zlib/gzwrite.c

   1 /* gzwrite.c -- zlib functions for writing gzip files
   2  * Copyright (C) 2004-2017 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 local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
  13
  14 /* Initialize state for writing a gzip file.  Mark initialization by setting
  15    state->size to non-zero.  Return -1 on a memory allocation failure, or 0 on
  16    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 buffer (double size for gzprintf) */
  24     state->in = (unsigned char *)malloc(state->want << 1);
  25     if (state->in == NULL) {
  26         gz_error(state, Z_MEM_ERROR, "out of memory");
  27         return -1;
  28     }
  29
  30     /* only need output buffer and deflate state if compressing */
  31     if (!state->direct) {
  32         /* allocate output buffer */
  33         state->out = (unsigned char *)malloc(state->want);
  34         if (state->out == NULL) {
  35             free(state->in);
  36             gz_error(state, Z_MEM_ERROR, "out of memory");
  37             return -1;
  38         }
  39
  40         /* allocate deflate memory, set up for gzip compression */
  41         strm->zalloc = Z_NULL;
  42         strm->zfree = Z_NULL;
  43         strm->opaque = Z_NULL;
  44         ret = deflateInit2(strm, state->level, Z_DEFLATED,
  45                            MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
  46         if (ret != Z_OK) {
  47             free(state->out);
  48             free(state->in);
  49             gz_error(state, Z_MEM_ERROR, "out of memory");
  50             return -1;
  51         }
  52         strm->next_in = NULL;
  53     }
  54
  55     /* mark state as initialized */
  56     state->size = state->want;
  57
  58     /* initialize write buffer if compressing */
  59     if (!state->direct) {
  60         strm->avail_out = state->size;
  61         strm->next_out = state->out;
  62         state->x.next = strm->next_out;
  63     }
  64     return 0;
  65 }
  66
  67 /* Compress whatever is at avail_in and next_in and write to the output file.
  68    Return -1 if there is an error writing to the output file or if gz_init()
  69    fails to allocate memory, otherwise 0.  flush is assumed to be a valid
  70    deflate() flush value.  If flush is Z_FINISH, then the deflate() state is
  71    reset to start a new gzip stream.  If gz->direct is true, then simply write
  72    to the output file without compressing, and ignore flush. */
  73 local int gz_comp(state, flush)
  74     gz_statep state;
  75     int flush;
  76 {
  77     int ret, writ;
  78     unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
  79     z_streamp strm = &(state->strm);
  80
  81     /* allocate memory if this is the first time through */
  82     if (state->size == 0 && gz_init(state) == -1)
  83         return -1;
  84
  85     /* write directly if requested */
  86     if (state->direct) {
  87         while (strm->avail_in) {
  88             put = strm->avail_in > max ? max : strm->avail_in;
  89             writ = write(state->fd, strm->next_in, put);
  90             if (writ < 0) {
  91                 gz_error(state, Z_ERRNO, zstrerror());
  92                 return -1;
  93             }
  94             strm->avail_in -= (unsigned)writ;
  95             strm->next_in += writ;
  96         }
  97         return 0;
  98     }
  99
 100     /* run deflate() on provided input until it produces no more output */
 101     ret = Z_OK;
 102     do {
 103         /* write out current buffer contents if full, or if flushing, but if
 104            doing Z_FINISH then don't write until we get to Z_STREAM_END */
 105         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
 106             (flush != Z_FINISH || ret == Z_STREAM_END))) {
 107             while (strm->next_out > state->x.next) {
 108                 put = strm->next_out - state->x.next > (int)max ? max :
 109                       (unsigned)(strm->next_out - state->x.next);
 110                 writ = write(state->fd, state->x.next, put);
 111                 if (writ < 0) {
 112                     gz_error(state, Z_ERRNO, zstrerror());
 113                     return -1;
 114                 }
 115                 state->x.next += writ;
 116             }
 117             if (strm->avail_out == 0) {
 118                 strm->avail_out = state->size;
 119                 strm->next_out = state->out;
 120                 state->x.next = state->out;
 121             }
 122         }
 123
 124         /* compress */
 125         have = strm->avail_out;
 126         ret = deflate(strm, flush);
 127         if (ret == Z_STREAM_ERROR) {
 128             gz_error(state, Z_STREAM_ERROR,
 129                       "internal error: deflate stream corrupt");
 130             return -1;
 131         }
 132         have -= strm->avail_out;
 133     } while (have);
 134
 135     /* if that completed a deflate stream, allow another to start */
 136     if (flush == Z_FINISH)
 137         deflateReset(strm);
 138
 139     /* all done, no errors */
 140     return 0;
 141 }
 142
 143 /* Compress len zeros to output.  Return -1 on a write error or memory
 144    allocation failure by gz_comp(), or 0 on success. */
 145 local int gz_zero(state, len)
 146     gz_statep state;
 147     z_off64_t len;
 148 {
 149     int first;
 150     unsigned n;
 151     z_streamp strm = &(state->strm);
 152
 153     /* consume whatever's left in the input buffer */
 154     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 155         return -1;
 156
 157     /* compress len zeros (len guaranteed > 0) */
 158     first = 1;
 159     while (len) {
 160         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
 161             (unsigned)len : state->size;
 162         if (first) {
 163             memset(state->in, 0, n);
 164             first = 0;
 165         }
 166         strm->avail_in = n;
 167         strm->next_in = state->in;
 168         state->x.pos += n;
 169         if (gz_comp(state, Z_NO_FLUSH) == -1)
 170             return -1;
 171         len -= n;
 172     }
 173     return 0;
 174 }
 175
 176 /* Write len bytes from buf to file.  Return the number of bytes written.  If
 177    the returned value is less than len, then there was an error. */
 178 local z_size_t gz_write(state, buf, len)
 179     gz_statep state;
 180     voidpc buf;
 181     z_size_t len;
 182 {
 183     z_size_t put = len;
 184
 185     /* if len is zero, avoid unnecessary operations */
 186     if (len == 0)
 187         return 0;
 188
 189     /* allocate memory if this is the first time through */
 190     if (state->size == 0 && gz_init(state) == -1)
 191         return 0;
 192
 193     /* check for seek request */
 194     if (state->seek) {
 195         state->seek = 0;
 196         if (gz_zero(state, state->skip) == -1)
 197             return 0;
 198     }
 199
 200     /* for small len, copy to input buffer, otherwise compress directly */
 201     if (len < state->size) {
 202         /* copy to input buffer, compress when full */
 203         do {
 204             unsigned have, copy;
 205
 206             if (state->strm.avail_in == 0)
 207                 state->strm.next_in = state->in;
 208             have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
 209                               state->in);
 210             copy = state->size - have;
 211             if (copy > len)
 212                 copy = len;
 213             memcpy(state->in + have, buf, copy);
 214             state->strm.avail_in += copy;
 215             state->x.pos += copy;
 216             buf = (const char *)buf + copy;
 217             len -= copy;
 218             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
 219                 return 0;
 220         } while (len);
 221     }
 222     else {
 223         /* consume whatever's left in the input buffer */
 224         if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 225             return 0;
 226
 227         /* directly compress user buffer to file */
 228         state->strm.next_in = (z_const Bytef *)buf;
 229         do {
 230             unsigned n = (unsigned)-1;
 231             if (n > len)
 232                 n = len;
 233             state->strm.avail_in = n;
 234             state->x.pos += n;
 235             if (gz_comp(state, Z_NO_FLUSH) == -1)
 236                 return 0;
 237             len -= n;
 238         } while (len);
 239     }
 240
 241     /* input was all buffered or compressed */
 242     return put;
 243 }
 244
 245 /* -- see zlib.h -- */
 246 int ZEXPORT gzwrite(file, buf, len)
 247     gzFile file;
 248     voidpc buf;
 249     unsigned len;
 250 {
 251     gz_statep state;
 252
 253     /* get internal structure */
 254     if (file == NULL)
 255         return 0;
 256     state = (gz_statep)file;
 257
 258     /* check that we're writing and that there's no error */
 259     if (state->mode != GZ_WRITE || state->err != Z_OK)
 260         return 0;
 261
 262     /* since an int is returned, make sure len fits in one, otherwise return
 263        with an error (this avoids a flaw in the interface) */
 264     if ((int)len < 0) {
 265         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
 266         return 0;
 267     }
 268
 269     /* write len bytes from buf (the return value will fit in an int) */
 270     return (int)gz_write(state, buf, len);
 271 }
 272
 273 /* -- see zlib.h -- */
 274 z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
 275     voidpc buf;
 276     z_size_t size;
 277     z_size_t nitems;
 278     gzFile file;
 279 {
 280     z_size_t len;
 281     gz_statep state;
 282
 283     /* get internal structure */
 284     if (file == NULL)
 285         return 0;
 286     state = (gz_statep)file;
 287
 288     /* check that we're writing and that there's no error */
 289     if (state->mode != GZ_WRITE || state->err != Z_OK)
 290         return 0;
 291
 292     /* compute bytes to read -- error on overflow */
 293     len = nitems * size;
 294     if (size && len / size != nitems) {
 295         gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
 296         return 0;
 297     }
 298
 299     /* write len bytes to buf, return the number of full items written */
 300     return len ? gz_write(state, buf, len) / size : 0;
 301 }
 302
 303 /* -- see zlib.h -- */
 304 int ZEXPORT gzputc(file, c)
 305     gzFile file;
 306     int c;
 307 {
 308     unsigned have;
 309     unsigned char buf[1];
 310     gz_statep state;
 311     z_streamp strm;
 312
 313     /* get internal structure */
 314     if (file == NULL)
 315         return -1;
 316     state = (gz_statep)file;
 317     strm = &(state->strm);
 318
 319     /* check that we're writing and that there's no error */
 320     if (state->mode != GZ_WRITE || state->err != Z_OK)
 321         return -1;
 322
 323     /* check for seek request */
 324     if (state->seek) {
 325         state->seek = 0;
 326         if (gz_zero(state, state->skip) == -1)
 327             return -1;
 328     }
 329
 330     /* try writing to input buffer for speed (state->size == 0 if buffer not
 331        initialized) */
 332     if (state->size) {
 333         if (strm->avail_in == 0)
 334             strm->next_in = state->in;
 335         have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
 336         if (have < state->size) {
 337             state->in[have] = (unsigned char)c;
 338             strm->avail_in++;
 339             state->x.pos++;
 340             return c & 0xff;
 341         }
 342     }
 343
 344     /* no room in buffer or not initialized, use gz_write() */
 345     buf[0] = (unsigned char)c;
 346     if (gz_write(state, buf, 1) != 1)
 347         return -1;
 348     return c & 0xff;
 349 }
 350
 351 /* -- see zlib.h -- */
 352 int ZEXPORT gzputs(file, str)
 353     gzFile file;
 354     const char *str;
 355 {
 356     int ret;
 357     z_size_t len;
 358     gz_statep state;
 359
 360     /* get internal structure */
 361     if (file == NULL)
 362         return -1;
 363     state = (gz_statep)file;
 364
 365     /* check that we're writing and that there's no error */
 366     if (state->mode != GZ_WRITE || state->err != Z_OK)
 367         return -1;
 368
 369     /* write string */
 370     len = strlen(str);
 371     ret = gz_write(state, str, len);
 372     return ret == 0 && len != 0 ? -1 : ret;
 373 }
 374
 375 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
 376 #include <stdarg.h>
 377
 378 /* -- see zlib.h -- */
 379 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
 380 {
 381     int len;
 382     unsigned left;
 383     char *next;
 384     gz_statep state;
 385     z_streamp strm;
 386
 387     /* get internal structure */
 388     if (file == NULL)
 389         return Z_STREAM_ERROR;
 390     state = (gz_statep)file;
 391     strm = &(state->strm);
 392
 393     /* check that we're writing and that there's no error */
 394     if (state->mode != GZ_WRITE || state->err != Z_OK)
 395         return Z_STREAM_ERROR;
 396
 397     /* make sure we have some buffer space */
 398     if (state->size == 0 && gz_init(state) == -1)
 399         return state->err;
 400
 401     /* check for seek request */
 402     if (state->seek) {
 403         state->seek = 0;
 404         if (gz_zero(state, state->skip) == -1)
 405             return state->err;
 406     }
 407
 408     /* do the printf() into the input buffer, put length in len -- the input
 409        buffer is double-sized just for this function, so there is guaranteed to
 410        be state->size bytes available after the current contents */
 411     if (strm->avail_in == 0)
 412         strm->next_in = state->in;
 413     next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
 414     next[state->size - 1] = 0;
 415 #ifdef NO_vsnprintf
 416 #  ifdef HAS_vsprintf_void
 417     (void)vsprintf(next, format, va);
 418     for (len = 0; len < state->size; len++)
 419         if (next[len] == 0) break;
 420 #  else
 421     len = vsprintf(next, format, va);
 422 #  endif
 423 #else
 424 #  ifdef HAS_vsnprintf_void
 425     (void)vsnprintf(next, state->size, format, va);
 426     len = strlen(next);
 427 #  else
 428     len = vsnprintf(next, state->size, format, va);
 429 #  endif
 430 #endif
 431
 432     /* check that printf() results fit in buffer */
 433     if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
 434         return 0;
 435
 436     /* update buffer and position, compress first half if past that */
 437     strm->avail_in += (unsigned)len;
 438     state->x.pos += len;
 439     if (strm->avail_in >= state->size) {
 440         left = strm->avail_in - state->size;
 441         strm->avail_in = state->size;
 442         if (gz_comp(state, Z_NO_FLUSH) == -1)
 443             return state->err;
 444         memcpy(state->in, state->in + state->size, left);
 445         strm->next_in = state->in;
 446         strm->avail_in = left;
 447     }
 448     return len;
 449 }
 450
 451 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
 452 {
 453     va_list va;
 454     int ret;
 455
 456     va_start(va, format);
 457     ret = gzvprintf(file, format, va);
 458     va_end(va);
 459     return ret;
 460 }
 461
 462 #else /* !STDC && !Z_HAVE_STDARG_H */
 463
 464 /* -- see zlib.h -- */
 465 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 466                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
 467     gzFile file;
 468     const char *format;
 469     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 470         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
 471 {
 472     unsigned len, left;
 473     char *next;
 474     gz_statep state;
 475     z_streamp strm;
 476
 477     /* get internal structure */
 478     if (file == NULL)
 479         return Z_STREAM_ERROR;
 480     state = (gz_statep)file;
 481     strm = &(state->strm);
 482
 483     /* check that can really pass pointer in ints */
 484     if (sizeof(int) != sizeof(void *))
 485         return Z_STREAM_ERROR;
 486
 487     /* check that we're writing and that there's no error */
 488     if (state->mode != GZ_WRITE || state->err != Z_OK)
 489         return Z_STREAM_ERROR;
 490
 491     /* make sure we have some buffer space */
 492     if (state->size == 0 && gz_init(state) == -1)
 493         return state->error;
 494
 495     /* check for seek request */
 496     if (state->seek) {
 497         state->seek = 0;
 498         if (gz_zero(state, state->skip) == -1)
 499             return state->error;
 500     }
 501
 502     /* do the printf() into the input buffer, put length in len -- the input
 503        buffer is double-sized just for this function, so there is guaranteed to
 504        be state->size bytes available after the current contents */
 505     if (strm->avail_in == 0)
 506         strm->next_in = state->in;
 507     next = (char *)(strm->next_in + strm->avail_in);
 508     next[state->size - 1] = 0;
 509 #ifdef NO_snprintf
 510 #  ifdef HAS_sprintf_void
 511     sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
 512             a13, a14, a15, a16, a17, a18, a19, a20);
 513     for (len = 0; len < size; len++)
 514         if (next[len] == 0)
 515             break;
 516 #  else
 517     len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
 518                   a12, a13, a14, a15, a16, a17, a18, a19, a20);
 519 #  endif
 520 #else
 521 #  ifdef HAS_snprintf_void
 522     snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
 523              a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 524     len = strlen(next);
 525 #  else
 526     len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
 527                    a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 528 #  endif
 529 #endif
 530
 531     /* check that printf() results fit in buffer */
 532     if (len == 0 || len >= state->size || next[state->size - 1] != 0)
 533         return 0;
 534
 535     /* update buffer and position, compress first half if past that */
 536     strm->avail_in += len;
 537     state->x.pos += len;
 538     if (strm->avail_in >= state->size) {
 539         left = strm->avail_in - state->size;
 540         strm->avail_in = state->size;
 541         if (gz_comp(state, Z_NO_FLUSH) == -1)
 542             return state->err;
 543         memcpy(state->in, state->in + state->size, left);
 544         strm->next_in = state->in;
 545         strm->avail_in = left;
 546     }
 547     return (int)len;
 548 }
 549
 550 #endif
 551
 552 /* -- see zlib.h -- */
 553 int ZEXPORT gzflush(file, flush)
 554     gzFile file;
 555     int flush;
 556 {
 557     gz_statep state;
 558
 559     /* get internal structure */
 560     if (file == NULL)
 561         return Z_STREAM_ERROR;
 562     state = (gz_statep)file;
 563
 564     /* check that we're writing and that there's no error */
 565     if (state->mode != GZ_WRITE || state->err != Z_OK)
 566         return Z_STREAM_ERROR;
 567
 568     /* check flush parameter */
 569     if (flush < 0 || flush > Z_FINISH)
 570         return Z_STREAM_ERROR;
 571
 572     /* check for seek request */
 573     if (state->seek) {
 574         state->seek = 0;
 575         if (gz_zero(state, state->skip) == -1)
 576             return state->err;
 577     }
 578
 579     /* compress remaining data with requested flush */
 580     (void)gz_comp(state, flush);
 581     return state->err;
 582 }
 583
 584 /* -- see zlib.h -- */
 585 int ZEXPORT gzsetparams(file, level, strategy)
 586     gzFile file;
 587     int level;
 588     int strategy;
 589 {
 590     gz_statep state;
 591     z_streamp strm;
 592
 593     /* get internal structure */
 594     if (file == NULL)
 595         return Z_STREAM_ERROR;
 596     state = (gz_statep)file;
 597     strm = &(state->strm);
 598
 599     /* check that we're writing and that there's no error */
 600     if (state->mode != GZ_WRITE || state->err != Z_OK)
 601         return Z_STREAM_ERROR;
 602
 603     /* if no change is requested, then do nothing */
 604     if (level == state->level && strategy == state->strategy)
 605         return Z_OK;
 606
 607     /* check for seek request */
 608     if (state->seek) {
 609         state->seek = 0;
 610         if (gz_zero(state, state->skip) == -1)
 611             return state->err;
 612     }
 613
 614     /* change compression parameters for subsequent input */
 615     if (state->size) {
 616         /* flush previous input with previous parameters before changing */
 617         if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
 618             return state->err;
 619         deflateParams(strm, level, strategy);
 620     }
 621     state->level = level;
 622     state->strategy = strategy;
 623     return Z_OK;
 624 }
 625
 626 /* -- see zlib.h -- */
 627 int ZEXPORT gzclose_w(file)
 628     gzFile file;
 629 {
 630     int ret = Z_OK;
 631     gz_statep state;
 632
 633     /* get internal structure */
 634     if (file == NULL)
 635         return Z_STREAM_ERROR;
 636     state = (gz_statep)file;
 637
 638     /* check that we're writing */
 639     if (state->mode != GZ_WRITE)
 640         return Z_STREAM_ERROR;
 641
 642     /* check for seek request */
 643     if (state->seek) {
 644         state->seek = 0;
 645         if (gz_zero(state, state->skip) == -1)
 646             ret = state->err;
 647     }
 648
 649     /* flush, free memory, and close file */
 650     if (gz_comp(state, Z_FINISH) == -1)
 651         ret = state->err;
 652     if (state->size) {
 653         if (!state->direct) {
 654             (void)deflateEnd(&(state->strm));
 655             free(state->out);
 656         }
 657         free(state->in);
 658     }
 659     gz_error(state, Z_OK, NULL);
 660     free(state->path);
 661     if (close(state->fd) == -1)
 662         ret = Z_ERRNO;
 663     free(state);
 664     return ret;
 665 }