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/* zlib.h -- interface of the 'zlib' general purpose compression library
2
  version 1.1.3, July 9th, 1998
3
 
4
  Copyright (C) 1995-1998 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 <linux/zconf.h>
35
 
36
#define ZLIB_VERSION "1.1.3"
37
 
38
/*
39
     The 'zlib' compression library provides in-memory compression and
40
  decompression functions, including integrity checks of the uncompressed
41
  data.  This version of the library supports only one compression method
42
  (deflation) but other algorithms will be added later and will have the same
43
  stream interface.
44
 
45
     Compression can be done in a single step if the buffers are large
46
  enough (for example if an input file is mmap'ed), or can be done by
47
  repeated calls of the compression function.  In the latter case, the
48
  application must provide more input and/or consume the output
49
  (providing more output space) before each call.
50
 
51
     The library also supports reading and writing files in gzip (.gz) format
52
  with an interface similar to that of stdio.
53
 
54
     The library does not install any signal handler. The decoder checks
55
  the consistency of the compressed data, so the library should never
56
  crash even in case of corrupted input.
57
*/
58
 
59
struct internal_state;
60
 
61
typedef struct z_stream_s {
62
    Byte    *next_in;   /* next input byte */
63
    uInt     avail_in;  /* number of bytes available at next_in */
64
    uLong    total_in;  /* total nb of input bytes read so far */
65
 
66
    Byte    *next_out;  /* next output byte should be put there */
67
    uInt     avail_out; /* remaining free space at next_out */
68
    uLong    total_out; /* total nb of bytes output so far */
69
 
70
    char     *msg;      /* last error message, NULL if no error */
71
    struct internal_state *state; /* not visible by applications */
72
 
73
    void     *workspace; /* memory allocated for this stream */
74
 
75
    int     data_type;  /* best guess about the data type: ascii or binary */
76
    uLong   adler;      /* adler32 value of the uncompressed data */
77
    uLong   reserved;   /* reserved for future use */
78
} z_stream;
79
 
80
typedef z_stream *z_streamp;
81
 
82
/*
83
   The application must update next_in and avail_in when avail_in has
84
   dropped to zero. It must update next_out and avail_out when avail_out
85
   has dropped to zero. The application must initialize zalloc, zfree and
86
   opaque before calling the init function. All other fields are set by the
87
   compression library and must not be updated by the application.
88
 
89
   The opaque value provided by the application will be passed as the first
90
   parameter for calls of zalloc and zfree. This can be useful for custom
91
   memory management. The compression library attaches no meaning to the
92
   opaque value.
93
 
94
   zalloc must return NULL if there is not enough memory for the object.
95
   If zlib is used in a multi-threaded application, zalloc and zfree must be
96
   thread safe.
97
 
98
   On 16-bit systems, the functions zalloc and zfree must be able to allocate
99
   exactly 65536 bytes, but will not be required to allocate more than this
100
   if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
101
   pointers returned by zalloc for objects of exactly 65536 bytes *must*
102
   have their offset normalized to zero. The default allocation function
103
   provided by this library ensures this (see zutil.c). To reduce memory
104
   requirements and avoid any allocation of 64K objects, at the expense of
105
   compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
106
 
107
   The fields total_in and total_out can be used for statistics or
108
   progress reports. After compression, total_in holds the total size of
109
   the uncompressed data and may be saved for use in the decompressor
110
   (particularly if the decompressor wants to decompress everything in
111
   a single step).
112
*/
113
 
114
                        /* constants */
115
 
116
#define Z_NO_FLUSH      0
117
#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
118
#define Z_PACKET_FLUSH  2
119
#define Z_SYNC_FLUSH    3
120
#define Z_FULL_FLUSH    4
121
#define Z_FINISH        5
122
/* Allowed flush values; see deflate() below for details */
123
 
124
#define Z_OK            0
125
#define Z_STREAM_END    1
126
#define Z_NEED_DICT     2
127
#define Z_ERRNO        (-1)
128
#define Z_STREAM_ERROR (-2)
129
#define Z_DATA_ERROR   (-3)
130
#define Z_MEM_ERROR    (-4)
131
#define Z_BUF_ERROR    (-5)
132
#define Z_VERSION_ERROR (-6)
133
/* Return codes for the compression/decompression functions. Negative
134
 * values are errors, positive values are used for special but normal events.
135
 */
136
 
137
#define Z_NO_COMPRESSION         0
138
#define Z_BEST_SPEED             1
139
#define Z_BEST_COMPRESSION       9
140
#define Z_DEFAULT_COMPRESSION  (-1)
141
/* compression levels */
142
 
143
#define Z_FILTERED            1
144
#define Z_HUFFMAN_ONLY        2
145
#define Z_DEFAULT_STRATEGY    0
146
/* compression strategy; see deflateInit2() below for details */
147
 
148
#define Z_BINARY   0
149
#define Z_ASCII    1
150
#define Z_UNKNOWN  2
151
/* Possible values of the data_type field */
152
 
153
#define Z_DEFLATED   8
154
/* The deflate compression method (the only one supported in this version) */
155
 
156
                        /* basic functions */
157
 
158
extern const char * zlib_zlibVersion (void);
159
/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
160
   If the first character differs, the library code actually used is
161
   not compatible with the zlib.h header file used by the application.
162
   This check is automatically made by deflateInit and inflateInit.
163
 */
164
 
165
extern int zlib_deflate_workspacesize (void);
166
/*
167
   Returns the number of bytes that needs to be allocated for a per-
168
   stream workspace.  A pointer to this number of bytes should be
169
   returned in stream->workspace before calling zlib_deflateInit().
170
*/
171
 
172
/*
173
extern int deflateInit (z_streamp strm, int level);
174
 
175
     Initializes the internal stream state for compression. The fields
176
   zalloc, zfree and opaque must be initialized before by the caller.
177
   If zalloc and zfree are set to NULL, deflateInit updates them to
178
   use default allocation functions.
179
 
180
     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
181
   1 gives best speed, 9 gives best compression, 0 gives no compression at
182
   all (the input data is simply copied a block at a time).
183
   Z_DEFAULT_COMPRESSION requests a default compromise between speed and
184
   compression (currently equivalent to level 6).
185
 
186
     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
187
   enough memory, Z_STREAM_ERROR if level is not a valid compression level,
188
   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
189
   with the version assumed by the caller (ZLIB_VERSION).
190
   msg is set to null if there is no error message.  deflateInit does not
191
   perform any compression: this will be done by deflate().
192
*/
193
 
194
 
195
extern int zlib_deflate (z_streamp strm, int flush);
196
/*
197
    deflate compresses as much data as possible, and stops when the input
198
  buffer becomes empty or the output buffer becomes full. It may introduce some
199
  output latency (reading input without producing any output) except when
200
  forced to flush.
201
 
202
    The detailed semantics are as follows. deflate performs one or both of the
203
  following actions:
204
 
205
  - Compress more input starting at next_in and update next_in and avail_in
206
    accordingly. If not all input can be processed (because there is not
207
    enough room in the output buffer), next_in and avail_in are updated and
208
    processing will resume at this point for the next call of deflate().
209
 
210
  - Provide more output starting at next_out and update next_out and avail_out
211
    accordingly. This action is forced if the parameter flush is non zero.
212
    Forcing flush frequently degrades the compression ratio, so this parameter
213
    should be set only when necessary (in interactive applications).
214
    Some output may be provided even if flush is not set.
215
 
216
  Before the call of deflate(), the application should ensure that at least
217
  one of the actions is possible, by providing more input and/or consuming
218
  more output, and updating avail_in or avail_out accordingly; avail_out
219
  should never be zero before the call. The application can consume the
220
  compressed output when it wants, for example when the output buffer is full
221
  (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
222
  and with zero avail_out, it must be called again after making room in the
223
  output buffer because there might be more output pending.
224
 
225
    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
226
  flushed to the output buffer and the output is aligned on a byte boundary, so
227
  that the decompressor can get all input data available so far. (In particular
228
  avail_in is zero after the call if enough output space has been provided
229
  before the call.)  Flushing may degrade compression for some compression
230
  algorithms and so it should be used only when necessary.
231
 
232
    If flush is set to Z_FULL_FLUSH, all output is flushed as with
233
  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
234
  restart from this point if previous compressed data has been damaged or if
235
  random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
236
  the compression.
237
 
238
    If deflate returns with avail_out == 0, this function must be called again
239
  with the same value of the flush parameter and more output space (updated
240
  avail_out), until the flush is complete (deflate returns with non-zero
241
  avail_out).
242
 
243
    If the parameter flush is set to Z_FINISH, pending input is processed,
244
  pending output is flushed and deflate returns with Z_STREAM_END if there
245
  was enough output space; if deflate returns with Z_OK, this function must be
246
  called again with Z_FINISH and more output space (updated avail_out) but no
247
  more input data, until it returns with Z_STREAM_END or an error. After
248
  deflate has returned Z_STREAM_END, the only possible operations on the
249
  stream are deflateReset or deflateEnd.
250
 
251
    Z_FINISH can be used immediately after deflateInit if all the compression
252
  is to be done in a single step. In this case, avail_out must be at least
253
  0.1% larger than avail_in plus 12 bytes.  If deflate does not return
254
  Z_STREAM_END, then it must be called again as described above.
255
 
256
    deflate() sets strm->adler to the adler32 checksum of all input read
257
  so far (that is, total_in bytes).
258
 
259
    deflate() may update data_type if it can make a good guess about
260
  the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
261
  binary. This field is only for information purposes and does not affect
262
  the compression algorithm in any manner.
263
 
264
    deflate() returns Z_OK if some progress has been made (more input
265
  processed or more output produced), Z_STREAM_END if all input has been
266
  consumed and all output has been produced (only when flush is set to
267
  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
268
  if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
269
  (for example avail_in or avail_out was zero).
270
*/
271
 
272
 
273
extern int zlib_deflateEnd (z_streamp strm);
274
/*
275
     All dynamically allocated data structures for this stream are freed.
276
   This function discards any unprocessed input and does not flush any
277
   pending output.
278
 
279
     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
280
   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
281
   prematurely (some input or output was discarded). In the error case,
282
   msg may be set but then points to a static string (which must not be
283
   deallocated).
284
*/
285
 
286
 
287
extern int zlib_inflate_workspacesize (void);
288
/*
289
   Returns the number of bytes that needs to be allocated for a per-
290
   stream workspace.  A pointer to this number of bytes should be
291
   returned in stream->workspace before calling zlib_inflateInit().
292
*/
293
 
294
/*
295
extern int zlib_inflateInit (z_streamp strm);
296
 
297
     Initializes the internal stream state for decompression. The fields
298
   next_in, avail_in, and workspace must be initialized before by
299
   the caller. If next_in is not NULL and avail_in is large enough (the exact
300
   value depends on the compression method), inflateInit determines the
301
   compression method from the zlib header and allocates all data structures
302
   accordingly; otherwise the allocation will be deferred to the first call of
303
   inflate.  If zalloc and zfree are set to NULL, inflateInit updates them to
304
   use default allocation functions.
305
 
306
     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
307
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
308
   version assumed by the caller.  msg is set to null if there is no error
309
   message. inflateInit does not perform any decompression apart from reading
310
   the zlib header if present: this will be done by inflate().  (So next_in and
311
   avail_in may be modified, but next_out and avail_out are unchanged.)
312
*/
313
 
314
 
315
extern int zlib_inflate (z_streamp strm, int flush);
316
/*
317
    inflate decompresses as much data as possible, and stops when the input
318
  buffer becomes empty or the output buffer becomes full. It may some
319
  introduce some output latency (reading input without producing any output)
320
  except when forced to flush.
321
 
322
  The detailed semantics are as follows. inflate performs one or both of the
323
  following actions:
324
 
325
  - Decompress more input starting at next_in and update next_in and avail_in
326
    accordingly. If not all input can be processed (because there is not
327
    enough room in the output buffer), next_in is updated and processing
328
    will resume at this point for the next call of inflate().
329
 
330
  - Provide more output starting at next_out and update next_out and avail_out
331
    accordingly.  inflate() provides as much output as possible, until there
332
    is no more input data or no more space in the output buffer (see below
333
    about the flush parameter).
334
 
335
  Before the call of inflate(), the application should ensure that at least
336
  one of the actions is possible, by providing more input and/or consuming
337
  more output, and updating the next_* and avail_* values accordingly.
338
  The application can consume the uncompressed output when it wants, for
339
  example when the output buffer is full (avail_out == 0), or after each
340
  call of inflate(). If inflate returns Z_OK and with zero avail_out, it
341
  must be called again after making room in the output buffer because there
342
  might be more output pending.
343
 
344
    If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much
345
  output as possible to the output buffer. The flushing behavior of inflate is
346
  not specified for values of the flush parameter other than Z_SYNC_FLUSH
347
  and Z_FINISH, but the current implementation actually flushes as much output
348
  as possible anyway.
349
 
350
    inflate() should normally be called until it returns Z_STREAM_END or an
351
  error. However if all decompression is to be performed in a single step
352
  (a single call of inflate), the parameter flush should be set to
353
  Z_FINISH. In this case all pending input is processed and all pending
354
  output is flushed; avail_out must be large enough to hold all the
355
  uncompressed data. (The size of the uncompressed data may have been saved
356
  by the compressor for this purpose.) The next operation on this stream must
357
  be inflateEnd to deallocate the decompression state. The use of Z_FINISH
358
  is never required, but can be used to inform inflate that a faster routine
359
  may be used for the single inflate() call.
360
 
361
     If a preset dictionary is needed at this point (see inflateSetDictionary
362
  below), inflate sets strm-adler to the adler32 checksum of the
363
  dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise
364
  it sets strm->adler to the adler32 checksum of all output produced
365
  so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or
366
  an error code as described below. At the end of the stream, inflate()
367
  checks that its computed adler32 checksum is equal to that saved by the
368
  compressor and returns Z_STREAM_END only if the checksum is correct.
369
 
370
    inflate() returns Z_OK if some progress has been made (more input processed
371
  or more output produced), Z_STREAM_END if the end of the compressed data has
372
  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
373
  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
374
  corrupted (input stream not conforming to the zlib format or incorrect
375
  adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent
376
  (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not
377
  enough memory, Z_BUF_ERROR if no progress is possible or if there was not
378
  enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR
379
  case, the application may then call inflateSync to look for a good
380
  compression block.
381
*/
382
 
383
 
384
extern int zlib_inflateEnd (z_streamp strm);
385
/*
386
     All dynamically allocated data structures for this stream are freed.
387
   This function discards any unprocessed input and does not flush any
388
   pending output.
389
 
390
     inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
391
   was inconsistent. In the error case, msg may be set but then points to a
392
   static string (which must not be deallocated).
393
*/
394
 
395
                        /* Advanced functions */
396
 
397
/*
398
    The following functions are needed only in some special applications.
399
*/
400
 
401
/*  
402
extern int deflateInit2 (z_streamp strm,
403
                                     int  level,
404
                                     int  method,
405
                                     int  windowBits,
406
                                     int  memLevel,
407
                                     int  strategy);
408
 
409
     This is another version of deflateInit with more compression options. The
410
   fields next_in, zalloc, zfree and opaque must be initialized before by
411
   the caller.
412
 
413
     The method parameter is the compression method. It must be Z_DEFLATED in
414
   this version of the library.
415
 
416
     The windowBits parameter is the base two logarithm of the window size
417
   (the size of the history buffer).  It should be in the range 8..15 for this
418
   version of the library. Larger values of this parameter result in better
419
   compression at the expense of memory usage. The default value is 15 if
420
   deflateInit is used instead.
421
 
422
     The memLevel parameter specifies how much memory should be allocated
423
   for the internal compression state. memLevel=1 uses minimum memory but
424
   is slow and reduces compression ratio; memLevel=9 uses maximum memory
425
   for optimal speed. The default value is 8. See zconf.h for total memory
426
   usage as a function of windowBits and memLevel.
427
 
428
     The strategy parameter is used to tune the compression algorithm. Use the
429
   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
430
   filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
431
   string match).  Filtered data consists mostly of small values with a
432
   somewhat random distribution. In this case, the compression algorithm is
433
   tuned to compress them better. The effect of Z_FILTERED is to force more
434
   Huffman coding and less string matching; it is somewhat intermediate
435
   between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
436
   the compression ratio but not the correctness of the compressed output even
437
   if it is not set appropriately.
438
 
439
      deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
440
   memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
441
   method). msg is set to null if there is no error message.  deflateInit2 does
442
   not perform any compression: this will be done by deflate().
443
*/
444
 
445
extern int zlib_deflateSetDictionary (z_streamp strm,
446
                                                     const Byte *dictionary,
447
                                                     uInt  dictLength);
448
/*
449
     Initializes the compression dictionary from the given byte sequence
450
   without producing any compressed output. This function must be called
451
   immediately after deflateInit, deflateInit2 or deflateReset, before any
452
   call of deflate. The compressor and decompressor must use exactly the same
453
   dictionary (see inflateSetDictionary).
454
 
455
     The dictionary should consist of strings (byte sequences) that are likely
456
   to be encountered later in the data to be compressed, with the most commonly
457
   used strings preferably put towards the end of the dictionary. Using a
458
   dictionary is most useful when the data to be compressed is short and can be
459
   predicted with good accuracy; the data can then be compressed better than
460
   with the default empty dictionary.
461
 
462
     Depending on the size of the compression data structures selected by
463
   deflateInit or deflateInit2, a part of the dictionary may in effect be
464
   discarded, for example if the dictionary is larger than the window size in
465
   deflate or deflate2. Thus the strings most likely to be useful should be
466
   put at the end of the dictionary, not at the front.
467
 
468
     Upon return of this function, strm->adler is set to the Adler32 value
469
   of the dictionary; the decompressor may later use this value to determine
470
   which dictionary has been used by the compressor. (The Adler32 value
471
   applies to the whole dictionary even if only a subset of the dictionary is
472
   actually used by the compressor.)
473
 
474
     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
475
   parameter is invalid (such as NULL dictionary) or the stream state is
476
   inconsistent (for example if deflate has already been called for this stream
477
   or if the compression method is bsort). deflateSetDictionary does not
478
   perform any compression: this will be done by deflate().
479
*/
480
 
481
extern int zlib_deflateCopy (z_streamp dest, 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
extern int zlib_deflateReset (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
extern int zlib_deflateParams (z_streamp strm, int level, int strategy);
510
/*
511
     Dynamically update the compression level and compression strategy.  The
512
   interpretation of level and strategy is as in deflateInit2.  This can be
513
   used to switch between compression and straight copy of the input data, or
514
   to switch to a different kind of input data requiring a different
515
   strategy. If the compression level is changed, the input available so far
516
   is compressed with the old level (and may be flushed); the new level will
517
   take effect only at the next call of deflate().
518
 
519
     Before the call of deflateParams, the stream state must be set as for
520
   a call of deflate(), since the currently available input may have to
521
   be compressed and flushed. In particular, strm->avail_out must be non-zero.
522
 
523
     deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
524
   stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
525
   if strm->avail_out was zero.
526
*/
527
 
528
/*  
529
extern int inflateInit2 (z_streamp strm, int  windowBits);
530
 
531
     This is another version of inflateInit with an extra parameter. The
532
   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
533
   before by the caller.
534
 
535
     The windowBits parameter is the base two logarithm of the maximum window
536
   size (the size of the history buffer).  It should be in the range 8..15 for
537
   this version of the library. The default value is 15 if inflateInit is used
538
   instead. If a compressed stream with a larger window size is given as
539
   input, inflate() will return with the error code Z_DATA_ERROR instead of
540
   trying to allocate a larger window.
541
 
542
      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
543
   memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
544
   memLevel). msg is set to null if there is no error message.  inflateInit2
545
   does not perform any decompression apart from reading the zlib header if
546
   present: this will be done by inflate(). (So next_in and avail_in may be
547
   modified, but next_out and avail_out are unchanged.)
548
*/
549
 
550
extern int zlib_inflateSetDictionary (z_streamp strm,
551
                                                     const Byte *dictionary,
552
                                                     uInt  dictLength);
553
/*
554
     Initializes the decompression dictionary from the given uncompressed byte
555
   sequence. This function must be called immediately after a call of inflate
556
   if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
557
   can be determined from the Adler32 value returned by this call of
558
   inflate. The compressor and decompressor must use exactly the same
559
   dictionary (see deflateSetDictionary).
560
 
561
     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
562
   parameter is invalid (such as NULL dictionary) or the stream state is
563
   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
564
   expected one (incorrect Adler32 value). inflateSetDictionary does not
565
   perform any decompression: this will be done by subsequent calls of
566
   inflate().
567
*/
568
 
569
extern int zlib_inflateSync (z_streamp strm);
570
/*
571
    Skips invalid compressed data until a full flush point (see above the
572
  description of deflate with Z_FULL_FLUSH) can be found, or until all
573
  available input is skipped. No output is provided.
574
 
575
    inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
576
  if no more input was provided, Z_DATA_ERROR if no flush point has been found,
577
  or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
578
  case, the application may save the current current value of total_in which
579
  indicates where valid compressed data was found. In the error case, the
580
  application may repeatedly call inflateSync, providing more input each time,
581
  until success or end of the input data.
582
*/
583
 
584
extern int zlib_inflateReset (z_streamp strm);
585
/*
586
     This function is equivalent to inflateEnd followed by inflateInit,
587
   but does not free and reallocate all the internal decompression state.
588
   The stream will keep attributes that may have been set by inflateInit2.
589
 
590
      inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
591
   stream state was inconsistent (such as zalloc or state being NULL).
592
*/
593
 
594
extern int zlib_inflateIncomp (z_stream *strm);
595
/*
596
     This function adds the data at next_in (avail_in bytes) to the output
597
   history without performing any output.  There must be no pending output,
598
   and the decompressor must be expecting to see the start of a block.
599
   Calling this function is equivalent to decompressing a stored block
600
   containing the data at next_in (except that the data is not output).
601
*/
602
 
603
                        /* various hacks, don't look :) */
604
 
605
/* deflateInit and inflateInit are macros to allow checking the zlib version
606
 * and the compiler's view of z_stream:
607
 */
608
extern int zlib_deflateInit_ (z_streamp strm, int level,
609
                                     const char *version, int stream_size);
610
extern int zlib_inflateInit_ (z_streamp strm,
611
                                     const char *version, int stream_size);
612
extern int zlib_deflateInit2_ (z_streamp strm, int  level, int  method,
613
                                      int windowBits, int memLevel,
614
                                      int strategy, const char *version,
615
                                      int stream_size);
616
extern int zlib_inflateInit2_ (z_streamp strm, int  windowBits,
617
                                      const char *version, int stream_size);
618
#define zlib_deflateInit(strm, level) \
619
        zlib_deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
620
#define zlib_inflateInit(strm) \
621
        zlib_inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
622
#define zlib_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
623
        zlib_deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
624
                      (strategy), ZLIB_VERSION, sizeof(z_stream))
625
#define zlib_inflateInit2(strm, windowBits) \
626
        zlib_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
627
 
628
 
629
#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
630
    struct internal_state {int dummy;}; /* hack for buggy compilers */
631
#endif
632
 
633
extern const char  * zlib_zError           (int err);
634
extern int           zlib_inflateSyncPoint (z_streamp z);
635
extern const uLong * zlib_get_crc_table    (void);
636
 
637
#endif /* _ZLIB_H */