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fgx_zlib.h
1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2  version 1.2.5, April 19th, 2010
3 
4  Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
5 
6  This software is provided 'as-is', without any express or implied
7  warranty. In no event will the authors be held liable for any damages
8  arising from the use of this software.
9 
10  Permission is granted to anyone to use this software for any purpose,
11  including commercial applications, and to alter it and redistribute it
12  freely, subject to the following restrictions:
13 
14  1. The origin of this software must not be misrepresented; you must not
15  claim that you wrote the original software. If you use this software
16  in a product, an acknowledgment in the product documentation would be
17  appreciated but is not required.
18  2. Altered source versions must be plainly marked as such, and must not be
19  misrepresented as being the original software.
20  3. This notice may not be removed or altered from any source distribution.
21 
22  Jean-loup Gailly Mark Adler
23  jloup@gzip.org madler@alumni.caltech.edu
24 
25 
26  The data format used by the zlib library is described by RFCs (Request for
27  Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
28  (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
29 */
30 
31 /* ------------------------------------------------------
32  fgx_zlib.h -- full import of the zlib-1.2.5.tar.gz source
33  Here version bumped to 1.2.5.1
34  2011-07-01 - Geoff R. McLane
35  link-in to the FGx application, providing zlib compression
36  and decompression services
37  ------------------------------------------------------ */
38 
39 #ifndef ZLIB_H
40 #define ZLIB_H
41 #define FGX_ZLIB_H /* modified version just for FGx */
42 
43 #include "fgx_zconf.h"
44 
45 #ifdef __cplusplus
46 extern "C" {
47 #endif
48 
49 #define ZLIB_VERSION "1.2.5.1"
50 #define ZLIB_VERNUM 0x1251
51 #define ZLIB_VER_MAJOR 1
52 #define ZLIB_VER_MINOR 2
53 #define ZLIB_VER_REVISION 5
54 #define ZLIB_VER_SUBREVISION 1
55 
56 /*
57  The 'zlib' compression library provides in-memory compression and
58  decompression functions, including integrity checks of the uncompressed data.
59  This version of the library supports only one compression method (deflation)
60  but other algorithms will be added later and will have the same stream
61  interface.
62 
63  Compression can be done in a single step if the buffers are large enough,
64  or can be done by repeated calls of the compression function. In the latter
65  case, the application must provide more input and/or consume the output
66  (providing more output space) before each call.
67 
68  The compressed data format used by default by the in-memory functions is
69  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
70  around a deflate stream, which is itself documented in RFC 1951.
71 
72  The library also supports reading and writing files in gzip (.gz) format
73  with an interface similar to that of stdio using the functions that start
74  with "gz". The gzip format is different from the zlib format. gzip is a
75  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
76 
77  This library can optionally read and write gzip streams in memory as well.
78 
79  The zlib format was designed to be compact and fast for use in memory
80  and on communications channels. The gzip format was designed for single-
81  file compression on file systems, has a larger header than zlib to maintain
82  directory information, and uses a different, slower check method than zlib.
83 
84  The library does not install any signal handler. The decoder checks
85  the consistency of the compressed data, so the library should never crash
86  even in case of corrupted input.
87 */
88 
89 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
90 typedef void (*free_func) OF((voidpf opaque, voidpf address));
91 
92 struct internal_state;
93 
94 typedef struct z_stream_s {
95  Bytef *next_in; /* next input byte */
96  uInt avail_in; /* number of bytes available at next_in */
97  uLong total_in; /* total nb of input bytes read so far */
98 
99  Bytef *next_out; /* next output byte should be put there */
100  uInt avail_out; /* remaining free space at next_out */
101  uLong total_out; /* total nb of bytes output so far */
102 
103  char *msg; /* last error message, NULL if no error */
104  struct internal_state FAR *state; /* not visible by applications */
105 
106  alloc_func zalloc; /* used to allocate the internal state */
107  free_func zfree; /* used to free the internal state */
108  voidpf opaque; /* private data object passed to zalloc and zfree */
109 
110  int data_type; /* best guess about the data type: binary or text */
111  uLong adler; /* adler32 value of the uncompressed data */
112  uLong reserved; /* reserved for future use */
113 } z_stream;
114 
115 typedef z_stream *z_streamp;
116 
117 /*
118  gzip header information passed to and from zlib routines. See RFC 1952
119  for more details on the meanings of these fields.
120 */
121 typedef struct gz_header_s {
122  int text; /* true if compressed data believed to be text */
123  uLong time; /* modification time */
124  int xflags; /* extra flags (not used when writing a gzip file) */
125  int os; /* operating system */
126  Bytef *extra; /* pointer to extra field or Z_NULL if none */
127  uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
128  uInt extra_max; /* space at extra (only when reading header) */
129  Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
130  uInt name_max; /* space at name (only when reading header) */
131  Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
132  uInt comm_max; /* space at comment (only when reading header) */
133  int hcrc; /* true if there was or will be a header crc */
134  int done; /* true when done reading gzip header (not used
135  when writing a gzip file) */
136 } gz_header;
137 
138 typedef gz_header *gz_headerp;
139 
140 /*
141  The application must update next_in and avail_in when avail_in has dropped
142  to zero. It must update next_out and avail_out when avail_out has dropped
143  to zero. The application must initialize zalloc, zfree and opaque before
144  calling the init function. All other fields are set by the compression
145  library and must not be updated by the application.
146 
147  The opaque value provided by the application will be passed as the first
148  parameter for calls of zalloc and zfree. This can be useful for custom
149  memory management. The compression library attaches no meaning to the
150  opaque value.
151 
152  zalloc must return Z_NULL if there is not enough memory for the object.
153  If zlib is used in a multi-threaded application, zalloc and zfree must be
154  thread safe.
155 
156  On 16-bit systems, the functions zalloc and zfree must be able to allocate
157  exactly 65536 bytes, but will not be required to allocate more than this if
158  the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
159  returned by zalloc for objects of exactly 65536 bytes *must* have their
160  offset normalized to zero. The default allocation function provided by this
161  library ensures this (see zutil.c). To reduce memory requirements and avoid
162  any allocation of 64K objects, at the expense of compression ratio, compile
163  the library with -DMAX_WBITS=14 (see zconf.h).
164 
165  The fields total_in and total_out can be used for statistics or progress
166  reports. After compression, total_in holds the total size of the
167  uncompressed data and may be saved for use in the decompressor (particularly
168  if the decompressor wants to decompress everything in a single step).
169 */
170 
171  /* constants */
172 
173 #define Z_NO_FLUSH 0
174 #define Z_PARTIAL_FLUSH 1
175 #define Z_SYNC_FLUSH 2
176 #define Z_FULL_FLUSH 3
177 #define Z_FINISH 4
178 #define Z_BLOCK 5
179 #define Z_TREES 6
180 /* Allowed flush values; see deflate() and inflate() below for details */
181 
182 #define Z_OK 0
183 #define Z_STREAM_END 1
184 #define Z_NEED_DICT 2
185 #define Z_ERRNO (-1)
186 #define Z_STREAM_ERROR (-2)
187 #define Z_DATA_ERROR (-3)
188 #define Z_MEM_ERROR (-4)
189 #define Z_BUF_ERROR (-5)
190 #define Z_VERSION_ERROR (-6)
191 /* Return codes for the compression/decompression functions. Negative values
192  * are errors, positive values are used for special but normal events.
193  */
194 
195 #define Z_NO_COMPRESSION 0
196 #define Z_BEST_SPEED 1
197 #define Z_BEST_COMPRESSION 9
198 #define Z_DEFAULT_COMPRESSION (-1)
199 /* compression levels */
200 
201 #define Z_FILTERED 1
202 #define Z_HUFFMAN_ONLY 2
203 #define Z_RLE 3
204 #define Z_FIXED 4
205 #define Z_DEFAULT_STRATEGY 0
206 /* compression strategy; see deflateInit2() below for details */
207 
208 #define Z_BINARY 0
209 #define Z_TEXT 1
210 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
211 #define Z_UNKNOWN 2
212 /* Possible values of the data_type field (though see inflate()) */
213 
214 #define Z_DEFLATED 8
215 /* The deflate compression method (the only one supported in this version) */
216 
217 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
218 
219 #define zlib_version zlibVersion()
220 /* for compatibility with versions < 1.0.2 */
221 
222 
223  /* basic functions */
224 
225 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
226 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
227  If the first character differs, the library code actually used is not
228  compatible with the zlib.h header file used by the application. This check
229  is automatically made by deflateInit and inflateInit.
230  */
231 
232 /*
233 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
234 
235  Initializes the internal stream state for compression. The fields
236  zalloc, zfree and opaque must be initialized before by the caller. If
237  zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
238  allocation functions.
239 
240  The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
241  1 gives best speed, 9 gives best compression, 0 gives no compression at all
242  (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
243  requests a default compromise between speed and compression (currently
244  equivalent to level 6).
245 
246  deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
247  memory, Z_STREAM_ERROR if level is not a valid compression level, or
248  Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
249  with the version assumed by the caller (ZLIB_VERSION). msg is set to null
250  if there is no error message. deflateInit does not perform any compression:
251  this will be done by deflate().
252 */
253 
254 
255 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
256 /*
257  deflate compresses as much data as possible, and stops when the input
258  buffer becomes empty or the output buffer becomes full. It may introduce
259  some output latency (reading input without producing any output) except when
260  forced to flush.
261 
262  The detailed semantics are as follows. deflate performs one or both of the
263  following actions:
264 
265  - Compress more input starting at next_in and update next_in and avail_in
266  accordingly. If not all input can be processed (because there is not
267  enough room in the output buffer), next_in and avail_in are updated and
268  processing will resume at this point for the next call of deflate().
269 
270  - Provide more output starting at next_out and update next_out and avail_out
271  accordingly. This action is forced if the parameter flush is non zero.
272  Forcing flush frequently degrades the compression ratio, so this parameter
273  should be set only when necessary (in interactive applications). Some
274  output may be provided even if flush is not set.
275 
276  Before the call of deflate(), the application should ensure that at least
277  one of the actions is possible, by providing more input and/or consuming more
278  output, and updating avail_in or avail_out accordingly; avail_out should
279  never be zero before the call. The application can consume the compressed
280  output when it wants, for example when the output buffer is full (avail_out
281  == 0), or after each call of deflate(). If deflate returns Z_OK and with
282  zero avail_out, it must be called again after making room in the output
283  buffer because there might be more output pending.
284 
285  Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
286  decide how much data to accumulate before producing output, in order to
287  maximize compression.
288 
289  If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
290  flushed to the output buffer and the output is aligned on a byte boundary, so
291  that the decompressor can get all input data available so far. (In
292  particular avail_in is zero after the call if enough output space has been
293  provided before the call.) Flushing may degrade compression for some
294  compression algorithms and so it should be used only when necessary. This
295  completes the current deflate block and follows it with an empty stored block
296  that is three bits plus filler bits to the next byte, followed by four bytes
297  (00 00 ff ff).
298 
299  If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
300  output buffer, but the output is not aligned to a byte boundary. All of the
301  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
302  This completes the current deflate block and follows it with an empty fixed
303  codes block that is 10 bits long. This assures that enough bytes are output
304  in order for the decompressor to finish the block before the empty fixed code
305  block.
306 
307  If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
308  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
309  seven bits of the current block are held to be written as the next byte after
310  the next deflate block is completed. In this case, the decompressor may not
311  be provided enough bits at this point in order to complete decompression of
312  the data provided so far to the compressor. It may need to wait for the next
313  block to be emitted. This is for advanced applications that need to control
314  the emission of deflate blocks.
315 
316  If flush is set to Z_FULL_FLUSH, all output is flushed as with
317  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
318  restart from this point if previous compressed data has been damaged or if
319  random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
320  compression.
321 
322  If deflate returns with avail_out == 0, this function must be called again
323  with the same value of the flush parameter and more output space (updated
324  avail_out), until the flush is complete (deflate returns with non-zero
325  avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
326  avail_out is greater than six to avoid repeated flush markers due to
327  avail_out == 0 on return.
328 
329  If the parameter flush is set to Z_FINISH, pending input is processed,
330  pending output is flushed and deflate returns with Z_STREAM_END if there was
331  enough output space; if deflate returns with Z_OK, this function must be
332  called again with Z_FINISH and more output space (updated avail_out) but no
333  more input data, until it returns with Z_STREAM_END or an error. After
334  deflate has returned Z_STREAM_END, the only possible operations on the stream
335  are deflateReset or deflateEnd.
336 
337  Z_FINISH can be used immediately after deflateInit if all the compression
338  is to be done in a single step. In this case, avail_out must be at least the
339  value returned by deflateBound (see below). If deflate does not return
340  Z_STREAM_END, then it must be called again as described above.
341 
342  deflate() sets strm->adler to the adler32 checksum of all input read
343  so far (that is, total_in bytes).
344 
345  deflate() may update strm->data_type if it can make a good guess about
346  the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
347  binary. This field is only for information purposes and does not affect the
348  compression algorithm in any manner.
349 
350  deflate() returns Z_OK if some progress has been made (more input
351  processed or more output produced), Z_STREAM_END if all input has been
352  consumed and all output has been produced (only when flush is set to
353  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
354  if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
355  (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
356  fatal, and deflate() can be called again with more input and more output
357  space to continue compressing.
358 */
359 
360 
361 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
362 /*
363  All dynamically allocated data structures for this stream are freed.
364  This function discards any unprocessed input and does not flush any pending
365  output.
366 
367  deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
368  stream state was inconsistent, Z_DATA_ERROR if the stream was freed
369  prematurely (some input or output was discarded). In the error case, msg
370  may be set but then points to a static string (which must not be
371  deallocated).
372 */
373 
374 
375 /*
376 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
377 
378  Initializes the internal stream state for decompression. The fields
379  next_in, avail_in, zalloc, zfree and opaque must be initialized before by
380  the caller. If next_in is not Z_NULL and avail_in is large enough (the
381  exact value depends on the compression method), inflateInit determines the
382  compression method from the zlib header and allocates all data structures
383  accordingly; otherwise the allocation will be deferred to the first call of
384  inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
385  use default allocation functions.
386 
387  inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
388  memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
389  version assumed by the caller, or Z_STREAM_ERROR if the parameters are
390  invalid, such as a null pointer to the structure. msg is set to null if
391  there is no error message. inflateInit does not perform any decompression
392  apart from possibly reading the zlib header if present: actual decompression
393  will be done by inflate(). (So next_in and avail_in may be modified, but
394  next_out and avail_out are unused and unchanged.) The current implementation
395  of inflateInit() does not process any header information -- that is deferred
396  until inflate() is called.
397 */
398 
399 
400 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
401 /*
402  inflate decompresses as much data as possible, and stops when the input
403  buffer becomes empty or the output buffer becomes full. It may introduce
404  some output latency (reading input without producing any output) except when
405  forced to flush.
406 
407  The detailed semantics are as follows. inflate performs one or both of the
408  following actions:
409 
410  - Decompress more input starting at next_in and update next_in and avail_in
411  accordingly. If not all input can be processed (because there is not
412  enough room in the output buffer), next_in is updated and processing will
413  resume at this point for the next call of inflate().
414 
415  - Provide more output starting at next_out and update next_out and avail_out
416  accordingly. inflate() provides as much output as possible, until there is
417  no more input data or no more space in the output buffer (see below about
418  the flush parameter).
419 
420  Before the call of inflate(), the application should ensure that at least
421  one of the actions is possible, by providing more input and/or consuming more
422  output, and updating the next_* and avail_* values accordingly. The
423  application can consume the uncompressed output when it wants, for example
424  when the output buffer is full (avail_out == 0), or after each call of
425  inflate(). If inflate returns Z_OK and with zero avail_out, it must be
426  called again after making room in the output buffer because there might be
427  more output pending.
428 
429  The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
430  Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
431  output as possible to the output buffer. Z_BLOCK requests that inflate()
432  stop if and when it gets to the next deflate block boundary. When decoding
433  the zlib or gzip format, this will cause inflate() to return immediately
434  after the header and before the first block. When doing a raw inflate,
435  inflate() will go ahead and process the first block, and will return when it
436  gets to the end of that block, or when it runs out of data.
437 
438  The Z_BLOCK option assists in appending to or combining deflate streams.
439  Also to assist in this, on return inflate() will set strm->data_type to the
440  number of unused bits in the last byte taken from strm->next_in, plus 64 if
441  inflate() is currently decoding the last block in the deflate stream, plus
442  128 if inflate() returned immediately after decoding an end-of-block code or
443  decoding the complete header up to just before the first byte of the deflate
444  stream. The end-of-block will not be indicated until all of the uncompressed
445  data from that block has been written to strm->next_out. The number of
446  unused bits may in general be greater than seven, except when bit 7 of
447  data_type is set, in which case the number of unused bits will be less than
448  eight. data_type is set as noted here every time inflate() returns for all
449  flush options, and so can be used to determine the amount of currently
450  consumed input in bits.
451 
452  The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
453  end of each deflate block header is reached, before any actual data in that
454  block is decoded. This allows the caller to determine the length of the
455  deflate block header for later use in random access within a deflate block.
456  256 is added to the value of strm->data_type when inflate() returns
457  immediately after reaching the end of the deflate block header.
458 
459  inflate() should normally be called until it returns Z_STREAM_END or an
460  error. However if all decompression is to be performed in a single step (a
461  single call of inflate), the parameter flush should be set to Z_FINISH. In
462  this case all pending input is processed and all pending output is flushed;
463  avail_out must be large enough to hold all the uncompressed data. (The size
464  of the uncompressed data may have been saved by the compressor for this
465  purpose.) The next operation on this stream must be inflateEnd to deallocate
466  the decompression state. The use of Z_FINISH is never required, but can be
467  used to inform inflate that a faster approach may be used for the single
468  inflate() call.
469 
470  In this implementation, inflate() always flushes as much output as
471  possible to the output buffer, and always uses the faster approach on the
472  first call. So the only effect of the flush parameter in this implementation
473  is on the return value of inflate(), as noted below, or when it returns early
474  because Z_BLOCK or Z_TREES is used.
475 
476  If a preset dictionary is needed after this call (see inflateSetDictionary
477  below), inflate sets strm->adler to the adler32 checksum of the dictionary
478  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
479  strm->adler to the adler32 checksum of all output produced so far (that is,
480  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
481  below. At the end of the stream, inflate() checks that its computed adler32
482  checksum is equal to that saved by the compressor and returns Z_STREAM_END
483  only if the checksum is correct.
484 
485  inflate() can decompress and check either zlib-wrapped or gzip-wrapped
486  deflate data. The header type is detected automatically, if requested when
487  initializing with inflateInit2(). Any information contained in the gzip
488  header is not retained, so applications that need that information should
489  instead use raw inflate, see inflateInit2() below, or inflateBack() and
490  perform their own processing of the gzip header and trailer.
491 
492  inflate() returns Z_OK if some progress has been made (more input processed
493  or more output produced), Z_STREAM_END if the end of the compressed data has
494  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
495  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
496  corrupted (input stream not conforming to the zlib format or incorrect check
497  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
498  next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
499  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
500  output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
501  inflate() can be called again with more input and more output space to
502  continue decompressing. If Z_DATA_ERROR is returned, the application may
503  then call inflateSync() to look for a good compression block if a partial
504  recovery of the data is desired.
505 */
506 
507 
508 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
509 /*
510  All dynamically allocated data structures for this stream are freed.
511  This function discards any unprocessed input and does not flush any pending
512  output.
513 
514  inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
515  was inconsistent. In the error case, msg may be set but then points to a
516  static string (which must not be deallocated).
517 */
518 
519 
520  /* Advanced functions */
521 
522 /*
523  The following functions are needed only in some special applications.
524 */
525 
526 /*
527 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
528  int level,
529  int method,
530  int windowBits,
531  int memLevel,
532  int strategy));
533 
534  This is another version of deflateInit with more compression options. The
535  fields next_in, zalloc, zfree and opaque must be initialized before by the
536  caller.
537 
538  The method parameter is the compression method. It must be Z_DEFLATED in
539  this version of the library.
540 
541  The windowBits parameter is the base two logarithm of the window size
542  (the size of the history buffer). It should be in the range 8..15 for this
543  version of the library. Larger values of this parameter result in better
544  compression at the expense of memory usage. The default value is 15 if
545  deflateInit is used instead.
546 
547  windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
548  determines the window size. deflate() will then generate raw deflate data
549  with no zlib header or trailer, and will not compute an adler32 check value.
550 
551  windowBits can also be greater than 15 for optional gzip encoding. Add
552  16 to windowBits to write a simple gzip header and trailer around the
553  compressed data instead of a zlib wrapper. The gzip header will have no
554  file name, no extra data, no comment, no modification time (set to zero), no
555  header crc, and the operating system will be set to 255 (unknown). If a
556  gzip stream is being written, strm->adler is a crc32 instead of an adler32.
557 
558  The memLevel parameter specifies how much memory should be allocated
559  for the internal compression state. memLevel=1 uses minimum memory but is
560  slow and reduces compression ratio; memLevel=9 uses maximum memory for
561  optimal speed. The default value is 8. See zconf.h for total memory usage
562  as a function of windowBits and memLevel.
563 
564  The strategy parameter is used to tune the compression algorithm. Use the
565  value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
566  filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
567  string match), or Z_RLE to limit match distances to one (run-length
568  encoding). Filtered data consists mostly of small values with a somewhat
569  random distribution. In this case, the compression algorithm is tuned to
570  compress them better. The effect of Z_FILTERED is to force more Huffman
571  coding and less string matching; it is somewhat intermediate between
572  Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
573  fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
574  strategy parameter only affects the compression ratio but not the
575  correctness of the compressed output even if it is not set appropriately.
576  Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
577  decoder for special applications.
578 
579  deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
580  memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
581  method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
582  incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
583  set to null if there is no error message. deflateInit2 does not perform any
584  compression: this will be done by deflate().
585 */
586 
587 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
588  const Bytef *dictionary,
589  uInt dictLength));
590 /*
591  Initializes the compression dictionary from the given byte sequence
592  without producing any compressed output. This function must be called
593  immediately after deflateInit, deflateInit2 or deflateReset, before any call
594  of deflate. The compressor and decompressor must use exactly the same
595  dictionary (see inflateSetDictionary).
596 
597  The dictionary should consist of strings (byte sequences) that are likely
598  to be encountered later in the data to be compressed, with the most commonly
599  used strings preferably put towards the end of the dictionary. Using a
600  dictionary is most useful when the data to be compressed is short and can be
601  predicted with good accuracy; the data can then be compressed better than
602  with the default empty dictionary.
603 
604  Depending on the size of the compression data structures selected by
605  deflateInit or deflateInit2, a part of the dictionary may in effect be
606  discarded, for example if the dictionary is larger than the window size
607  provided in deflateInit or deflateInit2. Thus the strings most likely to be
608  useful should be put at the end of the dictionary, not at the front. In
609  addition, the current implementation of deflate will use at most the window
610  size minus 262 bytes of the provided dictionary.
611 
612  Upon return of this function, strm->adler is set to the adler32 value
613  of the dictionary; the decompressor may later use this value to determine
614  which dictionary has been used by the compressor. (The adler32 value
615  applies to the whole dictionary even if only a subset of the dictionary is
616  actually used by the compressor.) If a raw deflate was requested, then the
617  adler32 value is not computed and strm->adler is not set.
618 
619  deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
620  parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
621  inconsistent (for example if deflate has already been called for this stream
622  or if the compression method is bsort). deflateSetDictionary does not
623  perform any compression: this will be done by deflate().
624 */
625 
626 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
627  z_streamp source));
628 /*
629  Sets the destination stream as a complete copy of the source stream.
630 
631  This function can be useful when several compression strategies will be
632  tried, for example when there are several ways of pre-processing the input
633  data with a filter. The streams that will be discarded should then be freed
634  by calling deflateEnd. Note that deflateCopy duplicates the internal
635  compression state which can be quite large, so this strategy is slow and can
636  consume lots of memory.
637 
638  deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
639  enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
640  (such as zalloc being Z_NULL). msg is left unchanged in both source and
641  destination.
642 */
643 
644 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
645 /*
646  This function is equivalent to deflateEnd followed by deflateInit,
647  but does not free and reallocate all the internal compression state. The
648  stream will keep the same compression level and any other attributes that
649  may have been set by deflateInit2.
650 
651  deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
652  stream state was inconsistent (such as zalloc or state being Z_NULL).
653 */
654 
655 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
656  int level,
657  int strategy));
658 /*
659  Dynamically update the compression level and compression strategy. The
660  interpretation of level and strategy is as in deflateInit2. This can be
661  used to switch between compression and straight copy of the input data, or
662  to switch to a different kind of input data requiring a different strategy.
663  If the compression level is changed, the input available so far is
664  compressed with the old level (and may be flushed); the new level will take
665  effect only at the next call of deflate().
666 
667  Before the call of deflateParams, the stream state must be set as for
668  a call of deflate(), since the currently available input may have to be
669  compressed and flushed. In particular, strm->avail_out must be non-zero.
670 
671  deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
672  stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
673  strm->avail_out was zero.
674 */
675 
676 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
677  int good_length,
678  int max_lazy,
679  int nice_length,
680  int max_chain));
681 /*
682  Fine tune deflate's internal compression parameters. This should only be
683  used by someone who understands the algorithm used by zlib's deflate for
684  searching for the best matching string, and even then only by the most
685  fanatic optimizer trying to squeeze out the last compressed bit for their
686  specific input data. Read the deflate.c source code for the meaning of the
687  max_lazy, good_length, nice_length, and max_chain parameters.
688 
689  deflateTune() can be called after deflateInit() or deflateInit2(), and
690  returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
691  */
692 
693 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
694  uLong sourceLen));
695 /*
696  deflateBound() returns an upper bound on the compressed size after
697  deflation of sourceLen bytes. It must be called after deflateInit() or
698  deflateInit2(), and after deflateSetHeader(), if used. This would be used
699  to allocate an output buffer for deflation in a single pass, and so would be
700  called before deflate().
701 */
702 
703 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
704  int bits,
705  int value));
706 /*
707  deflatePrime() inserts bits in the deflate output stream. The intent
708  is that this function is used to start off the deflate output with the bits
709  leftover from a previous deflate stream when appending to it. As such, this
710  function can only be used for raw deflate, and must be used before the first
711  deflate() call after a deflateInit2() or deflateReset(). bits must be less
712  than or equal to 16, and that many of the least significant bits of value
713  will be inserted in the output.
714 
715  deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
716  stream state was inconsistent.
717 */
718 
719 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
720  gz_headerp head));
721 /*
722  deflateSetHeader() provides gzip header information for when a gzip
723  stream is requested by deflateInit2(). deflateSetHeader() may be called
724  after deflateInit2() or deflateReset() and before the first call of
725  deflate(). The text, time, os, extra field, name, and comment information
726  in the provided gz_header structure are written to the gzip header (xflag is
727  ignored -- the extra flags are set according to the compression level). The
728  caller must assure that, if not Z_NULL, name and comment are terminated with
729  a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
730  available there. If hcrc is true, a gzip header crc is included. Note that
731  the current versions of the command-line version of gzip (up through version
732  1.3.x) do not support header crc's, and will report that it is a "multi-part
733  gzip file" and give up.
734 
735  If deflateSetHeader is not used, the default gzip header has text false,
736  the time set to zero, and os set to 255, with no extra, name, or comment
737  fields. The gzip header is returned to the default state by deflateReset().
738 
739  deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
740  stream state was inconsistent.
741 */
742 
743 /*
744 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
745  int windowBits));
746 
747  This is another version of inflateInit with an extra parameter. The
748  fields next_in, avail_in, zalloc, zfree and opaque must be initialized
749  before by the caller.
750 
751  The windowBits parameter is the base two logarithm of the maximum window
752  size (the size of the history buffer). It should be in the range 8..15 for
753  this version of the library. The default value is 15 if inflateInit is used
754  instead. windowBits must be greater than or equal to the windowBits value
755  provided to deflateInit2() while compressing, or it must be equal to 15 if
756  deflateInit2() was not used. If a compressed stream with a larger window
757  size is given as input, inflate() will return with the error code
758  Z_DATA_ERROR instead of trying to allocate a larger window.
759 
760  windowBits can also be zero to request that inflate use the window size in
761  the zlib header of the compressed stream.
762 
763  windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
764  determines the window size. inflate() will then process raw deflate data,
765  not looking for a zlib or gzip header, not generating a check value, and not
766  looking for any check values for comparison at the end of the stream. This
767  is for use with other formats that use the deflate compressed data format
768  such as zip. Those formats provide their own check values. If a custom
769  format is developed using the raw deflate format for compressed data, it is
770  recommended that a check value such as an adler32 or a crc32 be applied to
771  the uncompressed data as is done in the zlib, gzip, and zip formats. For
772  most applications, the zlib format should be used as is. Note that comments
773  above on the use in deflateInit2() applies to the magnitude of windowBits.
774 
775  windowBits can also be greater than 15 for optional gzip decoding. Add
776  32 to windowBits to enable zlib and gzip decoding with automatic header
777  detection, or add 16 to decode only the gzip format (the zlib format will
778  return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
779  crc32 instead of an adler32.
780 
781  inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
782  memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
783  version assumed by the caller, or Z_STREAM_ERROR if the parameters are
784  invalid, such as a null pointer to the structure. msg is set to null if
785  there is no error message. inflateInit2 does not perform any decompression
786  apart from possibly reading the zlib header if present: actual decompression
787  will be done by inflate(). (So next_in and avail_in may be modified, but
788  next_out and avail_out are unused and unchanged.) The current implementation
789  of inflateInit2() does not process any header information -- that is
790  deferred until inflate() is called.
791 */
792 
793 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
794  const Bytef *dictionary,
795  uInt dictLength));
796 /*
797  Initializes the decompression dictionary from the given uncompressed byte
798  sequence. This function must be called immediately after a call of inflate,
799  if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
800  can be determined from the adler32 value returned by that call of inflate.
801  The compressor and decompressor must use exactly the same dictionary (see
802  deflateSetDictionary). For raw inflate, this function can be called
803  immediately after inflateInit2() or inflateReset() and before any call of
804  inflate() to set the dictionary. The application must insure that the
805  dictionary that was used for compression is provided.
806 
807  inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
808  parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
809  inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
810  expected one (incorrect adler32 value). inflateSetDictionary does not
811  perform any decompression: this will be done by subsequent calls of
812  inflate().
813 */
814 
815 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
816 /*
817  Skips invalid compressed data until a full flush point (see above the
818  description of deflate with Z_FULL_FLUSH) can be found, or until all
819  available input is skipped. No output is provided.
820 
821  inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
822  if no more input was provided, Z_DATA_ERROR if no flush point has been
823  found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the
824  success case, the application may save the current current value of total_in
825  which indicates where valid compressed data was found. In the error case,
826  the application may repeatedly call inflateSync, providing more input each
827  time, until success or end of the input data.
828 */
829 
830 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
831  z_streamp source));
832 /*
833  Sets the destination stream as a complete copy of the source stream.
834 
835  This function can be useful when randomly accessing a large stream. The
836  first pass through the stream can periodically record the inflate state,
837  allowing restarting inflate at those points when randomly accessing the
838  stream.
839 
840  inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
841  enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
842  (such as zalloc being Z_NULL). msg is left unchanged in both source and
843  destination.
844 */
845 
846 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
847 /*
848  This function is equivalent to inflateEnd followed by inflateInit,
849  but does not free and reallocate all the internal decompression state. The
850  stream will keep attributes that may have been set by inflateInit2.
851 
852  inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
853  stream state was inconsistent (such as zalloc or state being Z_NULL).
854 */
855 
856 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
857  int windowBits));
858 /*
859  This function is the same as inflateReset, but it also permits changing
860  the wrap and window size requests. The windowBits parameter is interpreted
861  the same as it is for inflateInit2.
862 
863  inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
864  stream state was inconsistent (such as zalloc or state being Z_NULL), or if
865  the windowBits parameter is invalid.
866 */
867 
868 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
869  int bits,
870  int value));
871 /*
872  This function inserts bits in the inflate input stream. The intent is
873  that this function is used to start inflating at a bit position in the
874  middle of a byte. The provided bits will be used before any bytes are used
875  from next_in. This function should only be used with raw inflate, and
876  should be used before the first inflate() call after inflateInit2() or
877  inflateReset(). bits must be less than or equal to 16, and that many of the
878  least significant bits of value will be inserted in the input.
879 
880  If bits is negative, then the input stream bit buffer is emptied. Then
881  inflatePrime() can be called again to put bits in the buffer. This is used
882  to clear out bits leftover after feeding inflate a block description prior
883  to feeding inflate codes.
884 
885  inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
886  stream state was inconsistent.
887 */
888 
889 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
890 /*
891  This function returns two values, one in the lower 16 bits of the return
892  value, and the other in the remaining upper bits, obtained by shifting the
893  return value down 16 bits. If the upper value is -1 and the lower value is
894  zero, then inflate() is currently decoding information outside of a block.
895  If the upper value is -1 and the lower value is non-zero, then inflate is in
896  the middle of a stored block, with the lower value equaling the number of
897  bytes from the input remaining to copy. If the upper value is not -1, then
898  it is the number of bits back from the current bit position in the input of
899  the code (literal or length/distance pair) currently being processed. In
900  that case the lower value is the number of bytes already emitted for that
901  code.
902 
903  A code is being processed if inflate is waiting for more input to complete
904  decoding of the code, or if it has completed decoding but is waiting for
905  more output space to write the literal or match data.
906 
907  inflateMark() is used to mark locations in the input data for random
908  access, which may be at bit positions, and to note those cases where the
909  output of a code may span boundaries of random access blocks. The current
910  location in the input stream can be determined from avail_in and data_type
911  as noted in the description for the Z_BLOCK flush parameter for inflate.
912 
913  inflateMark returns the value noted above or -1 << 16 if the provided
914  source stream state was inconsistent.
915 */
916 
917 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
918  gz_headerp head));
919 /*
920  inflateGetHeader() requests that gzip header information be stored in the
921  provided gz_header structure. inflateGetHeader() may be called after
922  inflateInit2() or inflateReset(), and before the first call of inflate().
923  As inflate() processes the gzip stream, head->done is zero until the header
924  is completed, at which time head->done is set to one. If a zlib stream is
925  being decoded, then head->done is set to -1 to indicate that there will be
926  no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
927  used to force inflate() to return immediately after header processing is
928  complete and before any actual data is decompressed.
929 
930  The text, time, xflags, and os fields are filled in with the gzip header
931  contents. hcrc is set to true if there is a header CRC. (The header CRC
932  was valid if done is set to one.) If extra is not Z_NULL, then extra_max
933  contains the maximum number of bytes to write to extra. Once done is true,
934  extra_len contains the actual extra field length, and extra contains the
935  extra field, or that field truncated if extra_max is less than extra_len.
936  If name is not Z_NULL, then up to name_max characters are written there,
937  terminated with a zero unless the length is greater than name_max. If
938  comment is not Z_NULL, then up to comm_max characters are written there,
939  terminated with a zero unless the length is greater than comm_max. When any
940  of extra, name, or comment are not Z_NULL and the respective field is not
941  present in the header, then that field is set to Z_NULL to signal its
942  absence. This allows the use of deflateSetHeader() with the returned
943  structure to duplicate the header. However if those fields are set to
944  allocated memory, then the application will need to save those pointers
945  elsewhere so that they can be eventually freed.
946 
947  If inflateGetHeader is not used, then the header information is simply
948  discarded. The header is always checked for validity, including the header
949  CRC if present. inflateReset() will reset the process to discard the header
950  information. The application would need to call inflateGetHeader() again to
951  retrieve the header from the next gzip stream.
952 
953  inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
954  stream state was inconsistent.
955 */
956 
957 /*
958 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
959  unsigned char FAR *window));
960 
961  Initialize the internal stream state for decompression using inflateBack()
962  calls. The fields zalloc, zfree and opaque in strm must be initialized
963  before the call. If zalloc and zfree are Z_NULL, then the default library-
964  derived memory allocation routines are used. windowBits is the base two
965  logarithm of the window size, in the range 8..15. window is a caller
966  supplied buffer of that size. Except for special applications where it is
967  assured that deflate was used with small window sizes, windowBits must be 15
968  and a 32K byte window must be supplied to be able to decompress general
969  deflate streams.
970 
971  See inflateBack() for the usage of these routines.
972 
973  inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
974  the paramaters are invalid, Z_MEM_ERROR if the internal state could not be
975  allocated, or Z_VERSION_ERROR if the version of the library does not match
976  the version of the header file.
977 */
978 
979 typedef unsigned (*in_func) OF((void *, unsigned char * *));
980 typedef int (*out_func) OF((void *, unsigned char *, unsigned));
981 
982 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
983  in_func in, void *in_desc,
984  out_func out, void *out_desc));
985 /*
986  inflateBack() does a raw inflate with a single call using a call-back
987  interface for input and output. This is more efficient than inflate() for
988  file i/o applications in that it avoids copying between the output and the
989  sliding window by simply making the window itself the output buffer. This
990  function trusts the application to not change the output buffer passed by
991  the output function, at least until inflateBack() returns.
992 
993  inflateBackInit() must be called first to allocate the internal state
994  and to initialize the state with the user-provided window buffer.
995  inflateBack() may then be used multiple times to inflate a complete, raw
996  deflate stream with each call. inflateBackEnd() is then called to free the
997  allocated state.
998 
999  A raw deflate stream is one with no zlib or gzip header or trailer.
1000  This routine would normally be used in a utility that reads zip or gzip
1001  files and writes out uncompressed files. The utility would decode the
1002  header and process the trailer on its own, hence this routine expects only
1003  the raw deflate stream to decompress. This is different from the normal
1004  behavior of inflate(), which expects either a zlib or gzip header and
1005  trailer around the deflate stream.
1006 
1007  inflateBack() uses two subroutines supplied by the caller that are then
1008  called by inflateBack() for input and output. inflateBack() calls those
1009  routines until it reads a complete deflate stream and writes out all of the
1010  uncompressed data, or until it encounters an error. The function's
1011  parameters and return types are defined above in the in_func and out_func
1012  typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1013  number of bytes of provided input, and a pointer to that input in buf. If
1014  there is no input available, in() must return zero--buf is ignored in that
1015  case--and inflateBack() will return a buffer error. inflateBack() will call
1016  out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
1017  should return zero on success, or non-zero on failure. If out() returns
1018  non-zero, inflateBack() will return with an error. Neither in() nor out()
1019  are permitted to change the contents of the window provided to
1020  inflateBackInit(), which is also the buffer that out() uses to write from.
1021  The length written by out() will be at most the window size. Any non-zero
1022  amount of input may be provided by in().
1023 
1024  For convenience, inflateBack() can be provided input on the first call by
1025  setting strm->next_in and strm->avail_in. If that input is exhausted, then
1026  in() will be called. Therefore strm->next_in must be initialized before
1027  calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1028  immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1029  must also be initialized, and then if strm->avail_in is not zero, input will
1030  initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1031 
1032  The in_desc and out_desc parameters of inflateBack() is passed as the
1033  first parameter of in() and out() respectively when they are called. These
1034  descriptors can be optionally used to pass any information that the caller-
1035  supplied in() and out() functions need to do their job.
1036 
1037  On return, inflateBack() will set strm->next_in and strm->avail_in to
1038  pass back any unused input that was provided by the last in() call. The
1039  return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1040  if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1041  in the deflate stream (in which case strm->msg is set to indicate the nature
1042  of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1043  In the case of Z_BUF_ERROR, an input or output error can be distinguished
1044  using strm->next_in which will be Z_NULL only if in() returned an error. If
1045  strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1046  non-zero. (in() will always be called before out(), so strm->next_in is
1047  assured to be defined if out() returns non-zero.) Note that inflateBack()
1048  cannot return Z_OK.
1049 */
1050 
1051 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1052 /*
1053  All memory allocated by inflateBackInit() is freed.
1054 
1055  inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1056  state was inconsistent.
1057 */
1058 
1059 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1060 /* Return flags indicating compile-time options.
1061 
1062  Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1063  1.0: size of uInt
1064  3.2: size of uLong
1065  5.4: size of voidpf (pointer)
1066  7.6: size of z_off_t
1067 
1068  Compiler, assembler, and debug options:
1069  8: DEBUG
1070  9: ASMV or ASMINF -- use ASM code
1071  10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1072  11: 0 (reserved)
1073 
1074  One-time table building (smaller code, but not thread-safe if true):
1075  12: BUILDFIXED -- build static block decoding tables when needed
1076  13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1077  14,15: 0 (reserved)
1078 
1079  Library content (indicates missing functionality):
1080  16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1081  deflate code when not needed)
1082  17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1083  and decode gzip streams (to avoid linking crc code)
1084  18-19: 0 (reserved)
1085 
1086  Operation variations (changes in library functionality):
1087  20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1088  21: FASTEST -- deflate algorithm with only one, lowest compression level
1089  22,23: 0 (reserved)
1090 
1091  The sprintf variant used by gzprintf (zero is best):
1092  24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1093  25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1094  26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1095 
1096  Remainder:
1097  27-31: 0 (reserved)
1098  */
1099 
1100 
1101  /* utility functions */
1102 
1103 /*
1104  The following utility functions are implemented on top of the basic
1105  stream-oriented functions. To simplify the interface, some default options
1106  are assumed (compression level and memory usage, standard memory allocation
1107  functions). The source code of these utility functions can be modified if
1108  you need special options.
1109 */
1110 
1111 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1112  const Bytef *source, uLong sourceLen));
1113 /*
1114  Compresses the source buffer into the destination buffer. sourceLen is
1115  the byte length of the source buffer. Upon entry, destLen is the total size
1116  of the destination buffer, which must be at least the value returned by
1117  compressBound(sourceLen). Upon exit, destLen is the actual size of the
1118  compressed buffer.
1119 
1120  compress returns Z_OK if success, Z_MEM_ERROR if there was not
1121  enough memory, Z_BUF_ERROR if there was not enough room in the output
1122  buffer.
1123 */
1124 
1125 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1126  const Bytef *source, uLong sourceLen,
1127  int level));
1128 /*
1129  Compresses the source buffer into the destination buffer. The level
1130  parameter has the same meaning as in deflateInit. sourceLen is the byte
1131  length of the source buffer. Upon entry, destLen is the total size of the
1132  destination buffer, which must be at least the value returned by
1133  compressBound(sourceLen). Upon exit, destLen is the actual size of the
1134  compressed buffer.
1135 
1136  compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1137  memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1138  Z_STREAM_ERROR if the level parameter is invalid.
1139 */
1140 
1141 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1142 /*
1143  compressBound() returns an upper bound on the compressed size after
1144  compress() or compress2() on sourceLen bytes. It would be used before a
1145  compress() or compress2() call to allocate the destination buffer.
1146 */
1147 
1148 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1149  const Bytef *source, uLong sourceLen));
1150 /*
1151  Decompresses the source buffer into the destination buffer. sourceLen is
1152  the byte length of the source buffer. Upon entry, destLen is the total size
1153  of the destination buffer, which must be large enough to hold the entire
1154  uncompressed data. (The size of the uncompressed data must have been saved
1155  previously by the compressor and transmitted to the decompressor by some
1156  mechanism outside the scope of this compression library.) Upon exit, destLen
1157  is the actual size of the uncompressed buffer.
1158 
1159  uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1160  enough memory, Z_BUF_ERROR if there was not enough room in the output
1161  buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
1162 */
1163 
1164 
1165  /* gzip file access functions */
1166 
1167 /*
1168  This library supports reading and writing files in gzip (.gz) format with
1169  an interface similar to that of stdio, using the functions that start with
1170  "gz". The gzip format is different from the zlib format. gzip is a gzip
1171  wrapper, documented in RFC 1952, wrapped around a deflate stream.
1172 */
1173 
1174 typedef voidp gzFile; /* opaque gzip file descriptor */
1175 
1176 /*
1177 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1178 
1179  Opens a gzip (.gz) file for reading or writing. The mode parameter is as
1180  in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1181  a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1182  compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1183  for fixed code compression as in "wb9F". (See the description of
1184  deflateInit2 for more information about the strategy parameter.) Also "a"
1185  can be used instead of "w" to request that the gzip stream that will be
1186  written be appended to the file. "+" will result in an error, since reading
1187  and writing to the same gzip file is not supported.
1188 
1189  gzopen can be used to read a file which is not in gzip format; in this
1190  case gzread will directly read from the file without decompression.
1191 
1192  gzopen returns NULL if the file could not be opened, if there was
1193  insufficient memory to allocate the gzFile state, or if an invalid mode was
1194  specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1195  errno can be checked to determine if the reason gzopen failed was that the
1196  file could not be opened.
1197 */
1198 
1199 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1200 /*
1201  gzdopen associates a gzFile with the file descriptor fd. File descriptors
1202  are obtained from calls like open, dup, creat, pipe or fileno (if the file
1203  has been previously opened with fopen). The mode parameter is as in gzopen.
1204 
1205  The next call of gzclose on the returned gzFile will also close the file
1206  descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1207  fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1208  mode);. The duplicated descriptor should be saved to avoid a leak, since
1209  gzdopen does not close fd if it fails.
1210 
1211  gzdopen returns NULL if there was insufficient memory to allocate the
1212  gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1213  provided, or '+' was provided), or if fd is -1. The file descriptor is not
1214  used until the next gz* read, write, seek, or close operation, so gzdopen
1215  will not detect if fd is invalid (unless fd is -1).
1216 */
1217 
1218 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1219 /*
1220  Set the internal buffer size used by this library's functions. The
1221  default buffer size is 8192 bytes. This function must be called after
1222  gzopen() or gzdopen(), and before any other calls that read or write the
1223  file. The buffer memory allocation is always deferred to the first read or
1224  write. Two buffers are allocated, either both of the specified size when
1225  writing, or one of the specified size and the other twice that size when
1226  reading. A larger buffer size of, for example, 64K or 128K bytes will
1227  noticeably increase the speed of decompression (reading).
1228 
1229  The new buffer size also affects the maximum length for gzprintf().
1230 
1231  gzbuffer() returns 0 on success, or -1 on failure, such as being called
1232  too late.
1233 */
1234 
1235 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1236 /*
1237  Dynamically update the compression level or strategy. See the description
1238  of deflateInit2 for the meaning of these parameters.
1239 
1240  gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1241  opened for writing.
1242 */
1243 
1244 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1245 /*
1246  Reads the given number of uncompressed bytes from the compressed file. If
1247  the input file was not in gzip format, gzread copies the given number of
1248  bytes into the buffer.
1249 
1250  After reaching the end of a gzip stream in the input, gzread will continue
1251  to read, looking for another gzip stream, or failing that, reading the rest
1252  of the input file directly without decompression. The entire input file
1253  will be read if gzread is called until it returns less than the requested
1254  len.
1255 
1256  gzread returns the number of uncompressed bytes actually read, less than
1257  len for end of file, or -1 for error.
1258 */
1259 
1260 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1261  voidpc buf, unsigned len));
1262 /*
1263  Writes the given number of uncompressed bytes into the compressed file.
1264  gzwrite returns the number of uncompressed bytes written or 0 in case of
1265  error.
1266 */
1267 
1268 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
1269 /*
1270  Converts, formats, and writes the arguments to the compressed file under
1271  control of the format string, as in fprintf. gzprintf returns the number of
1272  uncompressed bytes actually written, or 0 in case of error. The number of
1273  uncompressed bytes written is limited to 8191, or one less than the buffer
1274  size given to gzbuffer(). The caller should assure that this limit is not
1275  exceeded. If it is exceeded, then gzprintf() will return an error (0) with
1276  nothing written. In this case, there may also be a buffer overflow with
1277  unpredictable consequences, which is possible only if zlib was compiled with
1278  the insecure functions sprintf() or vsprintf() because the secure snprintf()
1279  or vsnprintf() functions were not available. This can be determined using
1280  zlibCompileFlags().
1281 */
1282 
1283 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1284 /*
1285  Writes the given null-terminated string to the compressed file, excluding
1286  the terminating null character.
1287 
1288  gzputs returns the number of characters written, or -1 in case of error.
1289 */
1290 
1291 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1292 /*
1293  Reads bytes from the compressed file until len-1 characters are read, or a
1294  newline character is read and transferred to buf, or an end-of-file
1295  condition is encountered. If any characters are read or if len == 1, the
1296  string is terminated with a null character. If no characters are read due
1297  to an end-of-file or len < 1, then the buffer is left untouched.
1298 
1299  gzgets returns buf which is a null-terminated string, or it returns NULL
1300  for end-of-file or in case of error. If there was an error, the contents at
1301  buf are indeterminate.
1302 */
1303 
1304 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1305 /*
1306  Writes c, converted to an unsigned char, into the compressed file. gzputc
1307  returns the value that was written, or -1 in case of error.
1308 */
1309 
1310 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1311 /*
1312  Reads one byte from the compressed file. gzgetc returns this byte or -1
1313  in case of end of file or error.
1314 */
1315 
1316 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1317 /*
1318  Push one character back onto the stream to be read as the first character
1319  on the next read. At least one character of push-back is allowed.
1320  gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1321  fail if c is -1, and may fail if a character has been pushed but not read
1322  yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1323  output buffer size of pushed characters is allowed. (See gzbuffer above.)
1324  The pushed character will be discarded if the stream is repositioned with
1325  gzseek() or gzrewind().
1326 */
1327 
1328 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1329 /*
1330  Flushes all pending output into the compressed file. The parameter flush
1331  is as in the deflate() function. The return value is the zlib error number
1332  (see function gzerror below). gzflush is only permitted when writing.
1333 
1334  If the flush parameter is Z_FINISH, the remaining data is written and the
1335  gzip stream is completed in the output. If gzwrite() is called again, a new
1336  gzip stream will be started in the output. gzread() is able to read such
1337  concatented gzip streams.
1338 
1339  gzflush should be called only when strictly necessary because it will
1340  degrade compression if called too often.
1341 */
1342 
1343 /*
1344 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1345  z_off_t offset, int whence));
1346 
1347  Sets the starting position for the next gzread or gzwrite on the given
1348  compressed file. The offset represents a number of bytes in the
1349  uncompressed data stream. The whence parameter is defined as in lseek(2);
1350  the value SEEK_END is not supported.
1351 
1352  If the file is opened for reading, this function is emulated but can be
1353  extremely slow. If the file is opened for writing, only forward seeks are
1354  supported; gzseek then compresses a sequence of zeroes up to the new
1355  starting position.
1356 
1357  gzseek returns the resulting offset location as measured in bytes from
1358  the beginning of the uncompressed stream, or -1 in case of error, in
1359  particular if the file is opened for writing and the new starting position
1360  would be before the current position.
1361 */
1362 
1363 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1364 /*
1365  Rewinds the given file. This function is supported only for reading.
1366 
1367  gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1368 */
1369 
1370 /*
1371 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1372 
1373  Returns the starting position for the next gzread or gzwrite on the given
1374  compressed file. This position represents a number of bytes in the
1375  uncompressed data stream, and is zero when starting, even if appending or
1376  reading a gzip stream from the middle of a file using gzdopen().
1377 
1378  gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1379 */
1380 
1381 /*
1382 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1383 
1384  Returns the current offset in the file being read or written. This offset
1385  includes the count of bytes that precede the gzip stream, for example when
1386  appending or when using gzdopen() for reading. When reading, the offset
1387  does not include as yet unused buffered input. This information can be used
1388  for a progress indicator. On error, gzoffset() returns -1.
1389 */
1390 
1391 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1392 /*
1393  Returns true (1) if the end-of-file indicator has been set while reading,
1394  false (0) otherwise. Note that the end-of-file indicator is set only if the
1395  read tried to go past the end of the input, but came up short. Therefore,
1396  just like feof(), gzeof() may return false even if there is no more data to
1397  read, in the event that the last read request was for the exact number of
1398  bytes remaining in the input file. This will happen if the input file size
1399  is an exact multiple of the buffer size.
1400 
1401  If gzeof() returns true, then the read functions will return no more data,
1402  unless the end-of-file indicator is reset by gzclearerr() and the input file
1403  has grown since the previous end of file was detected.
1404 */
1405 
1406 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1407 /*
1408  Returns true (1) if file is being copied directly while reading, or false
1409  (0) if file is a gzip stream being decompressed. This state can change from
1410  false to true while reading the input file if the end of a gzip stream is
1411  reached, but is followed by data that is not another gzip stream.
1412 
1413  If the input file is empty, gzdirect() will return true, since the input
1414  does not contain a gzip stream.
1415 
1416  If gzdirect() is used immediately after gzopen() or gzdopen() it will
1417  cause buffers to be allocated to allow reading the file to determine if it
1418  is a gzip file. Therefore if gzbuffer() is used, it should be called before
1419  gzdirect().
1420 */
1421 
1422 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1423 /*
1424  Flushes all pending output if necessary, closes the compressed file and
1425  deallocates the (de)compression state. Note that once file is closed, you
1426  cannot call gzerror with file, since its structures have been deallocated.
1427  gzclose must not be called more than once on the same file, just as free
1428  must not be called more than once on the same allocation.
1429 
1430  gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1431  file operation error, or Z_OK on success.
1432 */
1433 
1434 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1435 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1436 /*
1437  Same as gzclose(), but gzclose_r() is only for use when reading, and
1438  gzclose_w() is only for use when writing or appending. The advantage to
1439  using these instead of gzclose() is that they avoid linking in zlib
1440  compression or decompression code that is not used when only reading or only
1441  writing respectively. If gzclose() is used, then both compression and
1442  decompression code will be included the application when linking to a static
1443  zlib library.
1444 */
1445 
1446 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1447 /*
1448  Returns the error message for the last error which occurred on the given
1449  compressed file. errnum is set to zlib error number. If an error occurred
1450  in the file system and not in the compression library, errnum is set to
1451  Z_ERRNO and the application may consult errno to get the exact error code.
1452 
1453  The application must not modify the returned string. Future calls to
1454  this function may invalidate the previously returned string. If file is
1455  closed, then the string previously returned by gzerror will no longer be
1456  available.
1457 
1458  gzerror() should be used to distinguish errors from end-of-file for those
1459  functions above that do not distinguish those cases in their return values.
1460 */
1461 
1462 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1463 /*
1464  Clears the error and end-of-file flags for file. This is analogous to the
1465  clearerr() function in stdio. This is useful for continuing to read a gzip
1466  file that is being written concurrently.
1467 */
1468 
1469 
1470  /* checksum functions */
1471 
1472 /*
1473  These functions are not related to compression but are exported
1474  anyway because they might be useful in applications using the compression
1475  library.
1476 */
1477 
1478 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1479 /*
1480  Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1481  return the updated checksum. If buf is Z_NULL, this function returns the
1482  required initial value for the checksum.
1483 
1484  An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1485  much faster.
1486 
1487  Usage example:
1488 
1489  uLong adler = adler32(0L, Z_NULL, 0);
1490 
1491  while (read_buffer(buffer, length) != EOF) {
1492  adler = adler32(adler, buffer, length);
1493  }
1494  if (adler != original_adler) error();
1495 */
1496 
1497 /*
1498 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1499  z_off_t len2));
1500 
1501  Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1502  and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1503  each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1504  seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
1505 */
1506 
1507 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
1508 /*
1509  Update a running CRC-32 with the bytes buf[0..len-1] and return the
1510  updated CRC-32. If buf is Z_NULL, this function returns the required
1511  initial value for the for the crc. Pre- and post-conditioning (one's
1512  complement) is performed within this function so it shouldn't be done by the
1513  application.
1514 
1515  Usage example:
1516 
1517  uLong crc = crc32(0L, Z_NULL, 0);
1518 
1519  while (read_buffer(buffer, length) != EOF) {
1520  crc = crc32(crc, buffer, length);
1521  }
1522  if (crc != original_crc) error();
1523 */
1524 
1525 /*
1526 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1527 
1528  Combine two CRC-32 check values into one. For two sequences of bytes,
1529  seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1530  calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1531  check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1532  len2.
1533 */
1534 
1535 
1536  /* various hacks, don't look :) */
1537 
1538 /* deflateInit and inflateInit are macros to allow checking the zlib version
1539  * and the compiler's view of z_stream:
1540  */
1541 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1542  const char *version, int stream_size));
1543 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1544  const char *version, int stream_size));
1545 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1546  int windowBits, int memLevel,
1547  int strategy, const char *version,
1548  int stream_size));
1549 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1550  const char *version, int stream_size));
1551 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1552  unsigned char *window,
1553  const char *version,
1554  int stream_size));
1555 #define deflateInit(strm, level) \
1556  deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1557 #define inflateInit(strm) \
1558  inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1559 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1560  deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1561  (strategy), ZLIB_VERSION, sizeof(z_stream))
1562 #define inflateInit2(strm, windowBits) \
1563  inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1564 #define inflateBackInit(strm, windowBits, window) \
1565  inflateBackInit_((strm), (windowBits), (window), \
1566  ZLIB_VERSION, sizeof(z_stream))
1567 
1568 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1569  * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1570  * both are true, the application gets the *64 functions, and the regular
1571  * functions are changed to 64 bits) -- in case these are set on systems
1572  * without large file support, _LFS64_LARGEFILE must also be true
1573  */
1574 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
1575  ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1576  ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1577  ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1578  ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1579  ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1580  ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1581 #endif
1582 
1583 #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
1584 # define gzopen gzopen64
1585 # define gzseek gzseek64
1586 # define gztell gztell64
1587 # define gzoffset gzoffset64
1588 # define adler32_combine adler32_combine64
1589 # define crc32_combine crc32_combine64
1590 # ifdef _LARGEFILE64_SOURCE
1591  ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1592  ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1593  ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1594  ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1595  ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
1596  ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
1597 # endif
1598 #else
1599  ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1600  ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1601  ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1602  ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1603  ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1604  ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1605 #endif
1606 
1607 /* hack for buggy compilers */
1608 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1609  struct internal_state {int dummy;};
1610 #endif
1611 
1612 /* undocumented functions */
1613 ZEXTERN const char * ZEXPORT zError OF((int));
1614 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
1615 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
1616 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
1617 
1618 #ifdef __cplusplus
1619 }
1620 #endif
1621 
1622 #endif /* ZLIB_H */