 483
 484 /* -- see zlib.h -- */
 485 int ZEXPORT gzsetparams(file, level, strategy)
 486     gzFile file;
 487     int level;
 488     int strategy;
 489 {
 490     gz_statep state;
 491     z_streamp strm;
 492
 493     /* get internal structure */
 494     if (file == NULL)
 495         return Z_STREAM_ERROR;
 496     state = (gz_statep)file;
 497     strm = &(state->strm);
 498
 499     /* check that we're writing and that there's no error */
 500     if (state->mode != GZ_WRITE || state->err != Z_OK)
 501         return Z_STREAM_ERROR;
 502
 503     /* if no change is requested, then do nothing */
 504     if (level == state->level && strategy == state->strategy)
 505         return Z_OK;
 506
 507     /* check for seek request */
 508     if (state->seek) {
 509         state->seek = 0;
 510         if (gz_zero(state, state->skip) == -1)
 511             return -1;
 512     }
 513
 514     /* change compression parameters for subsequent input */
 515     if (state->size) {
 516         /* flush previous input with previous parameters before changing */
 517         if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
 518             return state->err;
 519         deflateParams(strm, level, strategy);
 520     }
 521     state->level = level;
 522     state->strategy = strategy;
 523     return Z_OK;
 524 }
 525
 526 /* -- see zlib.h -- */
 527 int ZEXPORT gzclose_w(file)
 528     gzFile file;
 529 {
 530     int ret = Z_OK;
 531     gz_statep state;
 532
 533     /* get internal structure */
 534     if (file == NULL)
 535         return Z_STREAM_ERROR;
 536     state = (gz_statep)file;
 537
 538     /* check that we're writing */
 539     if (state->mode != GZ_WRITE)
 540         return Z_STREAM_ERROR;
 541
 542     /* check for seek request */
 543     if (state->seek) {
 544         state->seek = 0;
 545         if (gz_zero(state, state->skip) == -1)
 546             ret = state->err;
 547     }
 548
 549     /* flush, free memory, and close file */
 550     if (state->size) {
 551         if (gz_comp(state, Z_FINISH) == -1)
 552             ret = state->err;
 553         if (!state->direct) {
 554             (void)deflateEnd(&(state->strm));
 555             free(state->out);
 556         }
 557         free(state->in);
 558     }
 559     gz_error(state, Z_OK, NULL);
 560     free(state->path);
 561     if (close(state->fd) == -1)
 562         ret = Z_ERRNO;
 563     free(state);
 564     return ret;
 565 }