1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2 version 1.2.1.1, January 9th, 2004
4 Copyright (C) 1995-2004 Jean-loup Gailly and Mark Adler
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.
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:
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.
22 Jean-loup Gailly Mark Adler
23 jloup@gzip.org madler@alumni.caltech.edu
26 The data format used by the zlib library is described by RFCs (Request for
27 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
28 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
40 #define ZLIB_VERSION "1.2.1.1"
41 #define ZLIB_VERNUM 0x1211
44 The 'zlib' compression library provides in-memory compression and
45 decompression functions, including integrity checks of the uncompressed
46 data. This version of the library supports only one compression method
47 (deflation) but other algorithms will be added later and will have the same
50 Compression can be done in a single step if the buffers are large
51 enough (for example if an input file is mmap'ed), or can be done by
52 repeated calls of the compression function. In the latter case, the
53 application must provide more input and/or consume the output
54 (providing more output space) before each call.
56 The compressed data format used by the in-memory functions is the zlib
57 format, which is a zlib wrapper documented in RFC 1950, wrapped around a
58 deflate stream, which is itself documented in RFC 1951.
60 The library also supports reading and writing files in gzip (.gz) format
61 with an interface similar to that of stdio using the functions that start
62 with "gz". The gzip format is different from the zlib format. gzip is a
63 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
65 The zlib format was designed to be compact and fast for use in memory
66 and on communications channels. The gzip format was designed for single-
67 file compression on file systems, has a larger header than zlib to maintain
68 directory information, and uses a different, slower check method than zlib.
70 This library does not provide any functions to write gzip files in memory.
71 However such functions could be easily written using zlib's deflate function,
72 the documentation in the gzip RFC, and the examples in gzio.c.
74 The library does not install any signal handler. The decoder checks
75 the consistency of the compressed data, so the library should never
76 crash even in case of corrupted input.
79 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size))
81 typedef void (*free_func) OF((voidpf opaque, voidpf address))
84 struct internal_state;
86 typedef struct z_stream_s {
88 Bytef *next_in; /* next input byte */
89 uInt avail_in; /* number of bytes available at next_in */
90 uLong total_in; /* total nb of input bytes read so far */
93 Bytef *next_out; /* next output byte should be put there */
94 uInt avail_out; /* remaining free space at next_out */
95 uLong total_out; /* total nb of bytes output so far */
98 char *msg; /* last error message, NULL if no error */
100 struct internal_state FAR *state; /* not visible by applications */
103 alloc_func zalloc; /* used to allocate the internal state */
105 free_func zfree; /* used to free the internal state */
107 voidpf opaque; /* private data object passed to zalloc and zfree */
109 int data_type; /* best guess about the data type: ascii or binary */
110 uLong adler; /* adler32 value of the uncompressed data */
111 uLong reserved; /* reserved for future use */
114 typedef z_stream FAR *z_streamp;
117 The application must update next_in and avail_in when avail_in has
118 dropped to zero. It must update next_out and avail_out when avail_out
119 has dropped to zero. The application must initialize zalloc, zfree and
120 opaque before calling the init function. All other fields are set by the
121 compression library and must not be updated by the application.
123 The opaque value provided by the application will be passed as the first
124 parameter for calls of zalloc and zfree. This can be useful for custom
125 memory management. The compression library attaches no meaning to the
128 zalloc must return Z_NULL if there is not enough memory for the object.
129 If zlib is used in a multi-threaded application, zalloc and zfree must be
132 On 16-bit systems, the functions zalloc and zfree must be able to allocate
133 exactly 65536 bytes, but will not be required to allocate more than this
134 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
135 pointers returned by zalloc for objects of exactly 65536 bytes *must*
136 have their offset normalized to zero. The default allocation function
137 provided by this library ensures this (see zutil.c). To reduce memory
138 requirements and avoid any allocation of 64K objects, at the expense of
139 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
141 The fields total_in and total_out can be used for statistics or
142 progress reports. After compression, total_in holds the total size of
143 the uncompressed data and may be saved for use in the decompressor
144 (particularly if the decompressor wants to decompress everything in
151 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
152 #define Z_SYNC_FLUSH 2
153 #define Z_FULL_FLUSH 3
156 /* Allowed flush values; see deflate() and inflate() below for details */
159 #define Z_STREAM_END 1
160 #define Z_NEED_DICT 2
162 #define Z_STREAM_ERROR (-2)
163 #define Z_DATA_ERROR (-3)
164 #define Z_MEM_ERROR (-4)
165 #define Z_BUF_ERROR (-5)
166 #define Z_VERSION_ERROR (-6)
167 /* Return codes for the compression/decompression functions. Negative
168 * values are errors, positive values are used for special but normal events.
171 #define Z_NO_COMPRESSION 0
172 #define Z_BEST_SPEED 1
173 #define Z_BEST_COMPRESSION 9
174 #define Z_DEFAULT_COMPRESSION (-1)
175 /* compression levels */
178 #define Z_HUFFMAN_ONLY 2
180 #define Z_DEFAULT_STRATEGY 0
181 /* compression strategy; see deflateInit2() below for details */
186 /* Possible values of the data_type field (though see inflate()) */
189 /* The deflate compression method (the only one supported in this version) */
191 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
193 #define zlib_version zlibVersion()
194 /* for compatibility with versions < 1.0.2 */
196 /* basic functions */
198 ZEXTERN const char * ZEXPORT zlibVersion OF((void))
200 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
201 If the first character differs, the library code actually used is
202 not compatible with the zlib.h header file used by the application.
203 This check is automatically made by deflateInit and inflateInit.
207 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
209 Initializes the internal stream state for compression. The fields
210 zalloc, zfree and opaque must be initialized before by the caller.
211 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
212 use default allocation functions.
214 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
215 1 gives best speed, 9 gives best compression, 0 gives no compression at
216 all (the input data is simply copied a block at a time).
217 Z_DEFAULT_COMPRESSION requests a default compromise between speed and
218 compression (currently equivalent to level 6).
220 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
221 enough memory, Z_STREAM_ERROR if level is not a valid compression level,
222 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
223 with the version assumed by the caller (ZLIB_VERSION).
224 msg is set to null if there is no error message. deflateInit does not
225 perform any compression: this will be done by deflate().
229 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush))
230 /*@modifies strm @*/;
232 deflate compresses as much data as possible, and stops when the input
233 buffer becomes empty or the output buffer becomes full. It may introduce some
234 output latency (reading input without producing any output) except when
237 The detailed semantics are as follows. deflate performs one or both of the
240 - Compress more input starting at next_in and update next_in and avail_in
241 accordingly. If not all input can be processed (because there is not
242 enough room in the output buffer), next_in and avail_in are updated and
243 processing will resume at this point for the next call of deflate().
245 - Provide more output starting at next_out and update next_out and avail_out
246 accordingly. This action is forced if the parameter flush is non zero.
247 Forcing flush frequently degrades the compression ratio, so this parameter
248 should be set only when necessary (in interactive applications).
249 Some output may be provided even if flush is not set.
251 Before the call of deflate(), the application should ensure that at least
252 one of the actions is possible, by providing more input and/or consuming
253 more output, and updating avail_in or avail_out accordingly; avail_out
254 should never be zero before the call. The application can consume the
255 compressed output when it wants, for example when the output buffer is full
256 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
257 and with zero avail_out, it must be called again after making room in the
258 output buffer because there might be more output pending.
260 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
261 flushed to the output buffer and the output is aligned on a byte boundary, so
262 that the decompressor can get all input data available so far. (In particular
263 avail_in is zero after the call if enough output space has been provided
264 before the call.) Flushing may degrade compression for some compression
265 algorithms and so it should be used only when necessary.
267 If flush is set to Z_FULL_FLUSH, all output is flushed as with
268 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
269 restart from this point if previous compressed data has been damaged or if
270 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
273 If deflate returns with avail_out == 0, this function must be called again
274 with the same value of the flush parameter and more output space (updated
275 avail_out), until the flush is complete (deflate returns with non-zero
276 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
277 avail_out is greater than six to avoid repeated flush markers due to
278 avail_out == 0 on return.
280 If the parameter flush is set to Z_FINISH, pending input is processed,
281 pending output is flushed and deflate returns with Z_STREAM_END if there
282 was enough output space; if deflate returns with Z_OK, this function must be
283 called again with Z_FINISH and more output space (updated avail_out) but no
284 more input data, until it returns with Z_STREAM_END or an error. After
285 deflate has returned Z_STREAM_END, the only possible operations on the
286 stream are deflateReset or deflateEnd.
288 Z_FINISH can be used immediately after deflateInit if all the compression
289 is to be done in a single step. In this case, avail_out must be at least
290 the value returned by deflateBound (see below). If deflate does not return
291 Z_STREAM_END, then it must be called again as described above.
293 deflate() sets strm->adler to the adler32 checksum of all input read
294 so far (that is, total_in bytes).
296 deflate() may update data_type if it can make a good guess about
297 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
298 binary. This field is only for information purposes and does not affect
299 the compression algorithm in any manner.
301 deflate() returns Z_OK if some progress has been made (more input
302 processed or more output produced), Z_STREAM_END if all input has been
303 consumed and all output has been produced (only when flush is set to
304 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
305 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
306 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
307 fatal, and deflate() can be called again with more input and more output
308 space to continue compressing.
312 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm))
313 /*@modifies strm @*/;
315 All dynamically allocated data structures for this stream are freed.
316 This function discards any unprocessed input and does not flush any
319 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
320 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
321 prematurely (some input or output was discarded). In the error case,
322 msg may be set but then points to a static string (which must not be
328 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
330 Initializes the internal stream state for decompression. The fields
331 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
332 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
333 value depends on the compression method), inflateInit determines the
334 compression method from the zlib header and allocates all data structures
335 accordingly; otherwise the allocation will be deferred to the first call of
336 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
337 use default allocation functions.
339 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
340 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
341 version assumed by the caller. msg is set to null if there is no error
342 message. inflateInit does not perform any decompression apart from reading
343 the zlib header if present: this will be done by inflate(). (So next_in and
344 avail_in may be modified, but next_out and avail_out are unchanged.)
348 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush))
349 /*@modifies strm @*/;
351 inflate decompresses as much data as possible, and stops when the input
352 buffer becomes empty or the output buffer becomes full. It may introduce
353 some output latency (reading input without producing any output) except when
356 The detailed semantics are as follows. inflate performs one or both of the
359 - Decompress more input starting at next_in and update next_in and avail_in
360 accordingly. If not all input can be processed (because there is not
361 enough room in the output buffer), next_in is updated and processing
362 will resume at this point for the next call of inflate().
364 - Provide more output starting at next_out and update next_out and avail_out
365 accordingly. inflate() provides as much output as possible, until there
366 is no more input data or no more space in the output buffer (see below
367 about the flush parameter).
369 Before the call of inflate(), the application should ensure that at least
370 one of the actions is possible, by providing more input and/or consuming
371 more output, and updating the next_* and avail_* values accordingly.
372 The application can consume the uncompressed output when it wants, for
373 example when the output buffer is full (avail_out == 0), or after each
374 call of inflate(). If inflate returns Z_OK and with zero avail_out, it
375 must be called again after making room in the output buffer because there
376 might be more output pending.
378 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
379 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
380 output as possible to the output buffer. Z_BLOCK requests that inflate() stop
381 if and when it get to the next deflate block boundary. When decoding the zlib
382 or gzip format, this will cause inflate() to return immediately after the
383 header and before the first block. When doing a raw inflate, inflate() will
384 go ahead and process the first block, and will return when it gets to the end
385 of that block, or when it runs out of data.
387 The Z_BLOCK option assists in appending to or combining deflate streams.
388 Also to assist in this, on return inflate() will set strm->data_type to the
389 number of unused bits in the last byte taken from strm->next_in, plus 64
390 if inflate() is currently decoding the last block in the deflate stream,
391 plus 128 if inflate() returned immediately after decoding an end-of-block
392 code or decoding the complete header up to just before the first byte of the
393 deflate stream. The end-of-block will not be indicated until all of the
394 uncompressed data from that block has been written to strm->next_out. The
395 number of unused bits may in general be greater than seven, except when
396 bit 7 of data_type is set, in which case the number of unused bits will be
399 inflate() should normally be called until it returns Z_STREAM_END or an
400 error. However if all decompression is to be performed in a single step
401 (a single call of inflate), the parameter flush should be set to
402 Z_FINISH. In this case all pending input is processed and all pending
403 output is flushed; avail_out must be large enough to hold all the
404 uncompressed data. (The size of the uncompressed data may have been saved
405 by the compressor for this purpose.) The next operation on this stream must
406 be inflateEnd to deallocate the decompression state. The use of Z_FINISH
407 is never required, but can be used to inform inflate that a faster approach
408 may be used for the single inflate() call.
410 In this implementation, inflate() always flushes as much output as
411 possible to the output buffer, and always uses the faster approach on the
412 first call. So the only effect of the flush parameter in this implementation
413 is on the return value of inflate(), as noted below, or when it returns early
414 because Z_BLOCK is used.
416 If a preset dictionary is needed after this call (see inflateSetDictionary
417 below), inflate sets strm-adler to the adler32 checksum of the dictionary
418 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
419 strm->adler to the adler32 checksum of all output produced so far (that is,
420 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
421 below. At the end of the stream, inflate() checks that its computed adler32
422 checksum is equal to that saved by the compressor and returns Z_STREAM_END
423 only if the checksum is correct.
425 inflate() will decompress and check either zlib-wrapped or gzip-wrapped
426 deflate data. The header type is detected automatically. Any information
427 contained in the gzip header is not retained, so applications that need that
428 information should instead use raw inflate, see inflateInit2() below, or
429 inflateBack() and perform their own processing of the gzip header and
432 inflate() returns Z_OK if some progress has been made (more input processed
433 or more output produced), Z_STREAM_END if the end of the compressed data has
434 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
435 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
436 corrupted (input stream not conforming to the zlib format or incorrect check
437 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
438 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
439 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
440 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
441 inflate() can be called again with more input and more output space to
442 continue decompressing. If Z_DATA_ERROR is returned, the application may then
443 call inflateSync() to look for a good compression block if a partial recovery
444 of the data is desired.
448 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm))
449 /*@modifies strm @*/;
451 All dynamically allocated data structures for this stream are freed.
452 This function discards any unprocessed input and does not flush any
455 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
456 was inconsistent. In the error case, msg may be set but then points to a
457 static string (which must not be deallocated).
460 /* Advanced functions */
463 The following functions are needed only in some special applications.
467 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
474 This is another version of deflateInit with more compression options. The
475 fields next_in, zalloc, zfree and opaque must be initialized before by
478 The method parameter is the compression method. It must be Z_DEFLATED in
479 this version of the library.
481 The windowBits parameter is the base two logarithm of the window size
482 (the size of the history buffer). It should be in the range 8..15 for this
483 version of the library. Larger values of this parameter result in better
484 compression at the expense of memory usage. The default value is 15 if
485 deflateInit is used instead.
487 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
488 determines the window size. deflate() will then generate raw deflate data
489 with no zlib header or trailer, and will not compute an adler32 check value.
491 windowBits can also be greater than 15 for optional gzip encoding. Add
492 16 to windowBits to write a simple gzip header and trailer around the
493 compressed data instead of a zlib wrapper. The gzip header will have no
494 file name, no extra data, no comment, no modification time (set to zero),
495 no header crc, and the operating system will be set to 255 (unknown).
497 The memLevel parameter specifies how much memory should be allocated
498 for the internal compression state. memLevel=1 uses minimum memory but
499 is slow and reduces compression ratio; memLevel=9 uses maximum memory
500 for optimal speed. The default value is 8. See zconf.h for total memory
501 usage as a function of windowBits and memLevel.
503 The strategy parameter is used to tune the compression algorithm. Use the
504 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
505 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
506 string match), or Z_RLE to limit match distances to one (run-length
507 encoding). Filtered data consists mostly of small values with a somewhat
508 random distribution. In this case, the compression algorithm is tuned to
509 compress them better. The effect of Z_FILTERED is to force more Huffman
510 coding and less string matching; it is somewhat intermediate between
511 Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
512 Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
513 parameter only affects the compression ratio but not the correctness of the
514 compressed output even if it is not set appropriately.
516 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
517 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
518 method). msg is set to null if there is no error message. deflateInit2 does
519 not perform any compression: this will be done by deflate().
522 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
523 const Bytef *dictionary,
525 /*@modifies strm @*/;
527 Initializes the compression dictionary from the given byte sequence
528 without producing any compressed output. This function must be called
529 immediately after deflateInit, deflateInit2 or deflateReset, before any
530 call of deflate. The compressor and decompressor must use exactly the same
531 dictionary (see inflateSetDictionary).
533 The dictionary should consist of strings (byte sequences) that are likely
534 to be encountered later in the data to be compressed, with the most commonly
535 used strings preferably put towards the end of the dictionary. Using a
536 dictionary is most useful when the data to be compressed is short and can be
537 predicted with good accuracy; the data can then be compressed better than
538 with the default empty dictionary.
540 Depending on the size of the compression data structures selected by
541 deflateInit or deflateInit2, a part of the dictionary may in effect be
542 discarded, for example if the dictionary is larger than the window size in
543 deflate or deflate2. Thus the strings most likely to be useful should be
544 put at the end of the dictionary, not at the front.
546 Upon return of this function, strm->adler is set to the adler32 value
547 of the dictionary; the decompressor may later use this value to determine
548 which dictionary has been used by the compressor. (The adler32 value
549 applies to the whole dictionary even if only a subset of the dictionary is
550 actually used by the compressor.) If a raw deflate was requested, then the
551 adler32 value is not computed and strm->adler is not set.
553 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
554 parameter is invalid (such as NULL dictionary) or the stream state is
555 inconsistent (for example if deflate has already been called for this stream
556 or if the compression method is bsort). deflateSetDictionary does not
557 perform any compression: this will be done by deflate().
560 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
562 /*@modifies dest, source @*/;
564 Sets the destination stream as a complete copy of the source stream.
566 This function can be useful when several compression strategies will be
567 tried, for example when there are several ways of pre-processing the input
568 data with a filter. The streams that will be discarded should then be freed
569 by calling deflateEnd. Note that deflateCopy duplicates the internal
570 compression state which can be quite large, so this strategy is slow and
571 can consume lots of memory.
573 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
574 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
575 (such as zalloc being NULL). msg is left unchanged in both source and
579 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm))
580 /*@globals internalState @*/
581 /*@modifies strm, internalState @*/;
583 This function is equivalent to deflateEnd followed by deflateInit,
584 but does not free and reallocate all the internal compression state.
585 The stream will keep the same compression level and any other attributes
586 that may have been set by deflateInit2.
588 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
589 stream state was inconsistent (such as zalloc or state being NULL).
592 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
595 /*@modifies strm @*/;
597 Dynamically update the compression level and compression strategy. The
598 interpretation of level and strategy is as in deflateInit2. This can be
599 used to switch between compression and straight copy of the input data, or
600 to switch to a different kind of input data requiring a different
601 strategy. If the compression level is changed, the input available so far
602 is compressed with the old level (and may be flushed); the new level will
603 take effect only at the next call of deflate().
605 Before the call of deflateParams, the stream state must be set as for
606 a call of deflate(), since the currently available input may have to
607 be compressed and flushed. In particular, strm->avail_out must be non-zero.
609 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
610 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
611 if strm->avail_out was zero.
614 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
616 /*@modifies strm @*/;
618 deflateBound() returns an upper bound on the compressed size after
619 deflation of sourceLen bytes. It must be called after deflateInit()
620 or deflateInit2(). This would be used to allocate an output buffer
621 for deflation in a single pass, and so would be called before deflate().
624 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
627 /*@modifies strm @*/;
629 deflatePrime() inserts bits in the deflate output stream. The intent
630 is that this function is used to start off the deflate output with the
631 bits leftover from a previous deflate stream when appending to it. As such,
632 this function can only be used for raw deflate, and must be used before the
633 first deflate() call after a deflateInit2() or deflateReset(). bits must be
634 less than or equal to 16, and that many of the least significant bits of
635 value will be inserted in the output.
637 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
638 stream state was inconsistent.
642 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
645 This is another version of inflateInit with an extra parameter. The
646 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
647 before by the caller.
649 The windowBits parameter is the base two logarithm of the maximum window
650 size (the size of the history buffer). It should be in the range 8..15 for
651 this version of the library. The default value is 15 if inflateInit is used
652 instead. windowBits must be greater than or equal to the windowBits value
653 provided to deflateInit2() while compressing, or it must be equal to 15 if
654 deflateInit2() was not used. If a compressed stream with a larger window
655 size is given as input, inflate() will return with the error code
656 Z_DATA_ERROR instead of trying to allocate a larger window.
658 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
659 determines the window size. inflate() will then process raw deflate data,
660 not looking for a zlib or gzip header, not generating a check value, and not
661 looking for any check values for comparison at the end of the stream. This
662 is for use with other formats that use the deflate compressed data format
663 such as zip. Those formats provide their own check values. If a custom
664 format is developed using the raw deflate format for compressed data, it is
665 recommended that a check value such as an adler32 or a crc32 be applied to
666 the uncompressed data as is done in the zlib, gzip, and zip formats. For
667 most applications, the zlib format should be used as is. Note that comments
668 above on the use in deflateInit2() applies to the magnitude of windowBits.
670 windowBits can also be greater than 15 for optional gzip decoding. Add
671 32 to windowBits to enable zlib and gzip decoding with automatic header
672 detection, or add 16 to decode only the gzip format (the zlib format will
673 return a Z_DATA_ERROR).
675 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
676 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
677 memLevel). msg is set to null if there is no error message. inflateInit2
678 does not perform any decompression apart from reading the zlib header if
679 present: this will be done by inflate(). (So next_in and avail_in may be
680 modified, but next_out and avail_out are unchanged.)
683 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
684 const Bytef *dictionary,
686 /*@modifies strm @*/;
688 Initializes the decompression dictionary from the given uncompressed byte
689 sequence. This function must be called immediately after a call of inflate
690 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
691 can be determined from the adler32 value returned by this call of
692 inflate. The compressor and decompressor must use exactly the same
693 dictionary (see deflateSetDictionary).
695 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
696 parameter is invalid (such as NULL dictionary) or the stream state is
697 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
698 expected one (incorrect adler32 value). inflateSetDictionary does not
699 perform any decompression: this will be done by subsequent calls of
703 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm))
704 /*@modifies strm @*/;
706 Skips invalid compressed data until a full flush point (see above the
707 description of deflate with Z_FULL_FLUSH) can be found, or until all
708 available input is skipped. No output is provided.
710 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
711 if no more input was provided, Z_DATA_ERROR if no flush point has been found,
712 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
713 case, the application may save the current current value of total_in which
714 indicates where valid compressed data was found. In the error case, the
715 application may repeatedly call inflateSync, providing more input each time,
716 until success or end of the input data.
719 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
721 /*@modifies dest, source @*/;
723 Sets the destination stream as a complete copy of the source stream.
725 This function can be useful when randomly accessing a large stream. The
726 first pass through the stream can periodically record the inflate state,
727 allowing restarting inflate at those points when randomly accessing the
730 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
731 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
732 (such as zalloc being NULL). msg is left unchanged in both source and
736 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm))
737 /*@modifies strm @*/;
739 This function is equivalent to inflateEnd followed by inflateInit,
740 but does not free and reallocate all the internal decompression state.
741 The stream will keep attributes that may have been set by inflateInit2.
743 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
744 stream state was inconsistent (such as zalloc or state being NULL).
748 ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *strm, int windowBits,
749 unsigned char FAR *window));
751 Initialize the internal stream state for decompression using inflateBack()
752 calls. The fields zalloc, zfree and opaque in strm must be initialized
753 before the call. If zalloc and zfree are Z_NULL, then the default library-
754 derived memory allocation routines are used. windowBits is the base two
755 logarithm of the window size, in the range 8..15. window is a caller
756 supplied buffer of that size. Except for special applications where it is
757 assured that deflate was used with small window sizes, windowBits must be 15
758 and a 32K byte window must be supplied to be able to decompress general
761 See inflateBack() for the usage of these routines.
763 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
764 the paramaters are invalid, Z_MEM_ERROR if the internal state could not
765 be allocated, or Z_VERSION_ERROR if the version of the library does not
766 match the version of the header file.
769 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *))
771 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned))
774 ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm,
775 in_func in, void FAR *in_desc,
776 out_func out, void FAR *out_desc))
777 /*@modifies strm @*/;
779 inflateBack() does a raw inflate with a single call using a call-back
780 interface for input and output. This is more efficient than inflate() for
781 file i/o applications in that it avoids copying between the output and the
782 sliding window by simply making the window itself the output buffer. This
783 function trusts the application to not change the output buffer passed by
784 the output function, at least until inflateBack() returns.
786 inflateBackInit() must be called first to allocate the internal state
787 and to initialize the state with the user-provided window buffer.
788 inflateBack() may then be used multiple times to inflate a complete, raw
789 deflate stream with each call. inflateBackEnd() is then called to free
792 A raw deflate stream is one with no zlib or gzip header or trailer.
793 This routine would normally be used in a utility that reads zip or gzip
794 files and writes out uncompressed files. The utility would decode the
795 header and process the trailer on its own, hence this routine expects
796 only the raw deflate stream to decompress. This is different from the
797 normal behavior of inflate(), which expects either a zlib or gzip header and
798 trailer around the deflate stream.
800 inflateBack() uses two subroutines supplied by the caller that are then
801 called by inflateBack() for input and output. inflateBack() calls those
802 routines until it reads a complete deflate stream and writes out all of the
803 uncompressed data, or until it encounters an error. The function's
804 parameters and return types are defined above in the in_func and out_func
805 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
806 number of bytes of provided input, and a pointer to that input in buf. If
807 there is no input available, in() must return zero--buf is ignored in that
808 case--and inflateBack() will return a buffer error. inflateBack() will call
809 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
810 should return zero on success, or non-zero on failure. If out() returns
811 non-zero, inflateBack() will return with an error. Neither in() nor out()
812 are permitted to change the contents of the window provided to
813 inflateBackInit(), which is also the buffer that out() uses to write from.
814 The length written by out() will be at most the window size. Any non-zero
815 amount of input may be provided by in().
817 For convenience, inflateBack() can be provided input on the first call by
818 setting strm->next_in and strm->avail_in. If that input is exhausted, then
819 in() will be called. Therefore strm->next_in must be initialized before
820 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
821 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
822 must also be initialized, and then if strm->avail_in is not zero, input will
823 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
825 The in_desc and out_desc parameters of inflateBack() is passed as the
826 first parameter of in() and out() respectively when they are called. These
827 descriptors can be optionally used to pass any information that the caller-
828 supplied in() and out() functions need to do their job.
830 On return, inflateBack() will set strm->next_in and strm->avail_in to
831 pass back any unused input that was provided by the last in() call. The
832 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
833 if in() or out() returned an error, Z_DATA_ERROR if there was a format
834 error in the deflate stream (in which case strm->msg is set to indicate the
835 nature of the error), or Z_STREAM_ERROR if the stream was not properly
836 initialized. In the case of Z_BUF_ERROR, an input or output error can be
837 distinguished using strm->next_in which will be Z_NULL only if in() returned
838 an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
839 out() returning non-zero. (in() will always be called before out(), so
840 strm->next_in is assured to be defined if out() returns non-zero.) Note
841 that inflateBack() cannot return Z_OK.
844 ZEXTERN int ZEXPORT inflateBackEnd OF((z_stream FAR *strm))
845 /*@modifies strm @*/;
847 All memory allocated by inflateBackInit() is freed.
849 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
850 state was inconsistent.
853 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void))
855 /* Return flags indicating compile-time options.
857 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
860 5.4: size of voidpf (pointer)
863 Compiler, assembler, and debug options:
865 9: ASMV or ASMINF -- use ASM code
866 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
869 One-time table building (smaller code, but not thread-safe if true):
870 12: BUILDFIXED -- build static block decoding tables when needed
871 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
874 Library content (indicates missing functionality):
875 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
876 deflate code when not needed)
877 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
878 and decode gzip streams (to avoid linking crc code)
881 Operation variations (changes in library functionality):
882 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
883 21: FASTEST -- deflate algorithm with only one, lowest compression level
886 The sprintf variant used by gzprintf (zero is best):
887 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
888 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
889 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
896 /* utility functions */
899 The following utility functions are implemented on top of the
900 basic stream-oriented functions. To simplify the interface, some
901 default options are assumed (compression level and memory usage,
902 standard memory allocation functions). The source code of these
903 utility functions can easily be modified if you need special options.
906 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
907 const Bytef *source, uLong sourceLen))
908 /*@globals internalState @*/
909 /*@modifies *dest, *destLen, internalState @*/;
911 Compresses the source buffer into the destination buffer. sourceLen is
912 the byte length of the source buffer. Upon entry, destLen is the total
913 size of the destination buffer, which must be at least the value returned
914 by compressBound(sourceLen). Upon exit, destLen is the actual size of the
916 This function can be used to compress a whole file at once if the
917 input file is mmap'ed.
918 compress returns Z_OK if success, Z_MEM_ERROR if there was not
919 enough memory, Z_BUF_ERROR if there was not enough room in the output
923 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
924 const Bytef *source, uLong sourceLen,
926 /*@globals internalState @*/
927 /*@modifies *dest, *destLen, internalState @*/;
929 Compresses the source buffer into the destination buffer. The level
930 parameter has the same meaning as in deflateInit. sourceLen is the byte
931 length of the source buffer. Upon entry, destLen is the total size of the
932 destination buffer, which must be at least the value returned by
933 compressBound(sourceLen). Upon exit, destLen is the actual size of the
936 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
937 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
938 Z_STREAM_ERROR if the level parameter is invalid.
941 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen))
944 compressBound() returns an upper bound on the compressed size after
945 compress() or compress2() on sourceLen bytes. It would be used before
946 a compress() or compress2() call to allocate the destination buffer.
949 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
950 const Bytef *source, uLong sourceLen))
951 /*@modifies *dest, *destLen @*/;
953 Decompresses the source buffer into the destination buffer. sourceLen is
954 the byte length of the source buffer. Upon entry, destLen is the total
955 size of the destination buffer, which must be large enough to hold the
956 entire uncompressed data. (The size of the uncompressed data must have
957 been saved previously by the compressor and transmitted to the decompressor
958 by some mechanism outside the scope of this compression library.)
959 Upon exit, destLen is the actual size of the compressed buffer.
960 This function can be used to decompress a whole file at once if the
961 input file is mmap'ed.
963 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
964 enough memory, Z_BUF_ERROR if there was not enough room in the output
965 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
969 typedef voidp gzFile;
971 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode))
972 /*@globals fileSystem, internalState @*/
973 /*@modifies fileSystem, internalState @*/;
975 Opens a gzip (.gz) file for reading or writing. The mode parameter
976 is as in fopen ("rb" or "wb") but can also include a compression level
977 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
978 Huffman only compression as in "wb1h", or 'R' for run-length encoding
979 as in "wb1R". (See the description of deflateInit2 for more information
980 about the strategy parameter.)
982 gzopen can be used to read a file which is not in gzip format; in this
983 case gzread will directly read from the file without decompression.
985 gzopen returns NULL if the file could not be opened or if there was
986 insufficient memory to allocate the (de)compression state; errno
987 can be checked to distinguish the two cases (if errno is zero, the
988 zlib error is Z_MEM_ERROR). */
990 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode))
991 /*@globals fileSystem, internalState @*/
992 /*@modifies fileSystem, internalState @*/;
994 gzdopen() associates a gzFile with the file descriptor fd. File
995 descriptors are obtained from calls like open, dup, creat, pipe or
996 fileno (in the file has been previously opened with fopen).
997 The mode parameter is as in gzopen.
998 The next call of gzclose on the returned gzFile will also close the
999 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
1000 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
1001 gzdopen returns NULL if there was insufficient memory to allocate
1002 the (de)compression state.
1005 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy))
1006 /*@globals fileSystem @*/
1007 /*@modifies file, fileSystem @*/;
1009 Dynamically update the compression level or strategy. See the description
1010 of deflateInit2 for the meaning of these parameters.
1011 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1015 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len))
1016 /*@globals errno, fileSystem @*/
1017 /*@modifies file, *buf, errno, fileSystem @*/;
1019 Reads the given number of uncompressed bytes from the compressed file.
1020 If the input file was not in gzip format, gzread copies the given number
1021 of bytes into the buffer.
1022 gzread returns the number of uncompressed bytes actually read (0 for
1023 end of file, -1 for error). */
1025 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1026 voidpc buf, unsigned len))
1027 /*@globals fileSystem @*/
1028 /*@modifies file, fileSystem @*/;
1030 Writes the given number of uncompressed bytes into the compressed file.
1031 gzwrite returns the number of uncompressed bytes actually written
1032 (0 in case of error).
1035 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...))
1036 /*@globals fileSystem @*/
1037 /*@modifies file, fileSystem @*/;
1039 Converts, formats, and writes the args to the compressed file under
1040 control of the format string, as in fprintf. gzprintf returns the number of
1041 uncompressed bytes actually written (0 in case of error). The number of
1042 uncompressed bytes written is limited to 4095. The caller should assure that
1043 this limit is not exceeded. If it is exceeded, then gzprintf() will return
1044 return an error (0) with nothing written. In this case, there may also be a
1045 buffer overflow with unpredictable consequences, which is possible only if
1046 zlib was compiled with the insecure functions sprintf() or vsprintf()
1047 because the secure snprintf() or vsnprintf() functions were not available.
1050 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s))
1051 /*@globals fileSystem @*/
1052 /*@modifies file, fileSystem @*/;
1054 Writes the given null-terminated string to the compressed file, excluding
1055 the terminating null character.
1056 gzputs returns the number of characters written, or -1 in case of error.
1059 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len))
1060 /*@globals fileSystem @*/
1061 /*@modifies file, buf, fileSystem @*/;
1063 Reads bytes from the compressed file until len-1 characters are read, or
1064 a newline character is read and transferred to buf, or an end-of-file
1065 condition is encountered. The string is then terminated with a null
1067 gzgets returns buf, or Z_NULL in case of error.
1070 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c))
1071 /*@globals fileSystem @*/
1072 /*@modifies file, fileSystem @*/;
1074 Writes c, converted to an unsigned char, into the compressed file.
1075 gzputc returns the value that was written, or -1 in case of error.
1078 ZEXTERN int ZEXPORT gzgetc OF((gzFile file))
1079 /*@globals fileSystem @*/
1080 /*@modifies file, fileSystem @*/;
1082 Reads one byte from the compressed file. gzgetc returns this byte
1083 or -1 in case of end of file or error.
1086 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file))
1089 Push one character back onto the stream to be read again later.
1090 Only one character of push-back is allowed. gzungetc() returns the
1091 character pushed, or -1 on failure. gzungetc() will fail if a
1092 character has been pushed but not read yet, or if c is -1. The pushed
1093 character will be discarded if the stream is repositioned with gzseek()
1097 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush))
1098 /*@globals fileSystem @*/
1099 /*@modifies file, fileSystem @*/;
1101 Flushes all pending output into the compressed file. The parameter
1102 flush is as in the deflate() function. The return value is the zlib
1103 error number (see function gzerror below). gzflush returns Z_OK if
1104 the flush parameter is Z_FINISH and all output could be flushed.
1105 gzflush should be called only when strictly necessary because it can
1106 degrade compression.
1109 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1110 z_off_t offset, int whence))
1111 /*@globals fileSystem @*/
1112 /*@modifies file, fileSystem @*/;
1114 Sets the starting position for the next gzread or gzwrite on the
1115 given compressed file. The offset represents a number of bytes in the
1116 uncompressed data stream. The whence parameter is defined as in lseek(2);
1117 the value SEEK_END is not supported.
1118 If the file is opened for reading, this function is emulated but can be
1119 extremely slow. If the file is opened for writing, only forward seeks are
1120 supported; gzseek then compresses a sequence of zeroes up to the new
1123 gzseek returns the resulting offset location as measured in bytes from
1124 the beginning of the uncompressed stream, or -1 in case of error, in
1125 particular if the file is opened for writing and the new starting position
1126 would be before the current position.
1129 ZEXTERN int ZEXPORT gzrewind OF((gzFile file))
1130 /*@globals fileSystem @*/
1131 /*@modifies file, fileSystem @*/;
1133 Rewinds the given file. This function is supported only for reading.
1135 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1138 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file))
1139 /*@globals fileSystem @*/
1140 /*@modifies file, fileSystem @*/;
1142 Returns the starting position for the next gzread or gzwrite on the
1143 given compressed file. This position represents a number of bytes in the
1144 uncompressed data stream.
1146 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1149 ZEXTERN int ZEXPORT gzeof OF((gzFile file))
1152 Returns 1 when EOF has previously been detected reading the given
1153 input stream, otherwise zero.
1156 ZEXTERN int ZEXPORT gzclose OF((gzFile file))
1157 /*@globals fileSystem @*/
1158 /*@modifies file, fileSystem @*/;
1160 Flushes all pending output if necessary, closes the compressed file
1161 and deallocates all the (de)compression state. The return value is the zlib
1162 error number (see function gzerror below).
1165 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum))
1166 /*@modifies *errnum @*/;
1168 Returns the error message for the last error which occurred on the
1169 given compressed file. errnum is set to zlib error number. If an
1170 error occurred in the file system and not in the compression library,
1171 errnum is set to Z_ERRNO and the application may consult errno
1172 to get the exact error code.
1175 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file))
1178 Clears the error and end-of-file flags for file. This is analogous to the
1179 clearerr() function in stdio. This is useful for continuing to read a gzip
1180 file that is being written concurrently.
1183 /* checksum functions */
1186 These functions are not related to compression but are exported
1187 anyway because they might be useful in applications using the
1188 compression library.
1191 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len))
1195 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1196 return the updated checksum. If buf is NULL, this function returns
1197 the required initial value for the checksum.
1198 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1199 much faster. Usage example:
1201 uLong adler = adler32(0L, Z_NULL, 0);
1203 while (read_buffer(buffer, length) != EOF) {
1204 adler = adler32(adler, buffer, length);
1206 if (adler != original_adler) error();
1209 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len))
1212 Update a running crc with the bytes buf[0..len-1] and return the updated
1213 crc. If buf is NULL, this function returns the required initial value
1214 for the crc. Pre- and post-conditioning (one's complement) is performed
1215 within this function so it shouldn't be done by the application.
1218 uLong crc = crc32(0L, Z_NULL, 0);
1220 while (read_buffer(buffer, length) != EOF) {
1221 crc = crc32(crc, buffer, length);
1223 if (crc != original_crc) error();
1227 /* various hacks, don't look :) */
1229 /* deflateInit and inflateInit are macros to allow checking the zlib version
1230 * and the compiler's view of z_stream:
1232 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1233 const char *version, int stream_size))
1234 /*@globals internalState @*/
1235 /*@modifies strm, internalState @*/;
1236 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1237 const char *version, int stream_size))
1238 /*@modifies strm @*/;
1239 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1240 int windowBits, int memLevel,
1241 int strategy, const char *version,
1243 /*@globals internalState @*/
1244 /*@modifies strm, internalState @*/;
1245 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1246 const char *version, int stream_size))
1247 /*@modifies strm @*/;
1248 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits,
1249 unsigned char FAR *window,
1250 const char *version,
1252 /*@modifies strm @*/;
1253 #define deflateInit(strm, level) \
1254 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1255 #define inflateInit(strm) \
1256 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1257 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1258 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1259 (strategy), ZLIB_VERSION, sizeof(z_stream))
1260 #define inflateInit2(strm, windowBits) \
1261 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1262 #define inflateBackInit(strm, windowBits, window) \
1263 inflateBackInit_((strm), (windowBits), (window), \
1264 ZLIB_VERSION, sizeof(z_stream))
1267 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1268 struct internal_state {int dummy;}; /* hack for buggy compilers */
1271 ZEXTERN const char * ZEXPORT zError OF((int err))
1273 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z))
1275 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void))
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