2 * Changes made by the LLVM Team (llvmdev@cs.uiuc.edu, 2/6/2004):
3 * 1) Makefile was modified for building with the LLVM build system and tools.
4 * 2) Version numbers were updated as described in the FAQ.
5 * 3) LLVM LICENSE.TXT file was added describing licensing information.
7 /* zlib.h -- interface of the 'zlib' general purpose compression library
8 version 1.2.1, November 17th, 2003
10 Copyright (C) 1995-2003 Jean-loup Gailly and Mark Adler
12 This software is provided 'as-is', without any express or implied
13 warranty. In no event will the authors be held liable for any damages
14 arising from the use of this software.
16 Permission is granted to anyone to use this software for any purpose,
17 including commercial applications, and to alter it and redistribute it
18 freely, subject to the following restrictions:
20 1. The origin of this software must not be misrepresented; you must not
21 claim that you wrote the original software. If you use this software
22 in a product, an acknowledgment in the product documentation would be
23 appreciated but is not required.
24 2. Altered source versions must be plainly marked as such, and must not be
25 misrepresented as being the original software.
26 3. This notice may not be removed or altered from any source distribution.
28 Jean-loup Gailly Mark Adler
29 jloup@gzip.org madler@alumni.caltech.edu
32 The data format used by the zlib library is described by RFCs (Request for
33 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
34 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
46 #define ZLIB_VERSION "1.2.f-llvm"
47 #define ZLIB_VERNUM 0x121f
50 The 'zlib' compression library provides in-memory compression and
51 decompression functions, including integrity checks of the uncompressed
52 data. This version of the library supports only one compression method
53 (deflation) but other algorithms will be added later and will have the same
56 Compression can be done in a single step if the buffers are large
57 enough (for example if an input file is mmap'ed), or can be done by
58 repeated calls of the compression function. In the latter case, the
59 application must provide more input and/or consume the output
60 (providing more output space) before each call.
62 The compressed data format used by the in-memory functions is the zlib
63 format, which is a zlib wrapper documented in RFC 1950, wrapped around a
64 deflate stream, which is itself documented in RFC 1951.
66 The library also supports reading and writing files in gzip (.gz) format
67 with an interface similar to that of stdio using the functions that start
68 with "gz". The gzip format is different from the zlib format. gzip is a
69 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
71 The zlib format was designed to be compact and fast for use in memory
72 and on communications channels. The gzip format was designed for single-
73 file compression on file systems, has a larger header than zlib to maintain
74 directory information, and uses a different, slower check method than zlib.
76 This library does not provide any functions to write gzip files in memory.
77 However such functions could be easily written using zlib's deflate function,
78 the documentation in the gzip RFC, and the examples in gzio.c.
80 The library does not install any signal handler. The decoder checks
81 the consistency of the compressed data, so the library should never
82 crash even in case of corrupted input.
85 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
86 typedef void (*free_func) OF((voidpf opaque, voidpf address));
88 struct internal_state;
90 typedef struct z_stream_s {
91 Bytef *next_in; /* next input byte */
92 uInt avail_in; /* number of bytes available at next_in */
93 uLong total_in; /* total nb of input bytes read so far */
95 Bytef *next_out; /* next output byte should be put there */
96 uInt avail_out; /* remaining free space at next_out */
97 uLong total_out; /* total nb of bytes output so far */
99 char *msg; /* last error message, NULL if no error */
100 struct internal_state FAR *state; /* not visible by applications */
102 alloc_func zalloc; /* used to allocate the internal state */
103 free_func zfree; /* used to free the internal state */
104 voidpf opaque; /* private data object passed to zalloc and zfree */
106 int data_type; /* best guess about the data type: ascii or binary */
107 uLong adler; /* adler32 value of the uncompressed data */
108 uLong reserved; /* reserved for future use */
111 typedef z_stream FAR *z_streamp;
114 The application must update next_in and avail_in when avail_in has
115 dropped to zero. It must update next_out and avail_out when avail_out
116 has dropped to zero. The application must initialize zalloc, zfree and
117 opaque before calling the init function. All other fields are set by the
118 compression library and must not be updated by the application.
120 The opaque value provided by the application will be passed as the first
121 parameter for calls of zalloc and zfree. This can be useful for custom
122 memory management. The compression library attaches no meaning to the
125 zalloc must return Z_NULL if there is not enough memory for the object.
126 If zlib is used in a multi-threaded application, zalloc and zfree must be
129 On 16-bit systems, the functions zalloc and zfree must be able to allocate
130 exactly 65536 bytes, but will not be required to allocate more than this
131 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
132 pointers returned by zalloc for objects of exactly 65536 bytes *must*
133 have their offset normalized to zero. The default allocation function
134 provided by this library ensures this (see zutil.c). To reduce memory
135 requirements and avoid any allocation of 64K objects, at the expense of
136 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
138 The fields total_in and total_out can be used for statistics or
139 progress reports. After compression, total_in holds the total size of
140 the uncompressed data and may be saved for use in the decompressor
141 (particularly if the decompressor wants to decompress everything in
148 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
149 #define Z_SYNC_FLUSH 2
150 #define Z_FULL_FLUSH 3
153 /* Allowed flush values; see deflate() and inflate() below for details */
156 #define Z_STREAM_END 1
157 #define Z_NEED_DICT 2
159 #define Z_STREAM_ERROR (-2)
160 #define Z_DATA_ERROR (-3)
161 #define Z_MEM_ERROR (-4)
162 #define Z_BUF_ERROR (-5)
163 #define Z_VERSION_ERROR (-6)
164 /* Return codes for the compression/decompression functions. Negative
165 * values are errors, positive values are used for special but normal events.
168 #define Z_NO_COMPRESSION 0
169 #define Z_BEST_SPEED 1
170 #define Z_BEST_COMPRESSION 9
171 #define Z_DEFAULT_COMPRESSION (-1)
172 /* compression levels */
175 #define Z_HUFFMAN_ONLY 2
177 #define Z_DEFAULT_STRATEGY 0
178 /* compression strategy; see deflateInit2() below for details */
183 /* Possible values of the data_type field (though see inflate()) */
186 /* The deflate compression method (the only one supported in this version) */
188 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
190 #define zlib_version zlibVersion()
191 /* for compatibility with versions < 1.0.2 */
193 /* basic functions */
195 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
196 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
197 If the first character differs, the library code actually used is
198 not compatible with the zlib.h header file used by the application.
199 This check is automatically made by deflateInit and inflateInit.
203 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
205 Initializes the internal stream state for compression. The fields
206 zalloc, zfree and opaque must be initialized before by the caller.
207 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
208 use default allocation functions.
210 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
211 1 gives best speed, 9 gives best compression, 0 gives no compression at
212 all (the input data is simply copied a block at a time).
213 Z_DEFAULT_COMPRESSION requests a default compromise between speed and
214 compression (currently equivalent to level 6).
216 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
217 enough memory, Z_STREAM_ERROR if level is not a valid compression level,
218 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
219 with the version assumed by the caller (ZLIB_VERSION).
220 msg is set to null if there is no error message. deflateInit does not
221 perform any compression: this will be done by deflate().
225 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
227 deflate compresses as much data as possible, and stops when the input
228 buffer becomes empty or the output buffer becomes full. It may introduce some
229 output latency (reading input without producing any output) except when
232 The detailed semantics are as follows. deflate performs one or both of the
235 - Compress more input starting at next_in and update next_in and avail_in
236 accordingly. If not all input can be processed (because there is not
237 enough room in the output buffer), next_in and avail_in are updated and
238 processing will resume at this point for the next call of deflate().
240 - Provide more output starting at next_out and update next_out and avail_out
241 accordingly. This action is forced if the parameter flush is non zero.
242 Forcing flush frequently degrades the compression ratio, so this parameter
243 should be set only when necessary (in interactive applications).
244 Some output may be provided even if flush is not set.
246 Before the call of deflate(), the application should ensure that at least
247 one of the actions is possible, by providing more input and/or consuming
248 more output, and updating avail_in or avail_out accordingly; avail_out
249 should never be zero before the call. The application can consume the
250 compressed output when it wants, for example when the output buffer is full
251 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
252 and with zero avail_out, it must be called again after making room in the
253 output buffer because there might be more output pending.
255 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
256 flushed to the output buffer and the output is aligned on a byte boundary, so
257 that the decompressor can get all input data available so far. (In particular
258 avail_in is zero after the call if enough output space has been provided
259 before the call.) Flushing may degrade compression for some compression
260 algorithms and so it should be used only when necessary.
262 If flush is set to Z_FULL_FLUSH, all output is flushed as with
263 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
264 restart from this point if previous compressed data has been damaged or if
265 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
268 If deflate returns with avail_out == 0, this function must be called again
269 with the same value of the flush parameter and more output space (updated
270 avail_out), until the flush is complete (deflate returns with non-zero
271 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
272 avail_out is greater than six to avoid repeated flush markers due to
273 avail_out == 0 on return.
275 If the parameter flush is set to Z_FINISH, pending input is processed,
276 pending output is flushed and deflate returns with Z_STREAM_END if there
277 was enough output space; if deflate returns with Z_OK, this function must be
278 called again with Z_FINISH and more output space (updated avail_out) but no
279 more input data, until it returns with Z_STREAM_END or an error. After
280 deflate has returned Z_STREAM_END, the only possible operations on the
281 stream are deflateReset or deflateEnd.
283 Z_FINISH can be used immediately after deflateInit if all the compression
284 is to be done in a single step. In this case, avail_out must be at least
285 the value returned by deflateBound (see below). If deflate does not return
286 Z_STREAM_END, then it must be called again as described above.
288 deflate() sets strm->adler to the adler32 checksum of all input read
289 so far (that is, total_in bytes).
291 deflate() may update data_type if it can make a good guess about
292 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
293 binary. This field is only for information purposes and does not affect
294 the compression algorithm in any manner.
296 deflate() returns Z_OK if some progress has been made (more input
297 processed or more output produced), Z_STREAM_END if all input has been
298 consumed and all output has been produced (only when flush is set to
299 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
300 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
301 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
302 fatal, and deflate() can be called again with more input and more output
303 space to continue compressing.
307 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
309 All dynamically allocated data structures for this stream are freed.
310 This function discards any unprocessed input and does not flush any
313 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
314 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
315 prematurely (some input or output was discarded). In the error case,
316 msg may be set but then points to a static string (which must not be
322 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
324 Initializes the internal stream state for decompression. The fields
325 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
326 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
327 value depends on the compression method), inflateInit determines the
328 compression method from the zlib header and allocates all data structures
329 accordingly; otherwise the allocation will be deferred to the first call of
330 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
331 use default allocation functions.
333 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
334 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
335 version assumed by the caller. msg is set to null if there is no error
336 message. inflateInit does not perform any decompression apart from reading
337 the zlib header if present: this will be done by inflate(). (So next_in and
338 avail_in may be modified, but next_out and avail_out are unchanged.)
342 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
344 inflate decompresses as much data as possible, and stops when the input
345 buffer becomes empty or the output buffer becomes full. It may introduce
346 some output latency (reading input without producing any output) except when
349 The detailed semantics are as follows. inflate performs one or both of the
352 - Decompress more input starting at next_in and update next_in and avail_in
353 accordingly. If not all input can be processed (because there is not
354 enough room in the output buffer), next_in is updated and processing
355 will resume at this point for the next call of inflate().
357 - Provide more output starting at next_out and update next_out and avail_out
358 accordingly. inflate() provides as much output as possible, until there
359 is no more input data or no more space in the output buffer (see below
360 about the flush parameter).
362 Before the call of inflate(), the application should ensure that at least
363 one of the actions is possible, by providing more input and/or consuming
364 more output, and updating the next_* and avail_* values accordingly.
365 The application can consume the uncompressed output when it wants, for
366 example when the output buffer is full (avail_out == 0), or after each
367 call of inflate(). If inflate returns Z_OK and with zero avail_out, it
368 must be called again after making room in the output buffer because there
369 might be more output pending.
371 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
372 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
373 output as possible to the output buffer. Z_BLOCK requests that inflate() stop
374 if and when it get to the next deflate block boundary. When decoding the zlib
375 or gzip format, this will cause inflate() to return immediately after the
376 header and before the first block. When doing a raw inflate, inflate() will
377 go ahead and process the first block, and will return when it gets to the end
378 of that block, or when it runs out of data.
380 The Z_BLOCK option assists in appending to or combining deflate streams.
381 Also to assist in this, on return inflate() will set strm->data_type to the
382 number of unused bits in the last byte taken from strm->next_in, plus 64
383 if inflate() is currently decoding the last block in the deflate stream,
384 plus 128 if inflate() returned immediately after decoding an end-of-block
385 code or decoding the complete header up to just before the first byte of the
386 deflate stream. The end-of-block will not be indicated until all of the
387 uncompressed data from that block has been written to strm->next_out. The
388 number of unused bits may in general be greater than seven, except when
389 bit 7 of data_type is set, in which case the number of unused bits will be
392 inflate() should normally be called until it returns Z_STREAM_END or an
393 error. However if all decompression is to be performed in a single step
394 (a single call of inflate), the parameter flush should be set to
395 Z_FINISH. In this case all pending input is processed and all pending
396 output is flushed; avail_out must be large enough to hold all the
397 uncompressed data. (The size of the uncompressed data may have been saved
398 by the compressor for this purpose.) The next operation on this stream must
399 be inflateEnd to deallocate the decompression state. The use of Z_FINISH
400 is never required, but can be used to inform inflate that a faster approach
401 may be used for the single inflate() call.
403 In this implementation, inflate() always flushes as much output as
404 possible to the output buffer, and always uses the faster approach on the
405 first call. So the only effect of the flush parameter in this implementation
406 is on the return value of inflate(), as noted below, or when it returns early
407 because Z_BLOCK is used.
409 If a preset dictionary is needed after this call (see inflateSetDictionary
410 below), inflate sets strm-adler to the adler32 checksum of the dictionary
411 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
412 strm->adler to the adler32 checksum of all output produced so far (that is,
413 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
414 below. At the end of the stream, inflate() checks that its computed adler32
415 checksum is equal to that saved by the compressor and returns Z_STREAM_END
416 only if the checksum is correct.
418 inflate() will decompress and check either zlib-wrapped or gzip-wrapped
419 deflate data. The header type is detected automatically. Any information
420 contained in the gzip header is not retained, so applications that need that
421 information should instead use raw inflate, see inflateInit2() below, or
422 inflateBack() and perform their own processing of the gzip header and
425 inflate() returns Z_OK if some progress has been made (more input processed
426 or more output produced), Z_STREAM_END if the end of the compressed data has
427 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
428 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
429 corrupted (input stream not conforming to the zlib format or incorrect check
430 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
431 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
432 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
433 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
434 inflate() can be called again with more input and more output space to
435 continue decompressing. If Z_DATA_ERROR is returned, the application may then
436 call inflateSync() to look for a good compression block if a partial recovery
437 of the data is desired.
441 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
443 All dynamically allocated data structures for this stream are freed.
444 This function discards any unprocessed input and does not flush any
447 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
448 was inconsistent. In the error case, msg may be set but then points to a
449 static string (which must not be deallocated).
452 /* Advanced functions */
455 The following functions are needed only in some special applications.
459 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
466 This is another version of deflateInit with more compression options. The
467 fields next_in, zalloc, zfree and opaque must be initialized before by
470 The method parameter is the compression method. It must be Z_DEFLATED in
471 this version of the library.
473 The windowBits parameter is the base two logarithm of the window size
474 (the size of the history buffer). It should be in the range 8..15 for this
475 version of the library. Larger values of this parameter result in better
476 compression at the expense of memory usage. The default value is 15 if
477 deflateInit is used instead.
479 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
480 determines the window size. deflate() will then generate raw deflate data
481 with no zlib header or trailer, and will not compute an adler32 check value.
483 windowBits can also be greater than 15 for optional gzip encoding. Add
484 16 to windowBits to write a simple gzip header and trailer around the
485 compressed data instead of a zlib wrapper. The gzip header will have no
486 file name, no extra data, no comment, no modification time (set to zero),
487 no header crc, and the operating system will be set to 255 (unknown).
489 The memLevel parameter specifies how much memory should be allocated
490 for the internal compression state. memLevel=1 uses minimum memory but
491 is slow and reduces compression ratio; memLevel=9 uses maximum memory
492 for optimal speed. The default value is 8. See zconf.h for total memory
493 usage as a function of windowBits and memLevel.
495 The strategy parameter is used to tune the compression algorithm. Use the
496 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
497 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
498 string match), or Z_RLE to limit match distances to one (run-length
499 encoding). Filtered data consists mostly of small values with a somewhat
500 random distribution. In this case, the compression algorithm is tuned to
501 compress them better. The effect of Z_FILTERED is to force more Huffman
502 coding and less string matching; it is somewhat intermediate between
503 Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
504 Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
505 parameter only affects the compression ratio but not the correctness of the
506 compressed output even if it is not set appropriately.
508 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
509 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
510 method). msg is set to null if there is no error message. deflateInit2 does
511 not perform any compression: this will be done by deflate().
514 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
515 const Bytef *dictionary,
518 Initializes the compression dictionary from the given byte sequence
519 without producing any compressed output. This function must be called
520 immediately after deflateInit, deflateInit2 or deflateReset, before any
521 call of deflate. The compressor and decompressor must use exactly the same
522 dictionary (see inflateSetDictionary).
524 The dictionary should consist of strings (byte sequences) that are likely
525 to be encountered later in the data to be compressed, with the most commonly
526 used strings preferably put towards the end of the dictionary. Using a
527 dictionary is most useful when the data to be compressed is short and can be
528 predicted with good accuracy; the data can then be compressed better than
529 with the default empty dictionary.
531 Depending on the size of the compression data structures selected by
532 deflateInit or deflateInit2, a part of the dictionary may in effect be
533 discarded, for example if the dictionary is larger than the window size in
534 deflate or deflate2. Thus the strings most likely to be useful should be
535 put at the end of the dictionary, not at the front.
537 Upon return of this function, strm->adler is set to the adler32 value
538 of the dictionary; the decompressor may later use this value to determine
539 which dictionary has been used by the compressor. (The adler32 value
540 applies to the whole dictionary even if only a subset of the dictionary is
541 actually used by the compressor.) If a raw deflate was requested, then the
542 adler32 value is not computed and strm->adler is not set.
544 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
545 parameter is invalid (such as NULL dictionary) or the stream state is
546 inconsistent (for example if deflate has already been called for this stream
547 or if the compression method is bsort). deflateSetDictionary does not
548 perform any compression: this will be done by deflate().
551 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
554 Sets the destination stream as a complete copy of the source stream.
556 This function can be useful when several compression strategies will be
557 tried, for example when there are several ways of pre-processing the input
558 data with a filter. The streams that will be discarded should then be freed
559 by calling deflateEnd. Note that deflateCopy duplicates the internal
560 compression state which can be quite large, so this strategy is slow and
561 can consume lots of memory.
563 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
564 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
565 (such as zalloc being NULL). msg is left unchanged in both source and
569 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
571 This function is equivalent to deflateEnd followed by deflateInit,
572 but does not free and reallocate all the internal compression state.
573 The stream will keep the same compression level and any other attributes
574 that may have been set by deflateInit2.
576 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
577 stream state was inconsistent (such as zalloc or state being NULL).
580 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
584 Dynamically update the compression level and compression strategy. The
585 interpretation of level and strategy is as in deflateInit2. This can be
586 used to switch between compression and straight copy of the input data, or
587 to switch to a different kind of input data requiring a different
588 strategy. If the compression level is changed, the input available so far
589 is compressed with the old level (and may be flushed); the new level will
590 take effect only at the next call of deflate().
592 Before the call of deflateParams, the stream state must be set as for
593 a call of deflate(), since the currently available input may have to
594 be compressed and flushed. In particular, strm->avail_out must be non-zero.
596 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
597 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
598 if strm->avail_out was zero.
601 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
604 deflateBound() returns an upper bound on the compressed size after
605 deflation of sourceLen bytes. It must be called after deflateInit()
606 or deflateInit2(). This would be used to allocate an output buffer
607 for deflation in a single pass, and so would be called before deflate().
610 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
614 deflatePrime() inserts bits in the deflate output stream. The intent
615 is that this function is used to start off the deflate output with the
616 bits leftover from a previous deflate stream when appending to it. As such,
617 this function can only be used for raw deflate, and must be used before the
618 first deflate() call after a deflateInit2() or deflateReset(). bits must be
619 less than or equal to 16, and that many of the least significant bits of
620 value will be inserted in the output.
622 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
623 stream state was inconsistent.
627 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
630 This is another version of inflateInit with an extra parameter. The
631 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
632 before by the caller.
634 The windowBits parameter is the base two logarithm of the maximum window
635 size (the size of the history buffer). It should be in the range 8..15 for
636 this version of the library. The default value is 15 if inflateInit is used
637 instead. windowBits must be greater than or equal to the windowBits value
638 provided to deflateInit2() while compressing, or it must be equal to 15 if
639 deflateInit2() was not used. If a compressed stream with a larger window
640 size is given as input, inflate() will return with the error code
641 Z_DATA_ERROR instead of trying to allocate a larger window.
643 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
644 determines the window size. inflate() will then process raw deflate data,
645 not looking for a zlib or gzip header, not generating a check value, and not
646 looking for any check values for comparison at the end of the stream. This
647 is for use with other formats that use the deflate compressed data format
648 such as zip. Those formats provide their own check values. If a custom
649 format is developed using the raw deflate format for compressed data, it is
650 recommended that a check value such as an adler32 or a crc32 be applied to
651 the uncompressed data as is done in the zlib, gzip, and zip formats. For
652 most applications, the zlib format should be used as is. Note that comments
653 above on the use in deflateInit2() applies to the magnitude of windowBits.
655 windowBits can also be greater than 15 for optional gzip decoding. Add
656 32 to windowBits to enable zlib and gzip decoding with automatic header
657 detection, or add 16 to decode only the gzip format (the zlib format will
658 return a Z_DATA_ERROR).
660 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
661 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
662 memLevel). msg is set to null if there is no error message. inflateInit2
663 does not perform any decompression apart from reading the zlib header if
664 present: this will be done by inflate(). (So next_in and avail_in may be
665 modified, but next_out and avail_out are unchanged.)
668 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
669 const Bytef *dictionary,
672 Initializes the decompression dictionary from the given uncompressed byte
673 sequence. This function must be called immediately after a call of inflate
674 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
675 can be determined from the adler32 value returned by this call of
676 inflate. The compressor and decompressor must use exactly the same
677 dictionary (see deflateSetDictionary).
679 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
680 parameter is invalid (such as NULL dictionary) or the stream state is
681 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
682 expected one (incorrect adler32 value). inflateSetDictionary does not
683 perform any decompression: this will be done by subsequent calls of
687 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
689 Skips invalid compressed data until a full flush point (see above the
690 description of deflate with Z_FULL_FLUSH) can be found, or until all
691 available input is skipped. No output is provided.
693 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
694 if no more input was provided, Z_DATA_ERROR if no flush point has been found,
695 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
696 case, the application may save the current current value of total_in which
697 indicates where valid compressed data was found. In the error case, the
698 application may repeatedly call inflateSync, providing more input each time,
699 until success or end of the input data.
702 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
705 Sets the destination stream as a complete copy of the source stream.
707 This function can be useful when randomly accessing a large stream. The
708 first pass through the stream can periodically record the inflate state,
709 allowing restarting inflate at those points when randomly accessing the
712 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
713 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
714 (such as zalloc being NULL). msg is left unchanged in both source and
718 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
720 This function is equivalent to inflateEnd followed by inflateInit,
721 but does not free and reallocate all the internal decompression state.
722 The stream will keep attributes that may have been set by inflateInit2.
724 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
725 stream state was inconsistent (such as zalloc or state being NULL).
729 ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *strm, int windowBits,
730 unsigned char FAR *window));
732 Initialize the internal stream state for decompression using inflateBack()
733 calls. The fields zalloc, zfree and opaque in strm must be initialized
734 before the call. If zalloc and zfree are Z_NULL, then the default library-
735 derived memory allocation routines are used. windowBits is the base two
736 logarithm of the window size, in the range 8..15. window is a caller
737 supplied buffer of that size. Except for special applications where it is
738 assured that deflate was used with small window sizes, windowBits must be 15
739 and a 32K byte window must be supplied to be able to decompress general
742 See inflateBack() for the usage of these routines.
744 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
745 the paramaters are invalid, Z_MEM_ERROR if the internal state could not
746 be allocated, or Z_VERSION_ERROR if the version of the library does not
747 match the version of the header file.
750 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
751 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
753 ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm,
754 in_func in, void FAR *in_desc,
755 out_func out, void FAR *out_desc));
757 inflateBack() does a raw inflate with a single call using a call-back
758 interface for input and output. This is more efficient than inflate() for
759 file i/o applications in that it avoids copying between the output and the
760 sliding window by simply making the window itself the output buffer. This
761 function trusts the application to not change the output buffer passed by
762 the output function, at least until inflateBack() returns.
764 inflateBackInit() must be called first to allocate the internal state
765 and to initialize the state with the user-provided window buffer.
766 inflateBack() may then be used multiple times to inflate a complete, raw
767 deflate stream with each call. inflateBackEnd() is then called to free
770 A raw deflate stream is one with no zlib or gzip header or trailer.
771 This routine would normally be used in a utility that reads zip or gzip
772 files and writes out uncompressed files. The utility would decode the
773 header and process the trailer on its own, hence this routine expects
774 only the raw deflate stream to decompress. This is different from the
775 normal behavior of inflate(), which expects either a zlib or gzip header and
776 trailer around the deflate stream.
778 inflateBack() uses two subroutines supplied by the caller that are then
779 called by inflateBack() for input and output. inflateBack() calls those
780 routines until it reads a complete deflate stream and writes out all of the
781 uncompressed data, or until it encounters an error. The function's
782 parameters and return types are defined above in the in_func and out_func
783 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
784 number of bytes of provided input, and a pointer to that input in buf. If
785 there is no input available, in() must return zero--buf is ignored in that
786 case--and inflateBack() will return a buffer error. inflateBack() will call
787 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
788 should return zero on success, or non-zero on failure. If out() returns
789 non-zero, inflateBack() will return with an error. Neither in() nor out()
790 are permitted to change the contents of the window provided to
791 inflateBackInit(), which is also the buffer that out() uses to write from.
792 The length written by out() will be at most the window size. Any non-zero
793 amount of input may be provided by in().
795 For convenience, inflateBack() can be provided input on the first call by
796 setting strm->next_in and strm->avail_in. If that input is exhausted, then
797 in() will be called. Therefore strm->next_in must be initialized before
798 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
799 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
800 must also be initialized, and then if strm->avail_in is not zero, input will
801 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
803 The in_desc and out_desc parameters of inflateBack() is passed as the
804 first parameter of in() and out() respectively when they are called. These
805 descriptors can be optionally used to pass any information that the caller-
806 supplied in() and out() functions need to do their job.
808 On return, inflateBack() will set strm->next_in and strm->avail_in to
809 pass back any unused input that was provided by the last in() call. The
810 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
811 if in() or out() returned an error, Z_DATA_ERROR if there was a format
812 error in the deflate stream (in which case strm->msg is set to indicate the
813 nature of the error), or Z_STREAM_ERROR if the stream was not properly
814 initialized. In the case of Z_BUF_ERROR, an input or output error can be
815 distinguished using strm->next_in which will be Z_NULL only if in() returned
816 an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
817 out() returning non-zero. (in() will always be called before out(), so
818 strm->next_in is assured to be defined if out() returns non-zero.) Note
819 that inflateBack() cannot return Z_OK.
822 ZEXTERN int ZEXPORT inflateBackEnd OF((z_stream FAR *strm));
824 All memory allocated by inflateBackInit() is freed.
826 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
827 state was inconsistent.
830 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
831 /* Return flags indicating compile-time options.
833 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
836 5.4: size of voidpf (pointer)
839 Compiler, assembler, and debug options:
841 9: ASMV or ASMINF -- use ASM code
842 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
845 One-time table building (smaller code, but not thread-safe if true):
846 12: BUILDFIXED -- build static block decoding tables when needed
847 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
850 Library content (indicates missing functionality):
851 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
852 deflate code when not needed)
853 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
854 and decode gzip streams (to avoid linking crc code)
857 Operation variations (changes in library functionality):
858 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
859 21: FASTEST -- deflate algorithm with only one, lowest compression level
862 The sprintf variant used by gzprintf (zero is best):
863 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
864 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
865 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
872 /* utility functions */
875 The following utility functions are implemented on top of the
876 basic stream-oriented functions. To simplify the interface, some
877 default options are assumed (compression level and memory usage,
878 standard memory allocation functions). The source code of these
879 utility functions can easily be modified if you need special options.
882 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
883 const Bytef *source, uLong sourceLen));
885 Compresses the source buffer into the destination buffer. sourceLen is
886 the byte length of the source buffer. Upon entry, destLen is the total
887 size of the destination buffer, which must be at least the value returned
888 by compressBound(sourceLen). Upon exit, destLen is the actual size of the
890 This function can be used to compress a whole file at once if the
891 input file is mmap'ed.
892 compress returns Z_OK if success, Z_MEM_ERROR if there was not
893 enough memory, Z_BUF_ERROR if there was not enough room in the output
897 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
898 const Bytef *source, uLong sourceLen,
901 Compresses the source buffer into the destination buffer. The level
902 parameter has the same meaning as in deflateInit. sourceLen is the byte
903 length of the source buffer. Upon entry, destLen is the total size of the
904 destination buffer, which must be at least the value returned by
905 compressBound(sourceLen). Upon exit, destLen is the actual size of the
908 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
909 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
910 Z_STREAM_ERROR if the level parameter is invalid.
913 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
915 compressBound() returns an upper bound on the compressed size after
916 compress() or compress2() on sourceLen bytes. It would be used before
917 a compress() or compress2() call to allocate the destination buffer.
920 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
921 const Bytef *source, uLong sourceLen));
923 Decompresses the source buffer into the destination buffer. sourceLen is
924 the byte length of the source buffer. Upon entry, destLen is the total
925 size of the destination buffer, which must be large enough to hold the
926 entire uncompressed data. (The size of the uncompressed data must have
927 been saved previously by the compressor and transmitted to the decompressor
928 by some mechanism outside the scope of this compression library.)
929 Upon exit, destLen is the actual size of the compressed buffer.
930 This function can be used to decompress a whole file at once if the
931 input file is mmap'ed.
933 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
934 enough memory, Z_BUF_ERROR if there was not enough room in the output
935 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
939 typedef voidp gzFile;
941 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
943 Opens a gzip (.gz) file for reading or writing. The mode parameter
944 is as in fopen ("rb" or "wb") but can also include a compression level
945 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
946 Huffman only compression as in "wb1h", or 'R' for run-length encoding
947 as in "wb1R". (See the description of deflateInit2 for more information
948 about the strategy parameter.)
950 gzopen can be used to read a file which is not in gzip format; in this
951 case gzread will directly read from the file without decompression.
953 gzopen returns NULL if the file could not be opened or if there was
954 insufficient memory to allocate the (de)compression state; errno
955 can be checked to distinguish the two cases (if errno is zero, the
956 zlib error is Z_MEM_ERROR). */
958 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
960 gzdopen() associates a gzFile with the file descriptor fd. File
961 descriptors are obtained from calls like open, dup, creat, pipe or
962 fileno (in the file has been previously opened with fopen).
963 The mode parameter is as in gzopen.
964 The next call of gzclose on the returned gzFile will also close the
965 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
966 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
967 gzdopen returns NULL if there was insufficient memory to allocate
968 the (de)compression state.
971 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
973 Dynamically update the compression level or strategy. See the description
974 of deflateInit2 for the meaning of these parameters.
975 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
979 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
981 Reads the given number of uncompressed bytes from the compressed file.
982 If the input file was not in gzip format, gzread copies the given number
983 of bytes into the buffer.
984 gzread returns the number of uncompressed bytes actually read (0 for
985 end of file, -1 for error). */
987 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
988 voidpc buf, unsigned len));
990 Writes the given number of uncompressed bytes into the compressed file.
991 gzwrite returns the number of uncompressed bytes actually written
992 (0 in case of error).
995 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
997 Converts, formats, and writes the args to the compressed file under
998 control of the format string, as in fprintf. gzprintf returns the number of
999 uncompressed bytes actually written (0 in case of error). The number of
1000 uncompressed bytes written is limited to 4095. The caller should assure that
1001 this limit is not exceeded. If it is exceeded, then gzprintf() will return
1002 return an error (0) with nothing written. In this case, there may also be a
1003 buffer overflow with unpredictable consequences, which is possible only if
1004 zlib was compiled with the insecure functions sprintf() or vsprintf()
1005 because the secure snprintf() or vsnprintf() functions were not available.
1008 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1010 Writes the given null-terminated string to the compressed file, excluding
1011 the terminating null character.
1012 gzputs returns the number of characters written, or -1 in case of error.
1015 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1017 Reads bytes from the compressed file until len-1 characters are read, or
1018 a newline character is read and transferred to buf, or an end-of-file
1019 condition is encountered. The string is then terminated with a null
1021 gzgets returns buf, or Z_NULL in case of error.
1024 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1026 Writes c, converted to an unsigned char, into the compressed file.
1027 gzputc returns the value that was written, or -1 in case of error.
1030 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1032 Reads one byte from the compressed file. gzgetc returns this byte
1033 or -1 in case of end of file or error.
1036 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1038 Push one character back onto the stream to be read again later.
1039 Only one character of push-back is allowed. gzungetc() returns the
1040 character pushed, or -1 on failure. gzungetc() will fail if a
1041 character has been pushed but not read yet, or if c is -1. The pushed
1042 character will be discarded if the stream is repositioned with gzseek()
1046 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1048 Flushes all pending output into the compressed file. The parameter
1049 flush is as in the deflate() function. The return value is the zlib
1050 error number (see function gzerror below). gzflush returns Z_OK if
1051 the flush parameter is Z_FINISH and all output could be flushed.
1052 gzflush should be called only when strictly necessary because it can
1053 degrade compression.
1056 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1057 z_off_t offset, int whence));
1059 Sets the starting position for the next gzread or gzwrite on the
1060 given compressed file. The offset represents a number of bytes in the
1061 uncompressed data stream. The whence parameter is defined as in lseek(2);
1062 the value SEEK_END is not supported.
1063 If the file is opened for reading, this function is emulated but can be
1064 extremely slow. If the file is opened for writing, only forward seeks are
1065 supported; gzseek then compresses a sequence of zeroes up to the new
1068 gzseek returns the resulting offset location as measured in bytes from
1069 the beginning of the uncompressed stream, or -1 in case of error, in
1070 particular if the file is opened for writing and the new starting position
1071 would be before the current position.
1074 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1076 Rewinds the given file. This function is supported only for reading.
1078 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1081 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1083 Returns the starting position for the next gzread or gzwrite on the
1084 given compressed file. This position represents a number of bytes in the
1085 uncompressed data stream.
1087 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1090 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1092 Returns 1 when EOF has previously been detected reading the given
1093 input stream, otherwise zero.
1096 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1098 Flushes all pending output if necessary, closes the compressed file
1099 and deallocates all the (de)compression state. The return value is the zlib
1100 error number (see function gzerror below).
1103 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1105 Returns the error message for the last error which occurred on the
1106 given compressed file. errnum is set to zlib error number. If an
1107 error occurred in the file system and not in the compression library,
1108 errnum is set to Z_ERRNO and the application may consult errno
1109 to get the exact error code.
1112 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1114 Clears the error and end-of-file flags for file. This is analogous to the
1115 clearerr() function in stdio. This is useful for continuing to read a gzip
1116 file that is being written concurrently.
1119 /* checksum functions */
1122 These functions are not related to compression but are exported
1123 anyway because they might be useful in applications using the
1124 compression library.
1127 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1130 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1131 return the updated checksum. If buf is NULL, this function returns
1132 the required initial value for the checksum.
1133 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1134 much faster. Usage example:
1136 uLong adler = adler32(0L, Z_NULL, 0);
1138 while (read_buffer(buffer, length) != EOF) {
1139 adler = adler32(adler, buffer, length);
1141 if (adler != original_adler) error();
1144 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
1146 Update a running crc with the bytes buf[0..len-1] and return the updated
1147 crc. If buf is NULL, this function returns the required initial value
1148 for the crc. Pre- and post-conditioning (one's complement) is performed
1149 within this function so it shouldn't be done by the application.
1152 uLong crc = crc32(0L, Z_NULL, 0);
1154 while (read_buffer(buffer, length) != EOF) {
1155 crc = crc32(crc, buffer, length);
1157 if (crc != original_crc) error();
1161 /* various hacks, don't look :) */
1163 /* deflateInit and inflateInit are macros to allow checking the zlib version
1164 * and the compiler's view of z_stream:
1166 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1167 const char *version, int stream_size));
1168 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1169 const char *version, int stream_size));
1170 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1171 int windowBits, int memLevel,
1172 int strategy, const char *version,
1174 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1175 const char *version, int stream_size));
1176 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits,
1177 unsigned char FAR *window,
1178 const char *version,
1180 #define deflateInit(strm, level) \
1181 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1182 #define inflateInit(strm) \
1183 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1184 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1185 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1186 (strategy), ZLIB_VERSION, sizeof(z_stream))
1187 #define inflateInit2(strm, windowBits) \
1188 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1189 #define inflateBackInit(strm, windowBits, window) \
1190 inflateBackInit_((strm), (windowBits), (window), \
1191 ZLIB_VERSION, sizeof(z_stream))
1194 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1195 struct internal_state {int dummy;}; /* hack for buggy compilers */
1198 ZEXTERN const char * ZEXPORT zError OF((int err));
1199 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
1200 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));