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/* zlib.h -- interface of the 'zlib' general purpose compression library
2
  version 1.1.4, March 11th, 2002
3
 
4
  Copyright (C) 1995-2002 Jean-loup Gailly and Mark Adler
5
 
6
  This software is provided 'as-is', without any express or implied
7
  warranty.  In no event will the authors be held liable for any damages
8
  arising from the use of this software.
9
 
10
  Permission is granted to anyone to use this software for any purpose,
11
  including commercial applications, and to alter it and redistribute it
12
  freely, subject to the following restrictions:
13
 
14
  1. The origin of this software must not be misrepresented; you must not
15
     claim that you wrote the original software. If you use this software
16
     in a product, an acknowledgment in the product documentation would be
17
     appreciated but is not required.
18
  2. Altered source versions must be plainly marked as such, and must not be
19
     misrepresented as being the original software.
20
  3. This notice may not be removed or altered from any source distribution.
21
 
22
  Jean-loup Gailly        Mark Adler
23
  jloup@gzip.org          madler@alumni.caltech.edu
24
 
25
 
26
  The data format used by the zlib library is described by RFCs (Request for
27
  Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
28
  (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
29
*/
30
 
31
#ifndef _ZLIB_H
32
#define _ZLIB_H
33
 
34
#include "zconf.h"
35
 
36
#ifdef __cplusplus
37
extern "C" {
38
#endif
39
 
40
#define ZLIB_VERSION "1.1.4"
41
 
42
/*
43
     The 'zlib' compression library provides in-memory compression and
44
  decompression functions, including integrity checks of the uncompressed
45
  data.  This version of the library supports only one compression method
46
  (deflation) but other algorithms will be added later and will have the same
47
  stream interface.
48
 
49
     Compression can be done in a single step if the buffers are large
50
  enough (for example if an input file is mmap'ed), or can be done by
51
  repeated calls of the compression function.  In the latter case, the
52
  application must provide more input and/or consume the output
53
  (providing more output space) before each call.
54
 
55
     The library also supports reading and writing files in gzip (.gz) format
56
  with an interface similar to that of stdio.
57
 
58
     The library does not install any signal handler. The decoder checks
59
  the consistency of the compressed data, so the library should never
60
  crash even in case of corrupted input.
61
*/
62
 
63
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
64
typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
65
 
66
struct internal_state;
67
 
68
typedef struct z_stream_s {
69
    Bytef    *next_in;  /* next input byte */
70
    uInt     avail_in;  /* number of bytes available at next_in */
71
    uLong    total_in;  /* total nb of input bytes read so far */
72
 
73
    Bytef    *next_out; /* next output byte should be put there */
74
    uInt     avail_out; /* remaining free space at next_out */
75
    uLong    total_out; /* total nb of bytes output so far */
76
 
77
    char     *msg;      /* last error message, NULL if no error */
78
    struct internal_state FAR *state; /* not visible by applications */
79
 
80
    alloc_func zalloc;  /* used to allocate the internal state */
81
    free_func  zfree;   /* used to free the internal state */
82
    voidpf     opaque;  /* private data object passed to zalloc and zfree */
83
 
84
    int     data_type;  /* best guess about the data type: ascii or binary */
85
    uLong   adler;      /* adler32 value of the uncompressed data */
86
    uLong   reserved;   /* reserved for future use */
87
} z_stream;
88
 
89
typedef z_stream FAR *z_streamp;
90
 
91
/*
92
   The application must update next_in and avail_in when avail_in has
93
   dropped to zero. It must update next_out and avail_out when avail_out
94
   has dropped to zero. The application must initialize zalloc, zfree and
95
   opaque before calling the init function. All other fields are set by the
96
   compression library and must not be updated by the application.
97
 
98
   The opaque value provided by the application will be passed as the first
99
   parameter for calls of zalloc and zfree. This can be useful for custom
100
   memory management. The compression library attaches no meaning to the
101
   opaque value.
102
 
103
   zalloc must return Z_NULL if there is not enough memory for the object.
104
   If zlib is used in a multi-threaded application, zalloc and zfree must be
105
   thread safe.
106
 
107
   On 16-bit systems, the functions zalloc and zfree must be able to allocate
108
   exactly 65536 bytes, but will not be required to allocate more than this
109
   if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
110
   pointers returned by zalloc for objects of exactly 65536 bytes *must*
111
   have their offset normalized to zero. The default allocation function
112
   provided by this library ensures this (see zutil.c). To reduce memory
113
   requirements and avoid any allocation of 64K objects, at the expense of
114
   compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
115
 
116
   The fields total_in and total_out can be used for statistics or
117
   progress reports. After compression, total_in holds the total size of
118
   the uncompressed data and may be saved for use in the decompressor
119
   (particularly if the decompressor wants to decompress everything in
120
   a single step).
121
*/
122
 
123
                        /* constants */
124
 
125
#define Z_NO_FLUSH      0
126
#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
127
#define Z_SYNC_FLUSH    2
128
#define Z_FULL_FLUSH    3
129
#define Z_FINISH        4
130
/* Allowed flush values; see deflate() below for details */
131
 
132
#define Z_OK            0
133
#define Z_STREAM_END    1
134
#define Z_NEED_DICT     2
135
#define Z_ERRNO        (-1)
136
#define Z_STREAM_ERROR (-2)
137
#define Z_DATA_ERROR   (-3)
138
#define Z_MEM_ERROR    (-4)
139
#define Z_BUF_ERROR    (-5)
140
#define Z_VERSION_ERROR (-6)
141
/* Return codes for the compression/decompression functions. Negative
142
 * values are errors, positive values are used for special but normal events.
143
 */
144
 
145
#define Z_NO_COMPRESSION         0
146
#define Z_BEST_SPEED             1
147
#define Z_BEST_COMPRESSION       9
148
#define Z_DEFAULT_COMPRESSION  (-1)
149
/* compression levels */
150
 
151
#define Z_FILTERED            1
152
#define Z_HUFFMAN_ONLY        2
153
#define Z_DEFAULT_STRATEGY    0
154
/* compression strategy; see deflateInit2() below for details */
155
 
156
#define Z_BINARY   0
157
#define Z_ASCII    1
158
#define Z_UNKNOWN  2
159
/* Possible values of the data_type field */
160
 
161
#define Z_DEFLATED   8
162
/* The deflate compression method (the only one supported in this version) */
163
 
164
#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
165
 
166
#define zlib_version zlibVersion()
167
/* for compatibility with versions < 1.0.2 */
168
 
169
                        /* basic functions */
170
 
171
ZEXTERN const char * ZEXPORT zlibVersion OF((void));
172
/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
173
   If the first character differs, the library code actually used is
174
   not compatible with the zlib.h header file used by the application.
175
   This check is automatically made by deflateInit and inflateInit.
176
 */
177
 
178
/*
179
ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
180
 
181
     Initializes the internal stream state for compression. The fields
182
   zalloc, zfree and opaque must be initialized before by the caller.
183
   If zalloc and zfree are set to Z_NULL, deflateInit updates them to
184
   use default allocation functions.
185
 
186
     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
187
   1 gives best speed, 9 gives best compression, 0 gives no compression at
188
   all (the input data is simply copied a block at a time).
189
   Z_DEFAULT_COMPRESSION requests a default compromise between speed and
190
   compression (currently equivalent to level 6).
191
 
192
     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
193
   enough memory, Z_STREAM_ERROR if level is not a valid compression level,
194
   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
195
   with the version assumed by the caller (ZLIB_VERSION).
196
   msg is set to null if there is no error message.  deflateInit does not
197
   perform any compression: this will be done by deflate().
198
*/
199
 
200
 
201
ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
202
/*
203
    deflate compresses as much data as possible, and stops when the input
204
  buffer becomes empty or the output buffer becomes full. It may introduce some
205
  output latency (reading input without producing any output) except when
206
  forced to flush.
207
 
208
    The detailed semantics are as follows. deflate performs one or both of the
209
  following actions:
210
 
211
  - Compress more input starting at next_in and update next_in and avail_in
212
    accordingly. If not all input can be processed (because there is not
213
    enough room in the output buffer), next_in and avail_in are updated and
214
    processing will resume at this point for the next call of deflate().
215
 
216
  - Provide more output starting at next_out and update next_out and avail_out
217
    accordingly. This action is forced if the parameter flush is non zero.
218
    Forcing flush frequently degrades the compression ratio, so this parameter
219
    should be set only when necessary (in interactive applications).
220
    Some output may be provided even if flush is not set.
221
 
222
  Before the call of deflate(), the application should ensure that at least
223
  one of the actions is possible, by providing more input and/or consuming
224
  more output, and updating avail_in or avail_out accordingly; avail_out
225
  should never be zero before the call. The application can consume the
226
  compressed output when it wants, for example when the output buffer is full
227
  (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
228
  and with zero avail_out, it must be called again after making room in the
229
  output buffer because there might be more output pending.
230
 
231
    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
232
  flushed to the output buffer and the output is aligned on a byte boundary, so
233
  that the decompressor can get all input data available so far. (In particular
234
  avail_in is zero after the call if enough output space has been provided
235
  before the call.)  Flushing may degrade compression for some compression
236
  algorithms and so it should be used only when necessary.
237
 
238
    If flush is set to Z_FULL_FLUSH, all output is flushed as with
239
  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
240
  restart from this point if previous compressed data has been damaged or if
241
  random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
242
  the compression.
243
 
244
    If deflate returns with avail_out == 0, this function must be called again
245
  with the same value of the flush parameter and more output space (updated
246
  avail_out), until the flush is complete (deflate returns with non-zero
247
  avail_out).
248
 
249
    If the parameter flush is set to Z_FINISH, pending input is processed,
250
  pending output is flushed and deflate returns with Z_STREAM_END if there
251
  was enough output space; if deflate returns with Z_OK, this function must be
252
  called again with Z_FINISH and more output space (updated avail_out) but no
253
  more input data, until it returns with Z_STREAM_END or an error. After
254
  deflate has returned Z_STREAM_END, the only possible operations on the
255
  stream are deflateReset or deflateEnd.
256
 
257
    Z_FINISH can be used immediately after deflateInit if all the compression
258
  is to be done in a single step. In this case, avail_out must be at least
259
  0.1% larger than avail_in plus 12 bytes.  If deflate does not return
260
  Z_STREAM_END, then it must be called again as described above.
261
 
262
    deflate() sets strm->adler to the adler32 checksum of all input read
263
  so far (that is, total_in bytes).
264
 
265
    deflate() may update data_type if it can make a good guess about
266
  the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
267
  binary. This field is only for information purposes and does not affect
268
  the compression algorithm in any manner.
269
 
270
    deflate() returns Z_OK if some progress has been made (more input
271
  processed or more output produced), Z_STREAM_END if all input has been
272
  consumed and all output has been produced (only when flush is set to
273
  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
274
  if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
275
  (for example avail_in or avail_out was zero).
276
*/
277
 
278
 
279
ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
280
/*
281
     All dynamically allocated data structures for this stream are freed.
282
   This function discards any unprocessed input and does not flush any
283
   pending output.
284
 
285
     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
286
   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
287
   prematurely (some input or output was discarded). In the error case,
288
   msg may be set but then points to a static string (which must not be
289
   deallocated).
290
*/
291
 
292
 
293
/*
294
ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
295
 
296
     Initializes the internal stream state for decompression. The fields
297
   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
298
   the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
299
   value depends on the compression method), inflateInit determines the
300
   compression method from the zlib header and allocates all data structures
301
   accordingly; otherwise the allocation will be deferred to the first call of
302
   inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
303
   use default allocation functions.
304
 
305
     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
306
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
307
   version assumed by the caller.  msg is set to null if there is no error
308
   message. inflateInit does not perform any decompression apart from reading
309
   the zlib header if present: this will be done by inflate().  (So next_in and
310
   avail_in may be modified, but next_out and avail_out are unchanged.)
311
*/
312
 
313
 
314
ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
315
/*
316
    inflate decompresses as much data as possible, and stops when the input
317
  buffer becomes empty or the output buffer becomes full. It may some
318
  introduce some output latency (reading input without producing any output)
319
  except when forced to flush.
320
 
321
  The detailed semantics are as follows. inflate performs one or both of the
322
  following actions:
323
 
324
  - Decompress more input starting at next_in and update next_in and avail_in
325
    accordingly. If not all input can be processed (because there is not
326
    enough room in the output buffer), next_in is updated and processing
327
    will resume at this point for the next call of inflate().
328
 
329
  - Provide more output starting at next_out and update next_out and avail_out
330
    accordingly.  inflate() provides as much output as possible, until there
331
    is no more input data or no more space in the output buffer (see below
332
    about the flush parameter).
333
 
334
  Before the call of inflate(), the application should ensure that at least
335
  one of the actions is possible, by providing more input and/or consuming
336
  more output, and updating the next_* and avail_* values accordingly.
337
  The application can consume the uncompressed output when it wants, for
338
  example when the output buffer is full (avail_out == 0), or after each
339
  call of inflate(). If inflate returns Z_OK and with zero avail_out, it
340
  must be called again after making room in the output buffer because there
341
  might be more output pending.
342
 
343
    If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much
344
  output as possible to the output buffer. The flushing behavior of inflate is
345
  not specified for values of the flush parameter other than Z_SYNC_FLUSH
346
  and Z_FINISH, but the current implementation actually flushes as much output
347
  as possible anyway.
348
 
349
    inflate() should normally be called until it returns Z_STREAM_END or an
350
  error. However if all decompression is to be performed in a single step
351
  (a single call of inflate), the parameter flush should be set to
352
  Z_FINISH. In this case all pending input is processed and all pending
353
  output is flushed; avail_out must be large enough to hold all the
354
  uncompressed data. (The size of the uncompressed data may have been saved
355
  by the compressor for this purpose.) The next operation on this stream must
356
  be inflateEnd to deallocate the decompression state. The use of Z_FINISH
357
  is never required, but can be used to inform inflate that a faster routine
358
  may be used for the single inflate() call.
359
 
360
     If a preset dictionary is needed at this point (see inflateSetDictionary
361
  below), inflate sets strm-adler to the adler32 checksum of the
362
  dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise
363
  it sets strm->adler to the adler32 checksum of all output produced
364
  so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or
365
  an error code as described below. At the end of the stream, inflate()
366
  checks that its computed adler32 checksum is equal to that saved by the
367
  compressor and returns Z_STREAM_END only if the checksum is correct.
368
 
369
    inflate() returns Z_OK if some progress has been made (more input processed
370
  or more output produced), Z_STREAM_END if the end of the compressed data has
371
  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
372
  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
373
  corrupted (input stream not conforming to the zlib format or incorrect
374
  adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent
375
  (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not
376
  enough memory, Z_BUF_ERROR if no progress is possible or if there was not
377
  enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR
378
  case, the application may then call inflateSync to look for a good
379
  compression block.
380
*/
381
 
382
 
383
ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
384
/*
385
     All dynamically allocated data structures for this stream are freed.
386
   This function discards any unprocessed input and does not flush any
387
   pending output.
388
 
389
     inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
390
   was inconsistent. In the error case, msg may be set but then points to a
391
   static string (which must not be deallocated).
392
*/
393
 
394
                        /* Advanced functions */
395
 
396
/*
397
    The following functions are needed only in some special applications.
398
*/
399
 
400
/*  
401
ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
402
                                     int  level,
403
                                     int  method,
404
                                     int  windowBits,
405
                                     int  memLevel,
406
                                     int  strategy));
407
 
408
     This is another version of deflateInit with more compression options. The
409
   fields next_in, zalloc, zfree and opaque must be initialized before by
410
   the caller.
411
 
412
     The method parameter is the compression method. It must be Z_DEFLATED in
413
   this version of the library.
414
 
415
     The windowBits parameter is the base two logarithm of the window size
416
   (the size of the history buffer).  It should be in the range 8..15 for this
417
   version of the library. Larger values of this parameter result in better
418
   compression at the expense of memory usage. The default value is 15 if
419
   deflateInit is used instead.
420
 
421
     The memLevel parameter specifies how much memory should be allocated
422
   for the internal compression state. memLevel=1 uses minimum memory but
423
   is slow and reduces compression ratio; memLevel=9 uses maximum memory
424
   for optimal speed. The default value is 8. See zconf.h for total memory
425
   usage as a function of windowBits and memLevel.
426
 
427
     The strategy parameter is used to tune the compression algorithm. Use the
428
   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
429
   filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
430
   string match).  Filtered data consists mostly of small values with a
431
   somewhat random distribution. In this case, the compression algorithm is
432
   tuned to compress them better. The effect of Z_FILTERED is to force more
433
   Huffman coding and less string matching; it is somewhat intermediate
434
   between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
435
   the compression ratio but not the correctness of the compressed output even
436
   if it is not set appropriately.
437
 
438
      deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
439
   memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
440
   method). msg is set to null if there is no error message.  deflateInit2 does
441
   not perform any compression: this will be done by deflate().
442
*/
443
 
444
ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
445
                                             const Bytef *dictionary,
446
                                             uInt  dictLength));
447
/*
448
     Initializes the compression dictionary from the given byte sequence
449
   without producing any compressed output. This function must be called
450
   immediately after deflateInit, deflateInit2 or deflateReset, before any
451
   call of deflate. The compressor and decompressor must use exactly the same
452
   dictionary (see inflateSetDictionary).
453
 
454
     The dictionary should consist of strings (byte sequences) that are likely
455
   to be encountered later in the data to be compressed, with the most commonly
456
   used strings preferably put towards the end of the dictionary. Using a
457
   dictionary is most useful when the data to be compressed is short and can be
458
   predicted with good accuracy; the data can then be compressed better than
459
   with the default empty dictionary.
460
 
461
     Depending on the size of the compression data structures selected by
462
   deflateInit or deflateInit2, a part of the dictionary may in effect be
463
   discarded, for example if the dictionary is larger than the window size in
464
   deflate or deflate2. Thus the strings most likely to be useful should be
465
   put at the end of the dictionary, not at the front.
466
 
467
     Upon return of this function, strm->adler is set to the Adler32 value
468
   of the dictionary; the decompressor may later use this value to determine
469
   which dictionary has been used by the compressor. (The Adler32 value
470
   applies to the whole dictionary even if only a subset of the dictionary is
471
   actually used by the compressor.)
472
 
473
     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
474
   parameter is invalid (such as NULL dictionary) or the stream state is
475
   inconsistent (for example if deflate has already been called for this stream
476
   or if the compression method is bsort). deflateSetDictionary does not
477
   perform any compression: this will be done by deflate().
478
*/
479
 
480
ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
481
                                    z_streamp source));
482
/*
483
     Sets the destination stream as a complete copy of the source stream.
484
 
485
     This function can be useful when several compression strategies will be
486
   tried, for example when there are several ways of pre-processing the input
487
   data with a filter. The streams that will be discarded should then be freed
488
   by calling deflateEnd.  Note that deflateCopy duplicates the internal
489
   compression state which can be quite large, so this strategy is slow and
490
   can consume lots of memory.
491
 
492
     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
493
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
494
   (such as zalloc being NULL). msg is left unchanged in both source and
495
   destination.
496
*/
497
 
498
ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
499
/*
500
     This function is equivalent to deflateEnd followed by deflateInit,
501
   but does not free and reallocate all the internal compression state.
502
   The stream will keep the same compression level and any other attributes
503
   that may have been set by deflateInit2.
504
 
505
      deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
506
   stream state was inconsistent (such as zalloc or state being NULL).
507
*/
508
 
509
ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
510
                                      int level,
511
                                      int strategy));
512
/*
513
     Dynamically update the compression level and compression strategy.  The
514
   interpretation of level and strategy is as in deflateInit2.  This can be
515
   used to switch between compression and straight copy of the input data, or
516
   to switch to a different kind of input data requiring a different
517
   strategy. If the compression level is changed, the input available so far
518
   is compressed with the old level (and may be flushed); the new level will
519
   take effect only at the next call of deflate().
520
 
521
     Before the call of deflateParams, the stream state must be set as for
522
   a call of deflate(), since the currently available input may have to
523
   be compressed and flushed. In particular, strm->avail_out must be non-zero.
524
 
525
     deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
526
   stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
527
   if strm->avail_out was zero.
528
*/
529
 
530
/*  
531
ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
532
                                     int  windowBits));
533
 
534
     This is another version of inflateInit with an extra parameter. The
535
   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
536
   before by the caller.
537
 
538
     The windowBits parameter is the base two logarithm of the maximum window
539
   size (the size of the history buffer).  It should be in the range 8..15 for
540
   this version of the library. The default value is 15 if inflateInit is used
541
   instead. If a compressed stream with a larger window size is given as
542
   input, inflate() will return with the error code Z_DATA_ERROR instead of
543
   trying to allocate a larger window.
544
 
545
      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
546
   memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
547
   memLevel). msg is set to null if there is no error message.  inflateInit2
548
   does not perform any decompression apart from reading the zlib header if
549
   present: this will be done by inflate(). (So next_in and avail_in may be
550
   modified, but next_out and avail_out are unchanged.)
551
*/
552
 
553
ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
554
                                             const Bytef *dictionary,
555
                                             uInt  dictLength));
556
/*
557
     Initializes the decompression dictionary from the given uncompressed byte
558
   sequence. This function must be called immediately after a call of inflate
559
   if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
560
   can be determined from the Adler32 value returned by this call of
561
   inflate. The compressor and decompressor must use exactly the same
562
   dictionary (see deflateSetDictionary).
563
 
564
     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
565
   parameter is invalid (such as NULL dictionary) or the stream state is
566
   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
567
   expected one (incorrect Adler32 value). inflateSetDictionary does not
568
   perform any decompression: this will be done by subsequent calls of
569
   inflate().
570
*/
571
 
572
ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
573
/*
574
    Skips invalid compressed data until a full flush point (see above the
575
  description of deflate with Z_FULL_FLUSH) can be found, or until all
576
  available input is skipped. No output is provided.
577
 
578
    inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
579
  if no more input was provided, Z_DATA_ERROR if no flush point has been found,
580
  or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
581
  case, the application may save the current current value of total_in which
582
  indicates where valid compressed data was found. In the error case, the
583
  application may repeatedly call inflateSync, providing more input each time,
584
  until success or end of the input data.
585
*/
586
 
587
ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
588
/*
589
     This function is equivalent to inflateEnd followed by inflateInit,
590
   but does not free and reallocate all the internal decompression state.
591
   The stream will keep attributes that may have been set by inflateInit2.
592
 
593
      inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
594
   stream state was inconsistent (such as zalloc or state being NULL).
595
*/
596
 
597
 
598
                        /* utility functions */
599
 
600
/*
601
     The following utility functions are implemented on top of the
602
   basic stream-oriented functions. To simplify the interface, some
603
   default options are assumed (compression level and memory usage,
604
   standard memory allocation functions). The source code of these
605
   utility functions can easily be modified if you need special options.
606
*/
607
 
608
ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
609
                                 const Bytef *source, uLong sourceLen));
610
/*
611
     Compresses the source buffer into the destination buffer.  sourceLen is
612
   the byte length of the source buffer. Upon entry, destLen is the total
613
   size of the destination buffer, which must be at least 0.1% larger than
614
   sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the
615
   compressed buffer.
616
     This function can be used to compress a whole file at once if the
617
   input file is mmap'ed.
618
     compress returns Z_OK if success, Z_MEM_ERROR if there was not
619
   enough memory, Z_BUF_ERROR if there was not enough room in the output
620
   buffer.
621
*/
622
 
623
ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
624
                                  const Bytef *source, uLong sourceLen,
625
                                  int level));
626
/*
627
     Compresses the source buffer into the destination buffer. The level
628
   parameter has the same meaning as in deflateInit.  sourceLen is the byte
629
   length of the source buffer. Upon entry, destLen is the total size of the
630
   destination buffer, which must be at least 0.1% larger than sourceLen plus
631
   12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
632
 
633
     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
634
   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
635
   Z_STREAM_ERROR if the level parameter is invalid.
636
*/
637
 
638
ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
639
                                   const Bytef *source, uLong sourceLen));
640
/*
641
     Decompresses the source buffer into the destination buffer.  sourceLen is
642
   the byte length of the source buffer. Upon entry, destLen is the total
643
   size of the destination buffer, which must be large enough to hold the
644
   entire uncompressed data. (The size of the uncompressed data must have
645
   been saved previously by the compressor and transmitted to the decompressor
646
   by some mechanism outside the scope of this compression library.)
647
   Upon exit, destLen is the actual size of the compressed buffer.
648
     This function can be used to decompress a whole file at once if the
649
   input file is mmap'ed.
650
 
651
     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
652
   enough memory, Z_BUF_ERROR if there was not enough room in the output
653
   buffer, or Z_DATA_ERROR if the input data was corrupted.
654
*/
655
 
656
 
657
typedef voidp gzFile;
658
 
659
ZEXTERN gzFile ZEXPORT gzopen  OF((const char *path, const char *mode));
660
/*
661
     Opens a gzip (.gz) file for reading or writing. The mode parameter
662
   is as in fopen ("rb" or "wb") but can also include a compression level
663
   ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
664
   Huffman only compression as in "wb1h". (See the description
665
   of deflateInit2 for more information about the strategy parameter.)
666
 
667
     gzopen can be used to read a file which is not in gzip format; in this
668
   case gzread will directly read from the file without decompression.
669
 
670
     gzopen returns NULL if the file could not be opened or if there was
671
   insufficient memory to allocate the (de)compression state; errno
672
   can be checked to distinguish the two cases (if errno is zero, the
673
   zlib error is Z_MEM_ERROR).  */
674
 
675
ZEXTERN gzFile ZEXPORT gzdopen  OF((int fd, const char *mode));
676
/*
677
     gzdopen() associates a gzFile with the file descriptor fd.  File
678
   descriptors are obtained from calls like open, dup, creat, pipe or
679
   fileno (in the file has been previously opened with fopen).
680
   The mode parameter is as in gzopen.
681
     The next call of gzclose on the returned gzFile will also close the
682
   file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
683
   descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
684
     gzdopen returns NULL if there was insufficient memory to allocate
685
   the (de)compression state.
686
*/
687
 
688
ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
689
/*
690
     Dynamically update the compression level or strategy. See the description
691
   of deflateInit2 for the meaning of these parameters.
692
     gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
693
   opened for writing.
694
*/
695
 
696
ZEXTERN int ZEXPORT    gzread  OF((gzFile file, voidp buf, unsigned len));
697
/*
698
     Reads the given number of uncompressed bytes from the compressed file.
699
   If the input file was not in gzip format, gzread copies the given number
700
   of bytes into the buffer.
701
     gzread returns the number of uncompressed bytes actually read (0 for
702
   end of file, -1 for error). */
703
 
704
ZEXTERN int ZEXPORT    gzwrite OF((gzFile file,
705
                                   const voidp buf, unsigned len));
706
/*
707
     Writes the given number of uncompressed bytes into the compressed file.
708
   gzwrite returns the number of uncompressed bytes actually written
709
   (0 in case of error).
710
*/
711
 
712
ZEXTERN int ZEXPORTVA   gzprintf OF((gzFile file, const char *format, ...));
713
/*
714
     Converts, formats, and writes the args to the compressed file under
715
   control of the format string, as in fprintf. gzprintf returns the number of
716
   uncompressed bytes actually written (0 in case of error).
717
*/
718
 
719
ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
720
/*
721
      Writes the given null-terminated string to the compressed file, excluding
722
   the terminating null character.
723
      gzputs returns the number of characters written, or -1 in case of error.
724
*/
725
 
726
ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
727
/*
728
      Reads bytes from the compressed file until len-1 characters are read, or
729
   a newline character is read and transferred to buf, or an end-of-file
730
   condition is encountered.  The string is then terminated with a null
731
   character.
732
      gzgets returns buf, or Z_NULL in case of error.
733
*/
734
 
735
ZEXTERN int ZEXPORT    gzputc OF((gzFile file, int c));
736
/*
737
      Writes c, converted to an unsigned char, into the compressed file.
738
   gzputc returns the value that was written, or -1 in case of error.
739
*/
740
 
741
ZEXTERN int ZEXPORT    gzgetc OF((gzFile file));
742
/*
743
      Reads one byte from the compressed file. gzgetc returns this byte
744
   or -1 in case of end of file or error.
745
*/
746
 
747
ZEXTERN int ZEXPORT    gzflush OF((gzFile file, int flush));
748
/*
749
     Flushes all pending output into the compressed file. The parameter
750
   flush is as in the deflate() function. The return value is the zlib
751
   error number (see function gzerror below). gzflush returns Z_OK if
752
   the flush parameter is Z_FINISH and all output could be flushed.
753
     gzflush should be called only when strictly necessary because it can
754
   degrade compression.
755
*/
756
 
757
ZEXTERN z_off_t ZEXPORT    gzseek OF((gzFile file,
758
                                      z_off_t offset, int whence));
759
/*
760
      Sets the starting position for the next gzread or gzwrite on the
761
   given compressed file. The offset represents a number of bytes in the
762
   uncompressed data stream. The whence parameter is defined as in lseek(2);
763
   the value SEEK_END is not supported.
764
     If the file is opened for reading, this function is emulated but can be
765
   extremely slow. If the file is opened for writing, only forward seeks are
766
   supported; gzseek then compresses a sequence of zeroes up to the new
767
   starting position.
768
 
769
      gzseek returns the resulting offset location as measured in bytes from
770
   the beginning of the uncompressed stream, or -1 in case of error, in
771
   particular if the file is opened for writing and the new starting position
772
   would be before the current position.
773
*/
774
 
775
ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
776
/*
777
     Rewinds the given file. This function is supported only for reading.
778
 
779
   gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
780
*/
781
 
782
ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
783
/*
784
     Returns the starting position for the next gzread or gzwrite on the
785
   given compressed file. This position represents a number of bytes in the
786
   uncompressed data stream.
787
 
788
   gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
789
*/
790
 
791
ZEXTERN int ZEXPORT gzeof OF((gzFile file));
792
/*
793
     Returns 1 when EOF has previously been detected reading the given
794
   input stream, otherwise zero.
795
*/
796
 
797
ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
798
/*
799
     Flushes all pending output if necessary, closes the compressed file
800
   and deallocates all the (de)compression state. The return value is the zlib
801
   error number (see function gzerror below).
802
*/
803
 
804
ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
805
/*
806
     Returns the error message for the last error which occurred on the
807
   given compressed file. errnum is set to zlib error number. If an
808
   error occurred in the file system and not in the compression library,
809
   errnum is set to Z_ERRNO and the application may consult errno
810
   to get the exact error code.
811
*/
812
 
813
                        /* checksum functions */
814
 
815
/*
816
     These functions are not related to compression but are exported
817
   anyway because they might be useful in applications using the
818
   compression library.
819
*/
820
 
821
ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
822
 
823
/*
824
     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
825
   return the updated checksum. If buf is NULL, this function returns
826
   the required initial value for the checksum.
827
   An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
828
   much faster. Usage example:
829
 
830
     uLong adler = adler32(0L, Z_NULL, 0);
831
 
832
     while (read_buffer(buffer, length) != EOF) {
833
       adler = adler32(adler, buffer, length);
834
     }
835
     if (adler != original_adler) error();
836
*/
837
 
838
ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
839
/*
840
     Update a running crc with the bytes buf[0..len-1] and return the updated
841
   crc. If buf is NULL, this function returns the required initial value
842
   for the crc. Pre- and post-conditioning (one's complement) is performed
843
   within this function so it shouldn't be done by the application.
844
   Usage example:
845
 
846
     uLong crc = crc32(0L, Z_NULL, 0);
847
 
848
     while (read_buffer(buffer, length) != EOF) {
849
       crc = crc32(crc, buffer, length);
850
     }
851
     if (crc != original_crc) error();
852
*/
853
 
854
 
855
                        /* various hacks, don't look :) */
856
 
857
/* deflateInit and inflateInit are macros to allow checking the zlib version
858
 * and the compiler's view of z_stream:
859
 */
860
ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
861
                                     const char *version, int stream_size));
862
ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
863
                                     const char *version, int stream_size));
864
ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
865
                                      int windowBits, int memLevel,
866
                                      int strategy, const char *version,
867
                                      int stream_size));
868
ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
869
                                      const char *version, int stream_size));
870
#define deflateInit(strm, level) \
871
        deflateInit_((strm), (level),       ZLIB_VERSION, sizeof(z_stream))
872
#define inflateInit(strm) \
873
        inflateInit_((strm),                ZLIB_VERSION, sizeof(z_stream))
874
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
875
        deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
876
                      (strategy),           ZLIB_VERSION, sizeof(z_stream))
877
#define inflateInit2(strm, windowBits) \
878
        inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
879
 
880
 
881
#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
882
    struct internal_state {int dummy;}; /* hack for buggy compilers */
883
#endif
884
 
885
ZEXTERN const char   * ZEXPORT zError           OF((int err));
886
ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp z));
887
ZEXTERN const uLongf * ZEXPORT get_crc_table    OF((void));
888
 
889
#ifdef __cplusplus
890
}
891
#endif
892
 
893
#endif /* _ZLIB_H */