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/* zlib.h -- interface of the 'zlib' general purpose compression library
2
  version 1.2.3, July 18th, 2005
3
 
4
  Copyright (C) 1995-2005 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 http://www.ietf.org/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 "1.2.3"
41
#define ZLIB_VERNUM 0x1230
42
 
43
/*
44
     The 'zlib' compression library provides in-memory compression and
45
  decompression functions, including integrity checks of the uncompressed
46
  data.  This version of the library supports only one compression method
47
  (deflation) but other algorithms will be added later and will have the same
48
  stream interface.
49
 
50
     Compression can be done in a single step if the buffers are large
51
  enough (for example if an input file is mmap'ed), or can be done by
52
  repeated calls of the compression function.  In the latter case, the
53
  application must provide more input and/or consume the output
54
  (providing more output space) before each call.
55
 
56
     The compressed data format used by default by the in-memory functions is
57
  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
58
  around a deflate stream, which is itself documented in RFC 1951.
59
 
60
     The library also supports reading and writing files in gzip (.gz) format
61
  with an interface similar to that of stdio using the functions that start
62
  with "gz".  The gzip format is different from the zlib format.  gzip is a
63
  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
64
 
65
     This library can optionally read and write gzip streams in memory as well.
66
 
67
     The zlib format was designed to be compact and fast for use in memory
68
  and on communications channels.  The gzip format was designed for single-
69
  file compression on file systems, has a larger header than zlib to maintain
70
  directory information, and uses a different, slower check method than zlib.
71
 
72
     The library does not install any signal handler. The decoder checks
73
  the consistency of the compressed data, so the library should never
74
  crash even in case of corrupted input.
75
*/
76
 
77
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
78
typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
79
 
80
struct internal_state;
81
 
82
typedef struct z_stream_s {
83
    Bytef    *next_in;  /* next input byte */
84
    uInt     avail_in;  /* number of bytes available at next_in */
85
    uLong    total_in;  /* total nb of input bytes read so far */
86
 
87
    Bytef    *next_out; /* next output byte should be put there */
88
    uInt     avail_out; /* remaining free space at next_out */
89
    uLong    total_out; /* total nb of bytes output so far */
90
 
91
    char     *msg;      /* last error message, NULL if no error */
92
    struct internal_state FAR *state; /* not visible by applications */
93
 
94
    alloc_func zalloc;  /* used to allocate the internal state */
95
    free_func  zfree;   /* used to free the internal state */
96
    voidpf     opaque;  /* private data object passed to zalloc and zfree */
97
 
98
    int     data_type;  /* best guess about the data type: binary or text */
99
    uLong   adler;      /* adler32 value of the uncompressed data */
100
    uLong   reserved;   /* reserved for future use */
101
} z_stream;
102
 
103
typedef z_stream FAR *z_streamp;
104
 
105
/*
106
     gzip header information passed to and from zlib routines.  See RFC 1952
107
  for more details on the meanings of these fields.
108
*/
109
typedef struct gz_header_s {
110
    int     text;       /* true if compressed data believed to be text */
111
    uLong   time;       /* modification time */
112
    int     xflags;     /* extra flags (not used when writing a gzip file) */
113
    int     os;         /* operating system */
114
    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
115
    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
116
    uInt    extra_max;  /* space at extra (only when reading header) */
117
    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
118
    uInt    name_max;   /* space at name (only when reading header) */
119
    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
120
    uInt    comm_max;   /* space at comment (only when reading header) */
121
    int     hcrc;       /* true if there was or will be a header crc */
122
    int     done;       /* true when done reading gzip header (not used
123
                           when writing a gzip file) */
124
} gz_header;
125
 
126
typedef gz_header FAR *gz_headerp;
127
 
128
/*
129
   The application must update next_in and avail_in when avail_in has
130
   dropped to zero. It must update next_out and avail_out when avail_out
131
   has dropped to zero. The application must initialize zalloc, zfree and
132
   opaque before calling the init function. All other fields are set by the
133
   compression library and must not be updated by the application.
134
 
135
   The opaque value provided by the application will be passed as the first
136
   parameter for calls of zalloc and zfree. This can be useful for custom
137
   memory management. The compression library attaches no meaning to the
138
   opaque value.
139
 
140
   zalloc must return Z_NULL if there is not enough memory for the object.
141
   If zlib is used in a multi-threaded application, zalloc and zfree must be
142
   thread safe.
143
 
144
   On 16-bit systems, the functions zalloc and zfree must be able to allocate
145
   exactly 65536 bytes, but will not be required to allocate more than this
146
   if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
147
   pointers returned by zalloc for objects of exactly 65536 bytes *must*
148
   have their offset normalized to zero. The default allocation function
149
   provided by this library ensures this (see zutil.c). To reduce memory
150
   requirements and avoid any allocation of 64K objects, at the expense of
151
   compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
152
 
153
   The fields total_in and total_out can be used for statistics or
154
   progress reports. After compression, total_in holds the total size of
155
   the uncompressed data and may be saved for use in the decompressor
156
   (particularly if the decompressor wants to decompress everything in
157
   a single step).
158
*/
159
 
160
                        /* constants */
161
 
162
#define Z_NO_FLUSH      0
163
#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
164
#define Z_SYNC_FLUSH    2
165
#define Z_FULL_FLUSH    3
166
#define Z_FINISH        4
167
#define Z_BLOCK         5
168
/* Allowed flush values; see deflate() and inflate() below for details */
169
 
170
#define Z_OK            0
171
#define Z_STREAM_END    1
172
#define Z_NEED_DICT     2
173
#define Z_ERRNO        (-1)
174
#define Z_STREAM_ERROR (-2)
175
#define Z_DATA_ERROR   (-3)
176
#define Z_MEM_ERROR    (-4)
177
#define Z_BUF_ERROR    (-5)
178
#define Z_VERSION_ERROR (-6)
179
/* Return codes for the compression/decompression functions. Negative
180
 * values are errors, positive values are used for special but normal events.
181
 */
182
 
183
#define Z_NO_COMPRESSION         0
184
#define Z_BEST_SPEED             1
185
#define Z_BEST_COMPRESSION       9
186
#define Z_DEFAULT_COMPRESSION  (-1)
187
/* compression levels */
188
 
189
#define Z_FILTERED            1
190
#define Z_HUFFMAN_ONLY        2
191
#define Z_RLE                 3
192
#define Z_FIXED               4
193
#define Z_DEFAULT_STRATEGY    0
194
/* compression strategy; see deflateInit2() below for details */
195
 
196
#define Z_BINARY   0
197
#define Z_TEXT     1
198
#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
199
#define Z_UNKNOWN  2
200
/* Possible values of the data_type field (though see inflate()) */
201
 
202
#define Z_DEFLATED   8
203
/* The deflate compression method (the only one supported in this version) */
204
 
205
#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
206
 
207
#define zlib_version zlibVersion()
208
/* for compatibility with versions < 1.0.2 */
209
 
210
                        /* basic functions */
211
 
212
ZEXTERN const char * ZEXPORT zlibVersion OF((void));
213
/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
214
   If the first character differs, the library code actually used is
215
   not compatible with the zlib.h header file used by the application.
216
   This check is automatically made by deflateInit and inflateInit.
217
 */
218
 
219
/*
220
ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
221
 
222
     Initializes the internal stream state for compression. The fields
223
   zalloc, zfree and opaque must be initialized before by the caller.
224
   If zalloc and zfree are set to Z_NULL, deflateInit updates them to
225
   use default allocation functions.
226
 
227
     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
228
   1 gives best speed, 9 gives best compression, 0 gives no compression at
229
   all (the input data is simply copied a block at a time).
230
   Z_DEFAULT_COMPRESSION requests a default compromise between speed and
231
   compression (currently equivalent to level 6).
232
 
233
     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
234
   enough memory, Z_STREAM_ERROR if level is not a valid compression level,
235
   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
236
   with the version assumed by the caller (ZLIB_VERSION).
237
   msg is set to null if there is no error message.  deflateInit does not
238
   perform any compression: this will be done by deflate().
239
*/
240
 
241
 
242
ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
243
/*
244
    deflate compresses as much data as possible, and stops when the input
245
  buffer becomes empty or the output buffer becomes full. It may introduce some
246
  output latency (reading input without producing any output) except when
247
  forced to flush.
248
 
249
    The detailed semantics are as follows. deflate performs one or both of the
250
  following actions:
251
 
252
  - Compress more input starting at next_in and update next_in and avail_in
253
    accordingly. If not all input can be processed (because there is not
254
    enough room in the output buffer), next_in and avail_in are updated and
255
    processing will resume at this point for the next call of deflate().
256
 
257
  - Provide more output starting at next_out and update next_out and avail_out
258
    accordingly. This action is forced if the parameter flush is non zero.
259
    Forcing flush frequently degrades the compression ratio, so this parameter
260
    should be set only when necessary (in interactive applications).
261
    Some output may be provided even if flush is not set.
262
 
263
  Before the call of deflate(), the application should ensure that at least
264
  one of the actions is possible, by providing more input and/or consuming
265
  more output, and updating avail_in or avail_out accordingly; avail_out
266
  should never be zero before the call. The application can consume the
267
  compressed output when it wants, for example when the output buffer is full
268
  (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
269
  and with zero avail_out, it must be called again after making room in the
270
  output buffer because there might be more output pending.
271
 
272
    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
273
  decide how much data to accumualte before producing output, in order to
274
  maximize compression.
275
 
276
    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
277
  flushed to the output buffer and the output is aligned on a byte boundary, so
278
  that the decompressor can get all input data available so far. (In particular
279
  avail_in is zero after the call if enough output space has been provided
280
  before the call.)  Flushing may degrade compression for some compression
281
  algorithms and so it should be used only when necessary.
282
 
283
    If flush is set to Z_FULL_FLUSH, all output is flushed as with
284
  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
285
  restart from this point if previous compressed data has been damaged or if
286
  random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
287
  compression.
288
 
289
    If deflate returns with avail_out == 0, this function must be called again
290
  with the same value of the flush parameter and more output space (updated
291
  avail_out), until the flush is complete (deflate returns with non-zero
292
  avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
293
  avail_out is greater than six to avoid repeated flush markers due to
294
  avail_out == 0 on return.
295
 
296
    If the parameter flush is set to Z_FINISH, pending input is processed,
297
  pending output is flushed and deflate returns with Z_STREAM_END if there
298
  was enough output space; if deflate returns with Z_OK, this function must be
299
  called again with Z_FINISH and more output space (updated avail_out) but no
300
  more input data, until it returns with Z_STREAM_END or an error. After
301
  deflate has returned Z_STREAM_END, the only possible operations on the
302
  stream are deflateReset or deflateEnd.
303
 
304
    Z_FINISH can be used immediately after deflateInit if all the compression
305
  is to be done in a single step. In this case, avail_out must be at least
306
  the value returned by deflateBound (see below). If deflate does not return
307
  Z_STREAM_END, then it must be called again as described above.
308
 
309
    deflate() sets strm->adler to the adler32 checksum of all input read
310
  so far (that is, total_in bytes).
311
 
312
    deflate() may update strm->data_type if it can make a good guess about
313
  the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
314
  binary. This field is only for information purposes and does not affect
315
  the compression algorithm in any manner.
316
 
317
    deflate() returns Z_OK if some progress has been made (more input
318
  processed or more output produced), Z_STREAM_END if all input has been
319
  consumed and all output has been produced (only when flush is set to
320
  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
321
  if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
322
  (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
323
  fatal, and deflate() can be called again with more input and more output
324
  space to continue compressing.
325
*/
326
 
327
 
328
ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
329
/*
330
     All dynamically allocated data structures for this stream are freed.
331
   This function discards any unprocessed input and does not flush any
332
   pending output.
333
 
334
     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
335
   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
336
   prematurely (some input or output was discarded). In the error case,
337
   msg may be set but then points to a static string (which must not be
338
   deallocated).
339
*/
340
 
341
 
342
/*
343
ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
344
 
345
     Initializes the internal stream state for decompression. The fields
346
   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
347
   the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
348
   value depends on the compression method), inflateInit determines the
349
   compression method from the zlib header and allocates all data structures
350
   accordingly; otherwise the allocation will be deferred to the first call of
351
   inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
352
   use default allocation functions.
353
 
354
     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
355
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
356
   version assumed by the caller.  msg is set to null if there is no error
357
   message. inflateInit does not perform any decompression apart from reading
358
   the zlib header if present: this will be done by inflate().  (So next_in and
359
   avail_in may be modified, but next_out and avail_out are unchanged.)
360
*/
361
 
362
 
363
ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
364
/*
365
    inflate decompresses as much data as possible, and stops when the input
366
  buffer becomes empty or the output buffer becomes full. It may introduce
367
  some output latency (reading input without producing any output) except when
368
  forced to flush.
369
 
370
  The detailed semantics are as follows. inflate performs one or both of the
371
  following actions:
372
 
373
  - Decompress more input starting at next_in and update next_in and avail_in
374
    accordingly. If not all input can be processed (because there is not
375
    enough room in the output buffer), next_in is updated and processing
376
    will resume at this point for the next call of inflate().
377
 
378
  - Provide more output starting at next_out and update next_out and avail_out
379
    accordingly.  inflate() provides as much output as possible, until there
380
    is no more input data or no more space in the output buffer (see below
381
    about the flush parameter).
382
 
383
  Before the call of inflate(), the application should ensure that at least
384
  one of the actions is possible, by providing more input and/or consuming
385
  more output, and updating the next_* and avail_* values accordingly.
386
  The application can consume the uncompressed output when it wants, for
387
  example when the output buffer is full (avail_out == 0), or after each
388
  call of inflate(). If inflate returns Z_OK and with zero avail_out, it
389
  must be called again after making room in the output buffer because there
390
  might be more output pending.
391
 
392
    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
393
  Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
394
  output as possible to the output buffer. Z_BLOCK requests that inflate() stop
395
  if and when it gets to the next deflate block boundary. When decoding the
396
  zlib or gzip format, this will cause inflate() to return immediately after
397
  the header and before the first block. When doing a raw inflate, inflate()
398
  will go ahead and process the first block, and will return when it gets to
399
  the end of that block, or when it runs out of data.
400
 
401
    The Z_BLOCK option assists in appending to or combining deflate streams.
402
  Also to assist in this, on return inflate() will set strm->data_type to the
403
  number of unused bits in the last byte taken from strm->next_in, plus 64
404
  if inflate() is currently decoding the last block in the deflate stream,
405
  plus 128 if inflate() returned immediately after decoding an end-of-block
406
  code or decoding the complete header up to just before the first byte of the
407
  deflate stream. The end-of-block will not be indicated until all of the
408
  uncompressed data from that block has been written to strm->next_out.  The
409
  number of unused bits may in general be greater than seven, except when
410
  bit 7 of data_type is set, in which case the number of unused bits will be
411
  less than eight.
412
 
413
    inflate() should normally be called until it returns Z_STREAM_END or an
414
  error. However if all decompression is to be performed in a single step
415
  (a single call of inflate), the parameter flush should be set to
416
  Z_FINISH. In this case all pending input is processed and all pending
417
  output is flushed; avail_out must be large enough to hold all the
418
  uncompressed data. (The size of the uncompressed data may have been saved
419
  by the compressor for this purpose.) The next operation on this stream must
420
  be inflateEnd to deallocate the decompression state. The use of Z_FINISH
421
  is never required, but can be used to inform inflate that a faster approach
422
  may be used for the single inflate() call.
423
 
424
     In this implementation, inflate() always flushes as much output as
425
  possible to the output buffer, and always uses the faster approach on the
426
  first call. So the only effect of the flush parameter in this implementation
427
  is on the return value of inflate(), as noted below, or when it returns early
428
  because Z_BLOCK is used.
429
 
430
     If a preset dictionary is needed after this call (see inflateSetDictionary
431
  below), inflate sets strm->adler to the adler32 checksum of the dictionary
432
  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
433
  strm->adler to the adler32 checksum of all output produced so far (that is,
434
  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
435
  below. At the end of the stream, inflate() checks that its computed adler32
436
  checksum is equal to that saved by the compressor and returns Z_STREAM_END
437
  only if the checksum is correct.
438
 
439
    inflate() will decompress and check either zlib-wrapped or gzip-wrapped
440
  deflate data.  The header type is detected automatically.  Any information
441
  contained in the gzip header is not retained, so applications that need that
442
  information should instead use raw inflate, see inflateInit2() below, or
443
  inflateBack() and perform their own processing of the gzip header and
444
  trailer.
445
 
446
    inflate() returns Z_OK if some progress has been made (more input processed
447
  or more output produced), Z_STREAM_END if the end of the compressed data has
448
  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
449
  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
450
  corrupted (input stream not conforming to the zlib format or incorrect check
451
  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
452
  if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
453
  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
454
  output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
455
  inflate() can be called again with more input and more output space to
456
  continue decompressing. If Z_DATA_ERROR is returned, the application may then
457
  call inflateSync() to look for a good compression block if a partial recovery
458
  of the data is desired.
459
*/
460
 
461
 
462
ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
463
/*
464
     All dynamically allocated data structures for this stream are freed.
465
   This function discards any unprocessed input and does not flush any
466
   pending output.
467
 
468
     inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
469
   was inconsistent. In the error case, msg may be set but then points to a
470
   static string (which must not be deallocated).
471
*/
472
 
473
                        /* Advanced functions */
474
 
475
/*
476
    The following functions are needed only in some special applications.
477
*/
478
 
479
/*
480
ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
481
                                     int  level,
482
                                     int  method,
483
                                     int  windowBits,
484
                                     int  memLevel,
485
                                     int  strategy));
486
 
487
     This is another version of deflateInit with more compression options. The
488
   fields next_in, zalloc, zfree and opaque must be initialized before by
489
   the caller.
490
 
491
     The method parameter is the compression method. It must be Z_DEFLATED in
492
   this version of the library.
493
 
494
     The windowBits parameter is the base two logarithm of the window size
495
   (the size of the history buffer). It should be in the range 8..15 for this
496
   version of the library. Larger values of this parameter result in better
497
   compression at the expense of memory usage. The default value is 15 if
498
   deflateInit is used instead.
499
 
500
     windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
501
   determines the window size. deflate() will then generate raw deflate data
502
   with no zlib header or trailer, and will not compute an adler32 check value.
503
 
504
     windowBits can also be greater than 15 for optional gzip encoding. Add
505
   16 to windowBits to write a simple gzip header and trailer around the
506
   compressed data instead of a zlib wrapper. The gzip header will have no
507
   file name, no extra data, no comment, no modification time (set to zero),
508
   no header crc, and the operating system will be set to 255 (unknown).  If a
509
   gzip stream is being written, strm->adler is a crc32 instead of an adler32.
510
 
511
     The memLevel parameter specifies how much memory should be allocated
512
   for the internal compression state. memLevel=1 uses minimum memory but
513
   is slow and reduces compression ratio; memLevel=9 uses maximum memory
514
   for optimal speed. The default value is 8. See zconf.h for total memory
515
   usage as a function of windowBits and memLevel.
516
 
517
     The strategy parameter is used to tune the compression algorithm. Use the
518
   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
519
   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
520
   string match), or Z_RLE to limit match distances to one (run-length
521
   encoding). Filtered data consists mostly of small values with a somewhat
522
   random distribution. In this case, the compression algorithm is tuned to
523
   compress them better. The effect of Z_FILTERED is to force more Huffman
524
   coding and less string matching; it is somewhat intermediate between
525
   Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
526
   Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
527
   parameter only affects the compression ratio but not the correctness of the
528
   compressed output even if it is not set appropriately.  Z_FIXED prevents the
529
   use of dynamic Huffman codes, allowing for a simpler decoder for special
530
   applications.
531
 
532
      deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
533
   memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
534
   method). msg is set to null if there is no error message.  deflateInit2 does
535
   not perform any compression: this will be done by deflate().
536
*/
537
 
538
ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
539
                                             const Bytef *dictionary,
540
                                             uInt  dictLength));
541
/*
542
     Initializes the compression dictionary from the given byte sequence
543
   without producing any compressed output. This function must be called
544
   immediately after deflateInit, deflateInit2 or deflateReset, before any
545
   call of deflate. The compressor and decompressor must use exactly the same
546
   dictionary (see inflateSetDictionary).
547
 
548
     The dictionary should consist of strings (byte sequences) that are likely
549
   to be encountered later in the data to be compressed, with the most commonly
550
   used strings preferably put towards the end of the dictionary. Using a
551
   dictionary is most useful when the data to be compressed is short and can be
552
   predicted with good accuracy; the data can then be compressed better than
553
   with the default empty dictionary.
554
 
555
     Depending on the size of the compression data structures selected by
556
   deflateInit or deflateInit2, a part of the dictionary may in effect be
557
   discarded, for example if the dictionary is larger than the window size in
558
   deflate or deflate2. Thus the strings most likely to be useful should be
559
   put at the end of the dictionary, not at the front. In addition, the
560
   current implementation of deflate will use at most the window size minus
561
   262 bytes of the provided dictionary.
562
 
563
     Upon return of this function, strm->adler is set to the adler32 value
564
   of the dictionary; the decompressor may later use this value to determine
565
   which dictionary has been used by the compressor. (The adler32 value
566
   applies to the whole dictionary even if only a subset of the dictionary is
567
   actually used by the compressor.) If a raw deflate was requested, then the
568
   adler32 value is not computed and strm->adler is not set.
569
 
570
     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
571
   parameter is invalid (such as NULL dictionary) or the stream state is
572
   inconsistent (for example if deflate has already been called for this stream
573
   or if the compression method is bsort). deflateSetDictionary does not
574
   perform any compression: this will be done by deflate().
575
*/
576
 
577
ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
578
                                    z_streamp source));
579
/*
580
     Sets the destination stream as a complete copy of the source stream.
581
 
582
     This function can be useful when several compression strategies will be
583
   tried, for example when there are several ways of pre-processing the input
584
   data with a filter. The streams that will be discarded should then be freed
585
   by calling deflateEnd.  Note that deflateCopy duplicates the internal
586
   compression state which can be quite large, so this strategy is slow and
587
   can consume lots of memory.
588
 
589
     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
590
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
591
   (such as zalloc being NULL). msg is left unchanged in both source and
592
   destination.
593
*/
594
 
595
ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
596
/*
597
     This function is equivalent to deflateEnd followed by deflateInit,
598
   but does not free and reallocate all the internal compression state.
599
   The stream will keep the same compression level and any other attributes
600
   that may have been set by deflateInit2.
601
 
602
      deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
603
   stream state was inconsistent (such as zalloc or state being NULL).
604
*/
605
 
606
ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
607
                                      int level,
608
                                      int strategy));
609
/*
610
     Dynamically update the compression level and compression strategy.  The
611
   interpretation of level and strategy is as in deflateInit2.  This can be
612
   used to switch between compression and straight copy of the input data, or
613
   to switch to a different kind of input data requiring a different
614
   strategy. If the compression level is changed, the input available so far
615
   is compressed with the old level (and may be flushed); the new level will
616
   take effect only at the next call of deflate().
617
 
618
     Before the call of deflateParams, the stream state must be set as for
619
   a call of deflate(), since the currently available input may have to
620
   be compressed and flushed. In particular, strm->avail_out must be non-zero.
621
 
622
     deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
623
   stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
624
   if strm->avail_out was zero.
625
*/
626
 
627
ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
628
                                    int good_length,
629
                                    int max_lazy,
630
                                    int nice_length,
631
                                    int max_chain));
632
/*
633
     Fine tune deflate's internal compression parameters.  This should only be
634
   used by someone who understands the algorithm used by zlib's deflate for
635
   searching for the best matching string, and even then only by the most
636
   fanatic optimizer trying to squeeze out the last compressed bit for their
637
   specific input data.  Read the deflate.c source code for the meaning of the
638
   max_lazy, good_length, nice_length, and max_chain parameters.
639
 
640
     deflateTune() can be called after deflateInit() or deflateInit2(), and
641
   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
642
 */
643
 
644
ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
645
                                       uLong sourceLen));
646
/*
647
     deflateBound() returns an upper bound on the compressed size after
648
   deflation of sourceLen bytes.  It must be called after deflateInit()
649
   or deflateInit2().  This would be used to allocate an output buffer
650
   for deflation in a single pass, and so would be called before deflate().
651
*/
652
 
653
ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
654
                                     int bits,
655
                                     int value));
656
/*
657
     deflatePrime() inserts bits in the deflate output stream.  The intent
658
  is that this function is used to start off the deflate output with the
659
  bits leftover from a previous deflate stream when appending to it.  As such,
660
  this function can only be used for raw deflate, and must be used before the
661
  first deflate() call after a deflateInit2() or deflateReset().  bits must be
662
  less than or equal to 16, and that many of the least significant bits of
663
  value will be inserted in the output.
664
 
665
      deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
666
   stream state was inconsistent.
667
*/
668
 
669
ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
670
                                         gz_headerp head));
671
/*
672
      deflateSetHeader() provides gzip header information for when a gzip
673
   stream is requested by deflateInit2().  deflateSetHeader() may be called
674
   after deflateInit2() or deflateReset() and before the first call of
675
   deflate().  The text, time, os, extra field, name, and comment information
676
   in the provided gz_header structure are written to the gzip header (xflag is
677
   ignored -- the extra flags are set according to the compression level).  The
678
   caller must assure that, if not Z_NULL, name and comment are terminated with
679
   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
680
   available there.  If hcrc is true, a gzip header crc is included.  Note that
681
   the current versions of the command-line version of gzip (up through version
682
   1.3.x) do not support header crc's, and will report that it is a "multi-part
683
   gzip file" and give up.
684
 
685
      If deflateSetHeader is not used, the default gzip header has text false,
686
   the time set to zero, and os set to 255, with no extra, name, or comment
687
   fields.  The gzip header is returned to the default state by deflateReset().
688
 
689
      deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
690
   stream state was inconsistent.
691
*/
692
 
693
/*
694
ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
695
                                     int  windowBits));
696
 
697
     This is another version of inflateInit with an extra parameter. The
698
   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
699
   before by the caller.
700
 
701
     The windowBits parameter is the base two logarithm of the maximum window
702
   size (the size of the history buffer).  It should be in the range 8..15 for
703
   this version of the library. The default value is 15 if inflateInit is used
704
   instead. windowBits must be greater than or equal to the windowBits value
705
   provided to deflateInit2() while compressing, or it must be equal to 15 if
706
   deflateInit2() was not used. If a compressed stream with a larger window
707
   size is given as input, inflate() will return with the error code
708
   Z_DATA_ERROR instead of trying to allocate a larger window.
709
 
710
     windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
711
   determines the window size. inflate() will then process raw deflate data,
712
   not looking for a zlib or gzip header, not generating a check value, and not
713
   looking for any check values for comparison at the end of the stream. This
714
   is for use with other formats that use the deflate compressed data format
715
   such as zip.  Those formats provide their own check values. If a custom
716
   format is developed using the raw deflate format for compressed data, it is
717
   recommended that a check value such as an adler32 or a crc32 be applied to
718
   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
719
   most applications, the zlib format should be used as is. Note that comments
720
   above on the use in deflateInit2() applies to the magnitude of windowBits.
721
 
722
     windowBits can also be greater than 15 for optional gzip decoding. Add
723
   32 to windowBits to enable zlib and gzip decoding with automatic header
724
   detection, or add 16 to decode only the gzip format (the zlib format will
725
   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is
726
   a crc32 instead of an adler32.
727
 
728
     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
729
   memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg
730
   is set to null if there is no error message.  inflateInit2 does not perform
731
   any decompression apart from reading the zlib header if present: this will
732
   be done by inflate(). (So next_in and avail_in may be modified, but next_out
733
   and avail_out are unchanged.)
734
*/
735
 
736
ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
737
                                             const Bytef *dictionary,
738
                                             uInt  dictLength));
739
/*
740
     Initializes the decompression dictionary from the given uncompressed byte
741
   sequence. This function must be called immediately after a call of inflate,
742
   if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
743
   can be determined from the adler32 value returned by that call of inflate.
744
   The compressor and decompressor must use exactly the same dictionary (see
745
   deflateSetDictionary).  For raw inflate, this function can be called
746
   immediately after inflateInit2() or inflateReset() and before any call of
747
   inflate() to set the dictionary.  The application must insure that the
748
   dictionary that was used for compression is provided.
749
 
750
     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
751
   parameter is invalid (such as NULL dictionary) or the stream state is
752
   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
753
   expected one (incorrect adler32 value). inflateSetDictionary does not
754
   perform any decompression: this will be done by subsequent calls of
755
   inflate().
756
*/
757
 
758
ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
759
/*
760
    Skips invalid compressed data until a full flush point (see above the
761
  description of deflate with Z_FULL_FLUSH) can be found, or until all
762
  available input is skipped. No output is provided.
763
 
764
    inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
765
  if no more input was provided, Z_DATA_ERROR if no flush point has been found,
766
  or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
767
  case, the application may save the current current value of total_in which
768
  indicates where valid compressed data was found. In the error case, the
769
  application may repeatedly call inflateSync, providing more input each time,
770
  until success or end of the input data.
771
*/
772
 
773
ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
774
                                    z_streamp source));
775
/*
776
     Sets the destination stream as a complete copy of the source stream.
777
 
778
     This function can be useful when randomly accessing a large stream.  The
779
   first pass through the stream can periodically record the inflate state,
780
   allowing restarting inflate at those points when randomly accessing the
781
   stream.
782
 
783
     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
784
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
785
   (such as zalloc being NULL). msg is left unchanged in both source and
786
   destination.
787
*/
788
 
789
ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
790
/*
791
     This function is equivalent to inflateEnd followed by inflateInit,
792
   but does not free and reallocate all the internal decompression state.
793
   The stream will keep attributes that may have been set by inflateInit2.
794
 
795
      inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
796
   stream state was inconsistent (such as zalloc or state being NULL).
797
*/
798
 
799
ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
800
                                     int bits,
801
                                     int value));
802
/*
803
     This function inserts bits in the inflate input stream.  The intent is
804
  that this function is used to start inflating at a bit position in the
805
  middle of a byte.  The provided bits will be used before any bytes are used
806
  from next_in.  This function should only be used with raw inflate, and
807
  should be used before the first inflate() call after inflateInit2() or
808
  inflateReset().  bits must be less than or equal to 16, and that many of the
809
  least significant bits of value will be inserted in the input.
810
 
811
      inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
812
   stream state was inconsistent.
813
*/
814
 
815
ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
816
                                         gz_headerp head));
817
/*
818
      inflateGetHeader() requests that gzip header information be stored in the
819
   provided gz_header structure.  inflateGetHeader() may be called after
820
   inflateInit2() or inflateReset(), and before the first call of inflate().
821
   As inflate() processes the gzip stream, head->done is zero until the header
822
   is completed, at which time head->done is set to one.  If a zlib stream is
823
   being decoded, then head->done is set to -1 to indicate that there will be
824
   no gzip header information forthcoming.  Note that Z_BLOCK can be used to
825
   force inflate() to return immediately after header processing is complete
826
   and before any actual data is decompressed.
827
 
828
      The text, time, xflags, and os fields are filled in with the gzip header
829
   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
830
   was valid if done is set to one.)  If extra is not Z_NULL, then extra_max
831
   contains the maximum number of bytes to write to extra.  Once done is true,
832
   extra_len contains the actual extra field length, and extra contains the
833
   extra field, or that field truncated if extra_max is less than extra_len.
834
   If name is not Z_NULL, then up to name_max characters are written there,
835
   terminated with a zero unless the length is greater than name_max.  If
836
   comment is not Z_NULL, then up to comm_max characters are written there,
837
   terminated with a zero unless the length is greater than comm_max.  When
838
   any of extra, name, or comment are not Z_NULL and the respective field is
839
   not present in the header, then that field is set to Z_NULL to signal its
840
   absence.  This allows the use of deflateSetHeader() with the returned
841
   structure to duplicate the header.  However if those fields are set to
842
   allocated memory, then the application will need to save those pointers
843
   elsewhere so that they can be eventually freed.
844
 
845
      If inflateGetHeader is not used, then the header information is simply
846
   discarded.  The header is always checked for validity, including the header
847
   CRC if present.  inflateReset() will reset the process to discard the header
848
   information.  The application would need to call inflateGetHeader() again to
849
   retrieve the header from the next gzip stream.
850
 
851
      inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
852
   stream state was inconsistent.
853
*/
854
 
855
/*
856
ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
857
                                        unsigned char FAR *window));
858
 
859
     Initialize the internal stream state for decompression using inflateBack()
860
   calls.  The fields zalloc, zfree and opaque in strm must be initialized
861
   before the call.  If zalloc and zfree are Z_NULL, then the default library-
862
   derived memory allocation routines are used.  windowBits is the base two
863
   logarithm of the window size, in the range 8..15.  window is a caller
864
   supplied buffer of that size.  Except for special applications where it is
865
   assured that deflate was used with small window sizes, windowBits must be 15
866
   and a 32K byte window must be supplied to be able to decompress general
867
   deflate streams.
868
 
869
     See inflateBack() for the usage of these routines.
870
 
871
     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
872
   the paramaters are invalid, Z_MEM_ERROR if the internal state could not
873
   be allocated, or Z_VERSION_ERROR if the version of the library does not
874
   match the version of the header file.
875
*/
876
 
877
typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
878
typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
879
 
880
ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
881
                                    in_func in, void FAR *in_desc,
882
                                    out_func out, void FAR *out_desc));
883
/*
884
     inflateBack() does a raw inflate with a single call using a call-back
885
   interface for input and output.  This is more efficient than inflate() for
886
   file i/o applications in that it avoids copying between the output and the
887
   sliding window by simply making the window itself the output buffer.  This
888
   function trusts the application to not change the output buffer passed by
889
   the output function, at least until inflateBack() returns.
890
 
891
     inflateBackInit() must be called first to allocate the internal state
892
   and to initialize the state with the user-provided window buffer.
893
   inflateBack() may then be used multiple times to inflate a complete, raw
894
   deflate stream with each call.  inflateBackEnd() is then called to free
895
   the allocated state.
896
 
897
     A raw deflate stream is one with no zlib or gzip header or trailer.
898
   This routine would normally be used in a utility that reads zip or gzip
899
   files and writes out uncompressed files.  The utility would decode the
900
   header and process the trailer on its own, hence this routine expects
901
   only the raw deflate stream to decompress.  This is different from the
902
   normal behavior of inflate(), which expects either a zlib or gzip header and
903
   trailer around the deflate stream.
904
 
905
     inflateBack() uses two subroutines supplied by the caller that are then
906
   called by inflateBack() for input and output.  inflateBack() calls those
907
   routines until it reads a complete deflate stream and writes out all of the
908
   uncompressed data, or until it encounters an error.  The function's
909
   parameters and return types are defined above in the in_func and out_func
910
   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
911
   number of bytes of provided input, and a pointer to that input in buf.  If
912
   there is no input available, in() must return zero--buf is ignored in that
913
   case--and inflateBack() will return a buffer error.  inflateBack() will call
914
   out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
915
   should return zero on success, or non-zero on failure.  If out() returns
916
   non-zero, inflateBack() will return with an error.  Neither in() nor out()
917
   are permitted to change the contents of the window provided to
918
   inflateBackInit(), which is also the buffer that out() uses to write from.
919
   The length written by out() will be at most the window size.  Any non-zero
920
   amount of input may be provided by in().
921
 
922
     For convenience, inflateBack() can be provided input on the first call by
923
   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
924
   in() will be called.  Therefore strm->next_in must be initialized before
925
   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
926
   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
927
   must also be initialized, and then if strm->avail_in is not zero, input will
928
   initially be taken from strm->next_in[0 .. strm->avail_in - 1].
929
 
930
     The in_desc and out_desc parameters of inflateBack() is passed as the
931
   first parameter of in() and out() respectively when they are called.  These
932
   descriptors can be optionally used to pass any information that the caller-
933
   supplied in() and out() functions need to do their job.
934
 
935
     On return, inflateBack() will set strm->next_in and strm->avail_in to
936
   pass back any unused input that was provided by the last in() call.  The
937
   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
938
   if in() or out() returned an error, Z_DATA_ERROR if there was a format
939
   error in the deflate stream (in which case strm->msg is set to indicate the
940
   nature of the error), or Z_STREAM_ERROR if the stream was not properly
941
   initialized.  In the case of Z_BUF_ERROR, an input or output error can be
942
   distinguished using strm->next_in which will be Z_NULL only if in() returned
943
   an error.  If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
944
   out() returning non-zero.  (in() will always be called before out(), so
945
   strm->next_in is assured to be defined if out() returns non-zero.)  Note
946
   that inflateBack() cannot return Z_OK.
947
*/
948
 
949
ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
950
/*
951
     All memory allocated by inflateBackInit() is freed.
952
 
953
     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
954
   state was inconsistent.
955
*/
956
 
957
ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
958
/* Return flags indicating compile-time options.
959
 
960
    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
961
     1.0: size of uInt
962
     3.2: size of uLong
963
     5.4: size of voidpf (pointer)
964
     7.6: size of z_off_t
965
 
966
    Compiler, assembler, and debug options:
967
     8: DEBUG
968
     9: ASMV or ASMINF -- use ASM code
969
     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
970
     11: 0 (reserved)
971
 
972
    One-time table building (smaller code, but not thread-safe if true):
973
     12: BUILDFIXED -- build static block decoding tables when needed
974
     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
975
     14,15: 0 (reserved)
976
 
977
    Library content (indicates missing functionality):
978
     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
979
                          deflate code when not needed)
980
     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
981
                    and decode gzip streams (to avoid linking crc code)
982
     18-19: 0 (reserved)
983
 
984
    Operation variations (changes in library functionality):
985
     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
986
     21: FASTEST -- deflate algorithm with only one, lowest compression level
987
     22,23: 0 (reserved)
988
 
989
    The sprintf variant used by gzprintf (zero is best):
990
     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
991
     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
992
     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
993
 
994
    Remainder:
995
     27-31: 0 (reserved)
996
 */
997
 
998
 
999
                        /* utility functions */
1000
 
1001
/*
1002
     The following utility functions are implemented on top of the
1003
   basic stream-oriented functions. To simplify the interface, some
1004
   default options are assumed (compression level and memory usage,
1005
   standard memory allocation functions). The source code of these
1006
   utility functions can easily be modified if you need special options.
1007
*/
1008
 
1009
ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
1010
                                 const Bytef *source, uLong sourceLen));
1011
/*
1012
     Compresses the source buffer into the destination buffer.  sourceLen is
1013
   the byte length of the source buffer. Upon entry, destLen is the total
1014
   size of the destination buffer, which must be at least the value returned
1015
   by compressBound(sourceLen). Upon exit, destLen is the actual size of the
1016
   compressed buffer.
1017
     This function can be used to compress a whole file at once if the
1018
   input file is mmap'ed.
1019
     compress returns Z_OK if success, Z_MEM_ERROR if there was not
1020
   enough memory, Z_BUF_ERROR if there was not enough room in the output
1021
   buffer.
1022
*/
1023
 
1024
ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
1025
                                  const Bytef *source, uLong sourceLen,
1026
                                  int level));
1027
/*
1028
     Compresses the source buffer into the destination buffer. The level
1029
   parameter has the same meaning as in deflateInit.  sourceLen is the byte
1030
   length of the source buffer. Upon entry, destLen is the total size of the
1031
   destination buffer, which must be at least the value returned by
1032
   compressBound(sourceLen). Upon exit, destLen is the actual size of the
1033
   compressed buffer.
1034
 
1035
     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1036
   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1037
   Z_STREAM_ERROR if the level parameter is invalid.
1038
*/
1039
 
1040
ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1041
/*
1042
     compressBound() returns an upper bound on the compressed size after
1043
   compress() or compress2() on sourceLen bytes.  It would be used before
1044
   a compress() or compress2() call to allocate the destination buffer.
1045
*/
1046
 
1047
ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
1048
                                   const Bytef *source, uLong sourceLen));
1049
/*
1050
     Decompresses the source buffer into the destination buffer.  sourceLen is
1051
   the byte length of the source buffer. Upon entry, destLen is the total
1052
   size of the destination buffer, which must be large enough to hold the
1053
   entire uncompressed data. (The size of the uncompressed data must have
1054
   been saved previously by the compressor and transmitted to the decompressor
1055
   by some mechanism outside the scope of this compression library.)
1056
   Upon exit, destLen is the actual size of the compressed buffer.
1057
     This function can be used to decompress a whole file at once if the
1058
   input file is mmap'ed.
1059
 
1060
     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1061
   enough memory, Z_BUF_ERROR if there was not enough room in the output
1062
   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
1063
*/
1064
 
1065
 
1066
typedef voidp gzFile;
1067
 
1068
ZEXTERN gzFile ZEXPORT gzopen  OF((const char *path, const char *mode));
1069
/*
1070
     Opens a gzip (.gz) file for reading or writing. The mode parameter
1071
   is as in fopen ("rb" or "wb") but can also include a compression level
1072
   ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
1073
   Huffman only compression as in "wb1h", or 'R' for run-length encoding
1074
   as in "wb1R". (See the description of deflateInit2 for more information
1075
   about the strategy parameter.)
1076
 
1077
     gzopen can be used to read a file which is not in gzip format; in this
1078
   case gzread will directly read from the file without decompression.
1079
 
1080
     gzopen returns NULL if the file could not be opened or if there was
1081
   insufficient memory to allocate the (de)compression state; errno
1082
   can be checked to distinguish the two cases (if errno is zero, the
1083
   zlib error is Z_MEM_ERROR).  */
1084
 
1085
ZEXTERN gzFile ZEXPORT gzdopen  OF((int fd, const char *mode));
1086
/*
1087
     gzdopen() associates a gzFile with the file descriptor fd.  File
1088
   descriptors are obtained from calls like open, dup, creat, pipe or
1089
   fileno (in the file has been previously opened with fopen).
1090
   The mode parameter is as in gzopen.
1091
     The next call of gzclose on the returned gzFile will also close the
1092
   file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
1093
   descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
1094
     gzdopen returns NULL if there was insufficient memory to allocate
1095
   the (de)compression state.
1096
*/
1097
 
1098
ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1099
/*
1100
     Dynamically update the compression level or strategy. See the description
1101
   of deflateInit2 for the meaning of these parameters.
1102
     gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1103
   opened for writing.
1104
*/
1105
 
1106
ZEXTERN int ZEXPORT    gzread  OF((gzFile file, voidp buf, unsigned len));
1107
/*
1108
     Reads the given number of uncompressed bytes from the compressed file.
1109
   If the input file was not in gzip format, gzread copies the given number
1110
   of bytes into the buffer.
1111
     gzread returns the number of uncompressed bytes actually read (0 for
1112
   end of file, -1 for error). */
1113
 
1114
ZEXTERN int ZEXPORT    gzwrite OF((gzFile file,
1115
                                   voidpc buf, unsigned len));
1116
/*
1117
     Writes the given number of uncompressed bytes into the compressed file.
1118
   gzwrite returns the number of uncompressed bytes actually written
1119
   (0 in case of error).
1120
*/
1121
 
1122
ZEXTERN int ZEXPORTVA   gzprintf OF((gzFile file, const char *format, ...));
1123
/*
1124
     Converts, formats, and writes the args to the compressed file under
1125
   control of the format string, as in fprintf. gzprintf returns the number of
1126
   uncompressed bytes actually written (0 in case of error).  The number of
1127
   uncompressed bytes written is limited to 4095. The caller should assure that
1128
   this limit is not exceeded. If it is exceeded, then gzprintf() will return
1129
   return an error (0) with nothing written. In this case, there may also be a
1130
   buffer overflow with unpredictable consequences, which is possible only if
1131
   zlib was compiled with the insecure functions sprintf() or vsprintf()
1132
   because the secure snprintf() or vsnprintf() functions were not available.
1133
*/
1134
 
1135
ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1136
/*
1137
      Writes the given null-terminated string to the compressed file, excluding
1138
   the terminating null character.
1139
      gzputs returns the number of characters written, or -1 in case of error.
1140
*/
1141
 
1142
ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1143
/*
1144
      Reads bytes from the compressed file until len-1 characters are read, or
1145
   a newline character is read and transferred to buf, or an end-of-file
1146
   condition is encountered.  The string is then terminated with a null
1147
   character.
1148
      gzgets returns buf, or Z_NULL in case of error.
1149
*/
1150
 
1151
ZEXTERN int ZEXPORT    gzputc OF((gzFile file, int c));
1152
/*
1153
      Writes c, converted to an unsigned char, into the compressed file.
1154
   gzputc returns the value that was written, or -1 in case of error.
1155
*/
1156
 
1157
ZEXTERN int ZEXPORT    gzgetc OF((gzFile file));
1158
/*
1159
      Reads one byte from the compressed file. gzgetc returns this byte
1160
   or -1 in case of end of file or error.
1161
*/
1162
 
1163
ZEXTERN int ZEXPORT    gzungetc OF((int c, gzFile file));
1164
/*
1165
      Push one character back onto the stream to be read again later.
1166
   Only one character of push-back is allowed.  gzungetc() returns the
1167
   character pushed, or -1 on failure.  gzungetc() will fail if a
1168
   character has been pushed but not read yet, or if c is -1. The pushed
1169
   character will be discarded if the stream is repositioned with gzseek()
1170
   or gzrewind().
1171
*/
1172
 
1173
ZEXTERN int ZEXPORT    gzflush OF((gzFile file, int flush));
1174
/*
1175
     Flushes all pending output into the compressed file. The parameter
1176
   flush is as in the deflate() function. The return value is the zlib
1177
   error number (see function gzerror below). gzflush returns Z_OK if
1178
   the flush parameter is Z_FINISH and all output could be flushed.
1179
     gzflush should be called only when strictly necessary because it can
1180
   degrade compression.
1181
*/
1182
 
1183
ZEXTERN z_off_t ZEXPORT    gzseek OF((gzFile file,
1184
                                      z_off_t offset, int whence));
1185
/*
1186
      Sets the starting position for the next gzread or gzwrite on the
1187
   given compressed file. The offset represents a number of bytes in the
1188
   uncompressed data stream. The whence parameter is defined as in lseek(2);
1189
   the value SEEK_END is not supported.
1190
     If the file is opened for reading, this function is emulated but can be
1191
   extremely slow. If the file is opened for writing, only forward seeks are
1192
   supported; gzseek then compresses a sequence of zeroes up to the new
1193
   starting position.
1194
 
1195
      gzseek returns the resulting offset location as measured in bytes from
1196
   the beginning of the uncompressed stream, or -1 in case of error, in
1197
   particular if the file is opened for writing and the new starting position
1198
   would be before the current position.
1199
*/
1200
 
1201
ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
1202
/*
1203
     Rewinds the given file. This function is supported only for reading.
1204
 
1205
   gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1206
*/
1207
 
1208
ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
1209
/*
1210
     Returns the starting position for the next gzread or gzwrite on the
1211
   given compressed file. This position represents a number of bytes in the
1212
   uncompressed data stream.
1213
 
1214
   gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1215
*/
1216
 
1217
ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1218
/*
1219
     Returns 1 when EOF has previously been detected reading the given
1220
   input stream, otherwise zero.
1221
*/
1222
 
1223
ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1224
/*
1225
     Returns 1 if file is being read directly without decompression, otherwise
1226
   zero.
1227
*/
1228
 
1229
ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
1230
/*
1231
     Flushes all pending output if necessary, closes the compressed file
1232
   and deallocates all the (de)compression state. The return value is the zlib
1233
   error number (see function gzerror below).
1234
*/
1235
 
1236
ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1237
/*
1238
     Returns the error message for the last error which occurred on the
1239
   given compressed file. errnum is set to zlib error number. If an
1240
   error occurred in the file system and not in the compression library,
1241
   errnum is set to Z_ERRNO and the application may consult errno
1242
   to get the exact error code.
1243
*/
1244
 
1245
ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1246
/*
1247
     Clears the error and end-of-file flags for file. This is analogous to the
1248
   clearerr() function in stdio. This is useful for continuing to read a gzip
1249
   file that is being written concurrently.
1250
*/
1251
 
1252
                        /* checksum functions */
1253
 
1254
/*
1255
     These functions are not related to compression but are exported
1256
   anyway because they might be useful in applications using the
1257
   compression library.
1258
*/
1259
 
1260
ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1261
/*
1262
     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1263
   return the updated checksum. If buf is NULL, this function returns
1264
   the required initial value for the checksum.
1265
   An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1266
   much faster. Usage example:
1267
 
1268
     uLong adler = adler32(0L, Z_NULL, 0);
1269
 
1270
     while (read_buffer(buffer, length) != EOF) {
1271
       adler = adler32(adler, buffer, length);
1272
     }
1273
     if (adler != original_adler) error();
1274
*/
1275
 
1276
ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1277
                                          z_off_t len2));
1278
/*
1279
     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
1280
   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1281
   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
1282
   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
1283
*/
1284
 
1285
ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
1286
/*
1287
     Update a running CRC-32 with the bytes buf[0..len-1] and return the
1288
   updated CRC-32. If buf is NULL, this function returns the required initial
1289
   value for the for the crc. Pre- and post-conditioning (one's complement) is
1290
   performed within this function so it shouldn't be done by the application.
1291
   Usage example:
1292
 
1293
     uLong crc = crc32(0L, Z_NULL, 0);
1294
 
1295
     while (read_buffer(buffer, length) != EOF) {
1296
       crc = crc32(crc, buffer, length);
1297
     }
1298
     if (crc != original_crc) error();
1299
*/
1300
 
1301
ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1302
 
1303
/*
1304
     Combine two CRC-32 check values into one.  For two sequences of bytes,
1305
   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1306
   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
1307
   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1308
   len2.
1309
*/
1310
 
1311
 
1312
                        /* various hacks, don't look :) */
1313
 
1314
/* deflateInit and inflateInit are macros to allow checking the zlib version
1315
 * and the compiler's view of z_stream:
1316
 */
1317
ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1318
                                     const char *version, int stream_size));
1319
ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1320
                                     const char *version, int stream_size));
1321
ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
1322
                                      int windowBits, int memLevel,
1323
                                      int strategy, const char *version,
1324
                                      int stream_size));
1325
ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
1326
                                      const char *version, int stream_size));
1327
ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1328
                                         unsigned char FAR *window,
1329
                                         const char *version,
1330
                                         int stream_size));
1331
#define deflateInit(strm, level) \
1332
        deflateInit_((strm), (level),       ZLIB_VERSION, sizeof(z_stream))
1333
#define inflateInit(strm) \
1334
        inflateInit_((strm),                ZLIB_VERSION, sizeof(z_stream))
1335
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1336
        deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1337
                      (strategy),           ZLIB_VERSION, sizeof(z_stream))
1338
#define inflateInit2(strm, windowBits) \
1339
        inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1340
#define inflateBackInit(strm, windowBits, window) \
1341
        inflateBackInit_((strm), (windowBits), (window), \
1342
        ZLIB_VERSION, sizeof(z_stream))
1343
 
1344
 
1345
#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1346
    struct internal_state {int dummy;}; /* hack for buggy compilers */
1347
#endif
1348
 
1349
ZEXTERN const char   * ZEXPORT zError           OF((int));
1350
ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp z));
1351
ZEXTERN const uLongf * ZEXPORT get_crc_table    OF((void));
1352
 
1353
#ifdef __cplusplus
1354
}
1355
#endif
1356
 
1357
#endif /* ZLIB_H */

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