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220 mateuszvis 1
/* zlib.h -- interface of the 'zlib' general purpose compression library
2
  version 1.2.8, April 28th, 2013
3
 
4
  Copyright (C) 1995-2013 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://tools.ietf.org/html/rfc1950
28
  (zlib format), rfc1951 (deflate format) and rfc1952 (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 "1.2.8"
41
#define ZLIB_VERNUM 0x1280
42
#define ZLIB_VER_MAJOR 1
43
#define ZLIB_VER_MINOR 2
44
#define ZLIB_VER_REVISION 8
45
#define ZLIB_VER_SUBREVISION 0
46
 
47
/*
48
    The 'zlib' compression library provides in-memory compression and
49
  decompression functions, including integrity checks of the uncompressed data.
50
  This version of the library supports only one compression method (deflation)
51
  but other algorithms will be added later and will have the same stream
52
  interface.
53
 
54
    Compression can be done in a single step if the buffers are large enough,
55
  or can be done by repeated calls of the compression function.  In the latter
56
  case, the application must provide more input and/or consume the output
57
  (providing more output space) before each call.
58
 
59
    The compressed data format used by default by the in-memory functions is
60
  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
61
  around a deflate stream, which is itself documented in RFC 1951.
62
 
63
    The library also supports reading and writing files in gzip (.gz) format
64
  with an interface similar to that of stdio using the functions that start
65
  with "gz".  The gzip format is different from the zlib format.  gzip is a
66
  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
67
 
68
    This library can optionally read and write gzip streams in memory as well.
69
 
70
    The zlib format was designed to be compact and fast for use in memory
71
  and on communications channels.  The gzip format was designed for single-
72
  file compression on file systems, has a larger header than zlib to maintain
73
  directory information, and uses a different, slower check method than zlib.
74
 
75
    The library does not install any signal handler.  The decoder checks
76
  the consistency of the compressed data, so the library should never crash
77
  even in case of corrupted input.
78
*/
79
 
80
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
81
typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
82
 
83
struct internal_state;
84
 
85
typedef struct z_stream_s {
86
    z_const Bytef *next_in;     /* next input byte */
87
    uInt     avail_in;  /* number of bytes available at next_in */
88
    uLong    total_in;  /* total number of input bytes read so far */
89
 
90
    Bytef    *next_out; /* next output byte should be put there */
91
    uInt     avail_out; /* remaining free space at next_out */
92
    uLong    total_out; /* total number of bytes output so far */
93
 
94
    z_const char *msg;  /* last error message, NULL if no error */
95
    struct internal_state FAR *state; /* not visible by applications */
96
 
97
    alloc_func zalloc;  /* used to allocate the internal state */
98
    free_func  zfree;   /* used to free the internal state */
99
    voidpf     opaque;  /* private data object passed to zalloc and zfree */
100
 
101
    int     data_type;  /* best guess about the data type: binary or text */
102
    uLong   adler;      /* adler32 value of the uncompressed data */
103
    uLong   reserved;   /* reserved for future use */
104
} z_stream;
105
 
106
typedef z_stream FAR *z_streamp;
107
 
108
/*
109
     gzip header information passed to and from zlib routines.  See RFC 1952
110
  for more details on the meanings of these fields.
111
*/
112
typedef struct gz_header_s {
113
    int     text;       /* true if compressed data believed to be text */
114
    uLong   time;       /* modification time */
115
    int     xflags;     /* extra flags (not used when writing a gzip file) */
116
    int     os;         /* operating system */
117
    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
118
    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
119
    uInt    extra_max;  /* space at extra (only when reading header) */
120
    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
121
    uInt    name_max;   /* space at name (only when reading header) */
122
    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
123
    uInt    comm_max;   /* space at comment (only when reading header) */
124
    int     hcrc;       /* true if there was or will be a header crc */
125
    int     done;       /* true when done reading gzip header (not used
126
                           when writing a gzip file) */
127
} gz_header;
128
 
129
typedef gz_header FAR *gz_headerp;
130
 
131
/*
132
     The application must update next_in and avail_in when avail_in has dropped
133
   to zero.  It must update next_out and avail_out when avail_out has dropped
134
   to zero.  The application must initialize zalloc, zfree and opaque before
135
   calling the init function.  All other fields are set by the compression
136
   library and must not be updated by the application.
137
 
138
     The opaque value provided by the application will be passed as the first
139
   parameter for calls of zalloc and zfree.  This can be useful for custom
140
   memory management.  The compression library attaches no meaning to the
141
   opaque value.
142
 
143
     zalloc must return Z_NULL if there is not enough memory for the object.
144
   If zlib is used in a multi-threaded application, zalloc and zfree must be
145
   thread safe.
146
 
147
     On 16-bit systems, the functions zalloc and zfree must be able to allocate
148
   exactly 65536 bytes, but will not be required to allocate more than this if
149
   the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
150
   returned by zalloc for objects of exactly 65536 bytes *must* have their
151
   offset normalized to zero.  The default allocation function provided by this
152
   library ensures this (see zutil.c).  To reduce memory requirements and avoid
153
   any allocation of 64K objects, at the expense of compression ratio, compile
154
   the library with -DMAX_WBITS=14 (see zconf.h).
155
 
156
     The fields total_in and total_out can be used for statistics or progress
157
   reports.  After compression, total_in holds the total size of the
158
   uncompressed data and may be saved for use in the decompressor (particularly
159
   if the decompressor wants to decompress everything in a single step).
160
*/
161
 
162
                        /* constants */
163
 
164
#define Z_NO_FLUSH      0
165
#define Z_PARTIAL_FLUSH 1
166
#define Z_SYNC_FLUSH    2
167
#define Z_FULL_FLUSH    3
168
#define Z_FINISH        4
169
#define Z_BLOCK         5
170
#define Z_TREES         6
171
/* Allowed flush values; see deflate() and inflate() below for details */
172
 
173
#define Z_OK            0
174
#define Z_STREAM_END    1
175
#define Z_NEED_DICT     2
176
#define Z_ERRNO        (-1)
177
#define Z_STREAM_ERROR (-2)
178
#define Z_DATA_ERROR   (-3)
179
#define Z_MEM_ERROR    (-4)
180
#define Z_BUF_ERROR    (-5)
181
#define Z_VERSION_ERROR (-6)
182
/* Return codes for the compression/decompression functions. Negative values
183
 * are errors, positive values are used for special but normal events.
184
 */
185
 
186
#define Z_NO_COMPRESSION         0
187
#define Z_BEST_SPEED             1
188
#define Z_BEST_COMPRESSION       9
189
#define Z_DEFAULT_COMPRESSION  (-1)
190
/* compression levels */
191
 
192
#define Z_FILTERED            1
193
#define Z_HUFFMAN_ONLY        2
194
#define Z_RLE                 3
195
#define Z_FIXED               4
196
#define Z_DEFAULT_STRATEGY    0
197
/* compression strategy; see deflateInit2() below for details */
198
 
199
#define Z_BINARY   0
200
#define Z_TEXT     1
201
#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
202
#define Z_UNKNOWN  2
203
/* Possible values of the data_type field (though see inflate()) */
204
 
205
#define Z_DEFLATED   8
206
/* The deflate compression method (the only one supported in this version) */
207
 
208
#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
209
 
210
#define zlib_version zlibVersion()
211
/* for compatibility with versions < 1.0.2 */
212
 
213
 
214
                        /* basic functions */
215
 
216
ZEXTERN const char * ZEXPORT zlibVersion OF((void));
217
/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
218
   If the first character differs, the library code actually used is not
219
   compatible with the zlib.h header file used by the application.  This check
220
   is automatically made by deflateInit and inflateInit.
221
 */
222
 
223
/*
224
ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
225
 
226
     Initializes the internal stream state for compression.  The fields
227
   zalloc, zfree and opaque must be initialized before by the caller.  If
228
   zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
229
   allocation functions.
230
 
231
     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
232
   1 gives best speed, 9 gives best compression, 0 gives no compression at all
233
   (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
234
   requests a default compromise between speed and compression (currently
235
   equivalent to level 6).
236
 
237
     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
238
   memory, Z_STREAM_ERROR if level is not a valid compression level, or
239
   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
240
   with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
241
   if there is no error message.  deflateInit does not perform any compression:
242
   this will be done by deflate().
243
*/
244
 
245
 
246
ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
247
/*
248
    deflate compresses as much data as possible, and stops when the input
249
  buffer becomes empty or the output buffer becomes full.  It may introduce
250
  some output latency (reading input without producing any output) except when
251
  forced to flush.
252
 
253
    The detailed semantics are as follows.  deflate performs one or both of the
254
  following actions:
255
 
256
  - Compress more input starting at next_in and update next_in and avail_in
257
    accordingly.  If not all input can be processed (because there is not
258
    enough room in the output buffer), next_in and avail_in are updated and
259
    processing will resume at this point for the next call of deflate().
260
 
261
  - Provide more output starting at next_out and update next_out and avail_out
262
    accordingly.  This action is forced if the parameter flush is non zero.
263
    Forcing flush frequently degrades the compression ratio, so this parameter
264
    should be set only when necessary (in interactive applications).  Some
265
    output may be provided even if flush is not set.
266
 
267
    Before the call of deflate(), the application should ensure that at least
268
  one of the actions is possible, by providing more input and/or consuming more
269
  output, and updating avail_in or avail_out accordingly; avail_out should
270
  never be zero before the call.  The application can consume the compressed
271
  output when it wants, for example when the output buffer is full (avail_out
272
  == 0), or after each call of deflate().  If deflate returns Z_OK and with
273
  zero avail_out, it must be called again after making room in the output
274
  buffer because there might be more output pending.
275
 
276
    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
277
  decide how much data to accumulate before producing output, in order to
278
  maximize compression.
279
 
280
    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
281
  flushed to the output buffer and the output is aligned on a byte boundary, so
282
  that the decompressor can get all input data available so far.  (In
283
  particular avail_in is zero after the call if enough output space has been
284
  provided before the call.) Flushing may degrade compression for some
285
  compression algorithms and so it should be used only when necessary.  This
286
  completes the current deflate block and follows it with an empty stored block
287
  that is three bits plus filler bits to the next byte, followed by four bytes
288
  (00 00 ff ff).
289
 
290
    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
291
  output buffer, but the output is not aligned to a byte boundary.  All of the
292
  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
293
  This completes the current deflate block and follows it with an empty fixed
294
  codes block that is 10 bits long.  This assures that enough bytes are output
295
  in order for the decompressor to finish the block before the empty fixed code
296
  block.
297
 
298
    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
299
  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
300
  seven bits of the current block are held to be written as the next byte after
301
  the next deflate block is completed.  In this case, the decompressor may not
302
  be provided enough bits at this point in order to complete decompression of
303
  the data provided so far to the compressor.  It may need to wait for the next
304
  block to be emitted.  This is for advanced applications that need to control
305
  the emission of deflate blocks.
306
 
307
    If flush is set to Z_FULL_FLUSH, all output is flushed as with
308
  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
309
  restart from this point if previous compressed data has been damaged or if
310
  random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
311
  compression.
312
 
313
    If deflate returns with avail_out == 0, this function must be called again
314
  with the same value of the flush parameter and more output space (updated
315
  avail_out), until the flush is complete (deflate returns with non-zero
316
  avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
317
  avail_out is greater than six to avoid repeated flush markers due to
318
  avail_out == 0 on return.
319
 
320
    If the parameter flush is set to Z_FINISH, pending input is processed,
321
  pending output is flushed and deflate returns with Z_STREAM_END if there was
322
  enough output space; if deflate returns with Z_OK, this function must be
323
  called again with Z_FINISH and more output space (updated avail_out) but no
324
  more input data, until it returns with Z_STREAM_END or an error.  After
325
  deflate has returned Z_STREAM_END, the only possible operations on the stream
326
  are deflateReset or deflateEnd.
327
 
328
    Z_FINISH can be used immediately after deflateInit if all the compression
329
  is to be done in a single step.  In this case, avail_out must be at least the
330
  value returned by deflateBound (see below).  Then deflate is guaranteed to
331
  return Z_STREAM_END.  If not enough output space is provided, deflate will
332
  not return Z_STREAM_END, and it must be called again as described above.
333
 
334
    deflate() sets strm->adler to the adler32 checksum of all input read
335
  so far (that is, total_in bytes).
336
 
337
    deflate() may update strm->data_type if it can make a good guess about
338
  the input data type (Z_BINARY or Z_TEXT).  In doubt, the data is considered
339
  binary.  This field is only for information purposes and does not affect the
340
  compression algorithm in any manner.
341
 
342
    deflate() returns Z_OK if some progress has been made (more input
343
  processed or more output produced), Z_STREAM_END if all input has been
344
  consumed and all output has been produced (only when flush is set to
345
  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
346
  if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
347
  (for example avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not
348
  fatal, and deflate() can be called again with more input and more output
349
  space to continue compressing.
350
*/
351
 
352
 
353
ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
354
/*
355
     All dynamically allocated data structures for this stream are freed.
356
   This function discards any unprocessed input and does not flush any pending
357
   output.
358
 
359
     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
360
   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
361
   prematurely (some input or output was discarded).  In the error case, msg
362
   may be set but then points to a static string (which must not be
363
   deallocated).
364
*/
365
 
366
 
367
/*
368
ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
369
 
370
     Initializes the internal stream state for decompression.  The fields
371
   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
372
   the caller.  If next_in is not Z_NULL and avail_in is large enough (the
373
   exact value depends on the compression method), inflateInit determines the
374
   compression method from the zlib header and allocates all data structures
375
   accordingly; otherwise the allocation will be deferred to the first call of
376
   inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
377
   use default allocation functions.
378
 
379
     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
380
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
381
   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
382
   invalid, such as a null pointer to the structure.  msg is set to null if
383
   there is no error message.  inflateInit does not perform any decompression
384
   apart from possibly reading the zlib header if present: actual decompression
385
   will be done by inflate().  (So next_in and avail_in may be modified, but
386
   next_out and avail_out are unused and unchanged.) The current implementation
387
   of inflateInit() does not process any header information -- that is deferred
388
   until inflate() is called.
389
*/
390
 
391
 
392
ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
393
/*
394
    inflate decompresses as much data as possible, and stops when the input
395
  buffer becomes empty or the output buffer becomes full.  It may introduce
396
  some output latency (reading input without producing any output) except when
397
  forced to flush.
398
 
399
  The detailed semantics are as follows.  inflate performs one or both of the
400
  following actions:
401
 
402
  - Decompress more input starting at next_in and update next_in and avail_in
403
    accordingly.  If not all input can be processed (because there is not
404
    enough room in the output buffer), next_in is updated and processing will
405
    resume at this point for the next call of inflate().
406
 
407
  - Provide more output starting at next_out and update next_out and avail_out
408
    accordingly.  inflate() provides as much output as possible, until there is
409
    no more input data or no more space in the output buffer (see below about
410
    the flush parameter).
411
 
412
    Before the call of inflate(), the application should ensure that at least
413
  one of the actions is possible, by providing more input and/or consuming more
414
  output, and updating the next_* and avail_* values accordingly.  The
415
  application can consume the uncompressed output when it wants, for example
416
  when the output buffer is full (avail_out == 0), or after each call of
417
  inflate().  If inflate returns Z_OK and with zero avail_out, it must be
418
  called again after making room in the output buffer because there might be
419
  more output pending.
420
 
421
    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
422
  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
423
  output as possible to the output buffer.  Z_BLOCK requests that inflate()
424
  stop if and when it gets to the next deflate block boundary.  When decoding
425
  the zlib or gzip format, this will cause inflate() to return immediately
426
  after the header and before the first block.  When doing a raw inflate,
427
  inflate() will go ahead and process the first block, and will return when it
428
  gets to the end of that block, or when it runs out of data.
429
 
430
    The Z_BLOCK option assists in appending to or combining deflate streams.
431
  Also to assist in this, on return inflate() will set strm->data_type to the
432
  number of unused bits in the last byte taken from strm->next_in, plus 64 if
433
  inflate() is currently decoding the last block in the deflate stream, plus
434
  128 if inflate() returned immediately after decoding an end-of-block code or
435
  decoding the complete header up to just before the first byte of the deflate
436
  stream.  The end-of-block will not be indicated until all of the uncompressed
437
  data from that block has been written to strm->next_out.  The number of
438
  unused bits may in general be greater than seven, except when bit 7 of
439
  data_type is set, in which case the number of unused bits will be less than
440
  eight.  data_type is set as noted here every time inflate() returns for all
441
  flush options, and so can be used to determine the amount of currently
442
  consumed input in bits.
443
 
444
    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
445
  end of each deflate block header is reached, before any actual data in that
446
  block is decoded.  This allows the caller to determine the length of the
447
  deflate block header for later use in random access within a deflate block.
448
  256 is added to the value of strm->data_type when inflate() returns
449
  immediately after reaching the end of the deflate block header.
450
 
451
    inflate() should normally be called until it returns Z_STREAM_END or an
452
  error.  However if all decompression is to be performed in a single step (a
453
  single call of inflate), the parameter flush should be set to Z_FINISH.  In
454
  this case all pending input is processed and all pending output is flushed;
455
  avail_out must be large enough to hold all of the uncompressed data for the
456
  operation to complete.  (The size of the uncompressed data may have been
457
  saved by the compressor for this purpose.) The use of Z_FINISH is not
458
  required to perform an inflation in one step.  However it may be used to
459
  inform inflate that a faster approach can be used for the single inflate()
460
  call.  Z_FINISH also informs inflate to not maintain a sliding window if the
461
  stream completes, which reduces inflate's memory footprint.  If the stream
462
  does not complete, either because not all of the stream is provided or not
463
  enough output space is provided, then a sliding window will be allocated and
464
  inflate() can be called again to continue the operation as if Z_NO_FLUSH had
465
  been used.
466
 
467
     In this implementation, inflate() always flushes as much output as
468
  possible to the output buffer, and always uses the faster approach on the
469
  first call.  So the effects of the flush parameter in this implementation are
470
  on the return value of inflate() as noted below, when inflate() returns early
471
  when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
472
  memory for a sliding window when Z_FINISH is used.
473
 
474
     If a preset dictionary is needed after this call (see inflateSetDictionary
475
  below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
476
  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
477
  strm->adler to the Adler-32 checksum of all output produced so far (that is,
478
  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
479
  below.  At the end of the stream, inflate() checks that its computed adler32
480
  checksum is equal to that saved by the compressor and returns Z_STREAM_END
481
  only if the checksum is correct.
482
 
483
    inflate() can decompress and check either zlib-wrapped or gzip-wrapped
484
  deflate data.  The header type is detected automatically, if requested when
485
  initializing with inflateInit2().  Any information contained in the gzip
486
  header is not retained, so applications that need that information should
487
  instead use raw inflate, see inflateInit2() below, or inflateBack() and
488
  perform their own processing of the gzip header and trailer.  When processing
489
  gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
490
  producted so far.  The CRC-32 is checked against the gzip trailer.
491
 
492
    inflate() returns Z_OK if some progress has been made (more input processed
493
  or more output produced), Z_STREAM_END if the end of the compressed data has
494
  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
495
  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
496
  corrupted (input stream not conforming to the zlib format or incorrect check
497
  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
498
  next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
499
  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
500
  output buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
501
  inflate() can be called again with more input and more output space to
502
  continue decompressing.  If Z_DATA_ERROR is returned, the application may
503
  then call inflateSync() to look for a good compression block if a partial
504
  recovery of the data is desired.
505
*/
506
 
507
 
508
ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
509
/*
510
     All dynamically allocated data structures for this stream are freed.
511
   This function discards any unprocessed input and does not flush any pending
512
   output.
513
 
514
     inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
515
   was inconsistent.  In the error case, msg may be set but then points to a
516
   static string (which must not be deallocated).
517
*/
518
 
519
 
520
                        /* Advanced functions */
521
 
522
/*
523
    The following functions are needed only in some special applications.
524
*/
525
 
526
/*
527
ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
528
                                     int  level,
529
                                     int  method,
530
                                     int  windowBits,
531
                                     int  memLevel,
532
                                     int  strategy));
533
 
534
     This is another version of deflateInit with more compression options.  The
535
   fields next_in, zalloc, zfree and opaque must be initialized before by the
536
   caller.
537
 
538
     The method parameter is the compression method.  It must be Z_DEFLATED in
539
   this version of the library.
540
 
541
     The windowBits parameter is the base two logarithm of the window size
542
   (the size of the history buffer).  It should be in the range 8..15 for this
543
   version of the library.  Larger values of this parameter result in better
544
   compression at the expense of memory usage.  The default value is 15 if
545
   deflateInit is used instead.
546
 
547
     windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
548
   determines the window size.  deflate() will then generate raw deflate data
549
   with no zlib header or trailer, and will not compute an adler32 check value.
550
 
551
     windowBits can also be greater than 15 for optional gzip encoding.  Add
552
   16 to windowBits to write a simple gzip header and trailer around the
553
   compressed data instead of a zlib wrapper.  The gzip header will have no
554
   file name, no extra data, no comment, no modification time (set to zero), no
555
   header crc, and the operating system will be set to 255 (unknown).  If a
556
   gzip stream is being written, strm->adler is a crc32 instead of an adler32.
557
 
558
     The memLevel parameter specifies how much memory should be allocated
559
   for the internal compression state.  memLevel=1 uses minimum memory but is
560
   slow and reduces compression ratio; memLevel=9 uses maximum memory for
561
   optimal speed.  The default value is 8.  See zconf.h for total memory usage
562
   as a function of windowBits and memLevel.
563
 
564
     The strategy parameter is used to tune the compression algorithm.  Use the
565
   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
566
   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
567
   string match), or Z_RLE to limit match distances to one (run-length
568
   encoding).  Filtered data consists mostly of small values with a somewhat
569
   random distribution.  In this case, the compression algorithm is tuned to
570
   compress them better.  The effect of Z_FILTERED is to force more Huffman
571
   coding and less string matching; it is somewhat intermediate between
572
   Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
573
   fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
574
   strategy parameter only affects the compression ratio but not the
575
   correctness of the compressed output even if it is not set appropriately.
576
   Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
577
   decoder for special applications.
578
 
579
     deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
580
   memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
581
   method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
582
   incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
583
   set to null if there is no error message.  deflateInit2 does not perform any
584
   compression: this will be done by deflate().
585
*/
586
 
587
ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
588
                                             const Bytef *dictionary,
589
                                             uInt  dictLength));
590
/*
591
     Initializes the compression dictionary from the given byte sequence
592
   without producing any compressed output.  When using the zlib format, this
593
   function must be called immediately after deflateInit, deflateInit2 or
594
   deflateReset, and before any call of deflate.  When doing raw deflate, this
595
   function must be called either before any call of deflate, or immediately
596
   after the completion of a deflate block, i.e. after all input has been
597
   consumed and all output has been delivered when using any of the flush
598
   options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
599
   compressor and decompressor must use exactly the same dictionary (see
600
   inflateSetDictionary).
601
 
602
     The dictionary should consist of strings (byte sequences) that are likely
603
   to be encountered later in the data to be compressed, with the most commonly
604
   used strings preferably put towards the end of the dictionary.  Using a
605
   dictionary is most useful when the data to be compressed is short and can be
606
   predicted with good accuracy; the data can then be compressed better than
607
   with the default empty dictionary.
608
 
609
     Depending on the size of the compression data structures selected by
610
   deflateInit or deflateInit2, a part of the dictionary may in effect be
611
   discarded, for example if the dictionary is larger than the window size
612
   provided in deflateInit or deflateInit2.  Thus the strings most likely to be
613
   useful should be put at the end of the dictionary, not at the front.  In
614
   addition, the current implementation of deflate will use at most the window
615
   size minus 262 bytes of the provided dictionary.
616
 
617
     Upon return of this function, strm->adler is set to the adler32 value
618
   of the dictionary; the decompressor may later use this value to determine
619
   which dictionary has been used by the compressor.  (The adler32 value
620
   applies to the whole dictionary even if only a subset of the dictionary is
621
   actually used by the compressor.) If a raw deflate was requested, then the
622
   adler32 value is not computed and strm->adler is not set.
623
 
624
     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
625
   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
626
   inconsistent (for example if deflate has already been called for this stream
627
   or if not at a block boundary for raw deflate).  deflateSetDictionary does
628
   not perform any compression: this will be done by deflate().
629
*/
630
 
631
ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
632
                                    z_streamp source));
633
/*
634
     Sets the destination stream as a complete copy of the source stream.
635
 
636
     This function can be useful when several compression strategies will be
637
   tried, for example when there are several ways of pre-processing the input
638
   data with a filter.  The streams that will be discarded should then be freed
639
   by calling deflateEnd.  Note that deflateCopy duplicates the internal
640
   compression state which can be quite large, so this strategy is slow and can
641
   consume lots of memory.
642
 
643
     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
644
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
645
   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
646
   destination.
647
*/
648
 
649
ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
650
/*
651
     This function is equivalent to deflateEnd followed by deflateInit,
652
   but does not free and reallocate all the internal compression state.  The
653
   stream will keep the same compression level and any other attributes that
654
   may have been set by deflateInit2.
655
 
656
     deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
657
   stream state was inconsistent (such as zalloc or state being Z_NULL).
658
*/
659
 
660
ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
661
                                      int level,
662
                                      int strategy));
663
/*
664
     Dynamically update the compression level and compression strategy.  The
665
   interpretation of level and strategy is as in deflateInit2.  This can be
666
   used to switch between compression and straight copy of the input data, or
667
   to switch to a different kind of input data requiring a different strategy.
668
   If the compression level is changed, the input available so far is
669
   compressed with the old level (and may be flushed); the new level will take
670
   effect only at the next call of deflate().
671
 
672
     Before the call of deflateParams, the stream state must be set as for
673
   a call of deflate(), since the currently available input may have to be
674
   compressed and flushed.  In particular, strm->avail_out must be non-zero.
675
 
676
     deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
677
   stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
678
   strm->avail_out was zero.
679
*/
680
 
681
ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
682
                                    int good_length,
683
                                    int max_lazy,
684
                                    int nice_length,
685
                                    int max_chain));
686
/*
687
     Fine tune deflate's internal compression parameters.  This should only be
688
   used by someone who understands the algorithm used by zlib's deflate for
689
   searching for the best matching string, and even then only by the most
690
   fanatic optimizer trying to squeeze out the last compressed bit for their
691
   specific input data.  Read the deflate.c source code for the meaning of the
692
   max_lazy, good_length, nice_length, and max_chain parameters.
693
 
694
     deflateTune() can be called after deflateInit() or deflateInit2(), and
695
   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
696
 */
697
 
698
ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
699
                                       uLong sourceLen));
700
/*
701
     deflateBound() returns an upper bound on the compressed size after
702
   deflation of sourceLen bytes.  It must be called after deflateInit() or
703
   deflateInit2(), and after deflateSetHeader(), if used.  This would be used
704
   to allocate an output buffer for deflation in a single pass, and so would be
705
   called before deflate().  If that first deflate() call is provided the
706
   sourceLen input bytes, an output buffer allocated to the size returned by
707
   deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
708
   to return Z_STREAM_END.  Note that it is possible for the compressed size to
709
   be larger than the value returned by deflateBound() if flush options other
710
   than Z_FINISH or Z_NO_FLUSH are used.
711
*/
712
 
713
ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
714
                                       unsigned *pending,
715
                                       int *bits));
716
/*
717
     deflatePending() returns the number of bytes and bits of output that have
718
   been generated, but not yet provided in the available output.  The bytes not
719
   provided would be due to the available output space having being consumed.
720
   The number of bits of output not provided are between 0 and 7, where they
721
   await more bits to join them in order to fill out a full byte.  If pending
722
   or bits are Z_NULL, then those values are not set.
723
 
724
     deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
725
   stream state was inconsistent.
726
 */
727
 
728
ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
729
                                     int bits,
730
                                     int value));
731
/*
732
     deflatePrime() inserts bits in the deflate output stream.  The intent
733
   is that this function is used to start off the deflate output with the bits
734
   leftover from a previous deflate stream when appending to it.  As such, this
735
   function can only be used for raw deflate, and must be used before the first
736
   deflate() call after a deflateInit2() or deflateReset().  bits must be less
737
   than or equal to 16, and that many of the least significant bits of value
738
   will be inserted in the output.
739
 
740
     deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
741
   room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
742
   source stream state was inconsistent.
743
*/
744
 
745
ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
746
                                         gz_headerp head));
747
/*
748
     deflateSetHeader() provides gzip header information for when a gzip
749
   stream is requested by deflateInit2().  deflateSetHeader() may be called
750
   after deflateInit2() or deflateReset() and before the first call of
751
   deflate().  The text, time, os, extra field, name, and comment information
752
   in the provided gz_header structure are written to the gzip header (xflag is
753
   ignored -- the extra flags are set according to the compression level).  The
754
   caller must assure that, if not Z_NULL, name and comment are terminated with
755
   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
756
   available there.  If hcrc is true, a gzip header crc is included.  Note that
757
   the current versions of the command-line version of gzip (up through version
758
   1.3.x) do not support header crc's, and will report that it is a "multi-part
759
   gzip file" and give up.
760
 
761
     If deflateSetHeader is not used, the default gzip header has text false,
762
   the time set to zero, and os set to 255, with no extra, name, or comment
763
   fields.  The gzip header is returned to the default state by deflateReset().
764
 
765
     deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
766
   stream state was inconsistent.
767
*/
768
 
769
/*
770
ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
771
                                     int  windowBits));
772
 
773
     This is another version of inflateInit with an extra parameter.  The
774
   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
775
   before by the caller.
776
 
777
     The windowBits parameter is the base two logarithm of the maximum window
778
   size (the size of the history buffer).  It should be in the range 8..15 for
779
   this version of the library.  The default value is 15 if inflateInit is used
780
   instead.  windowBits must be greater than or equal to the windowBits value
781
   provided to deflateInit2() while compressing, or it must be equal to 15 if
782
   deflateInit2() was not used.  If a compressed stream with a larger window
783
   size is given as input, inflate() will return with the error code
784
   Z_DATA_ERROR instead of trying to allocate a larger window.
785
 
786
     windowBits can also be zero to request that inflate use the window size in
787
   the zlib header of the compressed stream.
788
 
789
     windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
790
   determines the window size.  inflate() will then process raw deflate data,
791
   not looking for a zlib or gzip header, not generating a check value, and not
792
   looking for any check values for comparison at the end of the stream.  This
793
   is for use with other formats that use the deflate compressed data format
794
   such as zip.  Those formats provide their own check values.  If a custom
795
   format is developed using the raw deflate format for compressed data, it is
796
   recommended that a check value such as an adler32 or a crc32 be applied to
797
   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
798
   most applications, the zlib format should be used as is.  Note that comments
799
   above on the use in deflateInit2() applies to the magnitude of windowBits.
800
 
801
     windowBits can also be greater than 15 for optional gzip decoding.  Add
802
   32 to windowBits to enable zlib and gzip decoding with automatic header
803
   detection, or add 16 to decode only the gzip format (the zlib format will
804
   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
805
   crc32 instead of an adler32.
806
 
807
     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
808
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
809
   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
810
   invalid, such as a null pointer to the structure.  msg is set to null if
811
   there is no error message.  inflateInit2 does not perform any decompression
812
   apart from possibly reading the zlib header if present: actual decompression
813
   will be done by inflate().  (So next_in and avail_in may be modified, but
814
   next_out and avail_out are unused and unchanged.) The current implementation
815
   of inflateInit2() does not process any header information -- that is
816
   deferred until inflate() is called.
817
*/
818
 
819
ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
820
                                             const Bytef *dictionary,
821
                                             uInt  dictLength));
822
/*
823
     Initializes the decompression dictionary from the given uncompressed byte
824
   sequence.  This function must be called immediately after a call of inflate,
825
   if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
826
   can be determined from the adler32 value returned by that call of inflate.
827
   The compressor and decompressor must use exactly the same dictionary (see
828
   deflateSetDictionary).  For raw inflate, this function can be called at any
829
   time to set the dictionary.  If the provided dictionary is smaller than the
830
   window and there is already data in the window, then the provided dictionary
831
   will amend what's there.  The application must insure that the dictionary
832
   that was used for compression is provided.
833
 
834
     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
835
   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
836
   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
837
   expected one (incorrect adler32 value).  inflateSetDictionary does not
838
   perform any decompression: this will be done by subsequent calls of
839
   inflate().
840
*/
841
 
842
ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
843
                                             Bytef *dictionary,
844
                                             uInt  *dictLength));
845
/*
846
     Returns the sliding dictionary being maintained by inflate.  dictLength is
847
   set to the number of bytes in the dictionary, and that many bytes are copied
848
   to dictionary.  dictionary must have enough space, where 32768 bytes is
849
   always enough.  If inflateGetDictionary() is called with dictionary equal to
850
   Z_NULL, then only the dictionary length is returned, and nothing is copied.
851
   Similary, if dictLength is Z_NULL, then it is not set.
852
 
853
     inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
854
   stream state is inconsistent.
855
*/
856
 
857
ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
858
/*
859
     Skips invalid compressed data until a possible full flush point (see above
860
   for the description of deflate with Z_FULL_FLUSH) can be found, or until all
861
   available input is skipped.  No output is provided.
862
 
863
     inflateSync searches for a 00 00 FF FF pattern in the compressed data.
864
   All full flush points have this pattern, but not all occurrences of this
865
   pattern are full flush points.
866
 
867
     inflateSync returns Z_OK if a possible full flush point has been found,
868
   Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
869
   has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
870
   In the success case, the application may save the current current value of
871
   total_in which indicates where valid compressed data was found.  In the
872
   error case, the application may repeatedly call inflateSync, providing more
873
   input each time, until success or end of the input data.
874
*/
875
 
876
ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
877
                                    z_streamp source));
878
/*
879
     Sets the destination stream as a complete copy of the source stream.
880
 
881
     This function can be useful when randomly accessing a large stream.  The
882
   first pass through the stream can periodically record the inflate state,
883
   allowing restarting inflate at those points when randomly accessing the
884
   stream.
885
 
886
     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
887
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
888
   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
889
   destination.
890
*/
891
 
892
ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
893
/*
894
     This function is equivalent to inflateEnd followed by inflateInit,
895
   but does not free and reallocate all the internal decompression state.  The
896
   stream will keep attributes that may have been set by inflateInit2.
897
 
898
     inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
899
   stream state was inconsistent (such as zalloc or state being Z_NULL).
900
*/
901
 
902
ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
903
                                      int windowBits));
904
/*
905
     This function is the same as inflateReset, but it also permits changing
906
   the wrap and window size requests.  The windowBits parameter is interpreted
907
   the same as it is for inflateInit2.
908
 
909
     inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
910
   stream state was inconsistent (such as zalloc or state being Z_NULL), or if
911
   the windowBits parameter is invalid.
912
*/
913
 
914
ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
915
                                     int bits,
916
                                     int value));
917
/*
918
     This function inserts bits in the inflate input stream.  The intent is
919
   that this function is used to start inflating at a bit position in the
920
   middle of a byte.  The provided bits will be used before any bytes are used
921
   from next_in.  This function should only be used with raw inflate, and
922
   should be used before the first inflate() call after inflateInit2() or
923
   inflateReset().  bits must be less than or equal to 16, and that many of the
924
   least significant bits of value will be inserted in the input.
925
 
926
     If bits is negative, then the input stream bit buffer is emptied.  Then
927
   inflatePrime() can be called again to put bits in the buffer.  This is used
928
   to clear out bits leftover after feeding inflate a block description prior
929
   to feeding inflate codes.
930
 
931
     inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
932
   stream state was inconsistent.
933
*/
934
 
935
ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
936
/*
937
     This function returns two values, one in the lower 16 bits of the return
938
   value, and the other in the remaining upper bits, obtained by shifting the
939
   return value down 16 bits.  If the upper value is -1 and the lower value is
940
   zero, then inflate() is currently decoding information outside of a block.
941
   If the upper value is -1 and the lower value is non-zero, then inflate is in
942
   the middle of a stored block, with the lower value equaling the number of
943
   bytes from the input remaining to copy.  If the upper value is not -1, then
944
   it is the number of bits back from the current bit position in the input of
945
   the code (literal or length/distance pair) currently being processed.  In
946
   that case the lower value is the number of bytes already emitted for that
947
   code.
948
 
949
     A code is being processed if inflate is waiting for more input to complete
950
   decoding of the code, or if it has completed decoding but is waiting for
951
   more output space to write the literal or match data.
952
 
953
     inflateMark() is used to mark locations in the input data for random
954
   access, which may be at bit positions, and to note those cases where the
955
   output of a code may span boundaries of random access blocks.  The current
956
   location in the input stream can be determined from avail_in and data_type
957
   as noted in the description for the Z_BLOCK flush parameter for inflate.
958
 
959
     inflateMark returns the value noted above or -1 << 16 if the provided
960
   source stream state was inconsistent.
961
*/
962
 
963
ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
964
                                         gz_headerp head));
965
/*
966
     inflateGetHeader() requests that gzip header information be stored in the
967
   provided gz_header structure.  inflateGetHeader() may be called after
968
   inflateInit2() or inflateReset(), and before the first call of inflate().
969
   As inflate() processes the gzip stream, head->done is zero until the header
970
   is completed, at which time head->done is set to one.  If a zlib stream is
971
   being decoded, then head->done is set to -1 to indicate that there will be
972
   no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
973
   used to force inflate() to return immediately after header processing is
974
   complete and before any actual data is decompressed.
975
 
976
     The text, time, xflags, and os fields are filled in with the gzip header
977
   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
978
   was valid if done is set to one.) If extra is not Z_NULL, then extra_max
979
   contains the maximum number of bytes to write to extra.  Once done is true,
980
   extra_len contains the actual extra field length, and extra contains the
981
   extra field, or that field truncated if extra_max is less than extra_len.
982
   If name is not Z_NULL, then up to name_max characters are written there,
983
   terminated with a zero unless the length is greater than name_max.  If
984
   comment is not Z_NULL, then up to comm_max characters are written there,
985
   terminated with a zero unless the length is greater than comm_max.  When any
986
   of extra, name, or comment are not Z_NULL and the respective field is not
987
   present in the header, then that field is set to Z_NULL to signal its
988
   absence.  This allows the use of deflateSetHeader() with the returned
989
   structure to duplicate the header.  However if those fields are set to
990
   allocated memory, then the application will need to save those pointers
991
   elsewhere so that they can be eventually freed.
992
 
993
     If inflateGetHeader is not used, then the header information is simply
994
   discarded.  The header is always checked for validity, including the header
995
   CRC if present.  inflateReset() will reset the process to discard the header
996
   information.  The application would need to call inflateGetHeader() again to
997
   retrieve the header from the next gzip stream.
998
 
999
     inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1000
   stream state was inconsistent.
1001
*/
1002
 
1003
/*
1004
ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1005
                                        unsigned char FAR *window));
1006
 
1007
     Initialize the internal stream state for decompression using inflateBack()
1008
   calls.  The fields zalloc, zfree and opaque in strm must be initialized
1009
   before the call.  If zalloc and zfree are Z_NULL, then the default library-
1010
   derived memory allocation routines are used.  windowBits is the base two
1011
   logarithm of the window size, in the range 8..15.  window is a caller
1012
   supplied buffer of that size.  Except for special applications where it is
1013
   assured that deflate was used with small window sizes, windowBits must be 15
1014
   and a 32K byte window must be supplied to be able to decompress general
1015
   deflate streams.
1016
 
1017
     See inflateBack() for the usage of these routines.
1018
 
1019
     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1020
   the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1021
   allocated, or Z_VERSION_ERROR if the version of the library does not match
1022
   the version of the header file.
1023
*/
1024
 
1025
typedef unsigned (*in_func) OF((void FAR *,
1026
                                z_const unsigned char FAR * FAR *));
1027
typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1028
 
1029
ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
1030
                                    in_func in, void FAR *in_desc,
1031
                                    out_func out, void FAR *out_desc));
1032
/*
1033
     inflateBack() does a raw inflate with a single call using a call-back
1034
   interface for input and output.  This is potentially more efficient than
1035
   inflate() for file i/o applications, in that it avoids copying between the
1036
   output and the sliding window by simply making the window itself the output
1037
   buffer.  inflate() can be faster on modern CPUs when used with large
1038
   buffers.  inflateBack() trusts the application to not change the output
1039
   buffer passed by the output function, at least until inflateBack() returns.
1040
 
1041
     inflateBackInit() must be called first to allocate the internal state
1042
   and to initialize the state with the user-provided window buffer.
1043
   inflateBack() may then be used multiple times to inflate a complete, raw
1044
   deflate stream with each call.  inflateBackEnd() is then called to free the
1045
   allocated state.
1046
 
1047
     A raw deflate stream is one with no zlib or gzip header or trailer.
1048
   This routine would normally be used in a utility that reads zip or gzip
1049
   files and writes out uncompressed files.  The utility would decode the
1050
   header and process the trailer on its own, hence this routine expects only
1051
   the raw deflate stream to decompress.  This is different from the normal
1052
   behavior of inflate(), which expects either a zlib or gzip header and
1053
   trailer around the deflate stream.
1054
 
1055
     inflateBack() uses two subroutines supplied by the caller that are then
1056
   called by inflateBack() for input and output.  inflateBack() calls those
1057
   routines until it reads a complete deflate stream and writes out all of the
1058
   uncompressed data, or until it encounters an error.  The function's
1059
   parameters and return types are defined above in the in_func and out_func
1060
   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
1061
   number of bytes of provided input, and a pointer to that input in buf.  If
1062
   there is no input available, in() must return zero--buf is ignored in that
1063
   case--and inflateBack() will return a buffer error.  inflateBack() will call
1064
   out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
1065
   should return zero on success, or non-zero on failure.  If out() returns
1066
   non-zero, inflateBack() will return with an error.  Neither in() nor out()
1067
   are permitted to change the contents of the window provided to
1068
   inflateBackInit(), which is also the buffer that out() uses to write from.
1069
   The length written by out() will be at most the window size.  Any non-zero
1070
   amount of input may be provided by in().
1071
 
1072
     For convenience, inflateBack() can be provided input on the first call by
1073
   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
1074
   in() will be called.  Therefore strm->next_in must be initialized before
1075
   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
1076
   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
1077
   must also be initialized, and then if strm->avail_in is not zero, input will
1078
   initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
1079
 
1080
     The in_desc and out_desc parameters of inflateBack() is passed as the
1081
   first parameter of in() and out() respectively when they are called.  These
1082
   descriptors can be optionally used to pass any information that the caller-
1083
   supplied in() and out() functions need to do their job.
1084
 
1085
     On return, inflateBack() will set strm->next_in and strm->avail_in to
1086
   pass back any unused input that was provided by the last in() call.  The
1087
   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1088
   if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1089
   in the deflate stream (in which case strm->msg is set to indicate the nature
1090
   of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1091
   In the case of Z_BUF_ERROR, an input or output error can be distinguished
1092
   using strm->next_in which will be Z_NULL only if in() returned an error.  If
1093
   strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1094
   non-zero.  (in() will always be called before out(), so strm->next_in is
1095
   assured to be defined if out() returns non-zero.) Note that inflateBack()
1096
   cannot return Z_OK.
1097
*/
1098
 
1099
ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1100
/*
1101
     All memory allocated by inflateBackInit() is freed.
1102
 
1103
     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1104
   state was inconsistent.
1105
*/
1106
 
1107
ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1108
/* Return flags indicating compile-time options.
1109
 
1110
    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1111
     1.0: size of uInt
1112
     3.2: size of uLong
1113
     5.4: size of voidpf (pointer)
1114
     7.6: size of z_off_t
1115
 
1116
    Compiler, assembler, and debug options:
1117
     8: DEBUG
1118
     9: ASMV or ASMINF -- use ASM code
1119
     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1120
     11: 0 (reserved)
1121
 
1122
    One-time table building (smaller code, but not thread-safe if true):
1123
     12: BUILDFIXED -- build static block decoding tables when needed
1124
     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1125
     14,15: 0 (reserved)
1126
 
1127
    Library content (indicates missing functionality):
1128
     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1129
                          deflate code when not needed)
1130
     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1131
                    and decode gzip streams (to avoid linking crc code)
1132
     18-19: 0 (reserved)
1133
 
1134
    Operation variations (changes in library functionality):
1135
     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1136
     21: FASTEST -- deflate algorithm with only one, lowest compression level
1137
     22,23: 0 (reserved)
1138
 
1139
    The sprintf variant used by gzprintf (zero is best):
1140
     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1141
     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1142
     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1143
 
1144
    Remainder:
1145
     27-31: 0 (reserved)
1146
 */
1147
 
1148
#ifndef Z_SOLO
1149
 
1150
                        /* utility functions */
1151
 
1152
/*
1153
     The following utility functions are implemented on top of the basic
1154
   stream-oriented functions.  To simplify the interface, some default options
1155
   are assumed (compression level and memory usage, standard memory allocation
1156
   functions).  The source code of these utility functions can be modified if
1157
   you need special options.
1158
*/
1159
 
1160
ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
1161
                                 const Bytef *source, uLong sourceLen));
1162
/*
1163
     Compresses the source buffer into the destination buffer.  sourceLen is
1164
   the byte length of the source buffer.  Upon entry, destLen is the total size
1165
   of the destination buffer, which must be at least the value returned by
1166
   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
1167
   compressed buffer.
1168
 
1169
     compress returns Z_OK if success, Z_MEM_ERROR if there was not
1170
   enough memory, Z_BUF_ERROR if there was not enough room in the output
1171
   buffer.
1172
*/
1173
 
1174
ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
1175
                                  const Bytef *source, uLong sourceLen,
1176
                                  int level));
1177
/*
1178
     Compresses the source buffer into the destination buffer.  The level
1179
   parameter has the same meaning as in deflateInit.  sourceLen is the byte
1180
   length of the source buffer.  Upon entry, destLen is the total size of the
1181
   destination buffer, which must be at least the value returned by
1182
   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
1183
   compressed buffer.
1184
 
1185
     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1186
   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1187
   Z_STREAM_ERROR if the level parameter is invalid.
1188
*/
1189
 
1190
ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1191
/*
1192
     compressBound() returns an upper bound on the compressed size after
1193
   compress() or compress2() on sourceLen bytes.  It would be used before a
1194
   compress() or compress2() call to allocate the destination buffer.
1195
*/
1196
 
1197
ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
1198
                                   const Bytef *source, uLong sourceLen));
1199
/*
1200
     Decompresses the source buffer into the destination buffer.  sourceLen is
1201
   the byte length of the source buffer.  Upon entry, destLen is the total size
1202
   of the destination buffer, which must be large enough to hold the entire
1203
   uncompressed data.  (The size of the uncompressed data must have been saved
1204
   previously by the compressor and transmitted to the decompressor by some
1205
   mechanism outside the scope of this compression library.) Upon exit, destLen
1206
   is the actual size of the uncompressed buffer.
1207
 
1208
     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1209
   enough memory, Z_BUF_ERROR if there was not enough room in the output
1210
   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
1211
   the case where there is not enough room, uncompress() will fill the output
1212
   buffer with the uncompressed data up to that point.
1213
*/
1214
 
1215
                        /* gzip file access functions */
1216
 
1217
/*
1218
     This library supports reading and writing files in gzip (.gz) format with
1219
   an interface similar to that of stdio, using the functions that start with
1220
   "gz".  The gzip format is different from the zlib format.  gzip is a gzip
1221
   wrapper, documented in RFC 1952, wrapped around a deflate stream.
1222
*/
1223
 
1224
typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */
1225
 
1226
/*
1227
ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1228
 
1229
     Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
1230
   in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1231
   a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1232
   compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1233
   for fixed code compression as in "wb9F".  (See the description of
1234
   deflateInit2 for more information about the strategy parameter.)  'T' will
1235
   request transparent writing or appending with no compression and not using
1236
   the gzip format.
1237
 
1238
     "a" can be used instead of "w" to request that the gzip stream that will
1239
   be written be appended to the file.  "+" will result in an error, since
1240
   reading and writing to the same gzip file is not supported.  The addition of
1241
   "x" when writing will create the file exclusively, which fails if the file
1242
   already exists.  On systems that support it, the addition of "e" when
1243
   reading or writing will set the flag to close the file on an execve() call.
1244
 
1245
     These functions, as well as gzip, will read and decode a sequence of gzip
1246
   streams in a file.  The append function of gzopen() can be used to create
1247
   such a file.  (Also see gzflush() for another way to do this.)  When
1248
   appending, gzopen does not test whether the file begins with a gzip stream,
1249
   nor does it look for the end of the gzip streams to begin appending.  gzopen
1250
   will simply append a gzip stream to the existing file.
1251
 
1252
     gzopen can be used to read a file which is not in gzip format; in this
1253
   case gzread will directly read from the file without decompression.  When
1254
   reading, this will be detected automatically by looking for the magic two-
1255
   byte gzip header.
1256
 
1257
     gzopen returns NULL if the file could not be opened, if there was
1258
   insufficient memory to allocate the gzFile state, or if an invalid mode was
1259
   specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1260
   errno can be checked to determine if the reason gzopen failed was that the
1261
   file could not be opened.
1262
*/
1263
 
1264
ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1265
/*
1266
     gzdopen associates a gzFile with the file descriptor fd.  File descriptors
1267
   are obtained from calls like open, dup, creat, pipe or fileno (if the file
1268
   has been previously opened with fopen).  The mode parameter is as in gzopen.
1269
 
1270
     The next call of gzclose on the returned gzFile will also close the file
1271
   descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1272
   fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1273
   mode);.  The duplicated descriptor should be saved to avoid a leak, since
1274
   gzdopen does not close fd if it fails.  If you are using fileno() to get the
1275
   file descriptor from a FILE *, then you will have to use dup() to avoid
1276
   double-close()ing the file descriptor.  Both gzclose() and fclose() will
1277
   close the associated file descriptor, so they need to have different file
1278
   descriptors.
1279
 
1280
     gzdopen returns NULL if there was insufficient memory to allocate the
1281
   gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1282
   provided, or '+' was provided), or if fd is -1.  The file descriptor is not
1283
   used until the next gz* read, write, seek, or close operation, so gzdopen
1284
   will not detect if fd is invalid (unless fd is -1).
1285
*/
1286
 
1287
ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1288
/*
1289
     Set the internal buffer size used by this library's functions.  The
1290
   default buffer size is 8192 bytes.  This function must be called after
1291
   gzopen() or gzdopen(), and before any other calls that read or write the
1292
   file.  The buffer memory allocation is always deferred to the first read or
1293
   write.  Two buffers are allocated, either both of the specified size when
1294
   writing, or one of the specified size and the other twice that size when
1295
   reading.  A larger buffer size of, for example, 64K or 128K bytes will
1296
   noticeably increase the speed of decompression (reading).
1297
 
1298
     The new buffer size also affects the maximum length for gzprintf().
1299
 
1300
     gzbuffer() returns 0 on success, or -1 on failure, such as being called
1301
   too late.
1302
*/
1303
 
1304
ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1305
/*
1306
     Dynamically update the compression level or strategy.  See the description
1307
   of deflateInit2 for the meaning of these parameters.
1308
 
1309
     gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1310
   opened for writing.
1311
*/
1312
 
1313
ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1314
/*
1315
     Reads the given number of uncompressed bytes from the compressed file.  If
1316
   the input file is not in gzip format, gzread copies the given number of
1317
   bytes into the buffer directly from the file.
1318
 
1319
     After reaching the end of a gzip stream in the input, gzread will continue
1320
   to read, looking for another gzip stream.  Any number of gzip streams may be
1321
   concatenated in the input file, and will all be decompressed by gzread().
1322
   If something other than a gzip stream is encountered after a gzip stream,
1323
   that remaining trailing garbage is ignored (and no error is returned).
1324
 
1325
     gzread can be used to read a gzip file that is being concurrently written.
1326
   Upon reaching the end of the input, gzread will return with the available
1327
   data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1328
   gzclearerr can be used to clear the end of file indicator in order to permit
1329
   gzread to be tried again.  Z_OK indicates that a gzip stream was completed
1330
   on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
1331
   middle of a gzip stream.  Note that gzread does not return -1 in the event
1332
   of an incomplete gzip stream.  This error is deferred until gzclose(), which
1333
   will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1334
   stream.  Alternatively, gzerror can be used before gzclose to detect this
1335
   case.
1336
 
1337
     gzread returns the number of uncompressed bytes actually read, less than
1338
   len for end of file, or -1 for error.
1339
*/
1340
 
1341
ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1342
                                voidpc buf, unsigned len));
1343
/*
1344
     Writes the given number of uncompressed bytes into the compressed file.
1345
   gzwrite returns the number of uncompressed bytes written or 0 in case of
1346
   error.
1347
*/
1348
 
1349
ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
1350
/*
1351
     Converts, formats, and writes the arguments to the compressed file under
1352
   control of the format string, as in fprintf.  gzprintf returns the number of
1353
   uncompressed bytes actually written, or 0 in case of error.  The number of
1354
   uncompressed bytes written is limited to 8191, or one less than the buffer
1355
   size given to gzbuffer().  The caller should assure that this limit is not
1356
   exceeded.  If it is exceeded, then gzprintf() will return an error (0) with
1357
   nothing written.  In this case, there may also be a buffer overflow with
1358
   unpredictable consequences, which is possible only if zlib was compiled with
1359
   the insecure functions sprintf() or vsprintf() because the secure snprintf()
1360
   or vsnprintf() functions were not available.  This can be determined using
1361
   zlibCompileFlags().
1362
*/
1363
 
1364
ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1365
/*
1366
     Writes the given null-terminated string to the compressed file, excluding
1367
   the terminating null character.
1368
 
1369
     gzputs returns the number of characters written, or -1 in case of error.
1370
*/
1371
 
1372
ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1373
/*
1374
     Reads bytes from the compressed file until len-1 characters are read, or a
1375
   newline character is read and transferred to buf, or an end-of-file
1376
   condition is encountered.  If any characters are read or if len == 1, the
1377
   string is terminated with a null character.  If no characters are read due
1378
   to an end-of-file or len < 1, then the buffer is left untouched.
1379
 
1380
     gzgets returns buf which is a null-terminated string, or it returns NULL
1381
   for end-of-file or in case of error.  If there was an error, the contents at
1382
   buf are indeterminate.
1383
*/
1384
 
1385
ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1386
/*
1387
     Writes c, converted to an unsigned char, into the compressed file.  gzputc
1388
   returns the value that was written, or -1 in case of error.
1389
*/
1390
 
1391
ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1392
/*
1393
     Reads one byte from the compressed file.  gzgetc returns this byte or -1
1394
   in case of end of file or error.  This is implemented as a macro for speed.
1395
   As such, it does not do all of the checking the other functions do.  I.e.
1396
   it does not check to see if file is NULL, nor whether the structure file
1397
   points to has been clobbered or not.
1398
*/
1399
 
1400
ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1401
/*
1402
     Push one character back onto the stream to be read as the first character
1403
   on the next read.  At least one character of push-back is allowed.
1404
   gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
1405
   fail if c is -1, and may fail if a character has been pushed but not read
1406
   yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
1407
   output buffer size of pushed characters is allowed.  (See gzbuffer above.)
1408
   The pushed character will be discarded if the stream is repositioned with
1409
   gzseek() or gzrewind().
1410
*/
1411
 
1412
ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1413
/*
1414
     Flushes all pending output into the compressed file.  The parameter flush
1415
   is as in the deflate() function.  The return value is the zlib error number
1416
   (see function gzerror below).  gzflush is only permitted when writing.
1417
 
1418
     If the flush parameter is Z_FINISH, the remaining data is written and the
1419
   gzip stream is completed in the output.  If gzwrite() is called again, a new
1420
   gzip stream will be started in the output.  gzread() is able to read such
1421
   concatented gzip streams.
1422
 
1423
     gzflush should be called only when strictly necessary because it will
1424
   degrade compression if called too often.
1425
*/
1426
 
1427
/*
1428
ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1429
                                   z_off_t offset, int whence));
1430
 
1431
     Sets the starting position for the next gzread or gzwrite on the given
1432
   compressed file.  The offset represents a number of bytes in the
1433
   uncompressed data stream.  The whence parameter is defined as in lseek(2);
1434
   the value SEEK_END is not supported.
1435
 
1436
     If the file is opened for reading, this function is emulated but can be
1437
   extremely slow.  If the file is opened for writing, only forward seeks are
1438
   supported; gzseek then compresses a sequence of zeroes up to the new
1439
   starting position.
1440
 
1441
     gzseek returns the resulting offset location as measured in bytes from
1442
   the beginning of the uncompressed stream, or -1 in case of error, in
1443
   particular if the file is opened for writing and the new starting position
1444
   would be before the current position.
1445
*/
1446
 
1447
ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
1448
/*
1449
     Rewinds the given file. This function is supported only for reading.
1450
 
1451
     gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1452
*/
1453
 
1454
/*
1455
ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
1456
 
1457
     Returns the starting position for the next gzread or gzwrite on the given
1458
   compressed file.  This position represents a number of bytes in the
1459
   uncompressed data stream, and is zero when starting, even if appending or
1460
   reading a gzip stream from the middle of a file using gzdopen().
1461
 
1462
     gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1463
*/
1464
 
1465
/*
1466
ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1467
 
1468
     Returns the current offset in the file being read or written.  This offset
1469
   includes the count of bytes that precede the gzip stream, for example when
1470
   appending or when using gzdopen() for reading.  When reading, the offset
1471
   does not include as yet unused buffered input.  This information can be used
1472
   for a progress indicator.  On error, gzoffset() returns -1.
1473
*/
1474
 
1475
ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1476
/*
1477
     Returns true (1) if the end-of-file indicator has been set while reading,
1478
   false (0) otherwise.  Note that the end-of-file indicator is set only if the
1479
   read tried to go past the end of the input, but came up short.  Therefore,
1480
   just like feof(), gzeof() may return false even if there is no more data to
1481
   read, in the event that the last read request was for the exact number of
1482
   bytes remaining in the input file.  This will happen if the input file size
1483
   is an exact multiple of the buffer size.
1484
 
1485
     If gzeof() returns true, then the read functions will return no more data,
1486
   unless the end-of-file indicator is reset by gzclearerr() and the input file
1487
   has grown since the previous end of file was detected.
1488
*/
1489
 
1490
ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1491
/*
1492
     Returns true (1) if file is being copied directly while reading, or false
1493
   (0) if file is a gzip stream being decompressed.
1494
 
1495
     If the input file is empty, gzdirect() will return true, since the input
1496
   does not contain a gzip stream.
1497
 
1498
     If gzdirect() is used immediately after gzopen() or gzdopen() it will
1499
   cause buffers to be allocated to allow reading the file to determine if it
1500
   is a gzip file.  Therefore if gzbuffer() is used, it should be called before
1501
   gzdirect().
1502
 
1503
     When writing, gzdirect() returns true (1) if transparent writing was
1504
   requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
1505
   gzdirect() is not needed when writing.  Transparent writing must be
1506
   explicitly requested, so the application already knows the answer.  When
1507
   linking statically, using gzdirect() will include all of the zlib code for
1508
   gzip file reading and decompression, which may not be desired.)
1509
*/
1510
 
1511
ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
1512
/*
1513
     Flushes all pending output if necessary, closes the compressed file and
1514
   deallocates the (de)compression state.  Note that once file is closed, you
1515
   cannot call gzerror with file, since its structures have been deallocated.
1516
   gzclose must not be called more than once on the same file, just as free
1517
   must not be called more than once on the same allocation.
1518
 
1519
     gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1520
   file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1521
   last read ended in the middle of a gzip stream, or Z_OK on success.
1522
*/
1523
 
1524
ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1525
ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1526
/*
1527
     Same as gzclose(), but gzclose_r() is only for use when reading, and
1528
   gzclose_w() is only for use when writing or appending.  The advantage to
1529
   using these instead of gzclose() is that they avoid linking in zlib
1530
   compression or decompression code that is not used when only reading or only
1531
   writing respectively.  If gzclose() is used, then both compression and
1532
   decompression code will be included the application when linking to a static
1533
   zlib library.
1534
*/
1535
 
1536
ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1537
/*
1538
     Returns the error message for the last error which occurred on the given
1539
   compressed file.  errnum is set to zlib error number.  If an error occurred
1540
   in the file system and not in the compression library, errnum is set to
1541
   Z_ERRNO and the application may consult errno to get the exact error code.
1542
 
1543
     The application must not modify the returned string.  Future calls to
1544
   this function may invalidate the previously returned string.  If file is
1545
   closed, then the string previously returned by gzerror will no longer be
1546
   available.
1547
 
1548
     gzerror() should be used to distinguish errors from end-of-file for those
1549
   functions above that do not distinguish those cases in their return values.
1550
*/
1551
 
1552
ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1553
/*
1554
     Clears the error and end-of-file flags for file.  This is analogous to the
1555
   clearerr() function in stdio.  This is useful for continuing to read a gzip
1556
   file that is being written concurrently.
1557
*/
1558
 
1559
#endif /* !Z_SOLO */
1560
 
1561
                        /* checksum functions */
1562
 
1563
/*
1564
     These functions are not related to compression but are exported
1565
   anyway because they might be useful in applications using the compression
1566
   library.
1567
*/
1568
 
1569
ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1570
/*
1571
     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1572
   return the updated checksum.  If buf is Z_NULL, this function returns the
1573
   required initial value for the checksum.
1574
 
1575
     An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1576
   much faster.
1577
 
1578
   Usage example:
1579
 
1580
     uLong adler = adler32(0L, Z_NULL, 0);
1581
 
1582
     while (read_buffer(buffer, length) != EOF) {
1583
       adler = adler32(adler, buffer, length);
1584
     }
1585
     if (adler != original_adler) error();
1586
*/
1587
 
1588
/*
1589
ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1590
                                          z_off_t len2));
1591
 
1592
     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
1593
   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1594
   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
1595
   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
1596
   that the z_off_t type (like off_t) is a signed integer.  If len2 is
1597
   negative, the result has no meaning or utility.
1598
*/
1599
 
1600
ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
1601
/*
1602
     Update a running CRC-32 with the bytes buf[0..len-1] and return the
1603
   updated CRC-32.  If buf is Z_NULL, this function returns the required
1604
   initial value for the crc.  Pre- and post-conditioning (one's complement) is
1605
   performed within this function so it shouldn't be done by the application.
1606
 
1607
   Usage example:
1608
 
1609
     uLong crc = crc32(0L, Z_NULL, 0);
1610
 
1611
     while (read_buffer(buffer, length) != EOF) {
1612
       crc = crc32(crc, buffer, length);
1613
     }
1614
     if (crc != original_crc) error();
1615
*/
1616
 
1617
/*
1618
ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1619
 
1620
     Combine two CRC-32 check values into one.  For two sequences of bytes,
1621
   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1622
   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
1623
   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1624
   len2.
1625
*/
1626
 
1627
 
1628
                        /* various hacks, don't look :) */
1629
 
1630
/* deflateInit and inflateInit are macros to allow checking the zlib version
1631
 * and the compiler's view of z_stream:
1632
 */
1633
ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1634
                                     const char *version, int stream_size));
1635
ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1636
                                     const char *version, int stream_size));
1637
ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
1638
                                      int windowBits, int memLevel,
1639
                                      int strategy, const char *version,
1640
                                      int stream_size));
1641
ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
1642
                                      const char *version, int stream_size));
1643
ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1644
                                         unsigned char FAR *window,
1645
                                         const char *version,
1646
                                         int stream_size));
1647
#define deflateInit(strm, level) \
1648
        deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1649
#define inflateInit(strm) \
1650
        inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1651
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1652
        deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1653
                      (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1654
#define inflateInit2(strm, windowBits) \
1655
        inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1656
                      (int)sizeof(z_stream))
1657
#define inflateBackInit(strm, windowBits, window) \
1658
        inflateBackInit_((strm), (windowBits), (window), \
1659
                      ZLIB_VERSION, (int)sizeof(z_stream))
1660
 
1661
#ifndef Z_SOLO
1662
 
1663
/* gzgetc() macro and its supporting function and exposed data structure.  Note
1664
 * that the real internal state is much larger than the exposed structure.
1665
 * This abbreviated structure exposes just enough for the gzgetc() macro.  The
1666
 * user should not mess with these exposed elements, since their names or
1667
 * behavior could change in the future, perhaps even capriciously.  They can
1668
 * only be used by the gzgetc() macro.  You have been warned.
1669
 */
1670
struct gzFile_s {
1671
    unsigned have;
1672
    unsigned char *next;
1673
    z_off64_t pos;
1674
};
1675
ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
1676
#ifdef Z_PREFIX_SET
1677
#  undef z_gzgetc
1678
#  define z_gzgetc(g) \
1679
          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
1680
#else
1681
#  define gzgetc(g) \
1682
          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
1683
#endif
1684
 
1685
/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1686
 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1687
 * both are true, the application gets the *64 functions, and the regular
1688
 * functions are changed to 64 bits) -- in case these are set on systems
1689
 * without large file support, _LFS64_LARGEFILE must also be true
1690
 */
1691
#ifdef Z_LARGE64
1692
   ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1693
   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1694
   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1695
   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1696
   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1697
   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1698
#endif
1699
 
1700
#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1701
#  ifdef Z_PREFIX_SET
1702
#    define z_gzopen z_gzopen64
1703
#    define z_gzseek z_gzseek64
1704
#    define z_gztell z_gztell64
1705
#    define z_gzoffset z_gzoffset64
1706
#    define z_adler32_combine z_adler32_combine64
1707
#    define z_crc32_combine z_crc32_combine64
1708
#  else
1709
#    define gzopen gzopen64
1710
#    define gzseek gzseek64
1711
#    define gztell gztell64
1712
#    define gzoffset gzoffset64
1713
#    define adler32_combine adler32_combine64
1714
#    define crc32_combine crc32_combine64
1715
#  endif
1716
#  ifndef Z_LARGE64
1717
     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1718
     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1719
     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1720
     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1721
     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
1722
     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
1723
#  endif
1724
#else
1725
   ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1726
   ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1727
   ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1728
   ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1729
   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1730
   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1731
#endif
1732
 
1733
#else /* Z_SOLO */
1734
 
1735
   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1736
   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1737
 
1738
#endif /* !Z_SOLO */
1739
 
1740
/* hack for buggy compilers */
1741
#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1742
    struct internal_state {int dummy;};
1743
#endif
1744
 
1745
/* undocumented functions */
1746
ZEXTERN const char   * ZEXPORT zError           OF((int));
1747
ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
1748
ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
1749
ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
1750
ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
1751
ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
1752
#if defined(_WIN32) && !defined(Z_SOLO)
1753
ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
1754
                                            const char *mode));
1755
#endif
1756
#if defined(STDC) || defined(Z_HAVE_STDARG_H)
1757
#  ifndef Z_SOLO
1758
ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file,
1759
                                                  const char *format,
1760
                                                  va_list va));
1761
#  endif
1762
#endif
1763
 
1764
#ifdef __cplusplus
1765
}
1766
#endif
1767
 
1768
#endif /* ZLIB_H */