root/cherokee/trunk/cherokee/zlib/zlib.h

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1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2   version 1.1.3, July 9th, 1998
3
4   Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
5
6   This software is provided 'as-is', without any express or implied
7   warranty.  In no event will the authors be held liable for any damages
8   arising from the use of this software.
9
10   Permission is granted to anyone to use this software for any purpose,
11   including commercial applications, and to alter it and redistribute it
12   freely, subject to the following restrictions:
13
14   1. The origin of this software must not be misrepresented; you must not
15      claim that you wrote the original software. If you use this software
16      in a product, an acknowledgment in the product documentation would be
17      appreciated but is not required.
18   2. Altered source versions must be plainly marked as such, and must not be
19      misrepresented as being the original software.
20   3. This notice may not be removed or altered from any source distribution.
21
22   Jean-loup Gailly        Mark Adler
23   jloup@gzip.org          madler@alumni.caltech.edu
24
25
26   The data format used by the zlib library is described by RFCs (Request for
27   Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
28   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
29 */
30
31 #ifndef _ZLIB_H
32 #define _ZLIB_H
33
34 #include "zconf.h"
35 #include <stdlib.h>
36 #include <string.h>
37
38 #define ZLIB_VERSION "1.1.3"
39
40 /*
41      The 'zlib' compression library provides in-memory compression and
42   decompression functions, including integrity checks of the uncompressed
43   data.  This version of the library supports only one compression method
44   (deflation) but other algorithms will be added later and will have the same
45   stream interface.
46
47      Compression can be done in a single step if the buffers are large
48   enough (for example if an input file is mmap'ed), or can be done by
49   repeated calls of the compression function.  In the latter case, the
50   application must provide more input and/or consume the output
51   (providing more output space) before each call.
52
53      The library also supports reading and writing files in gzip (.gz) format
54   with an interface similar to that of stdio.
55
56      The library does not install any signal handler. The decoder checks
57   the consistency of the compressed data, so the library should never
58   crash even in case of corrupted input.
59 */
60
61 struct internal_state;
62
63 typedef struct z_stream_s {
64     Byte    *next_in;   /* next input byte */
65     uInt     avail_in;  /* number of bytes available at next_in */
66     uLong    total_in;  /* total nb of input bytes read so far */
67
68     Byte    *next_out;  /* next output byte should be put there */
69     uInt     avail_out; /* remaining free space at next_out */
70     uLong    total_out; /* total nb of bytes output so far */
71
72     char     *msg;      /* last error message, NULL if no error */
73     struct internal_state *state; /* not visible by applications */
74
75     void     *workspace; /* memory allocated for this stream */
76
77     int     data_type;  /* best guess about the data type: ascii or binary */
78     uLong   adler;      /* adler32 value of the uncompressed data */
79     uLong   reserved;   /* reserved for future use */
80 } z_stream;
81
82 typedef z_stream *z_streamp;
83
84 /*
85    The application must update next_in and avail_in when avail_in has
86    dropped to zero. It must update next_out and avail_out when avail_out
87    has dropped to zero. The application must initialize zalloc, zfree and
88    opaque before calling the init function. All other fields are set by the
89    compression library and must not be updated by the application.
90
91    The opaque value provided by the application will be passed as the first
92    parameter for calls of zalloc and zfree. This can be useful for custom
93    memory management. The compression library attaches no meaning to the
94    opaque value.
95
96    zalloc must return NULL if there is not enough memory for the object.
97    If zlib is used in a multi-threaded application, zalloc and zfree must be
98    thread safe.
99
100    On 16-bit systems, the functions zalloc and zfree must be able to allocate
101    exactly 65536 bytes, but will not be required to allocate more than this
102    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
103    pointers returned by zalloc for objects of exactly 65536 bytes *must*
104    have their offset normalized to zero. The default allocation function
105    provided by this library ensures this (see zutil.c). To reduce memory
106    requirements and avoid any allocation of 64K objects, at the expense of
107    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
108
109    The fields total_in and total_out can be used for statistics or
110    progress reports. After compression, total_in holds the total size of
111    the uncompressed data and may be saved for use in the decompressor
112    (particularly if the decompressor wants to decompress everything in
113    a single step).
114 */
115
116                         /* constants */
117
118 #define Z_NO_FLUSH      0
119 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
120 #define Z_PACKET_FLUSH  2
121 #define Z_SYNC_FLUSH    3
122 #define Z_FULL_FLUSH    4
123 #define Z_FINISH        5
124 /* Allowed flush values; see deflate() below for details */
125
126 #define Z_OK            0
127 #define Z_STREAM_END    1
128 #define Z_NEED_DICT     2
129 #define Z_ERRNO        (-1)
130 #define Z_STREAM_ERROR (-2)
131 #define Z_DATA_ERROR   (-3)
132 #define Z_MEM_ERROR    (-4)
133 #define Z_BUF_ERROR    (-5)
134 #define Z_VERSION_ERROR (-6)
135 /* Return codes for the compression/decompression functions. Negative
136  * values are errors, positive values are used for special but normal events.
137  */
138
139 #define Z_NO_COMPRESSION         0
140 #define Z_BEST_SPEED             1
141 #define Z_BEST_COMPRESSION       9
142 #define Z_DEFAULT_COMPRESSION  (-1)
143 /* compression levels */
144
145 #define Z_FILTERED            1
146 #define Z_HUFFMAN_ONLY        2
147 #define Z_DEFAULT_STRATEGY    0
148 /* compression strategy; see deflateInit2() below for details */
149
150 #define Z_BINARY   0
151 #define Z_ASCII    1
152 #define Z_UNKNOWN  2
153 /* Possible values of the data_type field */
154
155 #define Z_DEFLATED   8
156 /* The deflate compression method (the only one supported in this version) */
157
158                         /* basic functions */
159
160 extern const char * zlib_zlibVersion (void);
161 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
162    If the first character differs, the library code actually used is
163    not compatible with the zlib.h header file used by the application.
164    This check is automatically made by deflateInit and inflateInit.
165  */
166
167 extern int zlib_deflate_workspacesize (void);
168 /*
169    Returns the number of bytes that needs to be allocated for a per-
170    stream workspace.  A pointer to this number of bytes should be
171    returned in stream->workspace before calling zlib_deflateInit().
172 */
173
174 /*
175 extern int deflateInit (z_streamp strm, int level);
176
177      Initializes the internal stream state for compression. The fields
178    zalloc, zfree and opaque must be initialized before by the caller.
179    If zalloc and zfree are set to NULL, deflateInit updates them to
180    use default allocation functions.
181
182      The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
183    1 gives best speed, 9 gives best compression, 0 gives no compression at
184    all (the input data is simply copied a block at a time).
185    Z_DEFAULT_COMPRESSION requests a default compromise between speed and
186    compression (currently equivalent to level 6).
187
188      deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
189    enough memory, Z_STREAM_ERROR if level is not a valid compression level,
190    Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
191    with the version assumed by the caller (ZLIB_VERSION).
192    msg is set to null if there is no error message.  deflateInit does not
193    perform any compression: this will be done by deflate().
194 */
195
196
197 extern int zlib_deflate (z_streamp strm, int flush);
198 /*
199     deflate compresses as much data as possible, and stops when the input
200   buffer becomes empty or the output buffer becomes full. It may introduce some
201   output latency (reading input without producing any output) except when
202   forced to flush.
203
204     The detailed semantics are as follows. deflate performs one or both of the
205   following actions:
206
207   - Compress more input starting at next_in and update next_in and avail_in
208     accordingly. If not all input can be processed (because there is not
209     enough room in the output buffer), next_in and avail_in are updated and
210     processing will resume at this point for the next call of deflate().
211
212   - Provide more output starting at next_out and update next_out and avail_out
213     accordingly. This action is forced if the parameter flush is non zero.
214     Forcing flush frequently degrades the compression ratio, so this parameter
215     should be set only when necessary (in interactive applications).
216     Some output may be provided even if flush is not set.
217
218   Before the call of deflate(), the application should ensure that at least
219   one of the actions is possible, by providing more input and/or consuming
220   more output, and updating avail_in or avail_out accordingly; avail_out
221   should never be zero before the call. The application can consume the
222   compressed output when it wants, for example when the output buffer is full
223   (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
224   and with zero avail_out, it must be called again after making room in the
225   output buffer because there might be more output pending.
226
227     If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
228   flushed to the output buffer and the output is aligned on a byte boundary, so
229   that the decompressor can get all input data available so far. (In particular
230   avail_in is zero after the call if enough output space has been provided
231   before the call.)  Flushing may degrade compression for some compression
232   algorithms and so it should be used only when necessary.
233
234     If flush is set to Z_FULL_FLUSH, all output is flushed as with
235   Z_SYNC_FLUSH, and the compression state is reset so that decompression can
236   restart from this point if previous compressed data has been damaged or if
237   random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
238   the compression.
239
240     If deflate returns with avail_out == 0, this function must be called again
241   with the same value of the flush parameter and more output space (updated
242   avail_out), until the flush is complete (deflate returns with non-zero
243   avail_out).
244
245     If the parameter flush is set to Z_FINISH, pending input is processed,
246   pending output is flushed and deflate returns with Z_STREAM_END if there
247   was enough output space; if deflate returns with Z_OK, this function must be
248   called again with Z_FINISH and more output space (updated avail_out) but no
249   more input data, until it returns with Z_STREAM_END or an error. After
250   deflate has returned Z_STREAM_END, the only possible operations on the
251   stream are deflateReset or deflateEnd.
252  
253     Z_FINISH can be used immediately after deflateInit if all the compression
254   is to be done in a single step. In this case, avail_out must be at least
255   0.1% larger than avail_in plus 12 bytes.  If deflate does not return
256   Z_STREAM_END, then it must be called again as described above.
257
258     deflate() sets strm->adler to the adler32 checksum of all input read
259   so far (that is, total_in bytes).
260
261     deflate() may update data_type if it can make a good guess about
262   the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
263   binary. This field is only for information purposes and does not affect
264   the compression algorithm in any manner.
265
266     deflate() returns Z_OK if some progress has been made (more input
267   processed or more output produced), Z_STREAM_END if all input has been
268   consumed and all output has been produced (only when flush is set to
269   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
270   if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
271   (for example avail_in or avail_out was zero).
272 */
273
274
275 extern int zlib_deflateEnd (z_streamp strm);
276 /*
277      All dynamically allocated data structures for this stream are freed.
278    This function discards any unprocessed input and does not flush any
279    pending output.
280
281      deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
282    stream state was inconsistent, Z_DATA_ERROR if the stream was freed
283    prematurely (some input or output was discarded). In the error case,
284    msg may be set but then points to a static string (which must not be
285    deallocated).
286 */
287
288
289 extern int zlib_inflate_workspacesize (void);
290 /*
291    Returns the number of bytes that needs to be allocated for a per-
292    stream workspace.  A pointer to this number of bytes should be
293    returned in stream->workspace before calling zlib_inflateInit().
294 */
295
296 /*
297 extern int zlib_inflateInit (z_streamp strm);
298
299      Initializes the internal stream state for decompression. The fields
300    next_in, avail_in, and workspace must be initialized before by
301    the caller. If next_in is not NULL and avail_in is large enough (the exact
302    value depends on the compression method), inflateInit determines the
303    compression method from the zlib header and allocates all data structures
304    accordingly; otherwise the allocation will be deferred to the first call of
305    inflate.  If zalloc and zfree are set to NULL, inflateInit updates them to
306    use default allocation functions.
307
308      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
309    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
310    version assumed by the caller.  msg is set to null if there is no error
311    message. inflateInit does not perform any decompression apart from reading
312    the zlib header if present: this will be done by inflate().  (So next_in and
313    avail_in may be modified, but next_out and avail_out are unchanged.)
314 */
315
316
317 extern int zlib_inflate (z_streamp strm, int flush);
318 /*
319     inflate decompresses as much data as possible, and stops when the input
320   buffer becomes empty or the output buffer becomes full. It may some
321   introduce some output latency (reading input without producing any output)
322   except when forced to flush.
323
324   The detailed semantics are as follows. inflate performs one or both of the
325   following actions:
326
327   - Decompress more input starting at next_in and update next_in and avail_in
328     accordingly. If not all input can be processed (because there is not
329     enough room in the output buffer), next_in is updated and processing
330     will resume at this point for the next call of inflate().
331
332   - Provide more output starting at next_out and update next_out and avail_out
333     accordingly.  inflate() provides as much output as possible, until there
334     is no more input data or no more space in the output buffer (see below
335     about the flush parameter).
336
337   Before the call of inflate(), the application should ensure that at least
338   one of the actions is possible, by providing more input and/or consuming
339   more output, and updating the next_* and avail_* values accordingly.
340   The application can consume the uncompressed output when it wants, for
341   example when the output buffer is full (avail_out == 0), or after each
342   call of inflate(). If inflate returns Z_OK and with zero avail_out, it
343   must be called again after making room in the output buffer because there
344   might be more output pending.
345
346     If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much
347   output as possible to the output buffer. The flushing behavior of inflate is
348   not specified for values of the flush parameter other than Z_SYNC_FLUSH
349   and Z_FINISH, but the current implementation actually flushes as much output
350   as possible anyway.
351
352     inflate() should normally be called until it returns Z_STREAM_END or an
353   error. However if all decompression is to be performed in a single step
354   (a single call of inflate), the parameter flush should be set to
355   Z_FINISH. In this case all pending input is processed and all pending
356   output is flushed; avail_out must be large enough to hold all the
357   uncompressed data. (The size of the uncompressed data may have been saved
358   by the compressor for this purpose.) The next operation on this stream must
359   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
360   is never required, but can be used to inform inflate that a faster routine
361   may be used for the single inflate() call.
362
363      If a preset dictionary is needed at this point (see inflateSetDictionary
364   below), inflate sets strm-adler to the adler32 checksum of the
365   dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise
366   it sets strm->adler to the adler32 checksum of all output produced
367   so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or
368   an error code as described below. At the end of the stream, inflate()
369   checks that its computed adler32 checksum is equal to that saved by the
370   compressor and returns Z_STREAM_END only if the checksum is correct.
371
372     inflate() returns Z_OK if some progress has been made (more input processed
373   or more output produced), Z_STREAM_END if the end of the compressed data has
374   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
375   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
376   corrupted (input stream not conforming to the zlib format or incorrect
377   adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent
378   (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not
379   enough memory, Z_BUF_ERROR if no progress is possible or if there was not
380   enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR
381   case, the application may then call inflateSync to look for a good
382   compression block.
383 */
384
385
386 extern int zlib_inflateEnd (z_streamp strm);
387 /*
388      All dynamically allocated data structures for this stream are freed.
389    This function discards any unprocessed input and does not flush any
390    pending output.
391
392      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
393    was inconsistent. In the error case, msg may be set but then points to a
394    static string (which must not be deallocated).
395 */
396
397                         /* Advanced functions */
398
399 /*
400     The following functions are needed only in some special applications.
401 */
402
403 /*   
404 extern int deflateInit2 (z_streamp strm,
405                                      int  level,
406                                      int  method,
407                                      int  windowBits,
408                                      int  memLevel,
409                                      int  strategy);
410
411      This is another version of deflateInit with more compression options. The
412    fields next_in, zalloc, zfree and opaque must be initialized before by
413    the caller.
414
415      The method parameter is the compression method. It must be Z_DEFLATED in
416    this version of the library.
417
418      The windowBits parameter is the base two logarithm of the window size
419    (the size of the history buffer).  It should be in the range 8..15 for this
420    version of the library. Larger values of this parameter result in better
421    compression at the expense of memory usage. The default value is 15 if
422    deflateInit is used instead.
423
424      The memLevel parameter specifies how much memory should be allocated
425    for the internal compression state. memLevel=1 uses minimum memory but
426    is slow and reduces compression ratio; memLevel=9 uses maximum memory
427    for optimal speed. The default value is 8. See zconf.h for total memory
428    usage as a function of windowBits and memLevel.
429
430      The strategy parameter is used to tune the compression algorithm. Use the
431    value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
432    filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
433    string match).  Filtered data consists mostly of small values with a
434    somewhat random distribution. In this case, the compression algorithm is
435    tuned to compress them better. The effect of Z_FILTERED is to force more
436    Huffman coding and less string matching; it is somewhat intermediate
437    between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
438    the compression ratio but not the correctness of the compressed output even
439    if it is not set appropriately.
440
441       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
442    memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
443    method). msg is set to null if there is no error message.  deflateInit2 does
444    not perform any compression: this will be done by deflate().
445 */
446                            
447 extern int zlib_deflateSetDictionary (z_streamp strm,
448                                                      const Byte *dictionary,
449                                                      uInt  dictLength);
450 /*
451      Initializes the compression dictionary from the given byte sequence
452    without producing any compressed output. This function must be called
453    immediately after deflateInit, deflateInit2 or deflateReset, before any
454    call of deflate. The compressor and decompressor must use exactly the same
455    dictionary (see inflateSetDictionary).
456
457      The dictionary should consist of strings (byte sequences) that are likely
458    to be encountered later in the data to be compressed, with the most commonly
459    used strings preferably put towards the end of the dictionary. Using a
460    dictionary is most useful when the data to be compressed is short and can be
461    predicted with good accuracy; the data can then be compressed better than
462    with the default empty dictionary.
463
464      Depending on the size of the compression data structures selected by
465    deflateInit or deflateInit2, a part of the dictionary may in effect be
466    discarded, for example if the dictionary is larger than the window size in
467    deflate or deflate2. Thus the strings most likely to be useful should be
468    put at the end of the dictionary, not at the front.
469
470      Upon return of this function, strm->adler is set to the Adler32 value
471    of the dictionary; the decompressor may later use this value to determine
472    which dictionary has been used by the compressor. (The Adler32 value
473    applies to the whole dictionary even if only a subset of the dictionary is
474    actually used by the compressor.)
475
476      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
477    parameter is invalid (such as NULL dictionary) or the stream state is
478    inconsistent (for example if deflate has already been called for this stream
479    or if the compression method is bsort). deflateSetDictionary does not
480    perform any compression: this will be done by deflate().
481 */
482
483 extern int zlib_deflateCopy (z_streamp dest, z_streamp source);
484 /*
485      Sets the destination stream as a complete copy of the source stream.
486
487      This function can be useful when several compression strategies will be
488    tried, for example when there are several ways of pre-processing the input
489    data with a filter. The streams that will be discarded should then be freed
490    by calling deflateEnd.  Note that deflateCopy duplicates the internal
491    compression state which can be quite large, so this strategy is slow and
492    can consume lots of memory.
493
494      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
495    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
496    (such as zalloc being NULL). msg is left unchanged in both source and
497    destination.
498 */
499
500 extern int zlib_deflateReset (z_streamp strm);
501 /*
502      This function is equivalent to deflateEnd followed by deflateInit,
503    but does not free and reallocate all the internal compression state.
504    The stream will keep the same compression level and any other attributes
505    that may have been set by deflateInit2.
506
507       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
508    stream state was inconsistent (such as zalloc or state being NULL).
509 */
510
511 extern int zlib_deflateParams (z_streamp strm, int level, int strategy);
512 /*
513      Dynamically update the compression level and compression strategy.  The
514    interpretation of level and strategy is as in deflateInit2.  This can be
515    used to switch between compression and straight copy of the input data, or
516    to switch to a different kind of input data requiring a different
517    strategy. If the compression level is changed, the input available so far
518    is compressed with the old level (and may be flushed); the new level will
519    take effect only at the next call of deflate().
520
521      Before the call of deflateParams, the stream state must be set as for
522    a call of deflate(), since the currently available input may have to
523    be compressed and flushed. In particular, strm->avail_out must be non-zero.
524
525      deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
526    stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
527    if strm->avail_out was zero.
528 */
529
530 /*   
531 extern int inflateInit2 (z_streamp strm, int  windowBits);
532
533      This is another version of inflateInit with an extra parameter. The
534    fields next_in, avail_in, zalloc, zfree and opaque must be initialized
535    before by the caller.
536
537      The windowBits parameter is the base two logarithm of the maximum window
538    size (the size of the history buffer).  It should be in the range 8..15 for
539    this version of the library. The default value is 15 if inflateInit is used
540    instead. If a compressed stream with a larger window size is given as
541    input, inflate() will return with the error code Z_DATA_ERROR instead of
542    trying to allocate a larger window.
543
544       inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
545    memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
546    memLevel). msg is set to null if there is no error message.  inflateInit2
547    does not perform any decompression apart from reading the zlib header if
548    present: this will be done by inflate(). (So next_in and avail_in may be
549    modified, but next_out and avail_out are unchanged.)
550 */
551
552 extern int zlib_inflateSetDictionary (z_streamp strm,
553                                                      const Byte *dictionary,
554                                                      uInt  dictLength);
555 /*
556      Initializes the decompression dictionary from the given uncompressed byte
557    sequence. This function must be called immediately after a call of inflate
558    if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
559    can be determined from the Adler32 value returned by this call of
560    inflate. The compressor and decompressor must use exactly the same
561    dictionary (see deflateSetDictionary).
562
563      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
564    parameter is invalid (such as NULL dictionary) or the stream state is
565    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
566    expected one (incorrect Adler32 value). inflateSetDictionary does not
567    perform any decompression: this will be done by subsequent calls of
568    inflate().
569 */
570
571 extern int zlib_inflateSync (z_streamp strm);
572 /*
573     Skips invalid compressed data until a full flush point (see above the
574   description of deflate with Z_FULL_FLUSH) can be found, or until all
575   available input is skipped. No output is provided.
576
577     inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
578   if no more input was provided, Z_DATA_ERROR if no flush point has been found,
579   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
580   case, the application may save the current current value of total_in which
581   indicates where valid compressed data was found. In the error case, the
582   application may repeatedly call inflateSync, providing more input each time,
583   until success or end of the input data.
584 */
585
586 extern int zlib_inflateReset (z_streamp strm);
587 /*
588      This function is equivalent to inflateEnd followed by inflateInit,
589    but does not free and reallocate all the internal decompression state.
590    The stream will keep attributes that may have been set by inflateInit2.
591
592       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
593    stream state was inconsistent (such as zalloc or state being NULL).
594 */
595
596 extern int zlib_inflateIncomp (z_stream *strm);
597 /*
598      This function adds the data at next_in (avail_in bytes) to the output
599    history without performing any output.  There must be no pending output,
600    and the decompressor must be expecting to see the start of a block.
601    Calling this function is equivalent to decompressing a stored block
602    containing the data at next_in (except that the data is not output).
603 */
604
605                         /* various hacks, don't look :) */
606
607 /* deflateInit and inflateInit are macros to allow checking the zlib version
608  * and the compiler's view of z_stream:
609  */
610 extern int zlib_deflateInit_ (z_streamp strm, int level,
611                                      const char *version, int stream_size);
612 extern int zlib_inflateInit_ (z_streamp strm,
613                                      const char *version, int stream_size);
614 extern int zlib_deflateInit2_ (z_streamp strm, int  level, int  method,
615                                       int windowBits, int memLevel,
616                                       int strategy, const char *version,
617                                       int stream_size);
618 extern int zlib_inflateInit2_ (z_streamp strm, int  windowBits,
619                                       const char *version, int stream_size);
620 #define zlib_deflateInit(strm, level) \
621         zlib_deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
622 #define zlib_inflateInit(strm) \
623         zlib_inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
624 #define zlib_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
625         zlib_deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
626                       (strategy), ZLIB_VERSION, sizeof(z_stream))
627 #define zlib_inflateInit2(strm, windowBits) \
628         zlib_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
629
630
631 #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
632     struct internal_state {int dummy;}; /* hack for buggy compilers */
633 #endif
634
635 extern const char  * zlib_zError           (int err);
636 extern int           zlib_inflateSyncPoint (z_streamp z);
637 extern const uLong * zlib_get_crc_table    (void);
638
639 #endif /* _ZLIB_H */
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