common/zlib.h

   1 /*      $Id: zlib.h,v 1.7 1997/11/27 06:03:33 paulus Exp $      */
   2
   3 /*
   4  * This file is derived from zlib.h and zconf.h from the zlib-1.0.4
   5  * distribution by Jean-loup Gailly and Mark Adler, with some additions
   6  * by Paul Mackerras to aid in implementing Deflate compression and
   7  * decompression for PPP packets.
   8  */
   9
  10 /*
  11  *  ==FILEVERSION 971127==
  12  *
  13  * This marker is used by the Linux installation script to determine
  14  * whether an up-to-date version of this file is already installed.
  15  */
  16
  17
  18 /* +++ zlib.h */
  19 /* zlib.h -- interface of the 'zlib' general purpose compression library
  20   version 1.0.4, Jul 24th, 1996.
  21
  22   Copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler
  23
  24   This software is provided 'as-is', without any express or implied
  25   warranty.  In no event will the authors be held liable for any damages
  26   arising from the use of this software.
  27
  28   Permission is granted to anyone to use this software for any purpose,
  29   including commercial applications, and to alter it and redistribute it
  30   freely, subject to the following restrictions:
  31
  32   1. The origin of this software must not be misrepresented; you must not
  33      claim that you wrote the original software. If you use this software
  34      in a product, an acknowledgment in the product documentation would be
  35      appreciated but is not required.
  36   2. Altered source versions must be plainly marked as such, and must not be
  37      misrepresented as being the original software.
  38   3. This notice may not be removed or altered from any source distribution.
  39
  40   Jean-loup Gailly        Mark Adler
  41   gzip@prep.ai.mit.edu    madler@alumni.caltech.edu
  42
  43
  44   The data format used by the zlib library is described by RFCs (Request for
  45   Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
  46   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
  47 */
  48
  49 #ifndef _ZLIB_H
  50 #define _ZLIB_H
  51
  52 #ifdef __cplusplus
  53 extern "C" {
  54 #endif
  55
  56
  57 /* +++ zconf.h */
  58 /* zconf.h -- configuration of the zlib compression library
  59  * Copyright (C) 1995-1996 Jean-loup Gailly.
  60  * For conditions of distribution and use, see copyright notice in zlib.h
  61  */
  62
  63 /* From: zconf.h,v 1.20 1996/07/02 15:09:28 me Exp $ */
  64
  65 #ifndef _ZCONF_H
  66 #define _ZCONF_H
  67
  68 /*
  69  * If you *really* need a unique prefix for all types and library functions,
  70  * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
  71  */
  72 #ifdef Z_PREFIX
  73 #  define deflateInit_  z_deflateInit_
  74 #  define deflate       z_deflate
  75 #  define deflateEnd    z_deflateEnd
  76 #  define inflateInit_  z_inflateInit_
  77 #  define inflate       z_inflate
  78 #  define inflateEnd    z_inflateEnd
  79 #  define deflateInit2_ z_deflateInit2_
  80 #  define deflateSetDictionary z_deflateSetDictionary
  81 #  define deflateCopy   z_deflateCopy
  82 #  define deflateReset  z_deflateReset
  83 #  define deflateParams z_deflateParams
  84 #  define inflateInit2_ z_inflateInit2_
  85 #  define inflateSetDictionary z_inflateSetDictionary
  86 #  define inflateSync   z_inflateSync
  87 #  define inflateReset  z_inflateReset
  88 #  define compress      z_compress
  89 #  define uncompress    z_uncompress
  90 #  define adler32       z_adler32
  91 #  define crc32         z_crc32
  92 #  define get_crc_table z_get_crc_table
  93
  94 #  define Byte          z_Byte
  95 #  define uInt          z_uInt
  96 #  define uLong         z_uLong
  97 #  define Bytef         z_Bytef
  98 #  define charf         z_charf
  99 #  define intf          z_intf
 100 #  define uIntf         z_uIntf
 101 #  define uLongf        z_uLongf
 102 #  define voidpf        z_voidpf
 103 #  define voidp         z_voidp
 104 #endif
 105
 106 #if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32)
 107 #  define WIN32
 108 #endif
 109 #if defined(__GNUC__) || defined(WIN32) || defined(__386__) || defined(i386)
 110 #  ifndef __32BIT__
 111 #    define __32BIT__
 112 #  endif
 113 #endif
 114 #if defined(__MSDOS__) && !defined(MSDOS)
 115 #  define MSDOS
 116 #endif
 117
 118 /*
 119  * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
 120  * than 64k bytes at a time (needed on systems with 16-bit int).
 121  */
 122 #if defined(MSDOS) && !defined(__32BIT__)
 123 #  define MAXSEG_64K
 124 #endif
 125 #ifdef MSDOS
 126 #  define UNALIGNED_OK
 127 #endif
 128
 129 #if (defined(MSDOS) || defined(_WINDOWS) || defined(WIN32))  && !defined(STDC)
 130 #  define STDC
 131 #endif
 132 #if (defined(__STDC__) || defined(__cplusplus)) && !defined(STDC)
 133 #  define STDC
 134 #endif
 135
 136 #ifndef STDC
 137 #  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
 138 #    define const
 139 #  endif
 140 #endif
 141
 142 /* Some Mac compilers merge all .h files incorrectly: */
 143 #if defined(__MWERKS__) || defined(applec) ||defined(THINK_C) ||defined(__SC__)
 144 #  define NO_DUMMY_DECL
 145 #endif
 146
 147 /* Maximum value for memLevel in deflateInit2 */
 148 #ifndef MAX_MEM_LEVEL
 149 #  ifdef MAXSEG_64K
 150 #    define MAX_MEM_LEVEL 8
 151 #  else
 152 #    define MAX_MEM_LEVEL 9
 153 #  endif
 154 #endif
 155
 156 /* Maximum value for windowBits in deflateInit2 and inflateInit2 */
 157 #ifndef MAX_WBITS
 158 #  define MAX_WBITS   15 /* 32K LZ77 window */
 159 #endif
 160
 161 /* The memory requirements for deflate are (in bytes):
 162             1 << (windowBits+2)   +  1 << (memLevel+9)
 163  that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
 164  plus a few kilobytes for small objects. For example, if you want to reduce
 165  the default memory requirements from 256K to 128K, compile with
 166      make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
 167  Of course this will generally degrade compression (there's no free lunch).
 168
 169    The memory requirements for inflate are (in bytes) 1 << windowBits
 170  that is, 32K for windowBits=15 (default value) plus a few kilobytes
 171  for small objects.
 172 */
 173
 174                         /* Type declarations */
 175
 176 #ifndef OF /* function prototypes */
 177 #  ifdef STDC
 178 #    define OF(args)  args
 179 #  else
 180 #    define OF(args)  ()
 181 #  endif
 182 #endif
 183
 184 /* The following definitions for FAR are needed only for MSDOS mixed
 185  * model programming (small or medium model with some far allocations).
 186  * This was tested only with MSC; for other MSDOS compilers you may have
 187  * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
 188  * just define FAR to be empty.
 189  */
 190 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(__32BIT__)
 191    /* MSC small or medium model */
 192 #  define SMALL_MEDIUM
 193 #  ifdef _MSC_VER
 194 #    define FAR __far
 195 #  else
 196 #    define FAR far
 197 #  endif
 198 #endif
 199 #if defined(__BORLANDC__) && (defined(__SMALL__) || defined(__MEDIUM__))
 200 #  ifndef __32BIT__
 201 #    define SMALL_MEDIUM
 202 #    define FAR __far
 203 #  endif
 204 #endif
 205 #ifndef FAR
 206 #   define FAR
 207 #endif
 208
 209 typedef unsigned char  Byte;  /* 8 bits */
 210 typedef unsigned int   uInt;  /* 16 bits or more */
 211 typedef unsigned long  uLong; /* 32 bits or more */
 212
 213 #if defined(__BORLANDC__) && defined(SMALL_MEDIUM)
 214    /* Borland C/C++ ignores FAR inside typedef */
 215 #  define Bytef Byte FAR
 216 #else
 217    typedef Byte  FAR Bytef;
 218 #endif
 219 typedef char  FAR charf;
 220 typedef int   FAR intf;
 221 typedef uInt  FAR uIntf;
 222 typedef uLong FAR uLongf;
 223
 224 #ifdef STDC
 225    typedef void FAR *voidpf;
 226    typedef void     *voidp;
 227 #else
 228    typedef Byte FAR *voidpf;
 229    typedef Byte     *voidp;
 230 #endif
 231
 232
 233 /* Compile with -DZLIB_DLL for Windows DLL support */
 234 #if (defined(_WINDOWS) || defined(WINDOWS)) && defined(ZLIB_DLL)
 235 #  include <windows.h>
 236 #  define EXPORT  WINAPI
 237 #else
 238 #  define EXPORT
 239 #endif
 240
 241 #endif /* _ZCONF_H */
 242 /* --- zconf.h */
 243
 244 #define ZLIB_VERSION "1.0.4P"
 245
 246 /*
 247      The 'zlib' compression library provides in-memory compression and
 248   decompression functions, including integrity checks of the uncompressed
 249   data.  This version of the library supports only one compression method
 250   (deflation) but other algorithms may be added later and will have the same
 251   stream interface.
 252
 253      For compression the application must provide the output buffer and
 254   may optionally provide the input buffer for optimization. For decompression,
 255   the application must provide the input buffer and may optionally provide
 256   the output buffer for optimization.
 257
 258      Compression can be done in a single step if the buffers are large
 259   enough (for example if an input file is mmap'ed), or can be done by
 260   repeated calls of the compression function.  In the latter case, the
 261   application must provide more input and/or consume the output
 262   (providing more output space) before each call.
 263
 264      The library does not install any signal handler. It is recommended to
 265   add at least a handler for SIGSEGV when decompressing; the library checks
 266   the consistency of the input data whenever possible but may go nuts
 267   for some forms of corrupted input.
 268 */
 269
 270 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
 271 typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
 272
 273 struct internal_state;
 274
 275 typedef struct z_stream_s {
 276     Bytef    *next_in;  /* next input byte */
 277     uInt     avail_in;  /* number of bytes available at next_in */
 278     uLong    total_in;  /* total nb of input bytes read so far */
 279
 280     Bytef    *next_out; /* next output byte should be put there */
 281     uInt     avail_out; /* remaining free space at next_out */
 282     uLong    total_out; /* total nb of bytes output so far */
 283
 284     char     *msg;      /* last error message, NULL if no error */
 285     struct internal_state FAR *state; /* not visible by applications */
 286
 287     alloc_func zalloc;  /* used to allocate the internal state */
 288     free_func  zfree;   /* used to free the internal state */
 289     voidpf     opaque;  /* private data object passed to zalloc and zfree */
 290
 291     int     data_type;  /* best guess about the data type: ascii or binary */
 292     uLong   adler;      /* adler32 value of the uncompressed data */
 293     uLong   reserved;   /* reserved for future use */
 294 } z_stream;
 295
 296 typedef z_stream FAR *z_streamp;
 297
 298 /*
 299    The application must update next_in and avail_in when avail_in has
 300    dropped to zero. It must update next_out and avail_out when avail_out
 301    has dropped to zero. The application must initialize zalloc, zfree and
 302    opaque before calling the init function. All other fields are set by the
 303    compression library and must not be updated by the application.
 304
 305    The opaque value provided by the application will be passed as the first
 306    parameter for calls of zalloc and zfree. This can be useful for custom
 307    memory management. The compression library attaches no meaning to the
 308    opaque value.
 309
 310    zalloc must return Z_NULL if there is not enough memory for the object.
 311    On 16-bit systems, the functions zalloc and zfree must be able to allocate
 312    exactly 65536 bytes, but will not be required to allocate more than this
 313    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
 314    pointers returned by zalloc for objects of exactly 65536 bytes *must*
 315    have their offset normalized to zero. The default allocation function
 316    provided by this library ensures this (see zutil.c). To reduce memory
 317    requirements and avoid any allocation of 64K objects, at the expense of
 318    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
 319
 320    The fields total_in and total_out can be used for statistics or
 321    progress reports. After compression, total_in holds the total size of
 322    the uncompressed data and may be saved for use in the decompressor
 323    (particularly if the decompressor wants to decompress everything in
 324    a single step).
 325 */
 326
 327                         /* constants */
 328
 329 #define Z_NO_FLUSH      0
 330 #define Z_PARTIAL_FLUSH 1
 331 #define Z_PACKET_FLUSH  2
 332 #define Z_SYNC_FLUSH    3
 333 #define Z_FULL_FLUSH    4
 334 #define Z_FINISH        5
 335 /* Allowed flush values; see deflate() below for details */
 336
 337 #define Z_OK            0
 338 #define Z_STREAM_END    1
 339 #define Z_NEED_DICT     2
 340 #define Z_ERRNO        (-1)
 341 #define Z_STREAM_ERROR (-2)
 342 #define Z_DATA_ERROR   (-3)
 343 #define Z_MEM_ERROR    (-4)
 344 #define Z_BUF_ERROR    (-5)
 345 #define Z_VERSION_ERROR (-6)
 346 /* Return codes for the compression/decompression functions. Negative
 347  * values are errors, positive values are used for special but normal events.
 348  */
 349
 350 #define Z_NO_COMPRESSION         0
 351 #define Z_BEST_SPEED             1
 352 #define Z_BEST_COMPRESSION       9
 353 #define Z_DEFAULT_COMPRESSION  (-1)
 354 /* compression levels */
 355
 356 #define Z_FILTERED            1
 357 #define Z_HUFFMAN_ONLY        2
 358 #define Z_DEFAULT_STRATEGY    0
 359 /* compression strategy; see deflateInit2() below for details */
 360
 361 #define Z_BINARY   0
 362 #define Z_ASCII    1
 363 #define Z_UNKNOWN  2
 364 /* Possible values of the data_type field */
 365
 366 #define Z_DEFLATED   8
 367 /* The deflate compression method (the only one supported in this version) */
 368
 369 #define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
 370
 371 #define zlib_version zlibVersion()
 372 /* for compatibility with versions < 1.0.2 */
 373
 374                         /* basic functions */
 375
 376 extern const char * EXPORT zlibVersion OF((void));
 377 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
 378    If the first character differs, the library code actually used is
 379    not compatible with the zlib.h header file used by the application.
 380    This check is automatically made by deflateInit and inflateInit.
 381  */
 382
 383 /*
 384 extern int EXPORT deflateInit OF((z_streamp strm, int level));
 385
 386      Initializes the internal stream state for compression. The fields
 387    zalloc, zfree and opaque must be initialized before by the caller.
 388    If zalloc and zfree are set to Z_NULL, deflateInit updates them to
 389    use default allocation functions.
 390
 391      The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
 392    1 gives best speed, 9 gives best compression, 0 gives no compression at
 393    all (the input data is simply copied a block at a time).
 394    Z_DEFAULT_COMPRESSION requests a default compromise between speed and
 395    compression (currently equivalent to level 6).
 396
 397      deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
 398    enough memory, Z_STREAM_ERROR if level is not a valid compression level,
 399    Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
 400    with the version assumed by the caller (ZLIB_VERSION).
 401    msg is set to null if there is no error message.  deflateInit does not
 402    perform any compression: this will be done by deflate().
 403 */
 404
 405
 406 extern int EXPORT deflate OF((z_streamp strm, int flush));
 407 /*
 408   Performs one or both of the following actions:
 409
 410   - Compress more input starting at next_in and update next_in and avail_in
 411     accordingly. If not all input can be processed (because there is not
 412     enough room in the output buffer), next_in and avail_in are updated and
 413     processing will resume at this point for the next call of deflate().
 414
 415   - Provide more output starting at next_out and update next_out and avail_out
 416     accordingly. This action is forced if the parameter flush is non zero.
 417     Forcing flush frequently degrades the compression ratio, so this parameter
 418     should be set only when necessary (in interactive applications).
 419     Some output may be provided even if flush is not set.
 420
 421   Before the call of deflate(), the application should ensure that at least
 422   one of the actions is possible, by providing more input and/or consuming
 423   more output, and updating avail_in or avail_out accordingly; avail_out
 424   should never be zero before the call. The application can consume the
 425   compressed output when it wants, for example when the output buffer is full
 426   (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
 427   and with zero avail_out, it must be called again after making room in the
 428   output buffer because there might be more output pending.
 429
 430     If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression
 431   block is terminated and flushed to the output buffer so that the
 432   decompressor can get all input data available so far. For method 9, a future
 433   variant on method 8, the current block will be flushed but not terminated.
 434   Z_SYNC_FLUSH has the same effect as partial flush except that the compressed
 435   output is byte aligned (the compressor can clear its internal bit buffer)
 436   and the current block is always terminated; this can be useful if the
 437   compressor has to be restarted from scratch after an interruption (in which
 438   case the internal state of the compressor may be lost).
 439     If flush is set to Z_FULL_FLUSH, the compression block is terminated, a
 440   special marker is output and the compression dictionary is discarded; this
 441   is useful to allow the decompressor to synchronize if one compressed block
 442   has been damaged (see inflateSync below).  Flushing degrades compression and
 443   so should be used only when necessary.  Using Z_FULL_FLUSH too often can
 444   seriously degrade the compression. If deflate returns with avail_out == 0,
 445   this function must be called again with the same value of the flush
 446   parameter and more output space (updated avail_out), until the flush is
 447   complete (deflate returns with non-zero avail_out).
 448
 449     If the parameter flush is set to Z_PACKET_FLUSH, the compression
 450   block is terminated, and a zero-length stored block is output,
 451   omitting the length bytes (the effect of this is that the 3-bit type
 452   code 000 for a stored block is output, and the output is then
 453   byte-aligned).  This is designed for use at the end of a PPP packet.
 454
 455     If the parameter flush is set to Z_FINISH, pending input is processed,
 456   pending output is flushed and deflate returns with Z_STREAM_END if there
 457   was enough output space; if deflate returns with Z_OK, this function must be
 458   called again with Z_FINISH and more output space (updated avail_out) but no
 459   more input data, until it returns with Z_STREAM_END or an error. After
 460   deflate has returned Z_STREAM_END, the only possible operations on the
 461   stream are deflateReset or deflateEnd.
 462
 463     Z_FINISH can be used immediately after deflateInit if all the compression
 464   is to be done in a single step. In this case, avail_out must be at least
 465   0.1% larger than avail_in plus 12 bytes.  If deflate does not return
 466   Z_STREAM_END, then it must be called again as described above.
 467
 468     deflate() may update data_type if it can make a good guess about
 469   the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
 470   binary. This field is only for information purposes and does not affect
 471   the compression algorithm in any manner.
 472
 473     deflate() returns Z_OK if some progress has been made (more input
 474   processed or more output produced), Z_STREAM_END if all input has been
 475   consumed and all output has been produced (only when flush is set to
 476   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
 477   if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible.
 478 */
 479
 480
 481 extern int EXPORT deflateEnd OF((z_streamp strm));
 482 /*
 483      All dynamically allocated data structures for this stream are freed.
 484    This function discards any unprocessed input and does not flush any
 485    pending output.
 486
 487      deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
 488    stream state was inconsistent, Z_DATA_ERROR if the stream was freed
 489    prematurely (some input or output was discarded). In the error case,
 490    msg may be set but then points to a static string (which must not be
 491    deallocated).
 492 */
 493
 494
 495 /*
 496 extern int EXPORT inflateInit OF((z_streamp strm));
 497
 498      Initializes the internal stream state for decompression. The fields
 499    zalloc, zfree and opaque must be initialized before by the caller.  If
 500    zalloc and zfree are set to Z_NULL, inflateInit updates them to use default
 501    allocation functions.
 502
 503      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
 504    enough memory, Z_VERSION_ERROR if the zlib library version is incompatible
 505    with the version assumed by the caller.  msg is set to null if there is no
 506    error message. inflateInit does not perform any decompression: this will be
 507    done by inflate().
 508 */
 509
 510
 511 extern int EXPORT inflate OF((z_streamp strm, int flush));
 512 /*
 513   Performs one or both of the following actions:
 514
 515   - Decompress more input starting at next_in and update next_in and avail_in
 516     accordingly. If not all input can be processed (because there is not
 517     enough room in the output buffer), next_in is updated and processing
 518     will resume at this point for the next call of inflate().
 519
 520   - Provide more output starting at next_out and update next_out and avail_out
 521     accordingly.  inflate() provides as much output as possible, until there
 522     is no more input data or no more space in the output buffer (see below
 523     about the flush parameter).
 524
 525   Before the call of inflate(), the application should ensure that at least
 526   one of the actions is possible, by providing more input and/or consuming
 527   more output, and updating the next_* and avail_* values accordingly.
 528   The application can consume the uncompressed output when it wants, for
 529   example when the output buffer is full (avail_out == 0), or after each
 530   call of inflate(). If inflate returns Z_OK and with zero avail_out, it
 531   must be called again after making room in the output buffer because there
 532   might be more output pending.
 533
 534     If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH,
 535   inflate flushes as much output as possible to the output buffer. The
 536   flushing behavior of inflate is not specified for values of the flush
 537   parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the
 538   current implementation actually flushes as much output as possible
 539   anyway.  For Z_PACKET_FLUSH, inflate checks that once all the input data
 540   has been consumed, it is expecting to see the length field of a stored
 541   block; if not, it returns Z_DATA_ERROR.
 542
 543     inflate() should normally be called until it returns Z_STREAM_END or an
 544   error. However if all decompression is to be performed in a single step
 545   (a single call of inflate), the parameter flush should be set to
 546   Z_FINISH. In this case all pending input is processed and all pending
 547   output is flushed; avail_out must be large enough to hold all the
 548   uncompressed data. (The size of the uncompressed data may have been saved
 549   by the compressor for this purpose.) The next operation on this stream must
 550   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
 551   is never required, but can be used to inform inflate that a faster routine
 552   may be used for the single inflate() call.
 553
 554     inflate() returns Z_OK if some progress has been made (more input
 555   processed or more output produced), Z_STREAM_END if the end of the
 556   compressed data has been reached and all uncompressed output has been
 557   produced, Z_NEED_DICT if a preset dictionary is needed at this point (see
 558   inflateSetDictionary below), Z_DATA_ERROR if the input data was corrupted,
 559   Z_STREAM_ERROR if the stream structure was inconsistent (for example if
 560   next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
 561   Z_BUF_ERROR if no progress is possible or if there was not enough room in
 562   the output buffer when Z_FINISH is used. In the Z_DATA_ERROR case, the
 563   application may then call inflateSync to look for a good compression block.
 564   In the Z_NEED_DICT case, strm->adler is set to the Adler32 value of the
 565   dictionary chosen by the compressor.
 566 */
 567
 568
 569 extern int EXPORT inflateEnd OF((z_streamp strm));
 570 /*
 571      All dynamically allocated data structures for this stream are freed.
 572    This function discards any unprocessed input and does not flush any
 573    pending output.
 574
 575      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
 576    was inconsistent. In the error case, msg may be set but then points to a
 577    static string (which must not be deallocated).
 578 */
 579
 580                         /* Advanced functions */
 581
 582 /*
 583     The following functions are needed only in some special applications.
 584 */
 585
 586 /*
 587 extern int EXPORT deflateInit2 OF((z_streamp strm,
 588                                    int  level,
 589                                    int  method,
 590                                    int  windowBits,
 591                                    int  memLevel,
 592                                    int  strategy));
 593
 594      This is another version of deflateInit with more compression options. The
 595    fields next_in, zalloc, zfree and opaque must be initialized before by
 596    the caller.
 597
 598      The method parameter is the compression method. It must be Z_DEFLATED in
 599    this version of the library. (Method 9 will allow a 64K history buffer and
 600    partial block flushes.)
 601
 602      The windowBits parameter is the base two logarithm of the window size
 603    (the size of the history buffer).  It should be in the range 8..15 for this
 604    version of the library (the value 16 will be allowed for method 9). Larger
 605    values of this parameter result in better compression at the expense of
 606    memory usage. The default value is 15 if deflateInit is used instead.
 607
 608      The memLevel parameter specifies how much memory should be allocated
 609    for the internal compression state. memLevel=1 uses minimum memory but
 610    is slow and reduces compression ratio; memLevel=9 uses maximum memory
 611    for optimal speed. The default value is 8. See zconf.h for total memory
 612    usage as a function of windowBits and memLevel.
 613
 614      The strategy parameter is used to tune the compression algorithm. Use the
 615    value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
 616    filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
 617    string match).  Filtered data consists mostly of small values with a
 618    somewhat random distribution. In this case, the compression algorithm is
 619    tuned to compress them better. The effect of Z_FILTERED is to force more
 620    Huffman coding and less string matching; it is somewhat intermediate
 621    between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
 622    the compression ratio but not the correctness of the compressed output even
 623    if it is not set appropriately.
 624
 625      If next_in is not null, the library will use this buffer to hold also
 626    some history information; the buffer must either hold the entire input
 627    data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in
 628    is null, the library will allocate its own history buffer (and leave next_in
 629    null). next_out need not be provided here but must be provided by the
 630    application for the next call of deflate().
 631
 632      If the history buffer is provided by the application, next_in must
 633    must never be changed by the application since the compressor maintains
 634    information inside this buffer from call to call; the application
 635    must provide more input only by increasing avail_in. next_in is always
 636    reset by the library in this case.
 637
 638       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
 639    not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
 640    an invalid method). msg is set to null if there is no error message.
 641    deflateInit2 does not perform any compression: this will be done by
 642    deflate().
 643 */
 644
 645 extern int EXPORT deflateSetDictionary OF((z_streamp strm,
 646                                            const Bytef *dictionary,
 647                                            uInt  dictLength));
 648 /*
 649      Initializes the compression dictionary (history buffer) from the given
 650    byte sequence without producing any compressed output. This function must
 651    be called immediately after deflateInit or deflateInit2, before any call
 652    of deflate. The compressor and decompressor must use exactly the same
 653    dictionary (see inflateSetDictionary).
 654      The dictionary should consist of strings (byte sequences) that are likely
 655    to be encountered later in the data to be compressed, with the most commonly
 656    used strings preferably put towards the end of the dictionary. Using a
 657    dictionary is most useful when the data to be compressed is short and
 658    can be predicted with good accuracy; the data can then be compressed better
 659    than with the default empty dictionary. In this version of the library,
 660    only the last 32K bytes of the dictionary are used.
 661      Upon return of this function, strm->adler is set to the Adler32 value
 662    of the dictionary; the decompressor may later use this value to determine
 663    which dictionary has been used by the compressor. (The Adler32 value
 664    applies to the whole dictionary even if only a subset of the dictionary is
 665    actually used by the compressor.)
 666
 667      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
 668    parameter is invalid (such as NULL dictionary) or the stream state
 669    is inconsistent (for example if deflate has already been called for this
 670    stream). deflateSetDictionary does not perform any compression: this will
 671    be done by deflate().
 672 */
 673
 674 extern int EXPORT deflateCopy OF((z_streamp dest,
 675                                   z_streamp source));
 676 /*
 677      Sets the destination stream as a complete copy of the source stream.  If
 678    the source stream is using an application-supplied history buffer, a new
 679    buffer is allocated for the destination stream.  The compressed output
 680    buffer is always application-supplied. It's the responsibility of the
 681    application to provide the correct values of next_out and avail_out for the
 682    next call of deflate.
 683
 684      This function can be useful when several compression strategies will be
 685    tried, for example when there are several ways of pre-processing the input
 686    data with a filter. The streams that will be discarded should then be freed
 687    by calling deflateEnd.  Note that deflateCopy duplicates the internal
 688    compression state which can be quite large, so this strategy is slow and
 689    can consume lots of memory.
 690
 691      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
 692    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
 693    (such as zalloc being NULL). msg is left unchanged in both source and
 694    destination.
 695 */
 696
 697 extern int EXPORT deflateReset OF((z_streamp strm));
 698 /*
 699      This function is equivalent to deflateEnd followed by deflateInit,
 700    but does not free and reallocate all the internal compression state.
 701    The stream will keep the same compression level and any other attributes
 702    that may have been set by deflateInit2.
 703
 704       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
 705    stream state was inconsistent (such as zalloc or state being NULL).
 706 */
 707
 708 extern int EXPORT deflateParams OF((z_streamp strm, int level, int strategy));
 709 /*
 710      Dynamically update the compression level and compression strategy.
 711    This can be used to switch between compression and straight copy of
 712    the input data, or to switch to a different kind of input data requiring
 713    a different strategy. If the compression level is changed, the input
 714    available so far is compressed with the old level (and may be flushed);
 715    the new level will take effect only at the next call of deflate().
 716
 717      Before the call of deflateParams, the stream state must be set as for
 718    a call of deflate(), since the currently available input may have to
 719    be compressed and flushed. In particular, strm->avail_out must be non-zero.
 720
 721      deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
 722    stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
 723    if strm->avail_out was zero.
 724 */
 725
 726 extern int EXPORT deflateOutputPending OF((z_streamp strm));
 727 /*
 728      Returns the number of bytes of output which are immediately
 729    available from the compressor (i.e. without any further input
 730    or flush).
 731 */
 732
 733 /*
 734 extern int EXPORT inflateInit2 OF((z_streamp strm,
 735                                    int  windowBits));
 736
 737      This is another version of inflateInit with more compression options. The
 738    fields next_out, zalloc, zfree and opaque must be initialized before by
 739    the caller.
 740
 741      The windowBits parameter is the base two logarithm of the maximum window
 742    size (the size of the history buffer).  It should be in the range 8..15 for
 743    this version of the library (the value 16 will be allowed soon). The
 744    default value is 15 if inflateInit is used instead. If a compressed stream
 745    with a larger window size is given as input, inflate() will return with
 746    the error code Z_DATA_ERROR instead of trying to allocate a larger window.
 747
 748      If next_out is not null, the library will use this buffer for the history
 749    buffer; the buffer must either be large enough to hold the entire output
 750    data, or have at least 1<<windowBits bytes.  If next_out is null, the
 751    library will allocate its own buffer (and leave next_out null). next_in
 752    need not be provided here but must be provided by the application for the
 753    next call of inflate().
 754
 755      If the history buffer is provided by the application, next_out must
 756    never be changed by the application since the decompressor maintains
 757    history information inside this buffer from call to call; the application
 758    can only reset next_out to the beginning of the history buffer when
 759    avail_out is zero and all output has been consumed.
 760
 761       inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
 762    not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
 763    windowBits < 8). msg is set to null if there is no error message.
 764    inflateInit2 does not perform any decompression: this will be done by
 765    inflate().
 766 */
 767
 768 extern int EXPORT inflateSetDictionary OF((z_streamp strm,
 769                                            const Bytef *dictionary,
 770                                            uInt  dictLength));
 771 /*
 772      Initializes the decompression dictionary (history buffer) from the given
 773    uncompressed byte sequence. This function must be called immediately after
 774    a call of inflate if this call returned Z_NEED_DICT. The dictionary chosen
 775    by the compressor can be determined from the Adler32 value returned by this
 776    call of inflate. The compressor and decompressor must use exactly the same
 777    dictionary (see deflateSetDictionary).
 778
 779      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
 780    parameter is invalid (such as NULL dictionary) or the stream state is
 781    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
 782    expected one (incorrect Adler32 value). inflateSetDictionary does not
 783    perform any decompression: this will be done by subsequent calls of
 784    inflate().
 785 */
 786
 787 extern int EXPORT inflateSync OF((z_streamp strm));
 788 /*
 789     Skips invalid compressed data until the special marker (see deflate()
 790   above) can be found, or until all available input is skipped. No output
 791   is provided.
 792
 793     inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR
 794   if no more input was provided, Z_DATA_ERROR if no marker has been found,
 795   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
 796   case, the application may save the current current value of total_in which
 797   indicates where valid compressed data was found. In the error case, the
 798   application may repeatedly call inflateSync, providing more input each time,
 799   until success or end of the input data.
 800 */
 801
 802 extern int EXPORT inflateReset OF((z_streamp strm));
 803 /*
 804      This function is equivalent to inflateEnd followed by inflateInit,
 805    but does not free and reallocate all the internal decompression state.
 806    The stream will keep attributes that may have been set by inflateInit2.
 807
 808       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
 809    stream state was inconsistent (such as zalloc or state being NULL).
 810 */
 811
 812 extern int inflateIncomp OF((z_stream *strm));
 813 /*
 814      This function adds the data at next_in (avail_in bytes) to the output
 815    history without performing any output.  There must be no pending output,
 816    and the decompressor must be expecting to see the start of a block.
 817    Calling this function is equivalent to decompressing a stored block
 818    containing the data at next_in (except that the data is not output).
 819 */
 820
 821                         /* utility functions */
 822
 823 /*
 824      The following utility functions are implemented on top of the
 825    basic stream-oriented functions. To simplify the interface, some
 826    default options are assumed (compression level, window size,
 827    standard memory allocation functions). The source code of these
 828    utility functions can easily be modified if you need special options.
 829 */
 830
 831 extern int EXPORT compress OF((Bytef *dest,   uLongf *destLen,
 832                                const Bytef *source, uLong sourceLen));
 833 /*
 834      Compresses the source buffer into the destination buffer.  sourceLen is
 835    the byte length of the source buffer. Upon entry, destLen is the total
 836    size of the destination buffer, which must be at least 0.1% larger than
 837    sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the
 838    compressed buffer.
 839      This function can be used to compress a whole file at once if the
 840    input file is mmap'ed.
 841      compress returns Z_OK if success, Z_MEM_ERROR if there was not
 842    enough memory, Z_BUF_ERROR if there was not enough room in the output
 843    buffer.
 844 */
 845
 846 extern int EXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
 847                                  const Bytef *source, uLong sourceLen));
 848 /*
 849      Decompresses the source buffer into the destination buffer.  sourceLen is
 850    the byte length of the source buffer. Upon entry, destLen is the total
 851    size of the destination buffer, which must be large enough to hold the
 852    entire uncompressed data. (The size of the uncompressed data must have
 853    been saved previously by the compressor and transmitted to the decompressor
 854    by some mechanism outside the scope of this compression library.)
 855    Upon exit, destLen is the actual size of the compressed buffer.
 856      This function can be used to decompress a whole file at once if the
 857    input file is mmap'ed.
 858
 859      uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
 860    enough memory, Z_BUF_ERROR if there was not enough room in the output
 861    buffer, or Z_DATA_ERROR if the input data was corrupted.
 862 */
 863
 864
 865 typedef voidp gzFile;
 866
 867 extern gzFile EXPORT gzopen  OF((const char *path, const char *mode));
 868 /*
 869      Opens a gzip (.gz) file for reading or writing. The mode parameter
 870    is as in fopen ("rb" or "wb") but can also include a compression level
 871    ("wb9").  gzopen can be used to read a file which is not in gzip format;
 872    in this case gzread will directly read from the file without decompression.
 873      gzopen returns NULL if the file could not be opened or if there was
 874    insufficient memory to allocate the (de)compression state; errno
 875    can be checked to distinguish the two cases (if errno is zero, the
 876    zlib error is Z_MEM_ERROR).
 877 */
 878
 879 extern gzFile EXPORT gzdopen  OF((int fd, const char *mode));
 880 /*
 881      gzdopen() associates a gzFile with the file descriptor fd.  File
 882    descriptors are obtained from calls like open, dup, creat, pipe or
 883    fileno (in the file has been previously opened with fopen).
 884    The mode parameter is as in gzopen.
 885      The next call of gzclose on the returned gzFile will also close the
 886    file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
 887    descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
 888      gzdopen returns NULL if there was insufficient memory to allocate
 889    the (de)compression state.
 890 */
 891
 892 extern int EXPORT    gzread  OF((gzFile file, voidp buf, unsigned len));
 893 /*
 894      Reads the given number of uncompressed bytes from the compressed file.
 895    If the input file was not in gzip format, gzread copies the given number
 896    of bytes into the buffer.
 897      gzread returns the number of uncompressed bytes actually read (0 for
 898    end of file, -1 for error). */
 899
 900 extern int EXPORT    gzwrite OF((gzFile file, const voidp buf, unsigned len));
 901 /*
 902      Writes the given number of uncompressed bytes into the compressed file.
 903    gzwrite returns the number of uncompressed bytes actually written
 904    (0 in case of error).
 905 */
 906
 907 extern int EXPORT    gzflush OF((gzFile file, int flush));
 908 /*
 909      Flushes all pending output into the compressed file. The parameter
 910    flush is as in the deflate() function. The return value is the zlib
 911    error number (see function gzerror below). gzflush returns Z_OK if
 912    the flush parameter is Z_FINISH and all output could be flushed.
 913      gzflush should be called only when strictly necessary because it can
 914    degrade compression.
 915 */
 916
 917 extern int EXPORT    gzclose OF((gzFile file));
 918 /*
 919      Flushes all pending output if necessary, closes the compressed file
 920    and deallocates all the (de)compression state. The return value is the zlib
 921    error number (see function gzerror below).
 922 */
 923
 924 extern const char * EXPORT gzerror OF((gzFile file, int *errnum));
 925 /*
 926      Returns the error message for the last error which occurred on the
 927    given compressed file. errnum is set to zlib error number. If an
 928    error occurred in the file system and not in the compression library,
 929    errnum is set to Z_ERRNO and the application may consult errno
 930    to get the exact error code.
 931 */
 932
 933                         /* checksum functions */
 934
 935 /*
 936      These functions are not related to compression but are exported
 937    anyway because they might be useful in applications using the
 938    compression library.
 939 */
 940
 941 extern uLong EXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
 942
 943 /*
 944      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
 945    return the updated checksum. If buf is NULL, this function returns
 946    the required initial value for the checksum.
 947    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
 948    much faster. Usage example:
 949
 950      uLong adler = adler32(0L, Z_NULL, 0);
 951
 952      while (read_buffer(buffer, length) != EOF) {
 953        adler = adler32(adler, buffer, length);
 954      }
 955      if (adler != original_adler) error();
 956 */
 957
 958 extern uLong EXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
 959 /*
 960      Update a running crc with the bytes buf[0..len-1] and return the updated
 961    crc. If buf is NULL, this function returns the required initial value
 962    for the crc. Pre- and post-conditioning (one's complement) is performed
 963    within this function so it shouldn't be done by the application.
 964    Usage example:
 965
 966      uLong crc = crc32(0L, Z_NULL, 0);
 967
 968      while (read_buffer(buffer, length) != EOF) {
 969        crc = crc32(crc, buffer, length);
 970      }
 971      if (crc != original_crc) error();
 972 */
 973
 974
 975                         /* various hacks, don't look :) */
 976
 977 /* deflateInit and inflateInit are macros to allow checking the zlib version
 978  * and the compiler's view of z_stream:
 979  */
 980 extern int EXPORT deflateInit_ OF((z_streamp strm, int level,
 981                                    const char *version, int stream_size));
 982 extern int EXPORT inflateInit_ OF((z_streamp strm,
 983                                    const char *version, int stream_size));
 984 extern int EXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
 985                                     int windowBits, int memLevel, int strategy,
 986                                     const char *version, int stream_size));
 987 extern int EXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
 988                                     const char *version, int stream_size));
 989 #define deflateInit(strm, level) \
 990         deflateInit_((strm), (level),       ZLIB_VERSION, sizeof(z_stream))
 991 #define inflateInit(strm) \
 992         inflateInit_((strm),                ZLIB_VERSION, sizeof(z_stream))
 993 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
 994         deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
 995                       (strategy),           ZLIB_VERSION, sizeof(z_stream))
 996 #define inflateInit2(strm, windowBits) \
 997         inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
 998
 999 #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
1000     struct internal_state {int dummy;}; /* hack for buggy compilers */
1001 #endif
1002
1003 uLongf *get_crc_table OF((void)); /* can be used by asm versions of crc32() */
1004
1005 #ifdef __cplusplus
1006 }
1007 #endif
1008
1009 #endif /* _ZLIB_H */
1010 /* --- zlib.h */