1    	/* zlib.h -- interface of the 'zlib' general purpose compression library
2    	  version 1.2.11, January 15th, 2017
3    	
4    	  Copyright (C) 1995-2017 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://tools.ietf.org/html/rfc1950
28   	  (zlib format), rfc1951 (deflate format) and rfc1952 (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 "1.2.11"
41   	#define ZLIB_VERNUM 0x12b0
42   	#define ZLIB_VER_MAJOR 1
43   	#define ZLIB_VER_MINOR 2
44   	#define ZLIB_VER_REVISION 11
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 and raw deflate streams in
69   	  memory as well.
70   	
71   	    The zlib format was designed to be compact and fast for use in memory
72   	  and on communications channels.  The gzip format was designed for single-
73   	  file compression on file systems, has a larger header than zlib to maintain
74   	  directory information, and uses a different, slower check method than zlib.
75   	
76   	    The library does not install any signal handler.  The decoder checks
77   	  the consistency of the compressed data, so the library should never crash
78   	  even in the case of corrupted input.
79   	*/
80   	
81   	typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
82   	typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
83   	
84   	struct internal_state;
85   	
86   	typedef struct z_stream_s {
87   	    z_const Bytef *next_in;     /* next input byte */
88   	    uInt     avail_in;  /* number of bytes available at next_in */
89   	    uLong    total_in;  /* total number of input bytes read so far */
90   	
91   	    Bytef    *next_out; /* next output byte will go here */
92   	    uInt     avail_out; /* remaining free space at next_out */
93   	    uLong    total_out; /* total number of bytes output so far */
94   	
95   	    z_const char *msg;  /* last error message, NULL if no error */
96   	    struct internal_state FAR *state; /* not visible by applications */
97   	
98   	    alloc_func zalloc;  /* used to allocate the internal state */
99   	    free_func  zfree;   /* used to free the internal state */
100  	    voidpf     opaque;  /* private data object passed to zalloc and zfree */
101  	
102  	    int     data_type;  /* best guess about the data type: binary or text
103  	                           for deflate, or the decoding state for inflate */
104  	    uLong   adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
105  	    uLong   reserved;   /* reserved for future use */
106  	} z_stream;
107  	
108  	typedef z_stream FAR *z_streamp;
109  	
110  	/*
111  	     gzip header information passed to and from zlib routines.  See RFC 1952
112  	  for more details on the meanings of these fields.
113  	*/
114  	typedef struct gz_header_s {
115  	    int     text;       /* true if compressed data believed to be text */
116  	    uLong   time;       /* modification time */
117  	    int     xflags;     /* extra flags (not used when writing a gzip file) */
118  	    int     os;         /* operating system */
119  	    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
120  	    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
121  	    uInt    extra_max;  /* space at extra (only when reading header) */
122  	    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
123  	    uInt    name_max;   /* space at name (only when reading header) */
124  	    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
125  	    uInt    comm_max;   /* space at comment (only when reading header) */
126  	    int     hcrc;       /* true if there was or will be a header crc */
127  	    int     done;       /* true when done reading gzip header (not used
128  	                           when writing a gzip file) */
129  	} gz_header;
130  	
131  	typedef gz_header FAR *gz_headerp;
132  	
133  	/*
134  	     The application must update next_in and avail_in when avail_in has dropped
135  	   to zero.  It must update next_out and avail_out when avail_out has dropped
136  	   to zero.  The application must initialize zalloc, zfree and opaque before
137  	   calling the init function.  All other fields are set by the compression
138  	   library and must not be updated by the application.
139  	
140  	     The opaque value provided by the application will be passed as the first
141  	   parameter for calls of zalloc and zfree.  This can be useful for custom
142  	   memory management.  The compression library attaches no meaning to the
143  	   opaque value.
144  	
145  	     zalloc must return Z_NULL if there is not enough memory for the object.
146  	   If zlib is used in a multi-threaded application, zalloc and zfree must be
147  	   thread safe.  In that case, zlib is thread-safe.  When zalloc and zfree are
148  	   Z_NULL on entry to the initialization function, they are set to internal
149  	   routines that use the standard library functions malloc() and free().
150  	
151  	     On 16-bit systems, the functions zalloc and zfree must be able to allocate
152  	   exactly 65536 bytes, but will not be required to allocate more than this if
153  	   the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
154  	   returned by zalloc for objects of exactly 65536 bytes *must* have their
155  	   offset normalized to zero.  The default allocation function provided by this
156  	   library ensures this (see zutil.c).  To reduce memory requirements and avoid
157  	   any allocation of 64K objects, at the expense of compression ratio, compile
158  	   the library with -DMAX_WBITS=14 (see zconf.h).
159  	
160  	     The fields total_in and total_out can be used for statistics or progress
161  	   reports.  After compression, total_in holds the total size of the
162  	   uncompressed data and may be saved for use by the decompressor (particularly
163  	   if the decompressor wants to decompress everything in a single step).
164  	*/
165  	
166  	                        /* constants */
167  	
168  	#define Z_NO_FLUSH      0
169  	#define Z_PARTIAL_FLUSH 1
170  	#define Z_SYNC_FLUSH    2
171  	#define Z_FULL_FLUSH    3
172  	#define Z_FINISH        4
173  	#define Z_BLOCK         5
174  	#define Z_TREES         6
175  	/* Allowed flush values; see deflate() and inflate() below for details */
176  	
177  	#define Z_OK            0
178  	#define Z_STREAM_END    1
179  	#define Z_NEED_DICT     2
180  	#define Z_ERRNO        (-1)
181  	#define Z_STREAM_ERROR (-2)
182  	#define Z_DATA_ERROR   (-3)
183  	#define Z_MEM_ERROR    (-4)
184  	#define Z_BUF_ERROR    (-5)
185  	#define Z_VERSION_ERROR (-6)
186  	/* Return codes for the compression/decompression functions. Negative values
187  	 * are errors, positive values are used for special but normal events.
188  	 */
189  	
190  	#define Z_NO_COMPRESSION         0
191  	#define Z_BEST_SPEED             1
192  	#define Z_BEST_COMPRESSION       9
193  	#define Z_DEFAULT_COMPRESSION  (-1)
194  	/* compression levels */
195  	
196  	#define Z_FILTERED            1
197  	#define Z_HUFFMAN_ONLY        2
198  	#define Z_RLE                 3
199  	#define Z_FIXED               4
200  	#define Z_DEFAULT_STRATEGY    0
201  	/* compression strategy; see deflateInit2() below for details */
202  	
203  	#define Z_BINARY   0
204  	#define Z_TEXT     1
205  	#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
206  	#define Z_UNKNOWN  2
207  	/* Possible values of the data_type field for deflate() */
208  	
209  	#define Z_DEFLATED   8
210  	/* The deflate compression method (the only one supported in this version) */
211  	
212  	#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
213  	
214  	#define zlib_version zlibVersion()
215  	/* for compatibility with versions < 1.0.2 */
216  	
217  	
218  	                        /* basic functions */
219  	
220  	ZEXTERN const char * ZEXPORT zlibVersion OF((void));
221  	/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
222  	   If the first character differs, the library code actually used is not
223  	   compatible with the zlib.h header file used by the application.  This check
224  	   is automatically made by deflateInit and inflateInit.
225  	 */
226  	
227  	/*
228  	ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
229  	
230  	     Initializes the internal stream state for compression.  The fields
231  	   zalloc, zfree and opaque must be initialized before by the caller.  If
232  	   zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
233  	   allocation functions.
234  	
235  	     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
236  	   1 gives best speed, 9 gives best compression, 0 gives no compression at all
237  	   (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
238  	   requests a default compromise between speed and compression (currently
239  	   equivalent to level 6).
240  	
241  	     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
242  	   memory, Z_STREAM_ERROR if level is not a valid compression level, or
243  	   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
244  	   with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
245  	   if there is no error message.  deflateInit does not perform any compression:
246  	   this will be done by deflate().
247  	*/
248  	
249  	
250  	ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
251  	/*
252  	    deflate compresses as much data as possible, and stops when the input
253  	  buffer becomes empty or the output buffer becomes full.  It may introduce
254  	  some output latency (reading input without producing any output) except when
255  	  forced to flush.
256  	
257  	    The detailed semantics are as follows.  deflate performs one or both of the
258  	  following actions:
259  	
260  	  - Compress more input starting at next_in and update next_in and avail_in
261  	    accordingly.  If not all input can be processed (because there is not
262  	    enough room in the output buffer), next_in and avail_in are updated and
263  	    processing will resume at this point for the next call of deflate().
264  	
265  	  - Generate more output starting at next_out and update next_out and avail_out
266  	    accordingly.  This action is forced if the parameter flush is non zero.
267  	    Forcing flush frequently degrades the compression ratio, so this parameter
268  	    should be set only when necessary.  Some output may be provided even if
269  	    flush is zero.
270  	
271  	    Before the call of deflate(), the application should ensure that at least
272  	  one of the actions is possible, by providing more input and/or consuming more
273  	  output, and updating avail_in or avail_out accordingly; avail_out should
274  	  never be zero before the call.  The application can consume the compressed
275  	  output when it wants, for example when the output buffer is full (avail_out
276  	  == 0), or after each call of deflate().  If deflate returns Z_OK and with
277  	  zero avail_out, it must be called again after making room in the output
278  	  buffer because there might be more output pending. See deflatePending(),
279  	  which can be used if desired to determine whether or not there is more ouput
280  	  in that case.
281  	
282  	    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
283  	  decide how much data to accumulate before producing output, in order to
284  	  maximize compression.
285  	
286  	    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
287  	  flushed to the output buffer and the output is aligned on a byte boundary, so
288  	  that the decompressor can get all input data available so far.  (In
289  	  particular avail_in is zero after the call if enough output space has been
290  	  provided before the call.) Flushing may degrade compression for some
291  	  compression algorithms and so it should be used only when necessary.  This
292  	  completes the current deflate block and follows it with an empty stored block
293  	  that is three bits plus filler bits to the next byte, followed by four bytes
294  	  (00 00 ff ff).
295  	
296  	    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
297  	  output buffer, but the output is not aligned to a byte boundary.  All of the
298  	  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
299  	  This completes the current deflate block and follows it with an empty fixed
300  	  codes block that is 10 bits long.  This assures that enough bytes are output
301  	  in order for the decompressor to finish the block before the empty fixed
302  	  codes block.
303  	
304  	    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
305  	  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
306  	  seven bits of the current block are held to be written as the next byte after
307  	  the next deflate block is completed.  In this case, the decompressor may not
308  	  be provided enough bits at this point in order to complete decompression of
309  	  the data provided so far to the compressor.  It may need to wait for the next
310  	  block to be emitted.  This is for advanced applications that need to control
311  	  the emission of deflate blocks.
312  	
313  	    If flush is set to Z_FULL_FLUSH, all output is flushed as with
314  	  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
315  	  restart from this point if previous compressed data has been damaged or if
316  	  random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
317  	  compression.
318  	
319  	    If deflate returns with avail_out == 0, this function must be called again
320  	  with the same value of the flush parameter and more output space (updated
321  	  avail_out), until the flush is complete (deflate returns with non-zero
322  	  avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
323  	  avail_out is greater than six to avoid repeated flush markers due to
324  	  avail_out == 0 on return.
325  	
326  	    If the parameter flush is set to Z_FINISH, pending input is processed,
327  	  pending output is flushed and deflate returns with Z_STREAM_END if there was
328  	  enough output space.  If deflate returns with Z_OK or Z_BUF_ERROR, this
329  	  function must be called again with Z_FINISH and more output space (updated
330  	  avail_out) but no more input data, until it returns with Z_STREAM_END or an
331  	  error.  After deflate has returned Z_STREAM_END, the only possible operations
332  	  on the stream are deflateReset or deflateEnd.
333  	
334  	    Z_FINISH can be used in the first deflate call after deflateInit if all the
335  	  compression is to be done in a single step.  In order to complete in one
336  	  call, avail_out must be at least the value returned by deflateBound (see
337  	  below).  Then deflate is guaranteed to return Z_STREAM_END.  If not enough
338  	  output space is provided, deflate will not return Z_STREAM_END, and it must
339  	  be called again as described above.
340  	
341  	    deflate() sets strm->adler to the Adler-32 checksum of all input read
342  	  so far (that is, total_in bytes).  If a gzip stream is being generated, then
343  	  strm->adler will be the CRC-32 checksum of the input read so far.  (See
344  	  deflateInit2 below.)
345  	
346  	    deflate() may update strm->data_type if it can make a good guess about
347  	  the input data type (Z_BINARY or Z_TEXT).  If in doubt, the data is
348  	  considered binary.  This field is only for information purposes and does not
349  	  affect the compression algorithm in any manner.
350  	
351  	    deflate() returns Z_OK if some progress has been made (more input
352  	  processed or more output produced), Z_STREAM_END if all input has been
353  	  consumed and all output has been produced (only when flush is set to
354  	  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
355  	  if next_in or next_out was Z_NULL or the state was inadvertently written over
356  	  by the application), or Z_BUF_ERROR if no progress is possible (for example
357  	  avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not fatal, and
358  	  deflate() can be called again with more input and more output space to
359  	  continue compressing.
360  	*/
361  	
362  	
363  	ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
364  	/*
365  	     All dynamically allocated data structures for this stream are freed.
366  	   This function discards any unprocessed input and does not flush any pending
367  	   output.
368  	
369  	     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
370  	   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
371  	   prematurely (some input or output was discarded).  In the error case, msg
372  	   may be set but then points to a static string (which must not be
373  	   deallocated).
374  	*/
375  	
376  	
377  	/*
378  	ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
379  	
380  	     Initializes the internal stream state for decompression.  The fields
381  	   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
382  	   the caller.  In the current version of inflate, the provided input is not
383  	   read or consumed.  The allocation of a sliding window will be deferred to
384  	   the first call of inflate (if the decompression does not complete on the
385  	   first call).  If zalloc and zfree are set to Z_NULL, inflateInit updates
386  	   them to use default allocation functions.
387  	
388  	     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
389  	   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
390  	   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
391  	   invalid, such as a null pointer to the structure.  msg is set to null if
392  	   there is no error message.  inflateInit does not perform any decompression.
393  	   Actual decompression will be done by inflate().  So next_in, and avail_in,
394  	   next_out, and avail_out are unused and unchanged.  The current
395  	   implementation of inflateInit() does not process any header information --
396  	   that is deferred 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), then next_in and avail_in are updated
413  	    accordingly, and processing will resume at this point for the next call of
414  	    inflate().
415  	
416  	  - Generate more output starting at next_out and update next_out and avail_out
417  	    accordingly.  inflate() provides as much output as possible, until there is
418  	    no more input data or no more space in the output buffer (see below about
419  	    the flush parameter).
420  	
421  	    Before the call of inflate(), the application should ensure that at least
422  	  one of the actions is possible, by providing more input and/or consuming more
423  	  output, and updating the next_* and avail_* values accordingly.  If the
424  	  caller of inflate() does not provide both available input and available
425  	  output space, it is possible that there will be no progress made.  The
426  	  application can consume the uncompressed output when it wants, for example
427  	  when the output buffer is full (avail_out == 0), or after each call of
428  	  inflate().  If inflate returns Z_OK and with zero avail_out, it must be
429  	  called again after making room in the output buffer because there might be
430  	  more output pending.
431  	
432  	    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
433  	  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
434  	  output as possible to the output buffer.  Z_BLOCK requests that inflate()
435  	  stop if and when it gets to the next deflate block boundary.  When decoding
436  	  the zlib or gzip format, this will cause inflate() to return immediately
437  	  after the header and before the first block.  When doing a raw inflate,
438  	  inflate() will go ahead and process the first block, and will return when it
439  	  gets to the end of that block, or when it runs out of data.
440  	
441  	    The Z_BLOCK option assists in appending to or combining deflate streams.
442  	  To assist in this, on return inflate() always sets strm->data_type to the
443  	  number of unused bits in the last byte taken from strm->next_in, plus 64 if
444  	  inflate() is currently decoding the last block in the deflate stream, plus
445  	  128 if inflate() returned immediately after decoding an end-of-block code or
446  	  decoding the complete header up to just before the first byte of the deflate
447  	  stream.  The end-of-block will not be indicated until all of the uncompressed
448  	  data from that block has been written to strm->next_out.  The number of
449  	  unused bits may in general be greater than seven, except when bit 7 of
450  	  data_type is set, in which case the number of unused bits will be less than
451  	  eight.  data_type is set as noted here every time inflate() returns for all
452  	  flush options, and so can be used to determine the amount of currently
453  	  consumed input in bits.
454  	
455  	    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
456  	  end of each deflate block header is reached, before any actual data in that
457  	  block is decoded.  This allows the caller to determine the length of the
458  	  deflate block header for later use in random access within a deflate block.
459  	  256 is added to the value of strm->data_type when inflate() returns
460  	  immediately after reaching the end of the deflate block header.
461  	
462  	    inflate() should normally be called until it returns Z_STREAM_END or an
463  	  error.  However if all decompression is to be performed in a single step (a
464  	  single call of inflate), the parameter flush should be set to Z_FINISH.  In
465  	  this case all pending input is processed and all pending output is flushed;
466  	  avail_out must be large enough to hold all of the uncompressed data for the
467  	  operation to complete.  (The size of the uncompressed data may have been
468  	  saved by the compressor for this purpose.)  The use of Z_FINISH is not
469  	  required to perform an inflation in one step.  However it may be used to
470  	  inform inflate that a faster approach can be used for the single inflate()
471  	  call.  Z_FINISH also informs inflate to not maintain a sliding window if the
472  	  stream completes, which reduces inflate's memory footprint.  If the stream
473  	  does not complete, either because not all of the stream is provided or not
474  	  enough output space is provided, then a sliding window will be allocated and
475  	  inflate() can be called again to continue the operation as if Z_NO_FLUSH had
476  	  been used.
477  	
478  	     In this implementation, inflate() always flushes as much output as
479  	  possible to the output buffer, and always uses the faster approach on the
480  	  first call.  So the effects of the flush parameter in this implementation are
481  	  on the return value of inflate() as noted below, when inflate() returns early
482  	  when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
483  	  memory for a sliding window when Z_FINISH is used.
484  	
485  	     If a preset dictionary is needed after this call (see inflateSetDictionary
486  	  below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
487  	  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
488  	  strm->adler to the Adler-32 checksum of all output produced so far (that is,
489  	  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
490  	  below.  At the end of the stream, inflate() checks that its computed Adler-32
491  	  checksum is equal to that saved by the compressor and returns Z_STREAM_END
492  	  only if the checksum is correct.
493  	
494  	    inflate() can decompress and check either zlib-wrapped or gzip-wrapped
495  	  deflate data.  The header type is detected automatically, if requested when
496  	  initializing with inflateInit2().  Any information contained in the gzip
497  	  header is not retained unless inflateGetHeader() is used.  When processing
498  	  gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
499  	  produced so far.  The CRC-32 is checked against the gzip trailer, as is the
500  	  uncompressed length, modulo 2^32.
501  	
502  	    inflate() returns Z_OK if some progress has been made (more input processed
503  	  or more output produced), Z_STREAM_END if the end of the compressed data has
504  	  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
505  	  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
506  	  corrupted (input stream not conforming to the zlib format or incorrect check
507  	  value, in which case strm->msg points to a string with a more specific
508  	  error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
509  	  next_in or next_out was Z_NULL, or the state was inadvertently written over
510  	  by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
511  	  if no progress was possible or if there was not enough room in the output
512  	  buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
513  	  inflate() can be called again with more input and more output space to
514  	  continue decompressing.  If Z_DATA_ERROR is returned, the application may
515  	  then call inflateSync() to look for a good compression block if a partial
516  	  recovery of the data is to be attempted.
517  	*/
518  	
519  	
520  	ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
521  	/*
522  	     All dynamically allocated data structures for this stream are freed.
523  	   This function discards any unprocessed input and does not flush any pending
524  	   output.
525  	
526  	     inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
527  	   was inconsistent.
528  	*/
529  	
530  	
531  	                        /* Advanced functions */
532  	
533  	/*
534  	    The following functions are needed only in some special applications.
535  	*/
536  	
537  	/*
538  	ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
539  	                                     int  level,
540  	                                     int  method,
541  	                                     int  windowBits,
542  	                                     int  memLevel,
543  	                                     int  strategy));
544  	
545  	     This is another version of deflateInit with more compression options.  The
546  	   fields next_in, zalloc, zfree and opaque must be initialized before by the
547  	   caller.
548  	
549  	     The method parameter is the compression method.  It must be Z_DEFLATED in
550  	   this version of the library.
551  	
552  	     The windowBits parameter is the base two logarithm of the window size
553  	   (the size of the history buffer).  It should be in the range 8..15 for this
554  	   version of the library.  Larger values of this parameter result in better
555  	   compression at the expense of memory usage.  The default value is 15 if
556  	   deflateInit is used instead.
557  	
558  	     For the current implementation of deflate(), a windowBits value of 8 (a
559  	   window size of 256 bytes) is not supported.  As a result, a request for 8
560  	   will result in 9 (a 512-byte window).  In that case, providing 8 to
561  	   inflateInit2() will result in an error when the zlib header with 9 is
562  	   checked against the initialization of inflate().  The remedy is to not use 8
563  	   with deflateInit2() with this initialization, or at least in that case use 9
564  	   with inflateInit2().
565  	
566  	     windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
567  	   determines the window size.  deflate() will then generate raw deflate data
568  	   with no zlib header or trailer, and will not compute a check value.
569  	
570  	     windowBits can also be greater than 15 for optional gzip encoding.  Add
571  	   16 to windowBits to write a simple gzip header and trailer around the
572  	   compressed data instead of a zlib wrapper.  The gzip header will have no
573  	   file name, no extra data, no comment, no modification time (set to zero), no
574  	   header crc, and the operating system will be set to the appropriate value,
575  	   if the operating system was determined at compile time.  If a gzip stream is
576  	   being written, strm->adler is a CRC-32 instead of an Adler-32.
577  	
578  	     For raw deflate or gzip encoding, a request for a 256-byte window is
579  	   rejected as invalid, since only the zlib header provides a means of
580  	   transmitting the window size to the decompressor.
581  	
582  	     The memLevel parameter specifies how much memory should be allocated
583  	   for the internal compression state.  memLevel=1 uses minimum memory but is
584  	   slow and reduces compression ratio; memLevel=9 uses maximum memory for
585  	   optimal speed.  The default value is 8.  See zconf.h for total memory usage
586  	   as a function of windowBits and memLevel.
587  	
588  	     The strategy parameter is used to tune the compression algorithm.  Use the
589  	   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
590  	   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
591  	   string match), or Z_RLE to limit match distances to one (run-length
592  	   encoding).  Filtered data consists mostly of small values with a somewhat
593  	   random distribution.  In this case, the compression algorithm is tuned to
594  	   compress them better.  The effect of Z_FILTERED is to force more Huffman
595  	   coding and less string matching; it is somewhat intermediate between
596  	   Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
597  	   fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
598  	   strategy parameter only affects the compression ratio but not the
599  	   correctness of the compressed output even if it is not set appropriately.
600  	   Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
601  	   decoder for special applications.
602  	
603  	     deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
604  	   memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
605  	   method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
606  	   incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
607  	   set to null if there is no error message.  deflateInit2 does not perform any
608  	   compression: this will be done by deflate().
609  	*/
610  	
611  	ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
612  	                                             const Bytef *dictionary,
613  	                                             uInt  dictLength));
614  	/*
615  	     Initializes the compression dictionary from the given byte sequence
616  	   without producing any compressed output.  When using the zlib format, this
617  	   function must be called immediately after deflateInit, deflateInit2 or
618  	   deflateReset, and before any call of deflate.  When doing raw deflate, this
619  	   function must be called either before any call of deflate, or immediately
620  	   after the completion of a deflate block, i.e. after all input has been
621  	   consumed and all output has been delivered when using any of the flush
622  	   options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
623  	   compressor and decompressor must use exactly the same dictionary (see
624  	   inflateSetDictionary).
625  	
626  	     The dictionary should consist of strings (byte sequences) that are likely
627  	   to be encountered later in the data to be compressed, with the most commonly
628  	   used strings preferably put towards the end of the dictionary.  Using a
629  	   dictionary is most useful when the data to be compressed is short and can be
630  	   predicted with good accuracy; the data can then be compressed better than
631  	   with the default empty dictionary.
632  	
633  	     Depending on the size of the compression data structures selected by
634  	   deflateInit or deflateInit2, a part of the dictionary may in effect be
635  	   discarded, for example if the dictionary is larger than the window size
636  	   provided in deflateInit or deflateInit2.  Thus the strings most likely to be
637  	   useful should be put at the end of the dictionary, not at the front.  In
638  	   addition, the current implementation of deflate will use at most the window
639  	   size minus 262 bytes of the provided dictionary.
640  	
641  	     Upon return of this function, strm->adler is set to the Adler-32 value
642  	   of the dictionary; the decompressor may later use this value to determine
643  	   which dictionary has been used by the compressor.  (The Adler-32 value
644  	   applies to the whole dictionary even if only a subset of the dictionary is
645  	   actually used by the compressor.) If a raw deflate was requested, then the
646  	   Adler-32 value is not computed and strm->adler is not set.
647  	
648  	     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
649  	   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
650  	   inconsistent (for example if deflate has already been called for this stream
651  	   or if not at a block boundary for raw deflate).  deflateSetDictionary does
652  	   not perform any compression: this will be done by deflate().
653  	*/
654  	
655  	ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
656  	                                             Bytef *dictionary,
657  	                                             uInt  *dictLength));
658  	/*
659  	     Returns the sliding dictionary being maintained by deflate.  dictLength is
660  	   set to the number of bytes in the dictionary, and that many bytes are copied
661  	   to dictionary.  dictionary must have enough space, where 32768 bytes is
662  	   always enough.  If deflateGetDictionary() is called with dictionary equal to
663  	   Z_NULL, then only the dictionary length is returned, and nothing is copied.
664  	   Similary, if dictLength is Z_NULL, then it is not set.
665  	
666  	     deflateGetDictionary() may return a length less than the window size, even
667  	   when more than the window size in input has been provided. It may return up
668  	   to 258 bytes less in that case, due to how zlib's implementation of deflate
669  	   manages the sliding window and lookahead for matches, where matches can be
670  	   up to 258 bytes long. If the application needs the last window-size bytes of
671  	   input, then that would need to be saved by the application outside of zlib.
672  	
673  	     deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
674  	   stream state is inconsistent.
675  	*/
676  	
677  	ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
678  	                                    z_streamp source));
679  	/*
680  	     Sets the destination stream as a complete copy of the source stream.
681  	
682  	     This function can be useful when several compression strategies will be
683  	   tried, for example when there are several ways of pre-processing the input
684  	   data with a filter.  The streams that will be discarded should then be freed
685  	   by calling deflateEnd.  Note that deflateCopy duplicates the internal
686  	   compression state which can be quite large, so this strategy is slow and can
687  	   consume lots of memory.
688  	
689  	     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
690  	   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
691  	   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
692  	   destination.
693  	*/
694  	
695  	ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
696  	/*
697  	     This function is equivalent to deflateEnd followed by deflateInit, but
698  	   does not free and reallocate the internal compression state.  The stream
699  	   will leave the compression level and any other attributes that may have been
700  	   set unchanged.
701  	
702  	     deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
703  	   stream state was inconsistent (such as zalloc or state being Z_NULL).
704  	*/
705  	
706  	ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
707  	                                      int level,
708  	                                      int strategy));
709  	/*
710  	     Dynamically update the compression level and compression strategy.  The
711  	   interpretation of level and strategy is as in deflateInit2().  This can be
712  	   used to switch between compression and straight copy of the input data, or
713  	   to switch to a different kind of input data requiring a different strategy.
714  	   If the compression approach (which is a function of the level) or the
715  	   strategy is changed, and if there have been any deflate() calls since the
716  	   state was initialized or reset, then the input available so far is
717  	   compressed with the old level and strategy using deflate(strm, Z_BLOCK).
718  	   There are three approaches for the compression levels 0, 1..3, and 4..9
719  	   respectively.  The new level and strategy will take effect at the next call
720  	   of deflate().
721  	
722  	     If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
723  	   not have enough output space to complete, then the parameter change will not
724  	   take effect.  In this case, deflateParams() can be called again with the
725  	   same parameters and more output space to try again.
726  	
727  	     In order to assure a change in the parameters on the first try, the
728  	   deflate stream should be flushed using deflate() with Z_BLOCK or other flush
729  	   request until strm.avail_out is not zero, before calling deflateParams().
730  	   Then no more input data should be provided before the deflateParams() call.
731  	   If this is done, the old level and strategy will be applied to the data
732  	   compressed before deflateParams(), and the new level and strategy will be
733  	   applied to the the data compressed after deflateParams().
734  	
735  	     deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
736  	   state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
737  	   there was not enough output space to complete the compression of the
738  	   available input data before a change in the strategy or approach.  Note that
739  	   in the case of a Z_BUF_ERROR, the parameters are not changed.  A return
740  	   value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
741  	   retried with more output space.
742  	*/
743  	
744  	ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
745  	                                    int good_length,
746  	                                    int max_lazy,
747  	                                    int nice_length,
748  	                                    int max_chain));
749  	/*
750  	     Fine tune deflate's internal compression parameters.  This should only be
751  	   used by someone who understands the algorithm used by zlib's deflate for
752  	   searching for the best matching string, and even then only by the most
753  	   fanatic optimizer trying to squeeze out the last compressed bit for their
754  	   specific input data.  Read the deflate.c source code for the meaning of the
755  	   max_lazy, good_length, nice_length, and max_chain parameters.
756  	
757  	     deflateTune() can be called after deflateInit() or deflateInit2(), and
758  	   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
759  	 */
760  	
761  	ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
762  	                                       uLong sourceLen));
763  	/*
764  	     deflateBound() returns an upper bound on the compressed size after
765  	   deflation of sourceLen bytes.  It must be called after deflateInit() or
766  	   deflateInit2(), and after deflateSetHeader(), if used.  This would be used
767  	   to allocate an output buffer for deflation in a single pass, and so would be
768  	   called before deflate().  If that first deflate() call is provided the
769  	   sourceLen input bytes, an output buffer allocated to the size returned by
770  	   deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
771  	   to return Z_STREAM_END.  Note that it is possible for the compressed size to
772  	   be larger than the value returned by deflateBound() if flush options other
773  	   than Z_FINISH or Z_NO_FLUSH are used.
774  	*/
775  	
776  	ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
777  	                                       unsigned *pending,
778  	                                       int *bits));
779  	/*
780  	     deflatePending() returns the number of bytes and bits of output that have
781  	   been generated, but not yet provided in the available output.  The bytes not
782  	   provided would be due to the available output space having being consumed.
783  	   The number of bits of output not provided are between 0 and 7, where they
784  	   await more bits to join them in order to fill out a full byte.  If pending
785  	   or bits are Z_NULL, then those values are not set.
786  	
787  	     deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
788  	   stream state was inconsistent.
789  	 */
790  	
791  	ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
792  	                                     int bits,
793  	                                     int value));
794  	/*
795  	     deflatePrime() inserts bits in the deflate output stream.  The intent
796  	   is that this function is used to start off the deflate output with the bits
797  	   leftover from a previous deflate stream when appending to it.  As such, this
798  	   function can only be used for raw deflate, and must be used before the first
799  	   deflate() call after a deflateInit2() or deflateReset().  bits must be less
800  	   than or equal to 16, and that many of the least significant bits of value
801  	   will be inserted in the output.
802  	
803  	     deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
804  	   room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
805  	   source stream state was inconsistent.
806  	*/
807  	
808  	ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
809  	                                         gz_headerp head));
810  	/*
811  	     deflateSetHeader() provides gzip header information for when a gzip
812  	   stream is requested by deflateInit2().  deflateSetHeader() may be called
813  	   after deflateInit2() or deflateReset() and before the first call of
814  	   deflate().  The text, time, os, extra field, name, and comment information
815  	   in the provided gz_header structure are written to the gzip header (xflag is
816  	   ignored -- the extra flags are set according to the compression level).  The
817  	   caller must assure that, if not Z_NULL, name and comment are terminated with
818  	   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
819  	   available there.  If hcrc is true, a gzip header crc is included.  Note that
820  	   the current versions of the command-line version of gzip (up through version
821  	   1.3.x) do not support header crc's, and will report that it is a "multi-part
822  	   gzip file" and give up.
823  	
824  	     If deflateSetHeader is not used, the default gzip header has text false,
825  	   the time set to zero, and os set to 255, with no extra, name, or comment
826  	   fields.  The gzip header is returned to the default state by deflateReset().
827  	
828  	     deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
829  	   stream state was inconsistent.
830  	*/
831  	
832  	/*
833  	ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
834  	                                     int  windowBits));
835  	
836  	     This is another version of inflateInit with an extra parameter.  The
837  	   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
838  	   before by the caller.
839  	
840  	     The windowBits parameter is the base two logarithm of the maximum window
841  	   size (the size of the history buffer).  It should be in the range 8..15 for
842  	   this version of the library.  The default value is 15 if inflateInit is used
843  	   instead.  windowBits must be greater than or equal to the windowBits value
844  	   provided to deflateInit2() while compressing, or it must be equal to 15 if
845  	   deflateInit2() was not used.  If a compressed stream with a larger window
846  	   size is given as input, inflate() will return with the error code
847  	   Z_DATA_ERROR instead of trying to allocate a larger window.
848  	
849  	     windowBits can also be zero to request that inflate use the window size in
850  	   the zlib header of the compressed stream.
851  	
852  	     windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
853  	   determines the window size.  inflate() will then process raw deflate data,
854  	   not looking for a zlib or gzip header, not generating a check value, and not
855  	   looking for any check values for comparison at the end of the stream.  This
856  	   is for use with other formats that use the deflate compressed data format
857  	   such as zip.  Those formats provide their own check values.  If a custom
858  	   format is developed using the raw deflate format for compressed data, it is
859  	   recommended that a check value such as an Adler-32 or a CRC-32 be applied to
860  	   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
861  	   most applications, the zlib format should be used as is.  Note that comments
862  	   above on the use in deflateInit2() applies to the magnitude of windowBits.
863  	
864  	     windowBits can also be greater than 15 for optional gzip decoding.  Add
865  	   32 to windowBits to enable zlib and gzip decoding with automatic header
866  	   detection, or add 16 to decode only the gzip format (the zlib format will
867  	   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
868  	   CRC-32 instead of an Adler-32.  Unlike the gunzip utility and gzread() (see
869  	   below), inflate() will not automatically decode concatenated gzip streams.
870  	   inflate() will return Z_STREAM_END at the end of the gzip stream.  The state
871  	   would need to be reset to continue decoding a subsequent gzip stream.
872  	
873  	     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
874  	   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
875  	   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
876  	   invalid, such as a null pointer to the structure.  msg is set to null if
877  	   there is no error message.  inflateInit2 does not perform any decompression
878  	   apart from possibly reading the zlib header if present: actual decompression
879  	   will be done by inflate().  (So next_in and avail_in may be modified, but
880  	   next_out and avail_out are unused and unchanged.) The current implementation
881  	   of inflateInit2() does not process any header information -- that is
882  	   deferred until inflate() is called.
883  	*/
884  	
885  	ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
886  	                                             const Bytef *dictionary,
887  	                                             uInt  dictLength));
888  	/*
889  	     Initializes the decompression dictionary from the given uncompressed byte
890  	   sequence.  This function must be called immediately after a call of inflate,
891  	   if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
892  	   can be determined from the Adler-32 value returned by that call of inflate.
893  	   The compressor and decompressor must use exactly the same dictionary (see
894  	   deflateSetDictionary).  For raw inflate, this function can be called at any
895  	   time to set the dictionary.  If the provided dictionary is smaller than the
896  	   window and there is already data in the window, then the provided dictionary
897  	   will amend what's there.  The application must insure that the dictionary
898  	   that was used for compression is provided.
899  	
900  	     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
901  	   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
902  	   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
903  	   expected one (incorrect Adler-32 value).  inflateSetDictionary does not
904  	   perform any decompression: this will be done by subsequent calls of
905  	   inflate().
906  	*/
907  	
908  	ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
909  	                                             Bytef *dictionary,
910  	                                             uInt  *dictLength));
911  	/*
912  	     Returns the sliding dictionary being maintained by inflate.  dictLength is
913  	   set to the number of bytes in the dictionary, and that many bytes are copied
914  	   to dictionary.  dictionary must have enough space, where 32768 bytes is
915  	   always enough.  If inflateGetDictionary() is called with dictionary equal to
916  	   Z_NULL, then only the dictionary length is returned, and nothing is copied.
917  	   Similary, if dictLength is Z_NULL, then it is not set.
918  	
919  	     inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
920  	   stream state is inconsistent.
921  	*/
922  	
923  	ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
924  	/*
925  	     Skips invalid compressed data until a possible full flush point (see above
926  	   for the description of deflate with Z_FULL_FLUSH) can be found, or until all
927  	   available input is skipped.  No output is provided.
928  	
929  	     inflateSync searches for a 00 00 FF FF pattern in the compressed data.
930  	   All full flush points have this pattern, but not all occurrences of this
931  	   pattern are full flush points.
932  	
933  	     inflateSync returns Z_OK if a possible full flush point has been found,
934  	   Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
935  	   has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
936  	   In the success case, the application may save the current current value of
937  	   total_in which indicates where valid compressed data was found.  In the
938  	   error case, the application may repeatedly call inflateSync, providing more
939  	   input each time, until success or end of the input data.
940  	*/
941  	
942  	ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
943  	                                    z_streamp source));
944  	/*
945  	     Sets the destination stream as a complete copy of the source stream.
946  	
947  	     This function can be useful when randomly accessing a large stream.  The
948  	   first pass through the stream can periodically record the inflate state,
949  	   allowing restarting inflate at those points when randomly accessing the
950  	   stream.
951  	
952  	     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
953  	   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
954  	   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
955  	   destination.
956  	*/
957  	
958  	ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
959  	/*
960  	     This function is equivalent to inflateEnd followed by inflateInit,
961  	   but does not free and reallocate the internal decompression state.  The
962  	   stream will keep attributes that may have been set by inflateInit2.
963  	
964  	     inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
965  	   stream state was inconsistent (such as zalloc or state being Z_NULL).
966  	*/
967  	
968  	ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
969  	                                      int windowBits));
970  	/*
971  	     This function is the same as inflateReset, but it also permits changing
972  	   the wrap and window size requests.  The windowBits parameter is interpreted
973  	   the same as it is for inflateInit2.  If the window size is changed, then the
974  	   memory allocated for the window is freed, and the window will be reallocated
975  	   by inflate() if needed.
976  	
977  	     inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
978  	   stream state was inconsistent (such as zalloc or state being Z_NULL), or if
979  	   the windowBits parameter is invalid.
980  	*/
981  	
982  	ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
983  	                                     int bits,
984  	                                     int value));
985  	/*
986  	     This function inserts bits in the inflate input stream.  The intent is
987  	   that this function is used to start inflating at a bit position in the
988  	   middle of a byte.  The provided bits will be used before any bytes are used
989  	   from next_in.  This function should only be used with raw inflate, and
990  	   should be used before the first inflate() call after inflateInit2() or
991  	   inflateReset().  bits must be less than or equal to 16, and that many of the
992  	   least significant bits of value will be inserted in the input.
993  	
994  	     If bits is negative, then the input stream bit buffer is emptied.  Then
995  	   inflatePrime() can be called again to put bits in the buffer.  This is used
996  	   to clear out bits leftover after feeding inflate a block description prior
997  	   to feeding inflate codes.
998  	
999  	     inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
1000 	   stream state was inconsistent.
1001 	*/
1002 	
1003 	ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
1004 	/*
1005 	     This function returns two values, one in the lower 16 bits of the return
1006 	   value, and the other in the remaining upper bits, obtained by shifting the
1007 	   return value down 16 bits.  If the upper value is -1 and the lower value is
1008 	   zero, then inflate() is currently decoding information outside of a block.
1009 	   If the upper value is -1 and the lower value is non-zero, then inflate is in
1010 	   the middle of a stored block, with the lower value equaling the number of
1011 	   bytes from the input remaining to copy.  If the upper value is not -1, then
1012 	   it is the number of bits back from the current bit position in the input of
1013 	   the code (literal or length/distance pair) currently being processed.  In
1014 	   that case the lower value is the number of bytes already emitted for that
1015 	   code.
1016 	
1017 	     A code is being processed if inflate is waiting for more input to complete
1018 	   decoding of the code, or if it has completed decoding but is waiting for
1019 	   more output space to write the literal or match data.
1020 	
1021 	     inflateMark() is used to mark locations in the input data for random
1022 	   access, which may be at bit positions, and to note those cases where the
1023 	   output of a code may span boundaries of random access blocks.  The current
1024 	   location in the input stream can be determined from avail_in and data_type
1025 	   as noted in the description for the Z_BLOCK flush parameter for inflate.
1026 	
1027 	     inflateMark returns the value noted above, or -65536 if the provided
1028 	   source stream state was inconsistent.
1029 	*/
1030 	
1031 	ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
1032 	                                         gz_headerp head));
1033 	/*
1034 	     inflateGetHeader() requests that gzip header information be stored in the
1035 	   provided gz_header structure.  inflateGetHeader() may be called after
1036 	   inflateInit2() or inflateReset(), and before the first call of inflate().
1037 	   As inflate() processes the gzip stream, head->done is zero until the header
1038 	   is completed, at which time head->done is set to one.  If a zlib stream is
1039 	   being decoded, then head->done is set to -1 to indicate that there will be
1040 	   no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
1041 	   used to force inflate() to return immediately after header processing is
1042 	   complete and before any actual data is decompressed.
1043 	
1044 	     The text, time, xflags, and os fields are filled in with the gzip header
1045 	   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
1046 	   was valid if done is set to one.) If extra is not Z_NULL, then extra_max
1047 	   contains the maximum number of bytes to write to extra.  Once done is true,
1048 	   extra_len contains the actual extra field length, and extra contains the
1049 	   extra field, or that field truncated if extra_max is less than extra_len.
1050 	   If name is not Z_NULL, then up to name_max characters are written there,
1051 	   terminated with a zero unless the length is greater than name_max.  If
1052 	   comment is not Z_NULL, then up to comm_max characters are written there,
1053 	   terminated with a zero unless the length is greater than comm_max.  When any
1054 	   of extra, name, or comment are not Z_NULL and the respective field is not
1055 	   present in the header, then that field is set to Z_NULL to signal its
1056 	   absence.  This allows the use of deflateSetHeader() with the returned
1057 	   structure to duplicate the header.  However if those fields are set to
1058 	   allocated memory, then the application will need to save those pointers
1059 	   elsewhere so that they can be eventually freed.
1060 	
1061 	     If inflateGetHeader is not used, then the header information is simply
1062 	   discarded.  The header is always checked for validity, including the header
1063 	   CRC if present.  inflateReset() will reset the process to discard the header
1064 	   information.  The application would need to call inflateGetHeader() again to
1065 	   retrieve the header from the next gzip stream.
1066 	
1067 	     inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1068 	   stream state was inconsistent.
1069 	*/
1070 	
1071 	/*
1072 	ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1073 	                                        unsigned char FAR *window));
1074 	
1075 	     Initialize the internal stream state for decompression using inflateBack()
1076 	   calls.  The fields zalloc, zfree and opaque in strm must be initialized
1077 	   before the call.  If zalloc and zfree are Z_NULL, then the default library-
1078 	   derived memory allocation routines are used.  windowBits is the base two
1079 	   logarithm of the window size, in the range 8..15.  window is a caller
1080 	   supplied buffer of that size.  Except for special applications where it is
1081 	   assured that deflate was used with small window sizes, windowBits must be 15
1082 	   and a 32K byte window must be supplied to be able to decompress general
1083 	   deflate streams.
1084 	
1085 	     See inflateBack() for the usage of these routines.
1086 	
1087 	     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1088 	   the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1089 	   allocated, or Z_VERSION_ERROR if the version of the library does not match
1090 	   the version of the header file.
1091 	*/
1092 	
1093 	typedef unsigned (*in_func) OF((void FAR *,
1094 	                                z_const unsigned char FAR * FAR *));
1095 	typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1096 	
1097 	ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
1098 	                                    in_func in, void FAR *in_desc,
1099 	                                    out_func out, void FAR *out_desc));
1100 	/*
1101 	     inflateBack() does a raw inflate with a single call using a call-back
1102 	   interface for input and output.  This is potentially more efficient than
1103 	   inflate() for file i/o applications, in that it avoids copying between the
1104 	   output and the sliding window by simply making the window itself the output
1105 	   buffer.  inflate() can be faster on modern CPUs when used with large
1106 	   buffers.  inflateBack() trusts the application to not change the output
1107 	   buffer passed by the output function, at least until inflateBack() returns.
1108 	
1109 	     inflateBackInit() must be called first to allocate the internal state
1110 	   and to initialize the state with the user-provided window buffer.
1111 	   inflateBack() may then be used multiple times to inflate a complete, raw
1112 	   deflate stream with each call.  inflateBackEnd() is then called to free the
1113 	   allocated state.
1114 	
1115 	     A raw deflate stream is one with no zlib or gzip header or trailer.
1116 	   This routine would normally be used in a utility that reads zip or gzip
1117 	   files and writes out uncompressed files.  The utility would decode the
1118 	   header and process the trailer on its own, hence this routine expects only
1119 	   the raw deflate stream to decompress.  This is different from the default
1120 	   behavior of inflate(), which expects a zlib header and trailer around the
1121 	   deflate stream.
1122 	
1123 	     inflateBack() uses two subroutines supplied by the caller that are then
1124 	   called by inflateBack() for input and output.  inflateBack() calls those
1125 	   routines until it reads a complete deflate stream and writes out all of the
1126 	   uncompressed data, or until it encounters an error.  The function's
1127 	   parameters and return types are defined above in the in_func and out_func
1128 	   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
1129 	   number of bytes of provided input, and a pointer to that input in buf.  If
1130 	   there is no input available, in() must return zero -- buf is ignored in that
1131 	   case -- and inflateBack() will return a buffer error.  inflateBack() will
1132 	   call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
1133 	   out() should return zero on success, or non-zero on failure.  If out()
1134 	   returns non-zero, inflateBack() will return with an error.  Neither in() nor
1135 	   out() are permitted to change the contents of the window provided to
1136 	   inflateBackInit(), which is also the buffer that out() uses to write from.
1137 	   The length written by out() will be at most the window size.  Any non-zero
1138 	   amount of input may be provided by in().
1139 	
1140 	     For convenience, inflateBack() can be provided input on the first call by
1141 	   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
1142 	   in() will be called.  Therefore strm->next_in must be initialized before
1143 	   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
1144 	   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
1145 	   must also be initialized, and then if strm->avail_in is not zero, input will
1146 	   initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
1147 	
1148 	     The in_desc and out_desc parameters of inflateBack() is passed as the
1149 	   first parameter of in() and out() respectively when they are called.  These
1150 	   descriptors can be optionally used to pass any information that the caller-
1151 	   supplied in() and out() functions need to do their job.
1152 	
1153 	     On return, inflateBack() will set strm->next_in and strm->avail_in to
1154 	   pass back any unused input that was provided by the last in() call.  The
1155 	   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1156 	   if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1157 	   in the deflate stream (in which case strm->msg is set to indicate the nature
1158 	   of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1159 	   In the case of Z_BUF_ERROR, an input or output error can be distinguished
1160 	   using strm->next_in which will be Z_NULL only if in() returned an error.  If
1161 	   strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1162 	   non-zero.  (in() will always be called before out(), so strm->next_in is
1163 	   assured to be defined if out() returns non-zero.)  Note that inflateBack()
1164 	   cannot return Z_OK.
1165 	*/
1166 	
1167 	ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1168 	/*
1169 	     All memory allocated by inflateBackInit() is freed.
1170 	
1171 	     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1172 	   state was inconsistent.
1173 	*/
1174 	
1175 	ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1176 	/* Return flags indicating compile-time options.
1177 	
1178 	    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1179 	     1.0: size of uInt
1180 	     3.2: size of uLong
1181 	     5.4: size of voidpf (pointer)
1182 	     7.6: size of z_off_t
1183 	
1184 	    Compiler, assembler, and debug options:
1185 	     8: ZLIB_DEBUG
1186 	     9: ASMV or ASMINF -- use ASM code
1187 	     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1188 	     11: 0 (reserved)
1189 	
1190 	    One-time table building (smaller code, but not thread-safe if true):
1191 	     12: BUILDFIXED -- build static block decoding tables when needed
1192 	     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1193 	     14,15: 0 (reserved)
1194 	
1195 	    Library content (indicates missing functionality):
1196 	     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1197 	                          deflate code when not needed)
1198 	     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1199 	                    and decode gzip streams (to avoid linking crc code)
1200 	     18-19: 0 (reserved)
1201 	
1202 	    Operation variations (changes in library functionality):
1203 	     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1204 	     21: FASTEST -- deflate algorithm with only one, lowest compression level
1205 	     22,23: 0 (reserved)
1206 	
1207 	    The sprintf variant used by gzprintf (zero is best):
1208 	     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1209 	     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1210 	     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1211 	
1212 	    Remainder:
1213 	     27-31: 0 (reserved)
1214 	 */
1215 	
1216 	#ifndef Z_SOLO
1217 	
1218 	                        /* utility functions */
1219 	
1220 	/*
1221 	     The following utility functions are implemented on top of the basic
1222 	   stream-oriented functions.  To simplify the interface, some default options
1223 	   are assumed (compression level and memory usage, standard memory allocation
1224 	   functions).  The source code of these utility functions can be modified if
1225 	   you need special options.
1226 	*/
1227 	
1228 	ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
1229 	                                 const Bytef *source, uLong sourceLen));
1230 	/*
1231 	     Compresses the source buffer into the destination buffer.  sourceLen is
1232 	   the byte length of the source buffer.  Upon entry, destLen is the total size
1233 	   of the destination buffer, which must be at least the value returned by
1234 	   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
1235 	   compressed data.  compress() is equivalent to compress2() with a level
1236 	   parameter of Z_DEFAULT_COMPRESSION.
1237 	
1238 	     compress returns Z_OK if success, Z_MEM_ERROR if there was not
1239 	   enough memory, Z_BUF_ERROR if there was not enough room in the output
1240 	   buffer.
1241 	*/
1242 	
1243 	ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
1244 	                                  const Bytef *source, uLong sourceLen,
1245 	                                  int level));
1246 	/*
1247 	     Compresses the source buffer into the destination buffer.  The level
1248 	   parameter has the same meaning as in deflateInit.  sourceLen is the byte
1249 	   length of the source buffer.  Upon entry, destLen is the total size of the
1250 	   destination buffer, which must be at least the value returned by
1251 	   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
1252 	   compressed data.
1253 	
1254 	     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1255 	   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1256 	   Z_STREAM_ERROR if the level parameter is invalid.
1257 	*/
1258 	
1259 	ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1260 	/*
1261 	     compressBound() returns an upper bound on the compressed size after
1262 	   compress() or compress2() on sourceLen bytes.  It would be used before a
1263 	   compress() or compress2() call to allocate the destination buffer.
1264 	*/
1265 	
1266 	ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
1267 	                                   const Bytef *source, uLong sourceLen));
1268 	/*
1269 	     Decompresses the source buffer into the destination buffer.  sourceLen is
1270 	   the byte length of the source buffer.  Upon entry, destLen is the total size
1271 	   of the destination buffer, which must be large enough to hold the entire
1272 	   uncompressed data.  (The size of the uncompressed data must have been saved
1273 	   previously by the compressor and transmitted to the decompressor by some
1274 	   mechanism outside the scope of this compression library.) Upon exit, destLen
1275 	   is the actual size of the uncompressed data.
1276 	
1277 	     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1278 	   enough memory, Z_BUF_ERROR if there was not enough room in the output
1279 	   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
1280 	   the case where there is not enough room, uncompress() will fill the output
1281 	   buffer with the uncompressed data up to that point.
1282 	*/
1283 	
1284 	ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest,   uLongf *destLen,
1285 	                                    const Bytef *source, uLong *sourceLen));
1286 	/*
1287 	     Same as uncompress, except that sourceLen is a pointer, where the
1288 	   length of the source is *sourceLen.  On return, *sourceLen is the number of
1289 	   source bytes consumed.
1290 	*/
1291 	
1292 	                        /* gzip file access functions */
1293 	
1294 	/*
1295 	     This library supports reading and writing files in gzip (.gz) format with
1296 	   an interface similar to that of stdio, using the functions that start with
1297 	   "gz".  The gzip format is different from the zlib format.  gzip is a gzip
1298 	   wrapper, documented in RFC 1952, wrapped around a deflate stream.
1299 	*/
1300 	
1301 	typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */
1302 	
1303 	/*
1304 	ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1305 	
1306 	     Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
1307 	   in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1308 	   a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1309 	   compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1310 	   for fixed code compression as in "wb9F".  (See the description of
1311 	   deflateInit2 for more information about the strategy parameter.)  'T' will
1312 	   request transparent writing or appending with no compression and not using
1313 	   the gzip format.
1314 	
1315 	     "a" can be used instead of "w" to request that the gzip stream that will
1316 	   be written be appended to the file.  "+" will result in an error, since
1317 	   reading and writing to the same gzip file is not supported.  The addition of
1318 	   "x" when writing will create the file exclusively, which fails if the file
1319 	   already exists.  On systems that support it, the addition of "e" when
1320 	   reading or writing will set the flag to close the file on an execve() call.
1321 	
1322 	     These functions, as well as gzip, will read and decode a sequence of gzip
1323 	   streams in a file.  The append function of gzopen() can be used to create
1324 	   such a file.  (Also see gzflush() for another way to do this.)  When
1325 	   appending, gzopen does not test whether the file begins with a gzip stream,
1326 	   nor does it look for the end of the gzip streams to begin appending.  gzopen
1327 	   will simply append a gzip stream to the existing file.
1328 	
1329 	     gzopen can be used to read a file which is not in gzip format; in this
1330 	   case gzread will directly read from the file without decompression.  When
1331 	   reading, this will be detected automatically by looking for the magic two-
1332 	   byte gzip header.
1333 	
1334 	     gzopen returns NULL if the file could not be opened, if there was
1335 	   insufficient memory to allocate the gzFile state, or if an invalid mode was
1336 	   specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1337 	   errno can be checked to determine if the reason gzopen failed was that the
1338 	   file could not be opened.
1339 	*/
1340 	
1341 	ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1342 	/*
1343 	     gzdopen associates a gzFile with the file descriptor fd.  File descriptors
1344 	   are obtained from calls like open, dup, creat, pipe or fileno (if the file
1345 	   has been previously opened with fopen).  The mode parameter is as in gzopen.
1346 	
1347 	     The next call of gzclose on the returned gzFile will also close the file
1348 	   descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1349 	   fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1350 	   mode);.  The duplicated descriptor should be saved to avoid a leak, since
1351 	   gzdopen does not close fd if it fails.  If you are using fileno() to get the
1352 	   file descriptor from a FILE *, then you will have to use dup() to avoid
1353 	   double-close()ing the file descriptor.  Both gzclose() and fclose() will
1354 	   close the associated file descriptor, so they need to have different file
1355 	   descriptors.
1356 	
1357 	     gzdopen returns NULL if there was insufficient memory to allocate the
1358 	   gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1359 	   provided, or '+' was provided), or if fd is -1.  The file descriptor is not
1360 	   used until the next gz* read, write, seek, or close operation, so gzdopen
1361 	   will not detect if fd is invalid (unless fd is -1).
1362 	*/
1363 	
1364 	ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1365 	/*
1366 	     Set the internal buffer size used by this library's functions.  The
1367 	   default buffer size is 8192 bytes.  This function must be called after
1368 	   gzopen() or gzdopen(), and before any other calls that read or write the
1369 	   file.  The buffer memory allocation is always deferred to the first read or
1370 	   write.  Three times that size in buffer space is allocated.  A larger buffer
1371 	   size of, for example, 64K or 128K bytes will noticeably increase the speed
1372 	   of decompression (reading).
1373 	
1374 	     The new buffer size also affects the maximum length for gzprintf().
1375 	
1376 	     gzbuffer() returns 0 on success, or -1 on failure, such as being called
1377 	   too late.
1378 	*/
1379 	
1380 	ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1381 	/*
1382 	     Dynamically update the compression level or strategy.  See the description
1383 	   of deflateInit2 for the meaning of these parameters.  Previously provided
1384 	   data is flushed before the parameter change.
1385 	
1386 	     gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
1387 	   opened for writing, Z_ERRNO if there is an error writing the flushed data,
1388 	   or Z_MEM_ERROR if there is a memory allocation error.
1389 	*/
1390 	
1391 	ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1392 	/*
1393 	     Reads the given number of uncompressed bytes from the compressed file.  If
1394 	   the input file is not in gzip format, gzread copies the given number of
1395 	   bytes into the buffer directly from the file.
1396 	
1397 	     After reaching the end of a gzip stream in the input, gzread will continue
1398 	   to read, looking for another gzip stream.  Any number of gzip streams may be
1399 	   concatenated in the input file, and will all be decompressed by gzread().
1400 	   If something other than a gzip stream is encountered after a gzip stream,
1401 	   that remaining trailing garbage is ignored (and no error is returned).
1402 	
1403 	     gzread can be used to read a gzip file that is being concurrently written.
1404 	   Upon reaching the end of the input, gzread will return with the available
1405 	   data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1406 	   gzclearerr can be used to clear the end of file indicator in order to permit
1407 	   gzread to be tried again.  Z_OK indicates that a gzip stream was completed
1408 	   on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
1409 	   middle of a gzip stream.  Note that gzread does not return -1 in the event
1410 	   of an incomplete gzip stream.  This error is deferred until gzclose(), which
1411 	   will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1412 	   stream.  Alternatively, gzerror can be used before gzclose to detect this
1413 	   case.
1414 	
1415 	     gzread returns the number of uncompressed bytes actually read, less than
1416 	   len for end of file, or -1 for error.  If len is too large to fit in an int,
1417 	   then nothing is read, -1 is returned, and the error state is set to
1418 	   Z_STREAM_ERROR.
1419 	*/
1420 	
1421 	ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
1422 	                                     gzFile file));
1423 	/*
1424 	     Read up to nitems items of size size from file to buf, otherwise operating
1425 	   as gzread() does.  This duplicates the interface of stdio's fread(), with
1426 	   size_t request and return types.  If the library defines size_t, then
1427 	   z_size_t is identical to size_t.  If not, then z_size_t is an unsigned
1428 	   integer type that can contain a pointer.
1429 	
1430 	     gzfread() returns the number of full items read of size size, or zero if
1431 	   the end of the file was reached and a full item could not be read, or if
1432 	   there was an error.  gzerror() must be consulted if zero is returned in
1433 	   order to determine if there was an error.  If the multiplication of size and
1434 	   nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
1435 	   is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
1436 	
1437 	     In the event that the end of file is reached and only a partial item is
1438 	   available at the end, i.e. the remaining uncompressed data length is not a
1439 	   multiple of size, then the final partial item is nevetheless read into buf
1440 	   and the end-of-file flag is set.  The length of the partial item read is not
1441 	   provided, but could be inferred from the result of gztell().  This behavior
1442 	   is the same as the behavior of fread() implementations in common libraries,
1443 	   but it prevents the direct use of gzfread() to read a concurrently written
1444 	   file, reseting and retrying on end-of-file, when size is not 1.
1445 	*/
1446 	
1447 	ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1448 	                                voidpc buf, unsigned len));
1449 	/*
1450 	     Writes the given number of uncompressed bytes into the compressed file.
1451 	   gzwrite returns the number of uncompressed bytes written or 0 in case of
1452 	   error.
1453 	*/
1454 	
1455 	ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
1456 	                                      z_size_t nitems, gzFile file));
1457 	/*
1458 	     gzfwrite() writes nitems items of size size from buf to file, duplicating
1459 	   the interface of stdio's fwrite(), with size_t request and return types.  If
1460 	   the library defines size_t, then z_size_t is identical to size_t.  If not,
1461 	   then z_size_t is an unsigned integer type that can contain a pointer.
1462 	
1463 	     gzfwrite() returns the number of full items written of size size, or zero
1464 	   if there was an error.  If the multiplication of size and nitems overflows,
1465 	   i.e. the product does not fit in a z_size_t, then nothing is written, zero
1466 	   is returned, and the error state is set to Z_STREAM_ERROR.
1467 	*/
1468 	
1469 	ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...))
1470 	#ifdef __GNUC__
1471 		__attribute__((__format__(__printf__,2,3)))
1472 	#endif
1473 	;
1474 	/*
1475 	     Converts, formats, and writes the arguments to the compressed file under
1476 	   control of the format string, as in fprintf.  gzprintf returns the number of
1477 	   uncompressed bytes actually written, or a negative zlib error code in case
1478 	   of error.  The number of uncompressed bytes written is limited to 8191, or
1479 	   one less than the buffer size given to gzbuffer().  The caller should assure
1480 	   that this limit is not exceeded.  If it is exceeded, then gzprintf() will
1481 	   return an error (0) with nothing written.  In this case, there may also be a
1482 	   buffer overflow with unpredictable consequences, which is possible only if
1483 	   zlib was compiled with the insecure functions sprintf() or vsprintf()
1484 	   because the secure snprintf() or vsnprintf() functions were not available.
1485 	   This can be determined using zlibCompileFlags().
1486 	*/
1487 	
1488 	ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1489 	/*
1490 	     Writes the given null-terminated string to the compressed file, excluding
1491 	   the terminating null character.
1492 	
1493 	     gzputs returns the number of characters written, or -1 in case of error.
1494 	*/
1495 	
1496 	ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1497 	/*
1498 	     Reads bytes from the compressed file until len-1 characters are read, or a
1499 	   newline character is read and transferred to buf, or an end-of-file
1500 	   condition is encountered.  If any characters are read or if len == 1, the
1501 	   string is terminated with a null character.  If no characters are read due
1502 	   to an end-of-file or len < 1, then the buffer is left untouched.
1503 	
1504 	     gzgets returns buf which is a null-terminated string, or it returns NULL
1505 	   for end-of-file or in case of error.  If there was an error, the contents at
1506 	   buf are indeterminate.
1507 	*/
1508 	
1509 	ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1510 	/*
1511 	     Writes c, converted to an unsigned char, into the compressed file.  gzputc
1512 	   returns the value that was written, or -1 in case of error.
1513 	*/
1514 	
1515 	ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1516 	/*
1517 	     Reads one byte from the compressed file.  gzgetc returns this byte or -1
1518 	   in case of end of file or error.  This is implemented as a macro for speed.
1519 	   As such, it does not do all of the checking the other functions do.  I.e.
1520 	   it does not check to see if file is NULL, nor whether the structure file
1521 	   points to has been clobbered or not.
1522 	*/
1523 	
1524 	ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1525 	/*
1526 	     Push one character back onto the stream to be read as the first character
1527 	   on the next read.  At least one character of push-back is allowed.
1528 	   gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
1529 	   fail if c is -1, and may fail if a character has been pushed but not read
1530 	   yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
1531 	   output buffer size of pushed characters is allowed.  (See gzbuffer above.)
1532 	   The pushed character will be discarded if the stream is repositioned with
1533 	   gzseek() or gzrewind().
1534 	*/
1535 	
1536 	ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1537 	/*
1538 	     Flushes all pending output into the compressed file.  The parameter flush
1539 	   is as in the deflate() function.  The return value is the zlib error number
1540 	   (see function gzerror below).  gzflush is only permitted when writing.
1541 	
1542 	     If the flush parameter is Z_FINISH, the remaining data is written and the
1543 	   gzip stream is completed in the output.  If gzwrite() is called again, a new
1544 	   gzip stream will be started in the output.  gzread() is able to read such
1545 	   concatenated gzip streams.
1546 	
1547 	     gzflush should be called only when strictly necessary because it will
1548 	   degrade compression if called too often.
1549 	*/
1550 	
1551 	/*
1552 	ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1553 	                                   z_off_t offset, int whence));
1554 	
1555 	     Sets the starting position for the next gzread or gzwrite on the given
1556 	   compressed file.  The offset represents a number of bytes in the
1557 	   uncompressed data stream.  The whence parameter is defined as in lseek(2);
1558 	   the value SEEK_END is not supported.
1559 	
1560 	     If the file is opened for reading, this function is emulated but can be
1561 	   extremely slow.  If the file is opened for writing, only forward seeks are
1562 	   supported; gzseek then compresses a sequence of zeroes up to the new
1563 	   starting position.
1564 	
1565 	     gzseek returns the resulting offset location as measured in bytes from
1566 	   the beginning of the uncompressed stream, or -1 in case of error, in
1567 	   particular if the file is opened for writing and the new starting position
1568 	   would be before the current position.
1569 	*/
1570 	
1571 	ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
1572 	/*
1573 	     Rewinds the given file. This function is supported only for reading.
1574 	
1575 	     gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1576 	*/
1577 	
1578 	/*
1579 	ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
1580 	
1581 	     Returns the starting position for the next gzread or gzwrite on the given
1582 	   compressed file.  This position represents a number of bytes in the
1583 	   uncompressed data stream, and is zero when starting, even if appending or
1584 	   reading a gzip stream from the middle of a file using gzdopen().
1585 	
1586 	     gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1587 	*/
1588 	
1589 	/*
1590 	ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1591 	
1592 	     Returns the current offset in the file being read or written.  This offset
1593 	   includes the count of bytes that precede the gzip stream, for example when
1594 	   appending or when using gzdopen() for reading.  When reading, the offset
1595 	   does not include as yet unused buffered input.  This information can be used
1596 	   for a progress indicator.  On error, gzoffset() returns -1.
1597 	*/
1598 	
1599 	ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1600 	/*
1601 	     Returns true (1) if the end-of-file indicator has been set while reading,
1602 	   false (0) otherwise.  Note that the end-of-file indicator is set only if the
1603 	   read tried to go past the end of the input, but came up short.  Therefore,
1604 	   just like feof(), gzeof() may return false even if there is no more data to
1605 	   read, in the event that the last read request was for the exact number of
1606 	   bytes remaining in the input file.  This will happen if the input file size
1607 	   is an exact multiple of the buffer size.
1608 	
1609 	     If gzeof() returns true, then the read functions will return no more data,
1610 	   unless the end-of-file indicator is reset by gzclearerr() and the input file
1611 	   has grown since the previous end of file was detected.
1612 	*/
1613 	
1614 	ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1615 	/*
1616 	     Returns true (1) if file is being copied directly while reading, or false
1617 	   (0) if file is a gzip stream being decompressed.
1618 	
1619 	     If the input file is empty, gzdirect() will return true, since the input
1620 	   does not contain a gzip stream.
1621 	
1622 	     If gzdirect() is used immediately after gzopen() or gzdopen() it will
1623 	   cause buffers to be allocated to allow reading the file to determine if it
1624 	   is a gzip file.  Therefore if gzbuffer() is used, it should be called before
1625 	   gzdirect().
1626 	
1627 	     When writing, gzdirect() returns true (1) if transparent writing was
1628 	   requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
1629 	   gzdirect() is not needed when writing.  Transparent writing must be
1630 	   explicitly requested, so the application already knows the answer.  When
1631 	   linking statically, using gzdirect() will include all of the zlib code for
1632 	   gzip file reading and decompression, which may not be desired.)
1633 	*/
1634 	
1635 	ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
1636 	/*
1637 	     Flushes all pending output if necessary, closes the compressed file and
1638 	   deallocates the (de)compression state.  Note that once file is closed, you
1639 	   cannot call gzerror with file, since its structures have been deallocated.
1640 	   gzclose must not be called more than once on the same file, just as free
1641 	   must not be called more than once on the same allocation.
1642 	
1643 	     gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1644 	   file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1645 	   last read ended in the middle of a gzip stream, or Z_OK on success.
1646 	*/
1647 	
1648 	ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1649 	ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1650 	/*
1651 	     Same as gzclose(), but gzclose_r() is only for use when reading, and
1652 	   gzclose_w() is only for use when writing or appending.  The advantage to
1653 	   using these instead of gzclose() is that they avoid linking in zlib
1654 	   compression or decompression code that is not used when only reading or only
1655 	   writing respectively.  If gzclose() is used, then both compression and
1656 	   decompression code will be included the application when linking to a static
1657 	   zlib library.
1658 	*/
1659 	
1660 	ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1661 	/*
1662 	     Returns the error message for the last error which occurred on the given
1663 	   compressed file.  errnum is set to zlib error number.  If an error occurred
1664 	   in the file system and not in the compression library, errnum is set to
1665 	   Z_ERRNO and the application may consult errno to get the exact error code.
1666 	
1667 	     The application must not modify the returned string.  Future calls to
1668 	   this function may invalidate the previously returned string.  If file is
1669 	   closed, then the string previously returned by gzerror will no longer be
1670 	   available.
1671 	
1672 	     gzerror() should be used to distinguish errors from end-of-file for those
1673 	   functions above that do not distinguish those cases in their return values.
1674 	*/
1675 	
1676 	ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1677 	/*
1678 	     Clears the error and end-of-file flags for file.  This is analogous to the
1679 	   clearerr() function in stdio.  This is useful for continuing to read a gzip
1680 	   file that is being written concurrently.
1681 	*/
1682 	
1683 	#endif /* !Z_SOLO */
1684 	
1685 	                        /* checksum functions */
1686 	
1687 	/*
1688 	     These functions are not related to compression but are exported
1689 	   anyway because they might be useful in applications using the compression
1690 	   library.
1691 	*/
1692 	
1693 	ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1694 	/*
1695 	     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1696 	   return the updated checksum.  If buf is Z_NULL, this function returns the
1697 	   required initial value for the checksum.
1698 	
1699 	     An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
1700 	   much faster.
1701 	
1702 	   Usage example:
1703 	
1704 	     uLong adler = adler32(0L, Z_NULL, 0);
1705 	
1706 	     while (read_buffer(buffer, length) != EOF) {
1707 	       adler = adler32(adler, buffer, length);
1708 	     }
1709 	     if (adler != original_adler) error();
1710 	*/
1711 	
1712 	ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
1713 	                                    z_size_t len));
1714 	/*
1715 	     Same as adler32(), but with a size_t length.
1716 	*/
1717 	
1718 	/*
1719 	ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1720 	                                          z_off_t len2));
1721 	
1722 	     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
1723 	   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1724 	   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
1725 	   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
1726 	   that the z_off_t type (like off_t) is a signed integer.  If len2 is
1727 	   negative, the result has no meaning or utility.
1728 	*/
1729 	
1730 	ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
1731 	/*
1732 	     Update a running CRC-32 with the bytes buf[0..len-1] and return the
1733 	   updated CRC-32.  If buf is Z_NULL, this function returns the required
1734 	   initial value for the crc.  Pre- and post-conditioning (one's complement) is
1735 	   performed within this function so it shouldn't be done by the application.
1736 	
1737 	   Usage example:
1738 	
1739 	     uLong crc = crc32(0L, Z_NULL, 0);
1740 	
1741 	     while (read_buffer(buffer, length) != EOF) {
1742 	       crc = crc32(crc, buffer, length);
1743 	     }
1744 	     if (crc != original_crc) error();
1745 	*/
1746 	
1747 	ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
1748 	                                  z_size_t len));
1749 	/*
1750 	     Same as crc32(), but with a size_t length.
1751 	*/
1752 	
1753 	/*
1754 	ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1755 	
1756 	     Combine two CRC-32 check values into one.  For two sequences of bytes,
1757 	   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1758 	   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
1759 	   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1760 	   len2.
1761 	*/
1762 	
1763 	
1764 	                        /* various hacks, don't look :) */
1765 	
1766 	/* deflateInit and inflateInit are macros to allow checking the zlib version
1767 	 * and the compiler's view of z_stream:
1768 	 */
1769 	ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1770 	                                     const char *version, int stream_size));
1771 	ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1772 	                                     const char *version, int stream_size));
1773 	ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
1774 	                                      int windowBits, int memLevel,
1775 	                                      int strategy, const char *version,
1776 	                                      int stream_size));
1777 	ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
1778 	                                      const char *version, int stream_size));
1779 	ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1780 	                                         unsigned char FAR *window,
1781 	                                         const char *version,
1782 	                                         int stream_size));
1783 	#ifdef Z_PREFIX_SET
1784 	#  define z_deflateInit(strm, level) \
1785 	          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1786 	#  define z_inflateInit(strm) \
1787 	          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1788 	#  define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1789 	          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1790 	                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1791 	#  define z_inflateInit2(strm, windowBits) \
1792 	          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1793 	                        (int)sizeof(z_stream))
1794 	#  define z_inflateBackInit(strm, windowBits, window) \
1795 	          inflateBackInit_((strm), (windowBits), (window), \
1796 	                           ZLIB_VERSION, (int)sizeof(z_stream))
1797 	#else
1798 	#  define deflateInit(strm, level) \
1799 	          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1800 	#  define inflateInit(strm) \
1801 	          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1802 	#  define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1803 	          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1804 	                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1805 	#  define inflateInit2(strm, windowBits) \
1806 	          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1807 	                        (int)sizeof(z_stream))
1808 	#  define inflateBackInit(strm, windowBits, window) \
1809 	          inflateBackInit_((strm), (windowBits), (window), \
1810 	                           ZLIB_VERSION, (int)sizeof(z_stream))
1811 	#endif
1812 	
1813 	#ifndef Z_SOLO
1814 	
1815 	/* gzgetc() macro and its supporting function and exposed data structure.  Note
1816 	 * that the real internal state is much larger than the exposed structure.
1817 	 * This abbreviated structure exposes just enough for the gzgetc() macro.  The
1818 	 * user should not mess with these exposed elements, since their names or
1819 	 * behavior could change in the future, perhaps even capriciously.  They can
1820 	 * only be used by the gzgetc() macro.  You have been warned.
1821 	 */
1822 	struct gzFile_s {
1823 	    unsigned have;
1824 	    unsigned char *next;
1825 	    z_off64_t pos;
1826 	};
1827 	ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
1828 	#ifdef Z_PREFIX_SET
1829 	#  undef z_gzgetc
1830 	#  define z_gzgetc(g) \
1831 	          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1832 	#else
1833 	#  define gzgetc(g) \
1834 	          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1835 	#endif
1836 	
1837 	/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1838 	 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1839 	 * both are true, the application gets the *64 functions, and the regular
1840 	 * functions are changed to 64 bits) -- in case these are set on systems
1841 	 * without large file support, _LFS64_LARGEFILE must also be true
1842 	 */
1843 	#ifdef Z_LARGE64
1844 	   ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1845 	   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1846 	   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1847 	   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1848 	   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1849 	   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1850 	#endif
1851 	
1852 	#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1853 	#  ifdef Z_PREFIX_SET
1854 	#    define z_gzopen z_gzopen64
1855 	#    define z_gzseek z_gzseek64
1856 	#    define z_gztell z_gztell64
1857 	#    define z_gzoffset z_gzoffset64
1858 	#    define z_adler32_combine z_adler32_combine64
1859 	#    define z_crc32_combine z_crc32_combine64
1860 	#  else
1861 	#    define gzopen gzopen64
1862 	#    define gzseek gzseek64
1863 	#    define gztell gztell64
1864 	#    define gzoffset gzoffset64
1865 	#    define adler32_combine adler32_combine64
1866 	#    define crc32_combine crc32_combine64
1867 	#  endif
1868 	#  ifndef Z_LARGE64
1869 	     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1870 	     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1871 	     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1872 	     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1873 	     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
1874 	     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
1875 	#  endif
1876 	#else
1877 	   ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1878 	   ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1879 	   ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1880 	   ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1881 	   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1882 	   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1883 	#endif
1884 	
1885 	#else /* Z_SOLO */
1886 	
1887 	   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1888 	   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1889 	
1890 	#endif /* !Z_SOLO */
1891 	
1892 	/* undocumented functions */
1893 	ZEXTERN const char   * ZEXPORT zError           OF((int));
1894 	ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
1895 	ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
1896 	ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
1897 	ZEXTERN int            ZEXPORT inflateValidate OF((z_streamp, int));
1898 	ZEXTERN unsigned long  ZEXPORT inflateCodesUsed OF ((z_streamp));
1899 	ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
1900 	ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
1901 	#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
1902 	ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
1903 	                                            const char *mode));
1904 	#endif
1905 	#if defined(STDC) || defined(Z_HAVE_STDARG_H)
1906 	#  ifndef Z_SOLO
1907 	ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file,
1908 	                                                  const char *format,
1909 	                                                  va_list va));
1910 	#  endif
1911 	#endif
1912 	
1913 	#ifdef __cplusplus
1914 	}
1915 	#endif
1916 	
1917 	#endif /* ZLIB_H */
1918