1 /* 2 * This file is derived from zlib.h and zconf.h from the zlib-1.2.3 3 * distribution by Jean-loup Gailly and Mark Adler, with some additions 4 * by Paul Mackerras to aid in implementing Deflate compression and 5 * decompression for PPP packets. 6 */ 7 8 /* 9 * ==FILEVERSION 960122== 10 * 11 * This marker is used by the Linux installation script to determine 12 * whether an up-to-date version of this file is already installed. 13 */ 14 15 /* zlib.h -- interface of the 'zlib' general purpose compression library 16 version 1.2.3, July 18th, 2005 17 18 Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler 19 20 This software is provided 'as-is', without any express or implied 21 warranty. In no event will the authors be held liable for any damages 22 arising from the use of this software. 23 24 Permission is granted to anyone to use this software for any purpose, 25 including commercial applications, and to alter it and redistribute it 26 freely, subject to the following restrictions: 27 28 1. The origin of this software must not be misrepresented; you must not 29 claim that you wrote the original software. If you use this software 30 in a product, an acknowledgment in the product documentation would be 31 appreciated but is not required. 32 2. Altered source versions must be plainly marked as such, and must not be 33 misrepresented as being the original software. 34 3. This notice may not be removed or altered from any source distribution. 35 36 Jean-loup Gailly Mark Adler 37 jloup@gzip.org madler@alumni.caltech.edu 38 39 The data format used by the zlib library is described by RFCs (Request for 40 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt 41 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 42 */ 43 44 #ifndef ZLIB_H 45 #define ZLIB_H 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 /* #include "zconf.h" */ /* included directly here */ 52 /* zconf.h -- configuration of the zlib compression library 53 * Copyright (C) 1995-2005 Jean-loup Gailly. 54 * For conditions of distribution and use, see copyright notice in zlib.h 55 */ 56 57 /* Begin of new zconf.h */ 58 /* 59 * If you *really* need a unique prefix for all types and library functions, 60 * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it. 61 */ 62 #ifdef Z_PREFIX 63 # define deflateInit_ z_deflateInit_ 64 # define deflate z_deflate 65 # define deflateEnd z_deflateEnd 66 # define inflateInit_ z_inflateInit_ 67 # define inflate z_inflate 68 # define inflateEnd z_inflateEnd 69 # define deflateInit2_ z_deflateInit2_ 70 # define deflateSetDictionary z_deflateSetDictionary 71 # define deflateCopy z_deflateCopy 72 # define deflateReset z_deflateReset 73 # define deflateParams z_deflateParams 74 # define deflateBound z_deflateBound 75 # define deflatePrime z_deflatePrime 76 # define inflateInit2_ z_inflateInit2_ 77 # define inflateSetDictionary z_inflateSetDictionary 78 # define inflateSync z_inflateSync 79 # define inflateSyncPoint z_inflateSyncPoint 80 # define inflateCopy z_inflateCopy 81 # define inflateReset z_inflateReset 82 # define inflateBack z_inflateBack 83 # define inflateBackEnd z_inflateBackEnd 84 # define compress z_compress 85 # define compress2 z_compress2 86 # define compressBound z_compressBound 87 # define uncompress z_uncompress 88 # define adler32 z_adler32 89 # define crc32 z_crc32 90 # define get_crc_table z_get_crc_table 91 # define zError z_zError 92 93 # define alloc_func z_alloc_func 94 # define free_func z_free_func 95 # define in_func z_in_func 96 # define out_func z_out_func 97 # define Byte z_Byte 98 # define uInt z_uInt 99 # define uLong z_uLong 100 # define Bytef z_Bytef 101 # define charf z_charf 102 # define intf z_intf 103 # define uIntf z_uIntf 104 # define uLongf z_uLongf 105 # define voidpf z_voidpf 106 # define voidp z_voidp 107 #endif 108 109 #if defined(ZLIB_CONST) && !defined(z_const) 110 # define z_const const 111 #else 112 # define z_const 113 #endif 114 115 #if defined(__MSDOS__) && !defined(MSDOS) 116 # define MSDOS 117 #endif 118 #if (defined(OS_2) || defined(__OS2__)) && !defined(OS2) 119 # define OS2 120 #endif 121 #if defined(_WINDOWS) && !defined(WINDOWS) 122 # define WINDOWS 123 #endif 124 #if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__) 125 # ifndef WIN32 126 # define WIN32 127 # endif 128 #endif 129 #if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32) 130 # if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__) 131 # ifndef SYS16BIT 132 # define SYS16BIT 133 # endif 134 # endif 135 #endif 136 137 /* 138 * Compile with -DMAXSEG_64K if the alloc function cannot allocate more 139 * than 64k bytes at a time (needed on systems with 16-bit int). 140 */ 141 #ifdef SYS16BIT 142 # define MAXSEG_64K 143 #endif 144 #ifdef MSDOS 145 # define UNALIGNED_OK 146 #endif 147 148 #ifdef __STDC_VERSION__ 149 # ifndef STDC 150 # define STDC 151 # endif 152 # if __STDC_VERSION__ >= 199901L 153 # ifndef STDC99 154 # define STDC99 155 # endif 156 # endif 157 #endif 158 #if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus)) 159 # define STDC 160 #endif 161 #if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__)) 162 # define STDC 163 #endif 164 #if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32)) 165 # define STDC 166 #endif 167 #if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__)) 168 # define STDC 169 #endif 170 171 #if defined(__OS400__) && !defined(STDC) /* iSeries (formerly AS/400). */ 172 # define STDC 173 #endif 174 175 #ifndef STDC 176 # ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */ 177 # define const /* note: need a more gentle solution here */ 178 # endif 179 #endif 180 181 /* Some Mac compilers merge all .h files incorrectly: */ 182 #if defined(__MWERKS__)||defined(applec)||defined(THINK_C)||defined(__SC__) 183 # define NO_DUMMY_DECL 184 #endif 185 186 /* Maximum value for memLevel in deflateInit2 */ 187 #ifndef MAX_MEM_LEVEL 188 # ifdef MAXSEG_64K 189 # define MAX_MEM_LEVEL 8 190 # else 191 # define MAX_MEM_LEVEL 9 192 # endif 193 #endif 194 195 /* Maximum value for windowBits in deflateInit2 and inflateInit2. 196 * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files 197 * created by gzip. (Files created by minigzip can still be extracted by 198 * gzip.) 199 */ 200 #ifndef MAX_WBITS 201 # define MAX_WBITS 15 /* 32K LZ77 window */ 202 #endif 203 204 /* The memory requirements for deflate are (in bytes): 205 (1 << (windowBits+2)) + (1 << (memLevel+9)) 206 that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) 207 plus a few kilobytes for small objects. For example, if you want to reduce 208 the default memory requirements from 256K to 128K, compile with 209 make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" 210 Of course this will generally degrade compression (there's no free lunch). 211 212 The memory requirements for inflate are (in bytes) 1 << windowBits 213 that is, 32K for windowBits=15 (default value) plus a few kilobytes 214 for small objects. 215 */ 216 217 /* Type declarations */ 218 219 #ifndef OF /* function prototypes */ 220 # ifdef STDC 221 # define OF(args) args 222 # else 223 # define OF(args) () 224 # endif 225 #endif 226 227 /* The following definitions for FAR are needed only for MSDOS mixed 228 * model programming (small or medium model with some far allocations). 229 * This was tested only with MSC; for other MSDOS compilers you may have 230 * to define NO_MEMCPY in zutil.h. If you don't need the mixed model, 231 * just define FAR to be empty. 232 */ 233 #ifdef SYS16BIT 234 # if defined(M_I86SM) || defined(M_I86MM) 235 /* MSC small or medium model */ 236 # define SMALL_MEDIUM 237 # ifdef _MSC_VER 238 # define FAR _far 239 # else 240 # define FAR far 241 # endif 242 # endif 243 # if (defined(__SMALL__) || defined(__MEDIUM__)) 244 /* Turbo C small or medium model */ 245 # define SMALL_MEDIUM 246 # ifdef __BORLANDC__ 247 # define FAR _far 248 # else 249 # define FAR far 250 # endif 251 # endif 252 #endif 253 254 #if defined(WINDOWS) || defined(WIN32) 255 /* If building or using zlib as a DLL, define ZLIB_DLL. 256 * This is not mandatory, but it offers a little performance increase. 257 */ 258 # ifdef ZLIB_DLL 259 # if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500)) 260 # ifdef ZLIB_INTERNAL 261 # define ZEXTERN extern __declspec(dllexport) 262 # else 263 # define ZEXTERN extern __declspec(dllimport) 264 # endif 265 # endif 266 # endif /* ZLIB_DLL */ 267 /* If building or using zlib with the WINAPI/WINAPIV calling convention, 268 * define ZLIB_WINAPI. 269 * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI. 270 */ 271 # ifdef ZLIB_WINAPI 272 # ifdef FAR 273 # undef FAR 274 # endif 275 # include <windows.h> 276 /* No need for _export, use ZLIB.DEF instead. */ 277 /* For complete Windows compatibility, use WINAPI, not __stdcall. */ 278 # define ZEXPORT WINAPI 279 # ifdef WIN32 280 # define ZEXPORTVA WINAPIV 281 # else 282 # define ZEXPORTVA FAR CDECL 283 # endif 284 # endif 285 #endif 286 287 #if defined (__BEOS__) 288 # ifdef ZLIB_DLL 289 # ifdef ZLIB_INTERNAL 290 # define ZEXPORT __declspec(dllexport) 291 # define ZEXPORTVA __declspec(dllexport) 292 # else 293 # define ZEXPORT __declspec(dllimport) 294 # define ZEXPORTVA __declspec(dllimport) 295 # endif 296 # endif 297 #endif 298 299 #ifndef ZEXTERN 300 # define ZEXTERN extern 301 #endif 302 #ifndef ZEXPORT 303 # define ZEXPORT 304 #endif 305 #ifndef ZEXPORTVA 306 # define ZEXPORTVA 307 #endif 308 309 #ifndef FAR 310 # define FAR 311 #endif 312 313 #if !defined(__MACTYPES__) 314 typedef unsigned char Byte; /* 8 bits */ 315 #endif 316 typedef unsigned int uInt; /* 16 bits or more */ 317 typedef unsigned long uLong; /* 32 bits or more */ 318 319 #ifdef SMALL_MEDIUM 320 /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */ 321 # define Bytef Byte FAR 322 #else 323 typedef Byte FAR Bytef; 324 #endif 325 typedef char FAR charf; 326 typedef int FAR intf; 327 typedef uInt FAR uIntf; 328 typedef uLong FAR uLongf; 329 330 #ifdef STDC 331 typedef void const *voidpc; 332 typedef void FAR *voidpf; 333 typedef void *voidp; 334 #else 335 typedef Byte const *voidpc; 336 typedef Byte FAR *voidpf; 337 typedef Byte *voidp; 338 #endif 339 340 # ifdef VMS 341 # include <unixio.h> /* for off_t */ 342 # endif 343 # define z_off_t off_t 344 #ifndef SEEK_SET 345 # define SEEK_SET 0 /* Seek from beginning of file. */ 346 # define SEEK_CUR 1 /* Seek from current position. */ 347 # define SEEK_END 2 /* Set file pointer to EOF plus "offset" */ 348 #endif 349 #ifndef z_off_t 350 # define z_off_t long 351 #endif 352 353 #if defined(__OS400__) 354 # define NO_vsnprintf 355 #endif 356 357 #if defined(__MVS__) 358 # define NO_vsnprintf 359 # ifdef FAR 360 # undef FAR 361 # endif 362 #endif 363 364 /* MVS linker does not support external names larger than 8 bytes */ 365 #if defined(__MVS__) 366 # pragma map(deflateInit_,"DEIN") 367 # pragma map(deflateInit2_,"DEIN2") 368 # pragma map(deflateEnd,"DEEND") 369 # pragma map(deflateBound,"DEBND") 370 # pragma map(inflateInit_,"ININ") 371 # pragma map(inflateInit2_,"ININ2") 372 # pragma map(inflateEnd,"INEND") 373 # pragma map(inflateSync,"INSY") 374 # pragma map(inflateSetDictionary,"INSEDI") 375 # pragma map(compressBound,"CMBND") 376 # pragma map(inflate_table,"INTABL") 377 # pragma map(inflate_fast,"INFA") 378 # pragma map(inflate_copyright,"INCOPY") 379 #endif 380 /* End of new zconf.h */ 381 382 /* 383 The 'zlib' compression library provides in-memory compression and 384 decompression functions, including integrity checks of the uncompressed 385 data. This version of the library supports only one compression method 386 (deflation) but other algorithms will be added later and will have the same 387 stream interface. 388 389 Compression can be done in a single step if the buffers are large 390 enough (for example if an input file is mmap'ed), or can be done by 391 repeated calls of the compression function. In the latter case, the 392 application must provide more input and/or consume the output 393 (providing more output space) before each call. 394 395 The compressed data format used by default by the in-memory functions is 396 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 397 around a deflate stream, which is itself documented in RFC 1951. 398 399 The library also supports reading and writing files in gzip (.gz) format 400 with an interface similar to that of stdio using the functions that start 401 with "gz". The gzip format is different from the zlib format. gzip is a 402 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 403 404 This library can optionally read and write gzip streams in memory as well. 405 406 The zlib format was designed to be compact and fast for use in memory 407 and on communications channels. The gzip format was designed for single- 408 file compression on file systems, has a larger header than zlib to maintain 409 directory information, and uses a different, slower check method than zlib. 410 411 The library does not install any signal handler. The decoder checks 412 the consistency of the compressed data, so the library should never 413 crash even in case of corrupted input. 414 */ 415 416 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 417 typedef void (*free_func) OF((voidpf opaque, voidpf address, uInt size)); 418 typedef void (*cb_func) OF((Bytef *buf, uInt len)); 419 420 struct internal_state; 421 422 typedef struct z_stream_s { 423 Bytef *next_in; /* next input byte */ 424 uInt avail_in; /* number of bytes available at next_in */ 425 uLong total_in; /* total nb of input bytes read so far */ 426 Bytef *next_out; /* next output byte should be put there */ 427 uInt avail_out; /* remaining free space at next_out */ 428 uLong total_out; /* total nb of bytes output so far */ 429 char *msg; /* last error message, NULL if no error */ 430 struct internal_state FAR *state; /* not visible by applications */ 431 alloc_func zalloc; /* used to allocate the internal state */ 432 free_func zfree; /* used to free the internal state */ 433 voidpf opaque; /* private data object passed to zalloc and zfree */ 434 int data_type; /* best guess about the data type: 435 binary or text */ 436 cb_func outcb; /* called regularly just before blocks of output */ 437 uLong adler; /* adler32 value of the uncompressed data */ 438 uLong reserved; /* reserved for future use */ 439 } z_stream; 440 441 typedef z_stream FAR *z_streamp; 442 443 /* 444 gzip header information passed to and from zlib routines. See RFC 1952 445 for more details on the meanings of these fields. 446 */ 447 typedef struct gz_header_s { 448 int text; /* true if compressed data believed to be text */ 449 uLong time; /* modification time */ 450 int xflags; /* extra flags (not used when writing a gzip file) */ 451 int os; /* operating system */ 452 Bytef *extra; /* pointer to extra field or Z_NULL if none */ 453 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ 454 uInt extra_max; /* space at extra (only when reading header) */ 455 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ 456 uInt name_max; /* space at name (only when reading header) */ 457 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ 458 uInt comm_max; /* space at comment (only when reading header) */ 459 int hcrc; /* true if there was or will be a header crc */ 460 int done; /* true when done reading gzip header (not used 461 when writing a gzip file) */ 462 } gz_header; 463 464 typedef gz_header FAR *gz_headerp; 465 466 /* constants */ 467 #define Z_NO_FLUSH 0 468 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ 469 #define Z_SYNC_FLUSH 2 470 #define Z_FULL_FLUSH 3 471 #define Z_FINISH 4 472 #define Z_BLOCK 5 473 /* Allowed flush values; see deflate() and inflate() below for details */ 474 475 #define Z_OK 0 476 #define Z_STREAM_END 1 477 #define Z_NEED_DICT 2 478 #define Z_ERRNO (-1) 479 #define Z_STREAM_ERROR (-2) 480 #define Z_DATA_ERROR (-3) 481 #define Z_MEM_ERROR (-4) 482 #define Z_BUF_ERROR (-5) 483 /* Return codes for the compression/decompression functions. Negative 484 * values are errors, positive values are used for special but normal events. 485 */ 486 487 #define Z_NO_COMPRESSION 0 488 #define Z_BEST_SPEED 1 489 #define Z_BEST_COMPRESSION 9 490 #define Z_DEFAULT_COMPRESSION (-1) 491 /* compression levels */ 492 493 #define Z_FILTERED 1 494 #define Z_HUFFMAN_ONLY 2 495 #define Z_RLE 3 496 #define Z_FIXED 4 497 #define Z_DEFAULT_STRATEGY 0 498 /* compression strategy; see deflateInit2() below for details */ 499 500 #define Z_BINARY 0 501 #define Z_TEXT 1 502 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 503 #define Z_UNKNOWN 2 504 /* Possible values of the data_type field (though see inflate()) */ 505 506 #define Z_DEFLATED 8 507 /* The deflate compression method (the only one supported in this version) */ 508 509 #define Z_NULL (void *)0 /* for initializing zalloc, zfree, opaque */ 510 511 /* basic functions */ 512 513 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 514 If the first character differs, the library code actually used is 515 not compatible with the zlib.h header file used by the application. 516 This check is automatically made by deflateInit and inflateInit. 517 */ 518 519 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 520 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 521 int stream_size)); 522 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 523 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 524 int windowBits, int memLevel, 525 int strategy, 526 int stream_size)); 527 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 528 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 529 const Bytef *dictionary, 530 uInt dictLength)); 531 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 532 gz_headerp head)); 533 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 534 int bits, 535 int value)); 536 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 537 int level, 538 int strategy)); 539 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, 540 int good_length, 541 int max_lazy, 542 int nice_length, 543 int max_chain)); 544 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 545 uLong sourceLen)); 546 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 547 z_streamp source)); 548 549 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 550 int stream_size)); 551 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 552 /* 553 inflate decompresses as much data as possible, and stops when the input 554 buffer becomes empty or the output buffer becomes full. It may introduce 555 some output latency (reading input without producing any output) except when 556 forced to flush. 557 558 The detailed semantics are as follows. inflate performs one or both of the 559 following actions: 560 561 - Decompress more input starting at next_in and update next_in and avail_in 562 accordingly. If not all input can be processed (because there is not 563 enough room in the output buffer), next_in is updated and processing 564 will resume at this point for the next call of inflate(). 565 566 - Provide more output starting at next_out and update next_out and avail_out 567 accordingly. inflate() provides as much output as possible, until there 568 is no more input data or no more space in the output buffer (see below 569 about the flush parameter). 570 571 Before the call of inflate(), the application should ensure that at least 572 one of the actions is possible, by providing more input and/or consuming 573 more output, and updating the next_* and avail_* values accordingly. 574 The application can consume the uncompressed output when it wants, for 575 example when the output buffer is full (avail_out == 0), or after each 576 call of inflate(). If inflate returns Z_OK and with zero avail_out, it 577 must be called again after making room in the output buffer because there 578 might be more output pending. 579 580 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, 581 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much 582 output as possible to the output buffer. Z_BLOCK requests that inflate() stop 583 if and when it gets to the next deflate block boundary. When decoding the 584 zlib or gzip format, this will cause inflate() to return immediately after 585 the header and before the first block. When doing a raw inflate, inflate() 586 will go ahead and process the first block, and will return when it gets to 587 the end of that block, or when it runs out of data. 588 589 The Z_BLOCK option assists in appending to or combining deflate streams. 590 Also to assist in this, on return inflate() will set strm->data_type to the 591 number of unused bits in the last byte taken from strm->next_in, plus 64 592 if inflate() is currently decoding the last block in the deflate stream, 593 plus 128 if inflate() returned immediately after decoding an end-of-block 594 code or decoding the complete header up to just before the first byte of the 595 deflate stream. The end-of-block will not be indicated until all of the 596 uncompressed data from that block has been written to strm->next_out. The 597 number of unused bits may in general be greater than seven, except when 598 bit 7 of data_type is set, in which case the number of unused bits will be 599 less than eight. 600 601 inflate() should normally be called until it returns Z_STREAM_END or an 602 error. However if all decompression is to be performed in a single step 603 (a single call of inflate), the parameter flush should be set to 604 Z_FINISH. In this case all pending input is processed and all pending 605 output is flushed; avail_out must be large enough to hold all the 606 uncompressed data. (The size of the uncompressed data may have been saved 607 by the compressor for this purpose.) The next operation on this stream must 608 be inflateEnd to deallocate the decompression state. The use of Z_FINISH 609 is never required, but can be used to inform inflate that a faster approach 610 may be used for the single inflate() call. 611 612 In this implementation, inflate() always flushes as much output as 613 possible to the output buffer, and always uses the faster approach on the 614 first call. So the only effect of the flush parameter in this implementation 615 is on the return value of inflate(), as noted below, or when it returns early 616 because Z_BLOCK is used. 617 618 If a preset dictionary is needed after this call (see inflateSetDictionary 619 below), inflate sets strm->adler to the adler32 checksum of the dictionary 620 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 621 strm->adler to the adler32 checksum of all output produced so far (that is, 622 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 623 below. At the end of the stream, inflate() checks that its computed adler32 624 checksum is equal to that saved by the compressor and returns Z_STREAM_END 625 only if the checksum is correct. 626 627 inflate() will decompress and check either zlib-wrapped or gzip-wrapped 628 deflate data. The header type is detected automatically. Any information 629 contained in the gzip header is not retained, so applications that need that 630 information should instead use raw inflate, see inflateInit2() below, or 631 inflateBack() and perform their own processing of the gzip header and 632 trailer. 633 634 inflate() returns Z_OK if some progress has been made (more input processed 635 or more output produced), Z_STREAM_END if the end of the compressed data has 636 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 637 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 638 corrupted (input stream not conforming to the zlib format or incorrect check 639 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 640 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, 641 Z_BUF_ERROR if no progress is possible or if there was not enough room in the 642 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 643 inflate() can be called again with more input and more output space to 644 continue decompressing. If Z_DATA_ERROR is returned, the application may then 645 call inflateSync() to look for a good compression block if a partial recovery 646 of the data is desired. 647 */ 648 649 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 650 /* 651 All dynamically allocated data structures for this stream are freed. 652 This function discards any unprocessed input and does not flush any 653 pending output. 654 655 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 656 was inconsistent. In the error case, msg may be set but then points to a 657 static string (which must not be deallocated). 658 */ 659 660 /* Advanced functions */ 661 662 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 663 664 /* utility functions */ 665 666 /* 667 The following utility functions are implemented on top of the 668 basic stream-oriented functions. To simplify the interface, some 669 default options are assumed (compression level and memory usage, 670 standard memory allocation functions). The source code of these 671 utility functions can easily be modified if you need special options. 672 */ 673 674 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 675 /* 676 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 677 return the updated checksum. If buf is NULL, this function returns 678 the required initial value for the checksum. 679 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 680 much faster. Usage example: 681 682 uLong adler = adler32(0L, Z_NULL, 0); 683 684 while (read_buffer(buffer, length) != EOF) { 685 adler = adler32(adler, buffer, length); 686 } 687 if (adler != original_adler) error(); 688 */ 689 690 /* 691 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 692 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 693 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 694 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. 695 */ 696 697 ZEXTERN uInt ZEXPORT crc32 OF((uInt crc, const Bytef *buf, uInt len)); 698 /* 699 Update a running CRC-32 with the bytes buf[0..len-1] and return the 700 updated CRC-32. If buf is NULL, this function returns the required initial 701 value for the for the crc. Pre- and post-conditioning (one's complement) is 702 performed within this function so it shouldn't be done by the application. 703 Usage example: 704 705 uLong crc = crc32(0L, Z_NULL, 0); 706 707 while (read_buffer(buffer, length) != EOF) { 708 crc = crc32(crc, buffer, length); 709 } 710 if (crc != original_crc) error(); 711 */ 712 713 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 714 const Bytef *source, uLong sourceLen)); 715 /* 716 Decompresses the source buffer into the destination buffer. sourceLen is 717 the byte length of the source buffer. Upon entry, destLen is the total size 718 of the destination buffer, which must be large enough to hold the entire 719 uncompressed data. (The size of the uncompressed data must have been saved 720 previously by the compressor and transmitted to the decompressor by some 721 mechanism outside the scope of this compression library.) Upon exit, destLen 722 is the actual size of the uncompressed data. 723 724 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 725 enough memory, Z_BUF_ERROR if there was not enough room in the output 726 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In 727 the case where there is not enough room, uncompress() will fill the output 728 buffer with the uncompressed data up to that point. 729 */ 730 731 ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen, 732 const Bytef *source, uLong *sourceLen)); 733 /* 734 Same as uncompress, except that sourceLen is a pointer, where the 735 length of the source is *sourceLen. On return, *sourceLen is the number of 736 source bytes consumed. 737 */ 738 739 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 740 int stream_size)); 741 #define inflateInit(strm) \ 742 inflateInit_((strm), sizeof(z_stream)) 743 #define inflateInit2(strm, windowBits) \ 744 inflateInit2_((strm), (windowBits), sizeof(z_stream)) 745 746 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) 747 struct internal_state {int dummy;}; /* hack for buggy compilers */ 748 #endif 749 750 extern void *gzalloc(void *, unsigned, unsigned); 751 extern void gzfree(void *, void *, unsigned); 752 753 #ifdef __cplusplus 754 } 755 #endif 756 757 #endif /* ZLIB_H */ 758