include/zlib.h

   1 /*
   2  * This file is derived from zlib.h and zconf.h from the zlib-0.95
   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 0.95, Aug 16th, 1995.
  17
  18   Copyright (C) 1995 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   gzip@prep.ai.mit.edu    madler@alumni.caltech.edu
  38  */
  39
  40 #ifndef _ZLIB_H
  41 #define _ZLIB_H
  42
  43 /* #include "zconf.h" */        /* included directly here */
  44
  45 /* zconf.h -- configuration of the zlib compression library
  46  * Copyright (C) 1995 Jean-loup Gailly.
  47  * For conditions of distribution and use, see copyright notice in zlib.h
  48  */
  49
  50 /* From: zconf.h,v 1.12 1995/05/03 17:27:12 jloup Exp */
  51
  52 /*
  53      The library does not install any signal handler. It is recommended to
  54   add at least a handler for SIGSEGV when decompressing; the library checks
  55   the consistency of the input data whenever possible but may go nuts
  56   for some forms of corrupted input.
  57  */
  58
  59 /*
  60  * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
  61  * than 64k bytes at a time (needed on systems with 16-bit int).
  62  * Compile with -DUNALIGNED_OK if it is OK to access shorts or ints
  63  * at addresses which are not a multiple of their size.
  64  * Under DOS, -DFAR=far or -DFAR=__far may be needed.
  65  */
  66
  67 #ifndef STDC
  68 #  if defined(MSDOS) || defined(__STDC__) || defined(__cplusplus)
  69 #    define STDC
  70 #  endif
  71 #endif
  72
  73 #ifdef  __MWERKS__ /* Metrowerks CodeWarrior declares fileno() in unix.h */
  74 #  include <unix.h>
  75 #endif
  76
  77 /* Maximum value for memLevel in deflateInit2 */
  78 #ifndef MAX_MEM_LEVEL
  79 #  ifdef MAXSEG_64K
  80 #    define MAX_MEM_LEVEL 8
  81 #  else
  82 #    define MAX_MEM_LEVEL 9
  83 #  endif
  84 #endif
  85
  86 #ifndef FAR
  87 #  define FAR
  88 #endif
  89
  90 /* Maximum value for windowBits in deflateInit2 and inflateInit2 */
  91 #ifndef MAX_WBITS
  92 #  define MAX_WBITS   15 /* 32K LZ77 window */
  93 #endif
  94
  95 /* The memory requirements for deflate are (in bytes):
  96             1 << (windowBits+2)   +  1 << (memLevel+9)
  97  that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
  98  plus a few kilobytes for small objects. For example, if you want to reduce
  99  the default memory requirements from 256K to 128K, compile with
 100      make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
 101  Of course this will generally degrade compression (there's no free lunch).
 102
 103    The memory requirements for inflate are (in bytes) 1 << windowBits
 104  that is, 32K for windowBits=15 (default value) plus a few kilobytes
 105  for small objects.
 106 */
 107
 108                         /* Type declarations */
 109
 110 #ifndef OF /* function prototypes */
 111 #  ifdef STDC
 112 #    define OF(args)  args
 113 #  else
 114 #    define OF(args)  ()
 115 #  endif
 116 #endif
 117
 118 typedef unsigned char  Byte;  /* 8 bits */
 119 typedef unsigned int   uInt;  /* 16 bits or more */
 120 typedef unsigned long  uLong; /* 32 bits or more */
 121
 122 typedef Byte FAR Bytef;
 123 typedef char FAR charf;
 124 typedef int FAR intf;
 125 typedef uInt FAR uIntf;
 126 typedef uLong FAR uLongf;
 127
 128 #ifdef STDC
 129    typedef void FAR *voidpf;
 130    typedef void     *voidp;
 131 #else
 132    typedef Byte FAR *voidpf;
 133    typedef Byte     *voidp;
 134 #endif
 135
 136 /* end of original zconf.h */
 137
 138 #define ZLIB_VERSION "0.95P"
 139
 140 /*
 141      The 'zlib' compression library provides in-memory compression and
 142   decompression functions, including integrity checks of the uncompressed
 143   data.  This version of the library supports only one compression method
 144   (deflation) but other algorithms may be added later and will have the same
 145   stream interface.
 146
 147      For compression the application must provide the output buffer and
 148   may optionally provide the input buffer for optimization. For decompression,
 149   the application must provide the input buffer and may optionally provide
 150   the output buffer for optimization.
 151
 152      Compression can be done in a single step if the buffers are large
 153   enough (for example if an input file is mmap'ed), or can be done by
 154   repeated calls of the compression function.  In the latter case, the
 155   application must provide more input and/or consume the output
 156   (providing more output space) before each call.
 157 */
 158
 159 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
 160 typedef void   (*free_func)  OF((voidpf opaque, voidpf address, uInt nbytes));
 161
 162 typedef void   (*cb_func)    OF((Bytef *buf, uInt len));
 163
 164 struct internal_state;
 165
 166 typedef struct z_stream_s {
 167     Bytef    *next_in;  /* next input byte */
 168     uInt     avail_in;  /* number of bytes available at next_in */
 169     uLong    total_in;  /* total nb of input bytes read so far */
 170
 171     Bytef    *next_out; /* next output byte should be put there */
 172     uInt     avail_out; /* remaining free space at next_out */
 173     uLong    total_out; /* total nb of bytes output so far */
 174
 175     char     *msg;      /* last error message, NULL if no error */
 176     struct internal_state FAR *state; /* not visible by applications */
 177
 178     alloc_func zalloc;  /* used to allocate the internal state */
 179     free_func  zfree;   /* used to free the internal state */
 180     voidp      opaque;  /* private data object passed to zalloc and zfree */
 181
 182     Byte     data_type; /* best guess about the data type: ascii or binary */
 183
 184     cb_func  outcb;     /* called regularly just before blocks of output */
 185
 186 } z_stream;
 187
 188 /*
 189    The application must update next_in and avail_in when avail_in has
 190    dropped to zero. It must update next_out and avail_out when avail_out
 191    has dropped to zero. The application must initialize zalloc, zfree and
 192    opaque before calling the init function. All other fields are set by the
 193    compression library and must not be updated by the application.
 194
 195    The opaque value provided by the application will be passed as the first
 196    parameter for calls of zalloc and zfree. This can be useful for custom
 197    memory management. The compression library attaches no meaning to the
 198    opaque value.
 199
 200    zalloc must return Z_NULL if there is not enough memory for the object.
 201    On 16-bit systems, the functions zalloc and zfree must be able to allocate
 202    exactly 65536 bytes, but will not be required to allocate more than this
 203    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
 204    pointers returned by zalloc for objects of exactly 65536 bytes *must*
 205    have their offset normalized to zero. The default allocation function
 206    provided by this library ensures this (see zutil.c). To reduce memory
 207    requirements and avoid any allocation of 64K objects, at the expense of
 208    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
 209
 210    The fields total_in and total_out can be used for statistics or
 211    progress reports. After compression, total_in holds the total size of
 212    the uncompressed data and may be saved for use in the decompressor
 213    (particularly if the decompressor wants to decompress everything in
 214    a single step).
 215 */
 216
 217                         /* constants */
 218
 219 #define Z_NO_FLUSH      0
 220 #define Z_PARTIAL_FLUSH 1
 221 #define Z_FULL_FLUSH    2
 222 #define Z_SYNC_FLUSH    3 /* experimental: partial_flush + byte align */
 223 #define Z_FINISH        4
 224 #define Z_PACKET_FLUSH  5
 225 /* See deflate() below for the usage of these constants */
 226
 227 #define Z_OK            0
 228 #define Z_STREAM_END    1
 229 #define Z_ERRNO        (-1)
 230 #define Z_STREAM_ERROR (-2)
 231 #define Z_DATA_ERROR   (-3)
 232 #define Z_MEM_ERROR    (-4)
 233 #define Z_BUF_ERROR    (-5)
 234 /* error codes for the compression/decompression functions */
 235
 236 #define Z_BEST_SPEED             1
 237 #define Z_BEST_COMPRESSION       9
 238 #define Z_DEFAULT_COMPRESSION  (-1)
 239 /* compression levels */
 240
 241 #define Z_FILTERED            1
 242 #define Z_HUFFMAN_ONLY        2
 243 #define Z_DEFAULT_STRATEGY    0
 244
 245 #define Z_BINARY   0
 246 #define Z_ASCII    1
 247 #define Z_UNKNOWN  2
 248 /* Used to set the data_type field */
 249
 250 #define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
 251
 252 extern char *zlib_version;
 253 /* The application can compare zlib_version and ZLIB_VERSION for consistency.
 254    If the first character differs, the library code actually used is
 255    not compatible with the zlib.h header file used by the application.
 256  */
 257
 258                         /* basic functions */
 259
 260 extern int inflateInit OF((z_stream *strm));
 261 /*
 262      Initializes the internal stream state for decompression. The fields
 263    zalloc and zfree must be initialized before by the caller.  If zalloc and
 264    zfree are set to Z_NULL, inflateInit updates them to use default allocation
 265    functions.
 266
 267      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
 268    enough memory.  msg is set to null if there is no error message.
 269    inflateInit does not perform any decompression: this will be done by
 270    inflate().
 271 */
 272
 273
 274 extern int inflate OF((z_stream *strm, int flush));
 275 /*
 276   Performs one or both of the following actions:
 277
 278   - Decompress more input starting at next_in and update next_in and avail_in
 279     accordingly. If not all input can be processed (because there is not
 280     enough room in the output buffer), next_in is updated and processing
 281     will resume at this point for the next call of inflate().
 282
 283   - Provide more output starting at next_out and update next_out and avail_out
 284     accordingly.  inflate() always provides as much output as possible
 285     (until there is no more input data or no more space in the output buffer).
 286
 287   Before the call of inflate(), the application should ensure that at least
 288   one of the actions is possible, by providing more input and/or consuming
 289   more output, and updating the next_* and avail_* values accordingly.
 290   The application can consume the uncompressed output when it wants, for
 291   example when the output buffer is full (avail_out == 0), or after each
 292   call of inflate().
 293
 294     If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH,
 295   inflate flushes as much output as possible to the output buffer. The
 296   flushing behavior of inflate is not specified for values of the flush
 297   parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the
 298   current implementation actually flushes as much output as possible
 299   anyway.  For Z_PACKET_FLUSH, inflate checks that once all the input data
 300   has been consumed, it is expecting to see the length field of a stored
 301   block; if not, it returns Z_DATA_ERROR.
 302
 303     inflate() should normally be called until it returns Z_STREAM_END or an
 304   error. However if all decompression is to be performed in a single step
 305   (a single call of inflate), the parameter flush should be set to
 306   Z_FINISH. In this case all pending input is processed and all pending
 307   output is flushed; avail_out must be large enough to hold all the
 308   uncompressed data. (The size of the uncompressed data may have been saved
 309   by the compressor for this purpose.) The next operation on this stream must
 310   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
 311   is never required, but can be used to inform inflate that a faster routine
 312   may be used for the single inflate() call.
 313
 314     inflate() returns Z_OK if some progress has been made (more input
 315   processed or more output produced), Z_STREAM_END if the end of the
 316   compressed data has been reached and all uncompressed output has been
 317   produced, Z_DATA_ERROR if the input data was corrupted, Z_STREAM_ERROR if
 318   the stream structure was inconsistent (for example if next_in or next_out
 319   was NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no
 320   progress is possible or if there was not enough room in the output buffer
 321   when Z_FINISH is used. In the Z_DATA_ERROR case, the application may then
 322   call inflateSync to look for a good compression block.  */
 323
 324
 325 extern int inflateEnd OF((z_stream *strm));
 326 /*
 327      All dynamically allocated data structures for this stream are freed.
 328    This function discards any unprocessed input and does not flush any
 329    pending output.
 330
 331      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
 332    was inconsistent. In the error case, msg may be set but then points to a
 333    static string (which must not be deallocated).
 334 */
 335
 336                         /* advanced functions */
 337
 338 extern int inflateInit2 OF((z_stream *strm,
 339                             int  windowBits));
 340 /*
 341      This is another version of inflateInit with more compression options. The
 342    fields next_out, zalloc and zfree must be initialized before by the caller.
 343
 344      The windowBits parameter is the base two logarithm of the maximum window
 345    size (the size of the history buffer).  It should be in the range 8..15 for
 346    this version of the library (the value 16 will be allowed soon). The
 347    default value is 15 if inflateInit is used instead. If a compressed stream
 348    with a larger window size is given as input, inflate() will return with
 349    the error code Z_DATA_ERROR instead of trying to allocate a larger window.
 350
 351      If next_out is not null, the library will use this buffer for the history
 352    buffer; the buffer must either be large enough to hold the entire output
 353    data, or have at least 1<<windowBits bytes.  If next_out is null, the
 354    library will allocate its own buffer (and leave next_out null). next_in
 355    need not be provided here but must be provided by the application for the
 356    next call of inflate().
 357
 358      If the history buffer is provided by the application, next_out must
 359    never be changed by the application since the decompressor maintains
 360    history information inside this buffer from call to call; the application
 361    can only reset next_out to the beginning of the history buffer when
 362    avail_out is zero and all output has been consumed.
 363
 364       inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
 365    not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
 366    windowBits < 8). msg is set to null if there is no error message.
 367    inflateInit2 does not perform any decompression: this will be done by
 368    inflate().
 369 */
 370
 371 extern int inflateSync OF((z_stream *strm));
 372 /*
 373     Skips invalid compressed data until the special marker (see deflate()
 374   above) can be found, or until all available input is skipped. No output
 375   is provided.
 376
 377     inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR
 378   if no more input was provided, Z_DATA_ERROR if no marker has been found,
 379   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
 380   case, the application may save the current current value of total_in which
 381   indicates where valid compressed data was found. In the error case, the
 382   application may repeatedly call inflateSync, providing more input each time,
 383   until success or end of the input data.
 384 */
 385
 386 extern int inflateReset OF((z_stream *strm));
 387 /*
 388      This function is equivalent to inflateEnd followed by inflateInit,
 389    but does not free and reallocate all the internal decompression state.
 390    The stream will keep attributes that may have been set by inflateInit2.
 391
 392       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
 393    stream state was inconsistent (such as zalloc or state being NULL).
 394 */
 395
 396 extern int inflateIncomp OF((z_stream *strm));
 397 /*
 398      This function adds the data at next_in (avail_in bytes) to the output
 399    history without performing any output.  There must be no pending output,
 400    and the decompressor must be expecting to see the start of a block.
 401    Calling this function is equivalent to decompressing a stored block
 402    containing the data at next_in (except that the data is not output).
 403 */
 404
 405                         /* checksum functions */
 406
 407 /*
 408      This function is not related to compression but is exported
 409    anyway because it might be useful in applications using the
 410    compression library.
 411 */
 412
 413 extern uLong adler32 OF((uLong adler, Bytef *buf, uInt len));
 414
 415 /*
 416      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
 417    return the updated checksum. If buf is NULL, this function returns
 418    the required initial value for the checksum.
 419    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
 420    much faster. Usage example:
 421
 422      uLong adler = adler32(0L, Z_NULL, 0);
 423
 424      while (read_buffer(buffer, length) != EOF) {
 425        adler = adler32(adler, buffer, length);
 426      }
 427      if (adler != original_adler) error();
 428 */
 429
 430 #ifndef _Z_UTIL_H
 431     struct internal_state {int dummy;}; /* hack for buggy compilers */
 432 #endif
 433
 434 #endif /* _ZLIB_H */