xref: /openbmc/u-boot/include/u-boot/zlib.h (revision 3e4d27b0)
1 /*
2  * This file is derived from zlib.h and zconf.h from the zlib-1.2.3
3  * distribution by Jean-loup Gailly and Mark Adler, with some additions
4  * by Paul Mackerras to aid in implementing Deflate compression and
5  * decompression for PPP packets.
6  */
7 
8  /*
9   * ==FILEVERSION 960122==
10   *
11   * This marker is used by the Linux installation script to determine
12   * whether an up-to-date version of this file is already installed.
13   */
14 
15 /* zlib.h -- interface of the 'zlib' general purpose compression library
16   version 1.2.3, July 18th, 2005
17 
18   Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
19 
20   This software is provided 'as-is', without any express or implied
21   warranty.  In no event will the authors be held liable for any damages
22   arising from the use of this software.
23 
24   Permission is granted to anyone to use this software for any purpose,
25   including commercial applications, and to alter it and redistribute it
26   freely, subject to the following restrictions:
27 
28   1. The origin of this software must not be misrepresented; you must not
29      claim that you wrote the original software. If you use this software
30      in a product, an acknowledgment in the product documentation would be
31      appreciated but is not required.
32   2. Altered source versions must be plainly marked as such, and must not be
33      misrepresented as being the original software.
34   3. This notice may not be removed or altered from any source distribution.
35 
36   Jean-loup Gailly        Mark Adler
37   jloup@gzip.org          madler@alumni.caltech.edu
38 
39 
40   The data format used by the zlib library is described by RFCs (Request for
41   Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
42   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
43 */
44 
45 #ifndef ZLIB_H
46 #define ZLIB_H
47 
48 #ifdef __cplusplus
49 extern "C" {
50 #endif
51 
52 #define ZLIB_VERSION "1.2.3"
53 #define ZLIB_VERNUM 0x1230
54 
55 /* #include "zconf.h" */        /* included directly here */
56 /* zconf.h -- configuration of the zlib compression library
57  * Copyright (C) 1995-2005 Jean-loup Gailly.
58  * For conditions of distribution and use, see copyright notice in zlib.h
59  */
60 
61 /* Begin of new zconf.h */
62 /*
63  * If you *really* need a unique prefix for all types and library functions,
64  * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
65  */
66 #ifdef Z_PREFIX
67 #  define deflateInit_          z_deflateInit_
68 #  define deflate               z_deflate
69 #  define deflateEnd            z_deflateEnd
70 #  define inflateInit_          z_inflateInit_
71 #  define inflate               z_inflate
72 #  define inflateEnd            z_inflateEnd
73 #  define deflateInit2_         z_deflateInit2_
74 #  define deflateSetDictionary  z_deflateSetDictionary
75 #  define deflateCopy           z_deflateCopy
76 #  define deflateReset          z_deflateReset
77 #  define deflateParams         z_deflateParams
78 #  define deflateBound          z_deflateBound
79 #  define deflatePrime          z_deflatePrime
80 #  define inflateInit2_         z_inflateInit2_
81 #  define inflateSetDictionary  z_inflateSetDictionary
82 #  define inflateSync           z_inflateSync
83 #  define inflateSyncPoint      z_inflateSyncPoint
84 #  define inflateCopy           z_inflateCopy
85 #  define inflateReset          z_inflateReset
86 #  define inflateBack           z_inflateBack
87 #  define inflateBackEnd        z_inflateBackEnd
88 #  define compress              z_compress
89 #  define compress2             z_compress2
90 #  define compressBound         z_compressBound
91 #  define uncompress            z_uncompress
92 #  define adler32               z_adler32
93 #  define crc32                 z_crc32
94 #  define get_crc_table         z_get_crc_table
95 #  define zError                z_zError
96 
97 #  define alloc_func            z_alloc_func
98 #  define free_func             z_free_func
99 #  define in_func               z_in_func
100 #  define out_func              z_out_func
101 #  define Byte                  z_Byte
102 #  define uInt                  z_uInt
103 #  define uLong                 z_uLong
104 #  define Bytef                 z_Bytef
105 #  define charf                 z_charf
106 #  define intf                  z_intf
107 #  define uIntf                 z_uIntf
108 #  define uLongf                z_uLongf
109 #  define voidpf                z_voidpf
110 #  define voidp                 z_voidp
111 #endif
112 
113 #if defined(__MSDOS__) && !defined(MSDOS)
114 #  define MSDOS
115 #endif
116 #if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
117 #  define OS2
118 #endif
119 #if defined(_WINDOWS) && !defined(WINDOWS)
120 #  define WINDOWS
121 #endif
122 #if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
123 #  ifndef WIN32
124 #    define WIN32
125 #  endif
126 #endif
127 #if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
128 #  if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
129 #    ifndef SYS16BIT
130 #      define SYS16BIT
131 #    endif
132 #  endif
133 #endif
134 
135 /*
136  * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
137  * than 64k bytes at a time (needed on systems with 16-bit int).
138  */
139 #ifdef SYS16BIT
140 #  define MAXSEG_64K
141 #endif
142 #ifdef MSDOS
143 #  define UNALIGNED_OK
144 #endif
145 
146 #ifdef __STDC_VERSION__
147 #  ifndef STDC
148 #    define STDC
149 #  endif
150 #  if __STDC_VERSION__ >= 199901L
151 #    ifndef STDC99
152 #      define STDC99
153 #    endif
154 #  endif
155 #endif
156 #if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
157 #  define STDC
158 #endif
159 #if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
160 #  define STDC
161 #endif
162 #if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
163 #  define STDC
164 #endif
165 #if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
166 #  define STDC
167 #endif
168 
169 #if defined(__OS400__) && !defined(STDC)    /* iSeries (formerly AS/400). */
170 #  define STDC
171 #endif
172 
173 #ifndef STDC
174 #  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
175 #    define const       /* note: need a more gentle solution here */
176 #  endif
177 #endif
178 
179 /* Some Mac compilers merge all .h files incorrectly: */
180 #if defined(__MWERKS__)||defined(applec)||defined(THINK_C)||defined(__SC__)
181 #  define NO_DUMMY_DECL
182 #endif
183 
184 /* Maximum value for memLevel in deflateInit2 */
185 #ifndef MAX_MEM_LEVEL
186 #  ifdef MAXSEG_64K
187 #    define MAX_MEM_LEVEL 8
188 #  else
189 #    define MAX_MEM_LEVEL 9
190 #  endif
191 #endif
192 
193 /* Maximum value for windowBits in deflateInit2 and inflateInit2.
194  * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
195  * created by gzip. (Files created by minigzip can still be extracted by
196  * gzip.)
197  */
198 #ifndef MAX_WBITS
199 #  define MAX_WBITS   15 /* 32K LZ77 window */
200 #endif
201 
202 /* The memory requirements for deflate are (in bytes):
203             (1 << (windowBits+2)) +  (1 << (memLevel+9))
204  that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
205  plus a few kilobytes for small objects. For example, if you want to reduce
206  the default memory requirements from 256K to 128K, compile with
207      make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
208  Of course this will generally degrade compression (there's no free lunch).
209 
210    The memory requirements for inflate are (in bytes) 1 << windowBits
211  that is, 32K for windowBits=15 (default value) plus a few kilobytes
212  for small objects.
213 */
214 
215                         /* Type declarations */
216 
217 #ifndef OF /* function prototypes */
218 #  ifdef STDC
219 #    define OF(args)  args
220 #  else
221 #    define OF(args)  ()
222 #  endif
223 #endif
224 
225 /* The following definitions for FAR are needed only for MSDOS mixed
226  * model programming (small or medium model with some far allocations).
227  * This was tested only with MSC; for other MSDOS compilers you may have
228  * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
229  * just define FAR to be empty.
230  */
231 #ifdef SYS16BIT
232 #  if defined(M_I86SM) || defined(M_I86MM)
233      /* MSC small or medium model */
234 #    define SMALL_MEDIUM
235 #    ifdef _MSC_VER
236 #      define FAR _far
237 #    else
238 #      define FAR far
239 #    endif
240 #  endif
241 #  if (defined(__SMALL__) || defined(__MEDIUM__))
242      /* Turbo C small or medium model */
243 #    define SMALL_MEDIUM
244 #    ifdef __BORLANDC__
245 #      define FAR _far
246 #    else
247 #      define FAR far
248 #    endif
249 #  endif
250 #endif
251 
252 #if defined(WINDOWS) || defined(WIN32)
253    /* If building or using zlib as a DLL, define ZLIB_DLL.
254     * This is not mandatory, but it offers a little performance increase.
255     */
256 #  ifdef ZLIB_DLL
257 #    if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
258 #      ifdef ZLIB_INTERNAL
259 #        define ZEXTERN extern __declspec(dllexport)
260 #      else
261 #        define ZEXTERN extern __declspec(dllimport)
262 #      endif
263 #    endif
264 #  endif  /* ZLIB_DLL */
265    /* If building or using zlib with the WINAPI/WINAPIV calling convention,
266     * define ZLIB_WINAPI.
267     * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
268     */
269 #  ifdef ZLIB_WINAPI
270 #    ifdef FAR
271 #      undef FAR
272 #    endif
273 #    include <windows.h>
274      /* No need for _export, use ZLIB.DEF instead. */
275      /* For complete Windows compatibility, use WINAPI, not __stdcall. */
276 #    define ZEXPORT WINAPI
277 #    ifdef WIN32
278 #      define ZEXPORTVA WINAPIV
279 #    else
280 #      define ZEXPORTVA FAR CDECL
281 #    endif
282 #  endif
283 #endif
284 
285 #if defined (__BEOS__)
286 #  ifdef ZLIB_DLL
287 #    ifdef ZLIB_INTERNAL
288 #      define ZEXPORT   __declspec(dllexport)
289 #      define ZEXPORTVA __declspec(dllexport)
290 #    else
291 #      define ZEXPORT   __declspec(dllimport)
292 #      define ZEXPORTVA __declspec(dllimport)
293 #    endif
294 #  endif
295 #endif
296 
297 #ifndef ZEXTERN
298 #  define ZEXTERN extern
299 #endif
300 #ifndef ZEXPORT
301 #  define ZEXPORT
302 #endif
303 #ifndef ZEXPORTVA
304 #  define ZEXPORTVA
305 #endif
306 
307 #ifndef FAR
308 #  define FAR
309 #endif
310 
311 #if !defined(__MACTYPES__)
312 typedef unsigned char  Byte;  /* 8 bits */
313 #endif
314 typedef unsigned int   uInt;  /* 16 bits or more */
315 typedef unsigned long  uLong; /* 32 bits or more */
316 
317 #ifdef SMALL_MEDIUM
318    /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
319 #  define Bytef Byte FAR
320 #else
321    typedef Byte  FAR Bytef;
322 #endif
323 typedef char  FAR charf;
324 typedef int   FAR intf;
325 typedef uInt  FAR uIntf;
326 typedef uLong FAR uLongf;
327 
328 #ifdef STDC
329    typedef void const *voidpc;
330    typedef void FAR   *voidpf;
331    typedef void       *voidp;
332 #else
333    typedef Byte const *voidpc;
334    typedef Byte FAR   *voidpf;
335    typedef Byte       *voidp;
336 #endif
337 
338 #  ifdef VMS
339 #    include <unixio.h>   /* for off_t */
340 #  endif
341 #  define z_off_t off_t
342 #ifndef SEEK_SET
343 #  define SEEK_SET        0       /* Seek from beginning of file.  */
344 #  define SEEK_CUR        1       /* Seek from current position.  */
345 #  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
346 #endif
347 #ifndef z_off_t
348 #  define z_off_t long
349 #endif
350 
351 #if defined(__OS400__)
352 #  define NO_vsnprintf
353 #endif
354 
355 #if defined(__MVS__)
356 #  define NO_vsnprintf
357 #  ifdef FAR
358 #    undef FAR
359 #  endif
360 #endif
361 
362 /* MVS linker does not support external names larger than 8 bytes */
363 #if defined(__MVS__)
364 #   pragma map(deflateInit_,"DEIN")
365 #   pragma map(deflateInit2_,"DEIN2")
366 #   pragma map(deflateEnd,"DEEND")
367 #   pragma map(deflateBound,"DEBND")
368 #   pragma map(inflateInit_,"ININ")
369 #   pragma map(inflateInit2_,"ININ2")
370 #   pragma map(inflateEnd,"INEND")
371 #   pragma map(inflateSync,"INSY")
372 #   pragma map(inflateSetDictionary,"INSEDI")
373 #   pragma map(compressBound,"CMBND")
374 #   pragma map(inflate_table,"INTABL")
375 #   pragma map(inflate_fast,"INFA")
376 #   pragma map(inflate_copyright,"INCOPY")
377 #endif
378 /* End of new zconf.h */
379 
380 /*
381      The 'zlib' compression library provides in-memory compression and
382   decompression functions, including integrity checks of the uncompressed
383   data.  This version of the library supports only one compression method
384   (deflation) but other algorithms will be added later and will have the same
385   stream interface.
386 
387      Compression can be done in a single step if the buffers are large
388   enough (for example if an input file is mmap'ed), or can be done by
389   repeated calls of the compression function.  In the latter case, the
390   application must provide more input and/or consume the output
391   (providing more output space) before each call.
392 
393      The compressed data format used by default by the in-memory functions is
394   the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
395   around a deflate stream, which is itself documented in RFC 1951.
396 
397      The library also supports reading and writing files in gzip (.gz) format
398   with an interface similar to that of stdio using the functions that start
399   with "gz".  The gzip format is different from the zlib format.  gzip is a
400   gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
401 
402      This library can optionally read and write gzip streams in memory as well.
403 
404      The zlib format was designed to be compact and fast for use in memory
405   and on communications channels.  The gzip format was designed for single-
406   file compression on file systems, has a larger header than zlib to maintain
407   directory information, and uses a different, slower check method than zlib.
408 
409      The library does not install any signal handler. The decoder checks
410   the consistency of the compressed data, so the library should never
411   crash even in case of corrupted input.
412 */
413 
414 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
415 typedef void   (*free_func)  OF((voidpf opaque, voidpf address, uInt size));
416 typedef void   (*cb_func)    OF((Bytef *buf, uInt len));
417 
418 struct internal_state;
419 
420 typedef struct z_stream_s {
421 	Bytef	*next_in; /* next input byte */
422 	uInt	avail_in; /* number of bytes available at next_in */
423 	uLong	total_in; /* total nb of input bytes read so far */
424 	Bytef	*next_out; /* next output byte should be put there */
425 	uInt	avail_out; /* remaining free space at next_out */
426 	uLong	total_out; /* total nb of bytes output so far */
427 	char	*msg;	/* last error message, NULL if no error */
428 	struct	internal_state FAR *state; /* not visible by applications */
429 	alloc_func	zalloc;	/* used to allocate the internal state */
430 	free_func	zfree;	/* used to free the internal state */
431 	voidpf	opaque;	/* private data object passed to zalloc and zfree */
432 	int	data_type;	/* best guess about the data type:
433 					binary or text */
434 	cb_func	outcb;	/* called regularly just before blocks of output */
435 	uLong	adler;	/* adler32 value of the uncompressed data */
436 	uLong	reserved;	/* reserved for future use */
437 } z_stream;
438 
439 typedef z_stream FAR *z_streamp;
440 
441 /*
442      gzip header information passed to and from zlib routines.  See RFC 1952
443   for more details on the meanings of these fields.
444 */
445 typedef struct gz_header_s {
446 	int	text;	/* true if compressed data believed to be text */
447 	uLong	time;	/* modification time */
448 	int	xflags;	/* extra flags (not used when writing a gzip file) */
449 	int	os;	/* operating system */
450 	Bytef	*extra;	/* pointer to extra field or Z_NULL if none */
451 	uInt	extra_len; /* extra field length (valid if extra != Z_NULL) */
452 	uInt	extra_max; /* space at extra (only when reading header) */
453 	Bytef	*name; /* pointer to zero-terminated file name or Z_NULL */
454 	uInt	name_max; /* space at name (only when reading header) */
455 	Bytef	*comment; /* pointer to zero-terminated comment or Z_NULL */
456 	uInt	comm_max; /* space at comment (only when reading header) */
457 	int	hcrc; /* true if there was or will be a header crc */
458 	int	done; /* true when done reading gzip header (not used
459 			when writing a gzip file) */
460 } gz_header;
461 
462 typedef gz_header FAR *gz_headerp;
463 
464                         /* constants */
465 #define Z_NO_FLUSH      0
466 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
467 #define Z_SYNC_FLUSH    2
468 #define Z_FULL_FLUSH    3
469 #define Z_FINISH        4
470 #define Z_BLOCK         5
471 /* Allowed flush values; see deflate() and inflate() below for details */
472 
473 #define Z_OK            0
474 #define Z_STREAM_END    1
475 #define Z_NEED_DICT     2
476 #define Z_ERRNO        (-1)
477 #define Z_STREAM_ERROR (-2)
478 #define Z_DATA_ERROR   (-3)
479 #define Z_MEM_ERROR    (-4)
480 #define Z_BUF_ERROR    (-5)
481 #define Z_VERSION_ERROR (-6)
482 /* Return codes for the compression/decompression functions. Negative
483  * values are errors, positive values are used for special but normal events.
484  */
485 
486 #define Z_NO_COMPRESSION         0
487 #define Z_BEST_SPEED             1
488 #define Z_BEST_COMPRESSION       9
489 #define Z_DEFAULT_COMPRESSION  (-1)
490 /* compression levels */
491 
492 #define Z_FILTERED            1
493 #define Z_HUFFMAN_ONLY        2
494 #define Z_RLE                 3
495 #define Z_FIXED               4
496 #define Z_DEFAULT_STRATEGY    0
497 /* compression strategy; see deflateInit2() below for details */
498 
499 #define Z_BINARY   0
500 #define Z_TEXT     1
501 #define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
502 #define Z_UNKNOWN  2
503 /* Possible values of the data_type field (though see inflate()) */
504 
505 #define Z_DEFLATED   8
506 /* The deflate compression method (the only one supported in this version) */
507 
508 #define Z_NULL  (void *)0  /* for initializing zalloc, zfree, opaque */
509 
510                         /* basic functions */
511 
512 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
513    If the first character differs, the library code actually used is
514    not compatible with the zlib.h header file used by the application.
515    This check is automatically made by deflateInit and inflateInit.
516    */
517 
518 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
519 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
520 			const char *version, int stream_size));
521 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
522 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
523 			int windowBits, int memLevel,
524 			int strategy, const char *version,
525 			int stream_size));
526 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
527 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
528 			const Bytef *dictionary,
529 			uInt  dictLength));
530 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
531 			gz_headerp head));
532 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
533 			int bits,
534 			int value));
535 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
536 			int level,
537 			int strategy));
538 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
539 			int good_length,
540 			int max_lazy,
541 			int nice_length,
542 			int max_chain));
543 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
544 			uLong sourceLen));
545 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
546 			z_streamp source));
547 
548 
549 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
550 			const char *version, int stream_size));
551 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
552 /*
553     inflate decompresses as much data as possible, and stops when the input
554   buffer becomes empty or the output buffer becomes full. It may introduce
555   some output latency (reading input without producing any output) except when
556   forced to flush.
557 
558   The detailed semantics are as follows. inflate performs one or both of the
559   following actions:
560 
561   - Decompress more input starting at next_in and update next_in and avail_in
562     accordingly. If not all input can be processed (because there is not
563     enough room in the output buffer), next_in is updated and processing
564     will resume at this point for the next call of inflate().
565 
566   - Provide more output starting at next_out and update next_out and avail_out
567     accordingly.  inflate() provides as much output as possible, until there
568     is no more input data or no more space in the output buffer (see below
569     about the flush parameter).
570 
571   Before the call of inflate(), the application should ensure that at least
572   one of the actions is possible, by providing more input and/or consuming
573   more output, and updating the next_* and avail_* values accordingly.
574   The application can consume the uncompressed output when it wants, for
575   example when the output buffer is full (avail_out == 0), or after each
576   call of inflate(). If inflate returns Z_OK and with zero avail_out, it
577   must be called again after making room in the output buffer because there
578   might be more output pending.
579 
580     The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
581   Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
582   output as possible to the output buffer. Z_BLOCK requests that inflate() stop
583   if and when it gets to the next deflate block boundary. When decoding the
584   zlib or gzip format, this will cause inflate() to return immediately after
585   the header and before the first block. When doing a raw inflate, inflate()
586   will go ahead and process the first block, and will return when it gets to
587   the end of that block, or when it runs out of data.
588 
589     The Z_BLOCK option assists in appending to or combining deflate streams.
590   Also to assist in this, on return inflate() will set strm->data_type to the
591   number of unused bits in the last byte taken from strm->next_in, plus 64
592   if inflate() is currently decoding the last block in the deflate stream,
593   plus 128 if inflate() returned immediately after decoding an end-of-block
594   code or decoding the complete header up to just before the first byte of the
595   deflate stream. The end-of-block will not be indicated until all of the
596   uncompressed data from that block has been written to strm->next_out.  The
597   number of unused bits may in general be greater than seven, except when
598   bit 7 of data_type is set, in which case the number of unused bits will be
599   less than eight.
600 
601     inflate() should normally be called until it returns Z_STREAM_END or an
602   error. However if all decompression is to be performed in a single step
603   (a single call of inflate), the parameter flush should be set to
604   Z_FINISH. In this case all pending input is processed and all pending
605   output is flushed; avail_out must be large enough to hold all the
606   uncompressed data. (The size of the uncompressed data may have been saved
607   by the compressor for this purpose.) The next operation on this stream must
608   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
609   is never required, but can be used to inform inflate that a faster approach
610   may be used for the single inflate() call.
611 
612      In this implementation, inflate() always flushes as much output as
613   possible to the output buffer, and always uses the faster approach on the
614   first call. So the only effect of the flush parameter in this implementation
615   is on the return value of inflate(), as noted below, or when it returns early
616   because Z_BLOCK is used.
617 
618      If a preset dictionary is needed after this call (see inflateSetDictionary
619   below), inflate sets strm->adler to the adler32 checksum of the dictionary
620   chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
621   strm->adler to the adler32 checksum of all output produced so far (that is,
622   total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
623   below. At the end of the stream, inflate() checks that its computed adler32
624   checksum is equal to that saved by the compressor and returns Z_STREAM_END
625   only if the checksum is correct.
626 
627     inflate() will decompress and check either zlib-wrapped or gzip-wrapped
628   deflate data.  The header type is detected automatically.  Any information
629   contained in the gzip header is not retained, so applications that need that
630   information should instead use raw inflate, see inflateInit2() below, or
631   inflateBack() and perform their own processing of the gzip header and
632   trailer.
633 
634     inflate() returns Z_OK if some progress has been made (more input processed
635   or more output produced), Z_STREAM_END if the end of the compressed data has
636   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
637   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
638   corrupted (input stream not conforming to the zlib format or incorrect check
639   value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
640   if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
641   Z_BUF_ERROR if no progress is possible or if there was not enough room in the
642   output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
643   inflate() can be called again with more input and more output space to
644   continue decompressing. If Z_DATA_ERROR is returned, the application may then
645   call inflateSync() to look for a good compression block if a partial recovery
646   of the data is desired.
647 */
648 
649 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
650 /*
651      All dynamically allocated data structures for this stream are freed.
652    This function discards any unprocessed input and does not flush any
653    pending output.
654 
655      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
656    was inconsistent. In the error case, msg may be set but then points to a
657    static string (which must not be deallocated).
658 */
659 
660                         /* Advanced functions */
661 
662 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
663 
664                         /* utility functions */
665 
666 /*
667      The following utility functions are implemented on top of the
668    basic stream-oriented functions. To simplify the interface, some
669    default options are assumed (compression level and memory usage,
670    standard memory allocation functions). The source code of these
671    utility functions can easily be modified if you need special options.
672 */
673 
674 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
675 /*
676      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
677    return the updated checksum. If buf is NULL, this function returns
678    the required initial value for the checksum.
679    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
680    much faster. Usage example:
681 
682      uLong adler = adler32(0L, Z_NULL, 0);
683 
684      while (read_buffer(buffer, length) != EOF) {
685        adler = adler32(adler, buffer, length);
686      }
687      if (adler != original_adler) error();
688 */
689 
690 /*
691      Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
692    and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
693    each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
694    seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
695 */
696 
697 ZEXTERN  uInt ZEXPORT crc32  OF((uInt crc, const Bytef *buf, uInt len));
698 /*
699      Update a running CRC-32 with the bytes buf[0..len-1] and return the
700    updated CRC-32. If buf is NULL, this function returns the required initial
701    value for the for the crc. Pre- and post-conditioning (one's complement) is
702    performed within this function so it shouldn't be done by the application.
703    Usage example:
704 
705      uLong crc = crc32(0L, Z_NULL, 0);
706 
707      while (read_buffer(buffer, length) != EOF) {
708        crc = crc32(crc, buffer, length);
709      }
710      if (crc != original_crc) error();
711 */
712 
713 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
714                                       const char *version, int stream_size));
715 #define inflateInit(strm) \
716 	inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
717 #define inflateInit2(strm, windowBits) \
718 	inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
719 
720 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
721 	struct internal_state {int dummy;}; /* hack for buggy compilers */
722 #endif
723 
724 extern void *gzalloc(void *, unsigned, unsigned);
725 extern void gzfree(void *, void *, unsigned);
726 
727 #ifdef __cplusplus
728 }
729 #endif
730 
731 #endif /* ZLIB_H */
732