zlib/gzwrite.c

   1 /* gzwrite.c -- zlib functions for writing gzip files
   2  * Copyright (C) 2004-2019 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     /* check for a pending reset */
 101     if (state->reset) {
 102         /* don't start a new gzip member unless there is data to write */
 103         if (strm->avail_in == 0)
 104             return 0;
 105         deflateReset(strm);
 106         state->reset = 0;
 107     }
 108
 109     /* run deflate() on provided input until it produces no more output */
 110     ret = Z_OK;
 111     do {
 112         /* write out current buffer contents if full, or if flushing, but if
 113            doing Z_FINISH then don't write until we get to Z_STREAM_END */
 114         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
 115             (flush != Z_FINISH || ret == Z_STREAM_END))) {
 116             while (strm->next_out > state->x.next) {
 117                 put = strm->next_out - state->x.next > (int)max ? max :
 118                       (unsigned)(strm->next_out - state->x.next);
 119                 writ = write(state->fd, state->x.next, put);
 120                 if (writ < 0) {
 121                     gz_error(state, Z_ERRNO, zstrerror());
 122                     return -1;
 123                 }
 124                 state->x.next += writ;
 125             }
 126             if (strm->avail_out == 0) {
 127                 strm->avail_out = state->size;
 128                 strm->next_out = state->out;
 129                 state->x.next = state->out;
 130             }
 131         }
 132
 133         /* compress */
 134         have = strm->avail_out;
 135         ret = deflate(strm, flush);
 136         if (ret == Z_STREAM_ERROR) {
 137             gz_error(state, Z_STREAM_ERROR,
 138                       "internal error: deflate stream corrupt");
 139             return -1;
 140         }
 141         have -= strm->avail_out;
 142     } while (have);
 143
 144     /* if that completed a deflate stream, allow another to start */
 145     if (flush == Z_FINISH)
 146         state->reset = 1;
 147
 148     /* all done, no errors */
 149     return 0;
 150 }
 151
 152 /* Compress len zeros to output.  Return -1 on a write error or memory
 153    allocation failure by gz_comp(), or 0 on success. */
 154 local int gz_zero(state, len)
 155     gz_statep state;
 156     z_off64_t len;
 157 {
 158     int first;
 159     unsigned n;
 160     z_streamp strm = &(state->strm);
 161
 162     /* consume whatever's left in the input buffer */
 163     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 164         return -1;
 165
 166     /* compress len zeros (len guaranteed > 0) */
 167     first = 1;
 168     while (len) {
 169         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
 170             (unsigned)len : state->size;
 171         if (first) {
 172             memset(state->in, 0, n);
 173             first = 0;
 174         }
 175         strm->avail_in = n;
 176         strm->next_in = state->in;
 177         state->x.pos += n;
 178         if (gz_comp(state, Z_NO_FLUSH) == -1)
 179             return -1;
 180         len -= n;
 181     }
 182     return 0;
 183 }
 184
 185 /* Write len bytes from buf to file.  Return the number of bytes written.  If
 186    the returned value is less than len, then there was an error. */
 187 local z_size_t gz_write(state, buf, len)
 188     gz_statep state;
 189     voidpc buf;
 190     z_size_t len;
 191 {
 192     z_size_t put = len;
 193
 194     /* if len is zero, avoid unnecessary operations */
 195     if (len == 0)
 196         return 0;
 197
 198     /* allocate memory if this is the first time through */
 199     if (state->size == 0 && gz_init(state) == -1)
 200         return 0;
 201
 202     /* check for seek request */
 203     if (state->seek) {
 204         state->seek = 0;
 205         if (gz_zero(state, state->skip) == -1)
 206             return 0;
 207     }
 208
 209     /* for small len, copy to input buffer, otherwise compress directly */
 210     if (len < state->size) {
 211         /* copy to input buffer, compress when full */
 212         do {
 213             unsigned have, copy;
 214
 215             if (state->strm.avail_in == 0)
 216                 state->strm.next_in = state->in;
 217             have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
 218                               state->in);
 219             copy = state->size - have;
 220             if (copy > len)
 221                 copy = (unsigned)len;
 222             memcpy(state->in + have, buf, copy);
 223             state->strm.avail_in += copy;
 224             state->x.pos += copy;
 225             buf = (const char *)buf + copy;
 226             len -= copy;
 227             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
 228                 return 0;
 229         } while (len);
 230     }
 231     else {
 232         /* consume whatever's left in the input buffer */
 233         if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
 234             return 0;
 235
 236         /* directly compress user buffer to file */
 237         state->strm.next_in = (z_const Bytef *)buf;
 238         do {
 239             unsigned n = (unsigned)-1;
 240             if (n > len)
 241                 n = (unsigned)len;
 242             state->strm.avail_in = n;
 243             state->x.pos += n;
 244             if (gz_comp(state, Z_NO_FLUSH) == -1)
 245                 return 0;
 246             len -= n;
 247         } while (len);
 248     }
 249
 250     /* input was all buffered or compressed */
 251     return put;
 252 }
 253
 254 /* -- see zlib.h -- */
 255 int ZEXPORT gzwrite(file, buf, len)
 256     gzFile file;
 257     voidpc buf;
 258     unsigned len;
 259 {
 260     gz_statep state;
 261
 262     /* get internal structure */
 263     if (file == NULL)
 264         return 0;
 265     state = (gz_statep)file;
 266
 267     /* check that we're writing and that there's no error */
 268     if (state->mode != GZ_WRITE || state->err != Z_OK)
 269         return 0;
 270
 271     /* since an int is returned, make sure len fits in one, otherwise return
 272        with an error (this avoids a flaw in the interface) */
 273     if ((int)len < 0) {
 274         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
 275         return 0;
 276     }
 277
 278     /* write len bytes from buf (the return value will fit in an int) */
 279     return (int)gz_write(state, buf, len);
 280 }
 281
 282 /* -- see zlib.h -- */
 283 z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
 284     voidpc buf;
 285     z_size_t size;
 286     z_size_t nitems;
 287     gzFile file;
 288 {
 289     z_size_t len;
 290     gz_statep state;
 291
 292     /* get internal structure */
 293     if (file == NULL)
 294         return 0;
 295     state = (gz_statep)file;
 296
 297     /* check that we're writing and that there's no error */
 298     if (state->mode != GZ_WRITE || state->err != Z_OK)
 299         return 0;
 300
 301     /* compute bytes to read -- error on overflow */
 302     len = nitems * size;
 303     if (size && len / size != nitems) {
 304         gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
 305         return 0;
 306     }
 307
 308     /* write len bytes to buf, return the number of full items written */
 309     return len ? gz_write(state, buf, len) / size : 0;
 310 }
 311
 312 /* -- see zlib.h -- */
 313 int ZEXPORT gzputc(file, c)
 314     gzFile file;
 315     int c;
 316 {
 317     unsigned have;
 318     unsigned char buf[1];
 319     gz_statep state;
 320     z_streamp strm;
 321
 322     /* get internal structure */
 323     if (file == NULL)
 324         return -1;
 325     state = (gz_statep)file;
 326     strm = &(state->strm);
 327
 328     /* check that we're writing and that there's no error */
 329     if (state->mode != GZ_WRITE || state->err != Z_OK)
 330         return -1;
 331
 332     /* check for seek request */
 333     if (state->seek) {
 334         state->seek = 0;
 335         if (gz_zero(state, state->skip) == -1)
 336             return -1;
 337     }
 338
 339     /* try writing to input buffer for speed (state->size == 0 if buffer not
 340        initialized) */
 341     if (state->size) {
 342         if (strm->avail_in == 0)
 343             strm->next_in = state->in;
 344         have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
 345         if (have < state->size) {
 346             state->in[have] = (unsigned char)c;
 347             strm->avail_in++;
 348             state->x.pos++;
 349             return c & 0xff;
 350         }
 351     }
 352
 353     /* no room in buffer or not initialized, use gz_write() */
 354     buf[0] = (unsigned char)c;
 355     if (gz_write(state, buf, 1) != 1)
 356         return -1;
 357     return c & 0xff;
 358 }
 359
 360 /* -- see zlib.h -- */
 361 int ZEXPORT gzputs(file, s)
 362     gzFile file;
 363     const char *s;
 364 {
 365     z_size_t len, put;
 366     gz_statep state;
 367
 368     /* get internal structure */
 369     if (file == NULL)
 370         return -1;
 371     state = (gz_statep)file;
 372
 373     /* check that we're writing and that there's no error */
 374     if (state->mode != GZ_WRITE || state->err != Z_OK)
 375         return -1;
 376
 377     /* write string */
 378     len = strlen(s);
 379     if ((int)len < 0 || (unsigned)len != len) {
 380         gz_error(state, Z_STREAM_ERROR, "string length does not fit in int");
 381         return -1;
 382     }
 383     put = gz_write(state, s, len);
 384     return put < len ? -1 : (int)len;
 385 }
 386
 387 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
 388 #include <stdarg.h>
 389
 390 /* -- see zlib.h -- */
 391 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
 392 {
 393     int len;
 394     unsigned left;
 395     char *next;
 396     gz_statep state;
 397     z_streamp strm;
 398
 399     /* get internal structure */
 400     if (file == NULL)
 401         return Z_STREAM_ERROR;
 402     state = (gz_statep)file;
 403     strm = &(state->strm);
 404
 405     /* check that we're writing and that there's no error */
 406     if (state->mode != GZ_WRITE || state->err != Z_OK)
 407         return Z_STREAM_ERROR;
 408
 409     /* make sure we have some buffer space */
 410     if (state->size == 0 && gz_init(state) == -1)
 411         return state->err;
 412
 413     /* check for seek request */
 414     if (state->seek) {
 415         state->seek = 0;
 416         if (gz_zero(state, state->skip) == -1)
 417             return state->err;
 418     }
 419
 420     /* do the printf() into the input buffer, put length in len -- the input
 421        buffer is double-sized just for this function, so there is guaranteed to
 422        be state->size bytes available after the current contents */
 423     if (strm->avail_in == 0)
 424         strm->next_in = state->in;
 425     next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
 426     next[state->size - 1] = 0;
 427 #ifdef NO_vsnprintf
 428 #  ifdef HAS_vsprintf_void
 429     (void)vsprintf(next, format, va);
 430     for (len = 0; len < state->size; len++)
 431         if (next[len] == 0) break;
 432 #  else
 433     len = vsprintf(next, format, va);
 434 #  endif
 435 #else
 436 #  ifdef HAS_vsnprintf_void
 437     (void)vsnprintf(next, state->size, format, va);
 438     len = strlen(next);
 439 #  else
 440     len = vsnprintf(next, state->size, format, va);
 441 #  endif
 442 #endif
 443
 444     /* check that printf() results fit in buffer */
 445     if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
 446         return 0;
 447
 448     /* update buffer and position, compress first half if past that */
 449     strm->avail_in += (unsigned)len;
 450     state->x.pos += len;
 451     if (strm->avail_in >= state->size) {
 452         left = strm->avail_in - state->size;
 453         strm->avail_in = state->size;
 454         if (gz_comp(state, Z_NO_FLUSH) == -1)
 455             return state->err;
 456         memmove(state->in, state->in + state->size, left);
 457         strm->next_in = state->in;
 458         strm->avail_in = left;
 459     }
 460     return len;
 461 }
 462
 463 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
 464 {
 465     va_list va;
 466     int ret;
 467
 468     va_start(va, format);
 469     ret = gzvprintf(file, format, va);
 470     va_end(va);
 471     return ret;
 472 }
 473
 474 #else /* !STDC && !Z_HAVE_STDARG_H */
 475
 476 /* -- see zlib.h -- */
 477 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 478                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
 479     gzFile file;
 480     const char *format;
 481     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
 482         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
 483 {
 484     unsigned len, left;
 485     char *next;
 486     gz_statep state;
 487     z_streamp strm;
 488
 489     /* get internal structure */
 490     if (file == NULL)
 491         return Z_STREAM_ERROR;
 492     state = (gz_statep)file;
 493     strm = &(state->strm);
 494
 495     /* check that can really pass pointer in ints */
 496     if (sizeof(int) != sizeof(void *))
 497         return Z_STREAM_ERROR;
 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     /* make sure we have some buffer space */
 504     if (state->size == 0 && gz_init(state) == -1)
 505         return state->error;
 506
 507     /* check for seek request */
 508     if (state->seek) {
 509         state->seek = 0;
 510         if (gz_zero(state, state->skip) == -1)
 511             return state->error;
 512     }
 513
 514     /* do the printf() into the input buffer, put length in len -- the input
 515        buffer is double-sized just for this function, so there is guaranteed to
 516        be state->size bytes available after the current contents */
 517     if (strm->avail_in == 0)
 518         strm->next_in = state->in;
 519     next = (char *)(strm->next_in + strm->avail_in);
 520     next[state->size - 1] = 0;
 521 #ifdef NO_snprintf
 522 #  ifdef HAS_sprintf_void
 523     sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
 524             a13, a14, a15, a16, a17, a18, a19, a20);
 525     for (len = 0; len < size; len++)
 526         if (next[len] == 0)
 527             break;
 528 #  else
 529     len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
 530                   a12, a13, a14, a15, a16, a17, a18, a19, a20);
 531 #  endif
 532 #else
 533 #  ifdef HAS_snprintf_void
 534     snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
 535              a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 536     len = strlen(next);
 537 #  else
 538     len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
 539                    a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
 540 #  endif
 541 #endif
 542
 543     /* check that printf() results fit in buffer */
 544     if (len == 0 || len >= state->size || next[state->size - 1] != 0)
 545         return 0;
 546
 547     /* update buffer and position, compress first half if past that */
 548     strm->avail_in += len;
 549     state->x.pos += len;
 550     if (strm->avail_in >= state->size) {
 551         left = strm->avail_in - state->size;
 552         strm->avail_in = state->size;
 553         if (gz_comp(state, Z_NO_FLUSH) == -1)
 554             return state->err;
 555         memmove(state->in, state->in + state->size, left);
 556         strm->next_in = state->in;
 557         strm->avail_in = left;
 558     }
 559     return (int)len;
 560 }
 561
 562 #endif
 563
 564 /* -- see zlib.h -- */
 565 int ZEXPORT gzflush(file, flush)
 566     gzFile file;
 567     int flush;
 568 {
 569     gz_statep state;
 570
 571     /* get internal structure */
 572     if (file == NULL)
 573         return Z_STREAM_ERROR;
 574     state = (gz_statep)file;
 575
 576     /* check that we're writing and that there's no error */
 577     if (state->mode != GZ_WRITE || state->err != Z_OK)
 578         return Z_STREAM_ERROR;
 579
 580     /* check flush parameter */
 581     if (flush < 0 || flush > Z_FINISH)
 582         return Z_STREAM_ERROR;
 583
 584     /* check for seek request */
 585     if (state->seek) {
 586         state->seek = 0;
 587         if (gz_zero(state, state->skip) == -1)
 588             return state->err;
 589     }
 590
 591     /* compress remaining data with requested flush */
 592     (void)gz_comp(state, flush);
 593     return state->err;
 594 }
 595
 596 /* -- see zlib.h -- */
 597 int ZEXPORT gzsetparams(file, level, strategy)
 598     gzFile file;
 599     int level;
 600     int strategy;
 601 {
 602     gz_statep state;
 603     z_streamp strm;
 604
 605     /* get internal structure */
 606     if (file == NULL)
 607         return Z_STREAM_ERROR;
 608     state = (gz_statep)file;
 609     strm = &(state->strm);
 610
 611     /* check that we're writing and that there's no error */
 612     if (state->mode != GZ_WRITE || state->err != Z_OK)
 613         return Z_STREAM_ERROR;
 614
 615     /* if no change is requested, then do nothing */
 616     if (level == state->level && strategy == state->strategy)
 617         return Z_OK;
 618
 619     /* check for seek request */
 620     if (state->seek) {
 621         state->seek = 0;
 622         if (gz_zero(state, state->skip) == -1)
 623             return state->err;
 624     }
 625
 626     /* change compression parameters for subsequent input */
 627     if (state->size) {
 628         /* flush previous input with previous parameters before changing */
 629         if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
 630             return state->err;
 631         deflateParams(strm, level, strategy);
 632     }
 633     state->level = level;
 634     state->strategy = strategy;
 635     return Z_OK;
 636 }
 637
 638 /* -- see zlib.h -- */
 639 int ZEXPORT gzclose_w(file)
 640     gzFile file;
 641 {
 642     int ret = Z_OK;
 643     gz_statep state;
 644
 645     /* get internal structure */
 646     if (file == NULL)
 647         return Z_STREAM_ERROR;
 648     state = (gz_statep)file;
 649
 650     /* check that we're writing */
 651     if (state->mode != GZ_WRITE)
 652         return Z_STREAM_ERROR;
 653
 654     /* check for seek request */
 655     if (state->seek) {
 656         state->seek = 0;
 657         if (gz_zero(state, state->skip) == -1)
 658             ret = state->err;
 659     }
 660
 661     /* flush, free memory, and close file */
 662     if (gz_comp(state, Z_FINISH) == -1)
 663         ret = state->err;
 664     if (state->size) {
 665         if (!state->direct) {
 666             (void)deflateEnd(&(state->strm));
 667             free(state->out);
 668         }
 669         free(state->in);
 670     }
 671     gz_error(state, Z_OK, NULL);
 672     free(state->path);
 673     if (close(state->fd) == -1)
 674         ret = Z_ERRNO;
 675     free(state);
 676     return ret;
 677 }