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zlib.h
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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 #ifndef ZLIB_H
32 #define ZLIB_H
33 
34 #include "zconf.h"
35 
36 #ifdef __cplusplus
37 extern "C" {
38 #endif
39 
40 #define ZLIB_VERSION "1.2.5"
41 #define ZLIB_VERNUM 0x1250
42 #define ZLIB_VER_MAJOR 1
43 #define ZLIB_VER_MINOR 2
44 #define ZLIB_VER_REVISION 5
45 #define ZLIB_VER_SUBREVISION 0
46 
47 /*
48  The 'zlib' compression library provides in-memory compression and
49  decompression functions, including integrity checks of the uncompressed data.
50  This version of the library supports only one compression method (deflation)
51  but other algorithms will be added later and will have the same stream
52  interface.
53 
54  Compression can be done in a single step if the buffers are large enough,
55  or can be done by repeated calls of the compression function. In the latter
56  case, the application must provide more input and/or consume the output
57  (providing more output space) before each call.
58 
59  The compressed data format used by default by the in-memory functions is
60  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
61  around a deflate stream, which is itself documented in RFC 1951.
62 
63  The library also supports reading and writing files in gzip (.gz) format
64  with an interface similar to that of stdio using the functions that start
65  with "gz". The gzip format is different from the zlib format. gzip is a
66  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
67 
68  This library can optionally read and write gzip streams in memory as well.
69 
70  The zlib format was designed to be compact and fast for use in memory
71  and on communications channels. The gzip format was designed for single-
72  file compression on file systems, has a larger header than zlib to maintain
73  directory information, and uses a different, slower check method than zlib.
74 
75  The library does not install any signal handler. The decoder checks
76  the consistency of the compressed data, so the library should never crash
77  even in case of corrupted input.
78 */
79 
80 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
81 typedef void (*free_func) OF((voidpf opaque, voidpf address));
82 
83 struct internal_state;
84 
85 typedef struct z_stream_s {
86  Bytef *next_in; /* next input byte */
87  uInt avail_in; /* number of bytes available at next_in */
88  uLong total_in; /* total nb of input bytes read so far */
89 
90  Bytef *next_out; /* next output byte should be put there */
91  uInt avail_out; /* remaining free space at next_out */
92  uLong total_out; /* total nb of bytes output so far */
93 
94  char *msg; /* last error message, NULL if no error */
95  struct internal_state FAR *state; /* not visible by applications */
96 
97  alloc_func zalloc; /* used to allocate the internal state */
98  free_func zfree; /* used to free the internal state */
99  voidpf opaque; /* private data object passed to zalloc and zfree */
100 
101  int data_type; /* best guess about the data type: binary or text */
102  uLong adler; /* adler32 value of the uncompressed data */
103  uLong reserved; /* reserved for future use */
104 } z_stream;
105 
107 
108 /*
109  gzip header information passed to and from zlib routines. See RFC 1952
110  for more details on the meanings of these fields.
111 */
112 typedef struct gz_header_s {
113  int text; /* true if compressed data believed to be text */
114  uLong time; /* modification time */
115  int xflags; /* extra flags (not used when writing a gzip file) */
116  int os; /* operating system */
117  Bytef *extra; /* pointer to extra field or Z_NULL if none */
118  uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
119  uInt extra_max; /* space at extra (only when reading header) */
120  Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
121  uInt name_max; /* space at name (only when reading header) */
122  Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
123  uInt comm_max; /* space at comment (only when reading header) */
124  int hcrc; /* true if there was or will be a header crc */
125  int done; /* true when done reading gzip header (not used
126  when writing a gzip file) */
127 } gz_header;
128 
130 
131 /*
132  The application must update next_in and avail_in when avail_in has dropped
133  to zero. It must update next_out and avail_out when avail_out has dropped
134  to zero. The application must initialize zalloc, zfree and opaque before
135  calling the init function. All other fields are set by the compression
136  library and must not be updated by the application.
137 
138  The opaque value provided by the application will be passed as the first
139  parameter for calls of zalloc and zfree. This can be useful for custom
140  memory management. The compression library attaches no meaning to the
141  opaque value.
142 
143  zalloc must return Z_NULL if there is not enough memory for the object.
144  If zlib is used in a multi-threaded application, zalloc and zfree must be
145  thread safe.
146 
147  On 16-bit systems, the functions zalloc and zfree must be able to allocate
148  exactly 65536 bytes, but will not be required to allocate more than this if
149  the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
150  returned by zalloc for objects of exactly 65536 bytes *must* have their
151  offset normalized to zero. The default allocation function provided by this
152  library ensures this (see zutil.c). To reduce memory requirements and avoid
153  any allocation of 64K objects, at the expense of compression ratio, compile
154  the library with -DMAX_WBITS=14 (see zconf.h).
155 
156  The fields total_in and total_out can be used for statistics or progress
157  reports. After compression, total_in holds the total size of the
158  uncompressed data and may be saved for use in the decompressor (particularly
159  if the decompressor wants to decompress everything in a single step).
160 */
161 
162  /* constants */
163 
164 #define Z_NO_FLUSH 0
165 #define Z_PARTIAL_FLUSH 1
166 #define Z_SYNC_FLUSH 2
167 #define Z_FULL_FLUSH 3
168 #define Z_FINISH 4
169 #define Z_BLOCK 5
170 #define Z_TREES 6
171 /* Allowed flush values; see deflate() and inflate() below for details */
172 
173 #define Z_OK 0
174 #define Z_STREAM_END 1
175 #define Z_NEED_DICT 2
176 #define Z_ERRNO (-1)
177 #define Z_STREAM_ERROR (-2)
178 #define Z_DATA_ERROR (-3)
179 #define Z_MEM_ERROR (-4)
180 #define Z_BUF_ERROR (-5)
181 #define Z_VERSION_ERROR (-6)
182 /* Return codes for the compression/decompression functions. Negative values
183  * are errors, positive values are used for special but normal events.
184  */
185 
186 #define Z_NO_COMPRESSION 0
187 #define Z_BEST_SPEED 1
188 #define Z_BEST_COMPRESSION 9
189 #define Z_DEFAULT_COMPRESSION (-1)
190 /* compression levels */
191 
192 #define Z_FILTERED 1
193 #define Z_HUFFMAN_ONLY 2
194 #define Z_RLE 3
195 #define Z_FIXED 4
196 #define Z_DEFAULT_STRATEGY 0
197 /* compression strategy; see deflateInit2() below for details */
198 
199 #define Z_BINARY 0
200 #define Z_TEXT 1
201 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
202 #define Z_UNKNOWN 2
203 /* Possible values of the data_type field (though see inflate()) */
204 
205 #define Z_DEFLATED 8
206 /* The deflate compression method (the only one supported in this version) */
207 
208 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
209 
210 #define zlib_version zlibVersion()
211 /* for compatibility with versions < 1.0.2 */
212 
213 
214  /* basic functions */
215 
216 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
217 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
218  If the first character differs, the library code actually used is not
219  compatible with the zlib.h header file used by the application. This check
220  is automatically made by deflateInit and inflateInit.
221  */
222 
223 /*
224 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
225 
226  Initializes the internal stream state for compression. The fields
227  zalloc, zfree and opaque must be initialized before by the caller. If
228  zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
229  allocation functions.
230 
231  The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
232  1 gives best speed, 9 gives best compression, 0 gives no compression at all
233  (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
234  requests a default compromise between speed and compression (currently
235  equivalent to level 6).
236 
237  deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
238  memory, Z_STREAM_ERROR if level is not a valid compression level, or
239  Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
240  with the version assumed by the caller (ZLIB_VERSION). msg is set to null
241  if there is no error message. deflateInit does not perform any compression:
242  this will be done by deflate().
243 */
244 
245 
246 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
247 /*
248  deflate compresses as much data as possible, and stops when the input
249  buffer becomes empty or the output buffer becomes full. It may introduce
250  some output latency (reading input without producing any output) except when
251  forced to flush.
252 
253  The detailed semantics are as follows. deflate performs one or both of the
254  following actions:
255 
256  - Compress more input starting at next_in and update next_in and avail_in
257  accordingly. If not all input can be processed (because there is not
258  enough room in the output buffer), next_in and avail_in are updated and
259  processing will resume at this point for the next call of deflate().
260 
261  - Provide more output starting at next_out and update next_out and avail_out
262  accordingly. This action is forced if the parameter flush is non zero.
263  Forcing flush frequently degrades the compression ratio, so this parameter
264  should be set only when necessary (in interactive applications). Some
265  output may be provided even if flush is not set.
266 
267  Before the call of deflate(), the application should ensure that at least
268  one of the actions is possible, by providing more input and/or consuming more
269  output, and updating avail_in or avail_out accordingly; avail_out should
270  never be zero before the call. The application can consume the compressed
271  output when it wants, for example when the output buffer is full (avail_out
272  == 0), or after each call of deflate(). If deflate returns Z_OK and with
273  zero avail_out, it must be called again after making room in the output
274  buffer because there might be more output pending.
275 
276  Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
277  decide how much data to accumulate before producing output, in order to
278  maximize compression.
279 
280  If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
281  flushed to the output buffer and the output is aligned on a byte boundary, so
282  that the decompressor can get all input data available so far. (In
283  particular avail_in is zero after the call if enough output space has been
284  provided before the call.) Flushing may degrade compression for some
285  compression algorithms and so it should be used only when necessary. This
286  completes the current deflate block and follows it with an empty stored block
287  that is three bits plus filler bits to the next byte, followed by four bytes
288  (00 00 ff ff).
289 
290  If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
291  output buffer, but the output is not aligned to a byte boundary. All of the
292  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
293  This completes the current deflate block and follows it with an empty fixed
294  codes block that is 10 bits long. This assures that enough bytes are output
295  in order for the decompressor to finish the block before the empty fixed code
296  block.
297 
298  If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
299  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
300  seven bits of the current block are held to be written as the next byte after
301  the next deflate block is completed. In this case, the decompressor may not
302  be provided enough bits at this point in order to complete decompression of
303  the data provided so far to the compressor. It may need to wait for the next
304  block to be emitted. This is for advanced applications that need to control
305  the emission of deflate blocks.
306 
307  If flush is set to Z_FULL_FLUSH, all output is flushed as with
308  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
309  restart from this point if previous compressed data has been damaged or if
310  random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
311  compression.
312 
313  If deflate returns with avail_out == 0, this function must be called again
314  with the same value of the flush parameter and more output space (updated
315  avail_out), until the flush is complete (deflate returns with non-zero
316  avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
317  avail_out is greater than six to avoid repeated flush markers due to
318  avail_out == 0 on return.
319 
320  If the parameter flush is set to Z_FINISH, pending input is processed,
321  pending output is flushed and deflate returns with Z_STREAM_END if there was
322  enough output space; if deflate returns with Z_OK, this function must be
323  called again with Z_FINISH and more output space (updated avail_out) but no
324  more input data, until it returns with Z_STREAM_END or an error. After
325  deflate has returned Z_STREAM_END, the only possible operations on the stream
326  are deflateReset or deflateEnd.
327 
328  Z_FINISH can be used immediately after deflateInit if all the compression
329  is to be done in a single step. In this case, avail_out must be at least the
330  value returned by deflateBound (see below). If deflate does not return
331  Z_STREAM_END, then it must be called again as described above.
332 
333  deflate() sets strm->adler to the adler32 checksum of all input read
334  so far (that is, total_in bytes).
335 
336  deflate() may update strm->data_type if it can make a good guess about
337  the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
338  binary. This field is only for information purposes and does not affect the
339  compression algorithm in any manner.
340 
341  deflate() returns Z_OK if some progress has been made (more input
342  processed or more output produced), Z_STREAM_END if all input has been
343  consumed and all output has been produced (only when flush is set to
344  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
345  if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
346  (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
347  fatal, and deflate() can be called again with more input and more output
348  space to continue compressing.
349 */
350 
351 
352 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
353 /*
354  All dynamically allocated data structures for this stream are freed.
355  This function discards any unprocessed input and does not flush any pending
356  output.
357 
358  deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
359  stream state was inconsistent, Z_DATA_ERROR if the stream was freed
360  prematurely (some input or output was discarded). In the error case, msg
361  may be set but then points to a static string (which must not be
362  deallocated).
363 */
364 
365 
366 /*
367 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
368 
369  Initializes the internal stream state for decompression. The fields
370  next_in, avail_in, zalloc, zfree and opaque must be initialized before by
371  the caller. If next_in is not Z_NULL and avail_in is large enough (the
372  exact value depends on the compression method), inflateInit determines the
373  compression method from the zlib header and allocates all data structures
374  accordingly; otherwise the allocation will be deferred to the first call of
375  inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
376  use default allocation functions.
377 
378  inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
379  memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
380  version assumed by the caller, or Z_STREAM_ERROR if the parameters are
381  invalid, such as a null pointer to the structure. msg is set to null if
382  there is no error message. inflateInit does not perform any decompression
383  apart from possibly reading the zlib header if present: actual decompression
384  will be done by inflate(). (So next_in and avail_in may be modified, but
385  next_out and avail_out are unused and unchanged.) The current implementation
386  of inflateInit() does not process any header information -- that is deferred
387  until inflate() is called.
388 */
389 
390 
391 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
392 /*
393  inflate decompresses as much data as possible, and stops when the input
394  buffer becomes empty or the output buffer becomes full. It may introduce
395  some output latency (reading input without producing any output) except when
396  forced to flush.
397 
398  The detailed semantics are as follows. inflate performs one or both of the
399  following actions:
400 
401  - Decompress more input starting at next_in and update next_in and avail_in
402  accordingly. If not all input can be processed (because there is not
403  enough room in the output buffer), next_in is updated and processing will
404  resume at this point for the next call of inflate().
405 
406  - Provide more output starting at next_out and update next_out and avail_out
407  accordingly. inflate() provides as much output as possible, until there is
408  no more input data or no more space in the output buffer (see below about
409  the flush parameter).
410 
411  Before the call of inflate(), the application should ensure that at least
412  one of the actions is possible, by providing more input and/or consuming more
413  output, and updating the next_* and avail_* values accordingly. The
414  application can consume the uncompressed output when it wants, for example
415  when the output buffer is full (avail_out == 0), or after each call of
416  inflate(). If inflate returns Z_OK and with zero avail_out, it must be
417  called again after making room in the output buffer because there might be
418  more output pending.
419 
420  The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
421  Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
422  output as possible to the output buffer. Z_BLOCK requests that inflate()
423  stop if and when it gets to the next deflate block boundary. When decoding
424  the zlib or gzip format, this will cause inflate() to return immediately
425  after the header and before the first block. When doing a raw inflate,
426  inflate() will go ahead and process the first block, and will return when it
427  gets to the end of that block, or when it runs out of data.
428 
429  The Z_BLOCK option assists in appending to or combining deflate streams.
430  Also to assist in this, on return inflate() will set strm->data_type to the
431  number of unused bits in the last byte taken from strm->next_in, plus 64 if
432  inflate() is currently decoding the last block in the deflate stream, plus
433  128 if inflate() returned immediately after decoding an end-of-block code or
434  decoding the complete header up to just before the first byte of the deflate
435  stream. The end-of-block will not be indicated until all of the uncompressed
436  data from that block has been written to strm->next_out. The number of
437  unused bits may in general be greater than seven, except when bit 7 of
438  data_type is set, in which case the number of unused bits will be less than
439  eight. data_type is set as noted here every time inflate() returns for all
440  flush options, and so can be used to determine the amount of currently
441  consumed input in bits.
442 
443  The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
444  end of each deflate block header is reached, before any actual data in that
445  block is decoded. This allows the caller to determine the length of the
446  deflate block header for later use in random access within a deflate block.
447  256 is added to the value of strm->data_type when inflate() returns
448  immediately after reaching the end of the deflate block header.
449 
450  inflate() should normally be called until it returns Z_STREAM_END or an
451  error. However if all decompression is to be performed in a single step (a
452  single call of inflate), the parameter flush should be set to Z_FINISH. In
453  this case all pending input is processed and all pending output is flushed;
454  avail_out must be large enough to hold all the uncompressed data. (The size
455  of the uncompressed data may have been saved by the compressor for this
456  purpose.) The next operation on this stream must be inflateEnd to deallocate
457  the decompression state. The use of Z_FINISH is never required, but can be
458  used to inform inflate that a faster approach may be used for the single
459  inflate() call.
460 
461  In this implementation, inflate() always flushes as much output as
462  possible to the output buffer, and always uses the faster approach on the
463  first call. So the only effect of the flush parameter in this implementation
464  is on the return value of inflate(), as noted below, or when it returns early
465  because Z_BLOCK or Z_TREES is used.
466 
467  If a preset dictionary is needed after this call (see inflateSetDictionary
468  below), inflate sets strm->adler to the adler32 checksum of the dictionary
469  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
470  strm->adler to the adler32 checksum of all output produced so far (that is,
471  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
472  below. At the end of the stream, inflate() checks that its computed adler32
473  checksum is equal to that saved by the compressor and returns Z_STREAM_END
474  only if the checksum is correct.
475 
476  inflate() can decompress and check either zlib-wrapped or gzip-wrapped
477  deflate data. The header type is detected automatically, if requested when
478  initializing with inflateInit2(). Any information contained in the gzip
479  header is not retained, so applications that need that information should
480  instead use raw inflate, see inflateInit2() below, or inflateBack() and
481  perform their own processing of the gzip header and trailer.
482 
483  inflate() returns Z_OK if some progress has been made (more input processed
484  or more output produced), Z_STREAM_END if the end of the compressed data has
485  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
486  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
487  corrupted (input stream not conforming to the zlib format or incorrect check
488  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
489  next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
490  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
491  output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
492  inflate() can be called again with more input and more output space to
493  continue decompressing. If Z_DATA_ERROR is returned, the application may
494  then call inflateSync() to look for a good compression block if a partial
495  recovery of the data is desired.
496 */
497 
498 
499 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
500 /*
501  All dynamically allocated data structures for this stream are freed.
502  This function discards any unprocessed input and does not flush any pending
503  output.
504 
505  inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
506  was inconsistent. In the error case, msg may be set but then points to a
507  static string (which must not be deallocated).
508 */
509 
510 
511  /* Advanced functions */
512 
513 /*
514  The following functions are needed only in some special applications.
515 */
516 
517 /*
518 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
519  int level,
520  int method,
521  int windowBits,
522  int memLevel,
523  int strategy));
524 
525  This is another version of deflateInit with more compression options. The
526  fields next_in, zalloc, zfree and opaque must be initialized before by the
527  caller.
528 
529  The method parameter is the compression method. It must be Z_DEFLATED in
530  this version of the library.
531 
532  The windowBits parameter is the base two logarithm of the window size
533  (the size of the history buffer). It should be in the range 8..15 for this
534  version of the library. Larger values of this parameter result in better
535  compression at the expense of memory usage. The default value is 15 if
536  deflateInit is used instead.
537 
538  windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
539  determines the window size. deflate() will then generate raw deflate data
540  with no zlib header or trailer, and will not compute an adler32 check value.
541 
542  windowBits can also be greater than 15 for optional gzip encoding. Add
543  16 to windowBits to write a simple gzip header and trailer around the
544  compressed data instead of a zlib wrapper. The gzip header will have no
545  file name, no extra data, no comment, no modification time (set to zero), no
546  header crc, and the operating system will be set to 255 (unknown). If a
547  gzip stream is being written, strm->adler is a crc32 instead of an adler32.
548 
549  The memLevel parameter specifies how much memory should be allocated
550  for the internal compression state. memLevel=1 uses minimum memory but is
551  slow and reduces compression ratio; memLevel=9 uses maximum memory for
552  optimal speed. The default value is 8. See zconf.h for total memory usage
553  as a function of windowBits and memLevel.
554 
555  The strategy parameter is used to tune the compression algorithm. Use the
556  value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
557  filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
558  string match), or Z_RLE to limit match distances to one (run-length
559  encoding). Filtered data consists mostly of small values with a somewhat
560  random distribution. In this case, the compression algorithm is tuned to
561  compress them better. The effect of Z_FILTERED is to force more Huffman
562  coding and less string matching; it is somewhat intermediate between
563  Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
564  fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
565  strategy parameter only affects the compression ratio but not the
566  correctness of the compressed output even if it is not set appropriately.
567  Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
568  decoder for special applications.
569 
570  deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
571  memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
572  method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
573  incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
574  set to null if there is no error message. deflateInit2 does not perform any
575  compression: this will be done by deflate().
576 */
577 
578 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
579  const Bytef *dictionary,
580  uInt dictLength));
581 /*
582  Initializes the compression dictionary from the given byte sequence
583  without producing any compressed output. This function must be called
584  immediately after deflateInit, deflateInit2 or deflateReset, before any call
585  of deflate. The compressor and decompressor must use exactly the same
586  dictionary (see inflateSetDictionary).
587 
588  The dictionary should consist of strings (byte sequences) that are likely
589  to be encountered later in the data to be compressed, with the most commonly
590  used strings preferably put towards the end of the dictionary. Using a
591  dictionary is most useful when the data to be compressed is short and can be
592  predicted with good accuracy; the data can then be compressed better than
593  with the default empty dictionary.
594 
595  Depending on the size of the compression data structures selected by
596  deflateInit or deflateInit2, a part of the dictionary may in effect be
597  discarded, for example if the dictionary is larger than the window size
598  provided in deflateInit or deflateInit2. Thus the strings most likely to be
599  useful should be put at the end of the dictionary, not at the front. In
600  addition, the current implementation of deflate will use at most the window
601  size minus 262 bytes of the provided dictionary.
602 
603  Upon return of this function, strm->adler is set to the adler32 value
604  of the dictionary; the decompressor may later use this value to determine
605  which dictionary has been used by the compressor. (The adler32 value
606  applies to the whole dictionary even if only a subset of the dictionary is
607  actually used by the compressor.) If a raw deflate was requested, then the
608  adler32 value is not computed and strm->adler is not set.
609 
610  deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
611  parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
612  inconsistent (for example if deflate has already been called for this stream
613  or if the compression method is bsort). deflateSetDictionary does not
614  perform any compression: this will be done by deflate().
615 */
616 
617 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
618  z_streamp source));
619 /*
620  Sets the destination stream as a complete copy of the source stream.
621 
622  This function can be useful when several compression strategies will be
623  tried, for example when there are several ways of pre-processing the input
624  data with a filter. The streams that will be discarded should then be freed
625  by calling deflateEnd. Note that deflateCopy duplicates the internal
626  compression state which can be quite large, so this strategy is slow and can
627  consume lots of memory.
628 
629  deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
630  enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
631  (such as zalloc being Z_NULL). msg is left unchanged in both source and
632  destination.
633 */
634 
635 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
636 /*
637  This function is equivalent to deflateEnd followed by deflateInit,
638  but does not free and reallocate all the internal compression state. The
639  stream will keep the same compression level and any other attributes that
640  may have been set by deflateInit2.
641 
642  deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
643  stream state was inconsistent (such as zalloc or state being Z_NULL).
644 */
645 
646 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
647  int level,
648  int strategy));
649 /*
650  Dynamically update the compression level and compression strategy. The
651  interpretation of level and strategy is as in deflateInit2. This can be
652  used to switch between compression and straight copy of the input data, or
653  to switch to a different kind of input data requiring a different strategy.
654  If the compression level is changed, the input available so far is
655  compressed with the old level (and may be flushed); the new level will take
656  effect only at the next call of deflate().
657 
658  Before the call of deflateParams, the stream state must be set as for
659  a call of deflate(), since the currently available input may have to be
660  compressed and flushed. In particular, strm->avail_out must be non-zero.
661 
662  deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
663  stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
664  strm->avail_out was zero.
665 */
666 
667 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
668  int good_length,
669  int max_lazy,
670  int nice_length,
671  int max_chain));
672 /*
673  Fine tune deflate's internal compression parameters. This should only be
674  used by someone who understands the algorithm used by zlib's deflate for
675  searching for the best matching string, and even then only by the most
676  fanatic optimizer trying to squeeze out the last compressed bit for their
677  specific input data. Read the deflate.c source code for the meaning of the
678  max_lazy, good_length, nice_length, and max_chain parameters.
679 
680  deflateTune() can be called after deflateInit() or deflateInit2(), and
681  returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
682  */
683 
684 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
685  uLong sourceLen));
686 /*
687  deflateBound() returns an upper bound on the compressed size after
688  deflation of sourceLen bytes. It must be called after deflateInit() or
689  deflateInit2(), and after deflateSetHeader(), if used. This would be used
690  to allocate an output buffer for deflation in a single pass, and so would be
691  called before deflate().
692 */
693 
694 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
695  int bits,
696  int value));
697 /*
698  deflatePrime() inserts bits in the deflate output stream. The intent
699  is that this function is used to start off the deflate output with the bits
700  leftover from a previous deflate stream when appending to it. As such, this
701  function can only be used for raw deflate, and must be used before the first
702  deflate() call after a deflateInit2() or deflateReset(). bits must be less
703  than or equal to 16, and that many of the least significant bits of value
704  will be inserted in the output.
705 
706  deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
707  stream state was inconsistent.
708 */
709 
710 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
711  gz_headerp head));
712 /*
713  deflateSetHeader() provides gzip header information for when a gzip
714  stream is requested by deflateInit2(). deflateSetHeader() may be called
715  after deflateInit2() or deflateReset() and before the first call of
716  deflate(). The text, time, os, extra field, name, and comment information
717  in the provided gz_header structure are written to the gzip header (xflag is
718  ignored -- the extra flags are set according to the compression level). The
719  caller must assure that, if not Z_NULL, name and comment are terminated with
720  a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
721  available there. If hcrc is true, a gzip header crc is included. Note that
722  the current versions of the command-line version of gzip (up through version
723  1.3.x) do not support header crc's, and will report that it is a "multi-part
724  gzip file" and give up.
725 
726  If deflateSetHeader is not used, the default gzip header has text false,
727  the time set to zero, and os set to 255, with no extra, name, or comment
728  fields. The gzip header is returned to the default state by deflateReset().
729 
730  deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
731  stream state was inconsistent.
732 */
733 
734 /*
735 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
736  int windowBits));
737 
738  This is another version of inflateInit with an extra parameter. The
739  fields next_in, avail_in, zalloc, zfree and opaque must be initialized
740  before by the caller.
741 
742  The windowBits parameter is the base two logarithm of the maximum window
743  size (the size of the history buffer). It should be in the range 8..15 for
744  this version of the library. The default value is 15 if inflateInit is used
745  instead. windowBits must be greater than or equal to the windowBits value
746  provided to deflateInit2() while compressing, or it must be equal to 15 if
747  deflateInit2() was not used. If a compressed stream with a larger window
748  size is given as input, inflate() will return with the error code
749  Z_DATA_ERROR instead of trying to allocate a larger window.
750 
751  windowBits can also be zero to request that inflate use the window size in
752  the zlib header of the compressed stream.
753 
754  windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
755  determines the window size. inflate() will then process raw deflate data,
756  not looking for a zlib or gzip header, not generating a check value, and not
757  looking for any check values for comparison at the end of the stream. This
758  is for use with other formats that use the deflate compressed data format
759  such as zip. Those formats provide their own check values. If a custom
760  format is developed using the raw deflate format for compressed data, it is
761  recommended that a check value such as an adler32 or a crc32 be applied to
762  the uncompressed data as is done in the zlib, gzip, and zip formats. For
763  most applications, the zlib format should be used as is. Note that comments
764  above on the use in deflateInit2() applies to the magnitude of windowBits.
765 
766  windowBits can also be greater than 15 for optional gzip decoding. Add
767  32 to windowBits to enable zlib and gzip decoding with automatic header
768  detection, or add 16 to decode only the gzip format (the zlib format will
769  return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
770  crc32 instead of an adler32.
771 
772  inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
773  memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
774  version assumed by the caller, or Z_STREAM_ERROR if the parameters are
775  invalid, such as a null pointer to the structure. msg is set to null if
776  there is no error message. inflateInit2 does not perform any decompression
777  apart from possibly reading the zlib header if present: actual decompression
778  will be done by inflate(). (So next_in and avail_in may be modified, but
779  next_out and avail_out are unused and unchanged.) The current implementation
780  of inflateInit2() does not process any header information -- that is
781  deferred until inflate() is called.
782 */
783 
784 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
785  const Bytef *dictionary,
786  uInt dictLength));
787 /*
788  Initializes the decompression dictionary from the given uncompressed byte
789  sequence. This function must be called immediately after a call of inflate,
790  if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
791  can be determined from the adler32 value returned by that call of inflate.
792  The compressor and decompressor must use exactly the same dictionary (see
793  deflateSetDictionary). For raw inflate, this function can be called
794  immediately after inflateInit2() or inflateReset() and before any call of
795  inflate() to set the dictionary. The application must insure that the
796  dictionary that was used for compression is provided.
797 
798  inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
799  parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
800  inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
801  expected one (incorrect adler32 value). inflateSetDictionary does not
802  perform any decompression: this will be done by subsequent calls of
803  inflate().
804 */
805 
806 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
807 /*
808  Skips invalid compressed data until a full flush point (see above the
809  description of deflate with Z_FULL_FLUSH) can be found, or until all
810  available input is skipped. No output is provided.
811 
812  inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
813  if no more input was provided, Z_DATA_ERROR if no flush point has been
814  found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the
815  success case, the application may save the current current value of total_in
816  which indicates where valid compressed data was found. In the error case,
817  the application may repeatedly call inflateSync, providing more input each
818  time, until success or end of the input data.
819 */
820 
821 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
822  z_streamp source));
823 /*
824  Sets the destination stream as a complete copy of the source stream.
825 
826  This function can be useful when randomly accessing a large stream. The
827  first pass through the stream can periodically record the inflate state,
828  allowing restarting inflate at those points when randomly accessing the
829  stream.
830 
831  inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
832  enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
833  (such as zalloc being Z_NULL). msg is left unchanged in both source and
834  destination.
835 */
836 
837 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
838 /*
839  This function is equivalent to inflateEnd followed by inflateInit,
840  but does not free and reallocate all the internal decompression state. The
841  stream will keep attributes that may have been set by inflateInit2.
842 
843  inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
844  stream state was inconsistent (such as zalloc or state being Z_NULL).
845 */
846 
847 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
848  int windowBits));
849 /*
850  This function is the same as inflateReset, but it also permits changing
851  the wrap and window size requests. The windowBits parameter is interpreted
852  the same as it is for inflateInit2.
853 
854  inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
855  stream state was inconsistent (such as zalloc or state being Z_NULL), or if
856  the windowBits parameter is invalid.
857 */
858 
859 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
860  int bits,
861  int value));
862 /*
863  This function inserts bits in the inflate input stream. The intent is
864  that this function is used to start inflating at a bit position in the
865  middle of a byte. The provided bits will be used before any bytes are used
866  from next_in. This function should only be used with raw inflate, and
867  should be used before the first inflate() call after inflateInit2() or
868  inflateReset(). bits must be less than or equal to 16, and that many of the
869  least significant bits of value will be inserted in the input.
870 
871  If bits is negative, then the input stream bit buffer is emptied. Then
872  inflatePrime() can be called again to put bits in the buffer. This is used
873  to clear out bits leftover after feeding inflate a block description prior
874  to feeding inflate codes.
875 
876  inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
877  stream state was inconsistent.
878 */
879 
880 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
881 /*
882  This function returns two values, one in the lower 16 bits of the return
883  value, and the other in the remaining upper bits, obtained by shifting the
884  return value down 16 bits. If the upper value is -1 and the lower value is
885  zero, then inflate() is currently decoding information outside of a block.
886  If the upper value is -1 and the lower value is non-zero, then inflate is in
887  the middle of a stored block, with the lower value equaling the number of
888  bytes from the input remaining to copy. If the upper value is not -1, then
889  it is the number of bits back from the current bit position in the input of
890  the code (literal or length/distance pair) currently being processed. In
891  that case the lower value is the number of bytes already emitted for that
892  code.
893 
894  A code is being processed if inflate is waiting for more input to complete
895  decoding of the code, or if it has completed decoding but is waiting for
896  more output space to write the literal or match data.
897 
898  inflateMark() is used to mark locations in the input data for random
899  access, which may be at bit positions, and to note those cases where the
900  output of a code may span boundaries of random access blocks. The current
901  location in the input stream can be determined from avail_in and data_type
902  as noted in the description for the Z_BLOCK flush parameter for inflate.
903 
904  inflateMark returns the value noted above or -1 << 16 if the provided
905  source stream state was inconsistent.
906 */
907 
908 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
909  gz_headerp head));
910 /*
911  inflateGetHeader() requests that gzip header information be stored in the
912  provided gz_header structure. inflateGetHeader() may be called after
913  inflateInit2() or inflateReset(), and before the first call of inflate().
914  As inflate() processes the gzip stream, head->done is zero until the header
915  is completed, at which time head->done is set to one. If a zlib stream is
916  being decoded, then head->done is set to -1 to indicate that there will be
917  no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
918  used to force inflate() to return immediately after header processing is
919  complete and before any actual data is decompressed.
920 
921  The text, time, xflags, and os fields are filled in with the gzip header
922  contents. hcrc is set to true if there is a header CRC. (The header CRC
923  was valid if done is set to one.) If extra is not Z_NULL, then extra_max
924  contains the maximum number of bytes to write to extra. Once done is true,
925  extra_len contains the actual extra field length, and extra contains the
926  extra field, or that field truncated if extra_max is less than extra_len.
927  If name is not Z_NULL, then up to name_max characters are written there,
928  terminated with a zero unless the length is greater than name_max. If
929  comment is not Z_NULL, then up to comm_max characters are written there,
930  terminated with a zero unless the length is greater than comm_max. When any
931  of extra, name, or comment are not Z_NULL and the respective field is not
932  present in the header, then that field is set to Z_NULL to signal its
933  absence. This allows the use of deflateSetHeader() with the returned
934  structure to duplicate the header. However if those fields are set to
935  allocated memory, then the application will need to save those pointers
936  elsewhere so that they can be eventually freed.
937 
938  If inflateGetHeader is not used, then the header information is simply
939  discarded. The header is always checked for validity, including the header
940  CRC if present. inflateReset() will reset the process to discard the header
941  information. The application would need to call inflateGetHeader() again to
942  retrieve the header from the next gzip stream.
943 
944  inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
945  stream state was inconsistent.
946 */
947 
948 /*
949 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
950  unsigned char FAR *window));
951 
952  Initialize the internal stream state for decompression using inflateBack()
953  calls. The fields zalloc, zfree and opaque in strm must be initialized
954  before the call. If zalloc and zfree are Z_NULL, then the default library-
955  derived memory allocation routines are used. windowBits is the base two
956  logarithm of the window size, in the range 8..15. window is a caller
957  supplied buffer of that size. Except for special applications where it is
958  assured that deflate was used with small window sizes, windowBits must be 15
959  and a 32K byte window must be supplied to be able to decompress general
960  deflate streams.
961 
962  See inflateBack() for the usage of these routines.
963 
964  inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
965  the paramaters are invalid, Z_MEM_ERROR if the internal state could not be
966  allocated, or Z_VERSION_ERROR if the version of the library does not match
967  the version of the header file.
968 */
969 
970 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
971 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
972 
973 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
974  in_func in, void FAR *in_desc,
975  out_func out, void FAR *out_desc));
976 /*
977  inflateBack() does a raw inflate with a single call using a call-back
978  interface for input and output. This is more efficient than inflate() for
979  file i/o applications in that it avoids copying between the output and the
980  sliding window by simply making the window itself the output buffer. This
981  function trusts the application to not change the output buffer passed by
982  the output function, at least until inflateBack() returns.
983 
984  inflateBackInit() must be called first to allocate the internal state
985  and to initialize the state with the user-provided window buffer.
986  inflateBack() may then be used multiple times to inflate a complete, raw
987  deflate stream with each call. inflateBackEnd() is then called to free the
988  allocated state.
989 
990  A raw deflate stream is one with no zlib or gzip header or trailer.
991  This routine would normally be used in a utility that reads zip or gzip
992  files and writes out uncompressed files. The utility would decode the
993  header and process the trailer on its own, hence this routine expects only
994  the raw deflate stream to decompress. This is different from the normal
995  behavior of inflate(), which expects either a zlib or gzip header and
996  trailer around the deflate stream.
997 
998  inflateBack() uses two subroutines supplied by the caller that are then
999  called by inflateBack() for input and output. inflateBack() calls those
1000  routines until it reads a complete deflate stream and writes out all of the
1001  uncompressed data, or until it encounters an error. The function's
1002  parameters and return types are defined above in the in_func and out_func
1003  typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1004  number of bytes of provided input, and a pointer to that input in buf. If
1005  there is no input available, in() must return zero--buf is ignored in that
1006  case--and inflateBack() will return a buffer error. inflateBack() will call
1007  out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
1008  should return zero on success, or non-zero on failure. If out() returns
1009  non-zero, inflateBack() will return with an error. Neither in() nor out()
1010  are permitted to change the contents of the window provided to
1011  inflateBackInit(), which is also the buffer that out() uses to write from.
1012  The length written by out() will be at most the window size. Any non-zero
1013  amount of input may be provided by in().
1014 
1015  For convenience, inflateBack() can be provided input on the first call by
1016  setting strm->next_in and strm->avail_in. If that input is exhausted, then
1017  in() will be called. Therefore strm->next_in must be initialized before
1018  calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1019  immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1020  must also be initialized, and then if strm->avail_in is not zero, input will
1021  initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1022 
1023  The in_desc and out_desc parameters of inflateBack() is passed as the
1024  first parameter of in() and out() respectively when they are called. These
1025  descriptors can be optionally used to pass any information that the caller-
1026  supplied in() and out() functions need to do their job.
1027 
1028  On return, inflateBack() will set strm->next_in and strm->avail_in to
1029  pass back any unused input that was provided by the last in() call. The
1030  return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1031  if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1032  in the deflate stream (in which case strm->msg is set to indicate the nature
1033  of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1034  In the case of Z_BUF_ERROR, an input or output error can be distinguished
1035  using strm->next_in which will be Z_NULL only if in() returned an error. If
1036  strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1037  non-zero. (in() will always be called before out(), so strm->next_in is
1038  assured to be defined if out() returns non-zero.) Note that inflateBack()
1039  cannot return Z_OK.
1040 */
1041 
1042 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1043 /*
1044  All memory allocated by inflateBackInit() is freed.
1045 
1046  inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1047  state was inconsistent.
1048 */
1049 
1051 /* Return flags indicating compile-time options.
1052 
1053  Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1054  1.0: size of uInt
1055  3.2: size of uLong
1056  5.4: size of voidpf (pointer)
1057  7.6: size of z_off_t
1058 
1059  Compiler, assembler, and debug options:
1060  8: DEBUG
1061  9: ASMV or ASMINF -- use ASM code
1062  10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1063  11: 0 (reserved)
1064 
1065  One-time table building (smaller code, but not thread-safe if true):
1066  12: BUILDFIXED -- build static block decoding tables when needed
1067  13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1068  14,15: 0 (reserved)
1069 
1070  Library content (indicates missing functionality):
1071  16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1072  deflate code when not needed)
1073  17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1074  and decode gzip streams (to avoid linking crc code)
1075  18-19: 0 (reserved)
1076 
1077  Operation variations (changes in library functionality):
1078  20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1079  21: FASTEST -- deflate algorithm with only one, lowest compression level
1080  22,23: 0 (reserved)
1081 
1082  The sprintf variant used by gzprintf (zero is best):
1083  24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1084  25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1085  26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1086 
1087  Remainder:
1088  27-31: 0 (reserved)
1089  */
1090 
1091 
1092  /* utility functions */
1093 
1094 /*
1095  The following utility functions are implemented on top of the basic
1096  stream-oriented functions. To simplify the interface, some default options
1097  are assumed (compression level and memory usage, standard memory allocation
1098  functions). The source code of these utility functions can be modified if
1099  you need special options.
1100 */
1101 
1102 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1103  const Bytef *source, uLong sourceLen));
1104 /*
1105  Compresses the source buffer into the destination buffer. sourceLen is
1106  the byte length of the source buffer. Upon entry, destLen is the total size
1107  of the destination buffer, which must be at least the value returned by
1108  compressBound(sourceLen). Upon exit, destLen is the actual size of the
1109  compressed buffer.
1110 
1111  compress returns Z_OK if success, Z_MEM_ERROR if there was not
1112  enough memory, Z_BUF_ERROR if there was not enough room in the output
1113  buffer.
1114 */
1115 
1116 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1117  const Bytef *source, uLong sourceLen,
1118  int level));
1119 /*
1120  Compresses the source buffer into the destination buffer. The level
1121  parameter has the same meaning as in deflateInit. sourceLen is the byte
1122  length of the source buffer. Upon entry, destLen is the total size of the
1123  destination buffer, which must be at least the value returned by
1124  compressBound(sourceLen). Upon exit, destLen is the actual size of the
1125  compressed buffer.
1126 
1127  compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1128  memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1129  Z_STREAM_ERROR if the level parameter is invalid.
1130 */
1131 
1132 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1133 /*
1134  compressBound() returns an upper bound on the compressed size after
1135  compress() or compress2() on sourceLen bytes. It would be used before a
1136  compress() or compress2() call to allocate the destination buffer.
1137 */
1138 
1139 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1140  const Bytef *source, uLong sourceLen));
1141 /*
1142  Decompresses the source buffer into the destination buffer. sourceLen is
1143  the byte length of the source buffer. Upon entry, destLen is the total size
1144  of the destination buffer, which must be large enough to hold the entire
1145  uncompressed data. (The size of the uncompressed data must have been saved
1146  previously by the compressor and transmitted to the decompressor by some
1147  mechanism outside the scope of this compression library.) Upon exit, destLen
1148  is the actual size of the uncompressed buffer.
1149 
1150  uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1151  enough memory, Z_BUF_ERROR if there was not enough room in the output
1152  buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
1153 */
1154 
1155 
1156  /* gzip file access functions */
1157 
1158 /*
1159  This library supports reading and writing files in gzip (.gz) format with
1160  an interface similar to that of stdio, using the functions that start with
1161  "gz". The gzip format is different from the zlib format. gzip is a gzip
1162  wrapper, documented in RFC 1952, wrapped around a deflate stream.
1163 */
1164 
1165 typedef voidp gzFile; /* opaque gzip file descriptor */
1166 
1167 /*
1168 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1169 
1170  Opens a gzip (.gz) file for reading or writing. The mode parameter is as
1171  in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1172  a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1173  compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1174  for fixed code compression as in "wb9F". (See the description of
1175  deflateInit2 for more information about the strategy parameter.) Also "a"
1176  can be used instead of "w" to request that the gzip stream that will be
1177  written be appended to the file. "+" will result in an error, since reading
1178  and writing to the same gzip file is not supported.
1179 
1180  gzopen can be used to read a file which is not in gzip format; in this
1181  case gzread will directly read from the file without decompression.
1182 
1183  gzopen returns NULL if the file could not be opened, if there was
1184  insufficient memory to allocate the gzFile state, or if an invalid mode was
1185  specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1186  errno can be checked to determine if the reason gzopen failed was that the
1187  file could not be opened.
1188 */
1189 
1190 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1191 /*
1192  gzdopen associates a gzFile with the file descriptor fd. File descriptors
1193  are obtained from calls like open, dup, creat, pipe or fileno (if the file
1194  has been previously opened with fopen). The mode parameter is as in gzopen.
1195 
1196  The next call of gzclose on the returned gzFile will also close the file
1197  descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1198  fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1199  mode);. The duplicated descriptor should be saved to avoid a leak, since
1200  gzdopen does not close fd if it fails.
1201 
1202  gzdopen returns NULL if there was insufficient memory to allocate the
1203  gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1204  provided, or '+' was provided), or if fd is -1. The file descriptor is not
1205  used until the next gz* read, write, seek, or close operation, so gzdopen
1206  will not detect if fd is invalid (unless fd is -1).
1207 */
1208 
1209 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1210 /*
1211  Set the internal buffer size used by this library's functions. The
1212  default buffer size is 8192 bytes. This function must be called after
1213  gzopen() or gzdopen(), and before any other calls that read or write the
1214  file. The buffer memory allocation is always deferred to the first read or
1215  write. Two buffers are allocated, either both of the specified size when
1216  writing, or one of the specified size and the other twice that size when
1217  reading. A larger buffer size of, for example, 64K or 128K bytes will
1218  noticeably increase the speed of decompression (reading).
1219 
1220  The new buffer size also affects the maximum length for gzprintf().
1221 
1222  gzbuffer() returns 0 on success, or -1 on failure, such as being called
1223  too late.
1224 */
1225 
1226 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1227 /*
1228  Dynamically update the compression level or strategy. See the description
1229  of deflateInit2 for the meaning of these parameters.
1230 
1231  gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1232  opened for writing.
1233 */
1234 
1235 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1236 /*
1237  Reads the given number of uncompressed bytes from the compressed file. If
1238  the input file was not in gzip format, gzread copies the given number of
1239  bytes into the buffer.
1240 
1241  After reaching the end of a gzip stream in the input, gzread will continue
1242  to read, looking for another gzip stream, or failing that, reading the rest
1243  of the input file directly without decompression. The entire input file
1244  will be read if gzread is called until it returns less than the requested
1245  len.
1246 
1247  gzread returns the number of uncompressed bytes actually read, less than
1248  len for end of file, or -1 for error.
1249 */
1250 
1251 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1252  voidpc buf, unsigned len));
1253 /*
1254  Writes the given number of uncompressed bytes into the compressed file.
1255  gzwrite returns the number of uncompressed bytes written or 0 in case of
1256  error.
1257 */
1258 
1259 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
1260 /*
1261  Converts, formats, and writes the arguments to the compressed file under
1262  control of the format string, as in fprintf. gzprintf returns the number of
1263  uncompressed bytes actually written, or 0 in case of error. The number of
1264  uncompressed bytes written is limited to 8191, or one less than the buffer
1265  size given to gzbuffer(). The caller should assure that this limit is not
1266  exceeded. If it is exceeded, then gzprintf() will return an error (0) with
1267  nothing written. In this case, there may also be a buffer overflow with
1268  unpredictable consequences, which is possible only if zlib was compiled with
1269  the insecure functions sprintf() or vsprintf() because the secure snprintf()
1270  or vsnprintf() functions were not available. This can be determined using
1271  zlibCompileFlags().
1272 */
1273 
1274 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1275 /*
1276  Writes the given null-terminated string to the compressed file, excluding
1277  the terminating null character.
1278 
1279  gzputs returns the number of characters written, or -1 in case of error.
1280 */
1281 
1282 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1283 /*
1284  Reads bytes from the compressed file until len-1 characters are read, or a
1285  newline character is read and transferred to buf, or an end-of-file
1286  condition is encountered. If any characters are read or if len == 1, the
1287  string is terminated with a null character. If no characters are read due
1288  to an end-of-file or len < 1, then the buffer is left untouched.
1289 
1290  gzgets returns buf which is a null-terminated string, or it returns NULL
1291  for end-of-file or in case of error. If there was an error, the contents at
1292  buf are indeterminate.
1293 */
1294 
1295 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1296 /*
1297  Writes c, converted to an unsigned char, into the compressed file. gzputc
1298  returns the value that was written, or -1 in case of error.
1299 */
1300 
1301 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1302 /*
1303  Reads one byte from the compressed file. gzgetc returns this byte or -1
1304  in case of end of file or error.
1305 */
1306 
1307 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1308 /*
1309  Push one character back onto the stream to be read as the first character
1310  on the next read. At least one character of push-back is allowed.
1311  gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1312  fail if c is -1, and may fail if a character has been pushed but not read
1313  yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1314  output buffer size of pushed characters is allowed. (See gzbuffer above.)
1315  The pushed character will be discarded if the stream is repositioned with
1316  gzseek() or gzrewind().
1317 */
1318 
1319 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1320 /*
1321  Flushes all pending output into the compressed file. The parameter flush
1322  is as in the deflate() function. The return value is the zlib error number
1323  (see function gzerror below). gzflush is only permitted when writing.
1324 
1325  If the flush parameter is Z_FINISH, the remaining data is written and the
1326  gzip stream is completed in the output. If gzwrite() is called again, a new
1327  gzip stream will be started in the output. gzread() is able to read such
1328  concatented gzip streams.
1329 
1330  gzflush should be called only when strictly necessary because it will
1331  degrade compression if called too often.
1332 */
1333 
1334 /*
1335 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1336  z_off_t offset, int whence));
1337 
1338  Sets the starting position for the next gzread or gzwrite on the given
1339  compressed file. The offset represents a number of bytes in the
1340  uncompressed data stream. The whence parameter is defined as in lseek(2);
1341  the value SEEK_END is not supported.
1342 
1343  If the file is opened for reading, this function is emulated but can be
1344  extremely slow. If the file is opened for writing, only forward seeks are
1345  supported; gzseek then compresses a sequence of zeroes up to the new
1346  starting position.
1347 
1348  gzseek returns the resulting offset location as measured in bytes from
1349  the beginning of the uncompressed stream, or -1 in case of error, in
1350  particular if the file is opened for writing and the new starting position
1351  would be before the current position.
1352 */
1353 
1354 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1355 /*
1356  Rewinds the given file. This function is supported only for reading.
1357 
1358  gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1359 */
1360 
1361 /*
1362 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1363 
1364  Returns the starting position for the next gzread or gzwrite on the given
1365  compressed file. This position represents a number of bytes in the
1366  uncompressed data stream, and is zero when starting, even if appending or
1367  reading a gzip stream from the middle of a file using gzdopen().
1368 
1369  gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1370 */
1371 
1372 /*
1373 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1374 
1375  Returns the current offset in the file being read or written. This offset
1376  includes the count of bytes that precede the gzip stream, for example when
1377  appending or when using gzdopen() for reading. When reading, the offset
1378  does not include as yet unused buffered input. This information can be used
1379  for a progress indicator. On error, gzoffset() returns -1.
1380 */
1381 
1382 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1383 /*
1384  Returns true (1) if the end-of-file indicator has been set while reading,
1385  false (0) otherwise. Note that the end-of-file indicator is set only if the
1386  read tried to go past the end of the input, but came up short. Therefore,
1387  just like feof(), gzeof() may return false even if there is no more data to
1388  read, in the event that the last read request was for the exact number of
1389  bytes remaining in the input file. This will happen if the input file size
1390  is an exact multiple of the buffer size.
1391 
1392  If gzeof() returns true, then the read functions will return no more data,
1393  unless the end-of-file indicator is reset by gzclearerr() and the input file
1394  has grown since the previous end of file was detected.
1395 */
1396 
1397 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1398 /*
1399  Returns true (1) if file is being copied directly while reading, or false
1400  (0) if file is a gzip stream being decompressed. This state can change from
1401  false to true while reading the input file if the end of a gzip stream is
1402  reached, but is followed by data that is not another gzip stream.
1403 
1404  If the input file is empty, gzdirect() will return true, since the input
1405  does not contain a gzip stream.
1406 
1407  If gzdirect() is used immediately after gzopen() or gzdopen() it will
1408  cause buffers to be allocated to allow reading the file to determine if it
1409  is a gzip file. Therefore if gzbuffer() is used, it should be called before
1410  gzdirect().
1411 */
1412 
1413 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1414 /*
1415  Flushes all pending output if necessary, closes the compressed file and
1416  deallocates the (de)compression state. Note that once file is closed, you
1417  cannot call gzerror with file, since its structures have been deallocated.
1418  gzclose must not be called more than once on the same file, just as free
1419  must not be called more than once on the same allocation.
1420 
1421  gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1422  file operation error, or Z_OK on success.
1423 */
1424 
1425 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1426 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1427 /*
1428  Same as gzclose(), but gzclose_r() is only for use when reading, and
1429  gzclose_w() is only for use when writing or appending. The advantage to
1430  using these instead of gzclose() is that they avoid linking in zlib
1431  compression or decompression code that is not used when only reading or only
1432  writing respectively. If gzclose() is used, then both compression and
1433  decompression code will be included the application when linking to a static
1434  zlib library.
1435 */
1436 
1437 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1438 /*
1439  Returns the error message for the last error which occurred on the given
1440  compressed file. errnum is set to zlib error number. If an error occurred
1441  in the file system and not in the compression library, errnum is set to
1442  Z_ERRNO and the application may consult errno to get the exact error code.
1443 
1444  The application must not modify the returned string. Future calls to
1445  this function may invalidate the previously returned string. If file is
1446  closed, then the string previously returned by gzerror will no longer be
1447  available.
1448 
1449  gzerror() should be used to distinguish errors from end-of-file for those
1450  functions above that do not distinguish those cases in their return values.
1451 */
1452 
1453 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1454 /*
1455  Clears the error and end-of-file flags for file. This is analogous to the
1456  clearerr() function in stdio. This is useful for continuing to read a gzip
1457  file that is being written concurrently.
1458 */
1459 
1460 
1461  /* checksum functions */
1462 
1463 /*
1464  These functions are not related to compression but are exported
1465  anyway because they might be useful in applications using the compression
1466  library.
1467 */
1468 
1469 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1470 /*
1471  Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1472  return the updated checksum. If buf is Z_NULL, this function returns the
1473  required initial value for the checksum.
1474 
1475  An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1476  much faster.
1477 
1478  Usage example:
1479 
1480  uLong adler = adler32(0L, Z_NULL, 0);
1481 
1482  while (read_buffer(buffer, length) != EOF) {
1483  adler = adler32(adler, buffer, length);
1484  }
1485  if (adler != original_adler) error();
1486 */
1487 
1488 /*
1489 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1490  z_off_t len2));
1491 
1492  Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1493  and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1494  each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1495  seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
1496 */
1497 
1499 /*
1500  Update a running CRC-32 with the bytes buf[0..len-1] and return the
1501  updated CRC-32. If buf is Z_NULL, this function returns the required
1502  initial value for the for the crc. Pre- and post-conditioning (one's
1503  complement) is performed within this function so it shouldn't be done by the
1504  application.
1505 
1506  Usage example:
1507 
1508  uLong crc = crc32(0L, Z_NULL, 0);
1509 
1510  while (read_buffer(buffer, length) != EOF) {
1511  crc = crc32(crc, buffer, length);
1512  }
1513  if (crc != original_crc) error();
1514 */
1515 
1516 /*
1517 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1518 
1519  Combine two CRC-32 check values into one. For two sequences of bytes,
1520  seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1521  calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1522  check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1523  len2.
1524 */
1525 
1526 
1527  /* various hacks, don't look :) */
1528 
1529 /* deflateInit and inflateInit are macros to allow checking the zlib version
1530  * and the compiler's view of z_stream:
1531  */
1532 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1533  const char *version, int stream_size));
1534 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1535  const char *version, int stream_size));
1536 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1537  int windowBits, int memLevel,
1538  int strategy, const char *version,
1539  int stream_size));
1540 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1541  const char *version, int stream_size));
1542 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1543  unsigned char FAR *window,
1544  const char *version,
1545  int stream_size));
1546 #define deflateInit(strm, level) \
1547  deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1548 #define inflateInit(strm) \
1549  inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1550 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1551  deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1552  (strategy), ZLIB_VERSION, sizeof(z_stream))
1553 #define inflateInit2(strm, windowBits) \
1554  inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1555 #define inflateBackInit(strm, windowBits, window) \
1556  inflateBackInit_((strm), (windowBits), (window), \
1557  ZLIB_VERSION, sizeof(z_stream))
1558 
1559 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1560  * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1561  * both are true, the application gets the *64 functions, and the regular
1562  * functions are changed to 64 bits) -- in case these are set on systems
1563  * without large file support, _LFS64_LARGEFILE must also be true
1564  */
1565 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
1566  ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1567  ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1568  ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1572 #endif
1573 
1574 #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
1575 # define gzopen gzopen64
1576 # define gzseek gzseek64
1577 # define gztell gztell64
1578 # define gzoffset gzoffset64
1579 # define adler32_combine adler32_combine64
1580 # define crc32_combine crc32_combine64
1581 # ifdef _LARGEFILE64_SOURCE
1582  ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1583  ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1584  ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1585  ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1588 # endif
1589 #else
1590  ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1591  ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1592  ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1593  ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1596 #endif
1597 
1598 /* hack for buggy compilers */
1599 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1600  struct internal_state {int dummy;};
1601 #endif
1602 
1603 /* undocumented functions */
1604 ZEXTERN const char * ZEXPORT zError OF((int));
1605 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
1606 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
1607 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
1608 
1609 #ifdef __cplusplus
1610 }
1611 #endif
1612 
1613 #endif /* ZLIB_H */