master
1/* $NetBSD: zlib.h,v 1.15 2020/03/05 07:46:49 riastradh Exp $ */
2
3/* zlib.h -- interface of the 'zlib' general purpose compression library
4 version 1.1.4, March 11th, 2002
5
6 Copyright (C) 1995-2002 Jean-loup Gailly and Mark Adler
7
8 This software is provided 'as-is', without any express or implied
9 warranty. In no event will the authors be held liable for any damages
10 arising from the use of this software.
11
12 Permission is granted to anyone to use this software for any purpose,
13 including commercial applications, and to alter it and redistribute it
14 freely, subject to the following restrictions:
15
16 1. The origin of this software must not be misrepresented; you must not
17 claim that you wrote the original software. If you use this software
18 in a product, an acknowledgment in the product documentation would be
19 appreciated but is not required.
20 2. Altered source versions must be plainly marked as such, and must not be
21 misrepresented as being the original software.
22 3. This notice may not be removed or altered from any source distribution.
23
24 Jean-loup Gailly Mark Adler
25 jloup@gzip.org madler@alumni.caltech.edu
26
27
28 The data format used by the zlib library is described by RFCs (Request for
29 Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
30 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
31*/
32
33#ifndef _NET_ZLIB_H_
34#define _NET_ZLIB_H_
35
36#ifdef __NetBSD__
37#include <sys/cdefs.h>
38#endif
39
40/* +++ zconf.h */
41/* zconf.h -- configuration of the zlib compression library
42 * Copyright (C) 1995-2002 Jean-loup Gailly.
43 * For conditions of distribution and use, see copyright notice in zlib.h
44 */
45
46/* @(#) $Id: zlib.h,v 1.15 2020/03/05 07:46:49 riastradh Exp $ */
47
48#ifndef ZCONF_H
49#define ZCONF_H
50
51/*
52 * Warning: This file pollutes the user's namespace with:
53 * Byte Bytef EXPORT FAR OF STDC
54 * charf intf uInt uIntf uLong uLonf
55 * Programs using this library appear to expect those...
56 */
57
58#include <sys/types.h>
59
60/*
61 * If you *really* need a unique prefix for all types and library functions,
62 * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
63 */
64#ifdef Z_PREFIX
65# define deflateInit_ z_deflateInit_
66# define deflate z_deflate
67# define deflateEnd z_deflateEnd
68# define inflateInit_ z_inflateInit_
69# define inflate z_inflate
70# define inflateEnd z_inflateEnd
71# define deflateInit2_ z_deflateInit2_
72# define deflateSetDictionary z_deflateSetDictionary
73# define deflateCopy z_deflateCopy
74# define deflateReset z_deflateReset
75# define deflateParams z_deflateParams
76# define inflateInit2_ z_inflateInit2_
77# define inflateSetDictionary z_inflateSetDictionary
78# define inflateSync z_inflateSync
79# define inflateSyncPoint z_inflateSyncPoint
80# define inflateReset z_inflateReset
81# define compress z_compress
82# define compress2 z_compress2
83# define uncompress z_uncompress
84# define adler32 z_adler32
85# define crc32 z_crc32
86# define get_crc_table z_get_crc_table
87
88# define Byte z_Byte
89# define uInt z_uInt
90# define uLong z_uLong
91# define Bytef z_Bytef
92# define charf z_charf
93# define intf z_intf
94# define uIntf z_uIntf
95# define uLongf z_uLongf
96# define voidpf z_voidpf
97# define voidp z_voidp
98#endif
99
100#ifndef __32BIT__
101/* Don't be alarmed; this just means we have at least 32-bits */
102# define __32BIT__
103#endif
104
105/*
106 * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
107 * than 64k bytes at a time (needed on systems with 16-bit int).
108 */
109#if defined(MSDOS) && !defined(__32BIT__)
110# define MAXSEG_64K
111#endif
112
113#if 0
114/* XXX: Are there machines where we should define this? m68k? */
115# define UNALIGNED_OK
116#endif
117
118#if (defined(__STDC__) || defined(__cplusplus)) && !defined(STDC)
119/* XXX: Look out - this is used in zutil.h and elsewhere... */
120# define STDC
121#endif
122#if defined(__STDC__) || defined(__cplusplus) || defined(__OS2__)
123# ifndef STDC
124# define STDC
125# endif
126#endif
127
128#ifndef STDC
129# ifndef const
130# define const
131# endif
132#endif
133
134/* Some Mac compilers merge all .h files incorrectly: */
135#if defined(__MWERKS__) || defined(applec) ||defined(THINK_C) ||defined(__SC__)
136# define NO_DUMMY_DECL
137#endif
138#define NO_DUMMY_DECL
139
140/* Old Borland C incorrectly complains about missing returns: */
141#if defined(__BORLANDC__) && (__BORLANDC__ < 0x500)
142# define NEED_DUMMY_RETURN
143#endif
144
145
146/* Maximum value for memLevel in deflateInit2 */
147#ifndef MAX_MEM_LEVEL
148# ifdef MAXSEG_64K
149# define MAX_MEM_LEVEL 8
150# else
151# define MAX_MEM_LEVEL 9
152# endif
153#endif
154
155/* Maximum value for windowBits in deflateInit2 and inflateInit2.
156 * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
157 * created by gzip. (Files created by minigzip can still be extracted by
158 * gzip.)
159 */
160#ifndef MAX_WBITS
161# define MAX_WBITS 15 /* 32K LZ77 window */
162#endif
163
164/* The memory requirements for deflate are (in bytes):
165 (1 << (windowBits+2)) + (1 << (memLevel+9))
166 that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values)
167 plus a few kilobytes for small objects. For example, if you want to reduce
168 the default memory requirements from 256K to 128K, compile with
169 make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
170 Of course this will generally degrade compression (there's no free lunch).
171
172 The memory requirements for inflate are (in bytes) 1 << windowBits
173 that is, 32K for windowBits=15 (default value) plus a few kilobytes
174 for small objects.
175*/
176
177 /* Type declarations */
178
179#ifndef __P /* function prototypes */
180# ifdef STDC
181# define __P(args) args
182# else
183# define __P(args) ()
184# endif
185#endif
186
187/* The following definitions for FAR are needed only for MSDOS mixed
188 * model programming (small or medium model with some far allocations).
189 * This was tested only with MSC; for other MSDOS compilers you may have
190 * to define NO_MEMCPY in zutil.h. If you don't need the mixed model,
191 * just define FAR to be empty.
192 */
193#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(__32BIT__)
194 /* MSC small or medium model */
195# define SMALL_MEDIUM
196# ifdef _MSC_VER
197# define FAR _far
198# else
199# define FAR far
200# endif
201#endif
202#if defined(__BORLANDC__) && (defined(__SMALL__) || defined(__MEDIUM__))
203# ifndef __32BIT__
204# define SMALL_MEDIUM
205# define FAR _far
206# endif
207#endif
208
209/* Compile with -DZLIB_DLL for Windows DLL support */
210#if defined(ZLIB_DLL)
211# if defined(_WINDOWS) || defined(WINDOWS)
212# ifdef FAR
213# undef FAR
214# endif
215# include <windows.h>
216# define ZEXPORT WINAPI
217# ifdef WIN32
218# define ZEXPORTVA WINAPIV
219# else
220# define ZEXPORTVA FAR _cdecl _export
221# endif
222# endif
223# if defined (__BORLANDC__)
224# if (__BORLANDC__ >= 0x0500) && defined (WIN32)
225# include <windows.h>
226# define ZEXPORT __declspec(dllexport) WINAPI
227# define ZEXPORTRVA __declspec(dllexport) WINAPIV
228# else
229# if defined (_Windows) && defined (__DLL__)
230# define ZEXPORT _export
231# define ZEXPORTVA _export
232# endif
233# endif
234# endif
235#endif
236
237#if defined (__BEOS__)
238# if defined (ZLIB_DLL)
239# define ZEXTERN extern __declspec(dllexport)
240# else
241# define ZEXTERN extern __declspec(dllimport)
242# endif
243#endif
244
245#ifndef ZEXPORT
246# define ZEXPORT
247#endif
248#ifndef ZEXPORTVA
249# define ZEXPORTVA
250#endif
251#ifndef ZEXTERN
252# define ZEXTERN extern
253#endif
254
255#ifndef FAR
256# define FAR
257#endif
258
259#if !defined(MACOS) && !defined(TARGET_OS_MAC)
260typedef unsigned char Byte; /* 8 bits */
261#endif
262typedef unsigned int uInt; /* 16 bits or more */
263typedef unsigned long uLong; /* 32 bits or more */
264
265#ifdef SMALL_MEDIUM
266 /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
267# define Bytef Byte FAR
268#else
269 typedef Byte FAR Bytef;
270#endif
271typedef char FAR charf;
272typedef int FAR intf;
273typedef uInt FAR uIntf;
274typedef uLong FAR uLongf;
275
276#ifdef STDC
277 typedef void FAR *voidpf;
278 typedef void *voidp;
279#else
280 typedef Byte FAR *voidpf;
281 typedef Byte *voidp;
282#endif
283
284#if (defined(HAVE_UNISTD_H) || defined(__NetBSD__)) && !defined(_KERNEL)
285# include <sys/types.h> /* for off_t */
286# include <unistd.h> /* for SEEK_* and off_t */
287# define z_off_t off_t
288#endif
289#ifndef SEEK_SET
290# define SEEK_SET 0 /* Seek from beginning of file. */
291# define SEEK_CUR 1 /* Seek from current position. */
292# define SEEK_END 2 /* Set file pointer to EOF plus "offset" */
293#endif
294#ifndef z_off_t
295# define z_off_t long
296#endif
297
298/* MVS linker does not support external names larger than 8 bytes */
299#if defined(__MVS__)
300# pragma map(deflateInit_,"DEIN")
301# pragma map(deflateInit2_,"DEIN2")
302# pragma map(deflateEnd,"DEEND")
303# pragma map(inflateInit_,"ININ")
304# pragma map(inflateInit2_,"ININ2")
305# pragma map(inflateEnd,"INEND")
306# pragma map(inflateSync,"INSY")
307# pragma map(inflateSetDictionary,"INSEDI")
308# pragma map(inflate_blocks,"INBL")
309# pragma map(inflate_blocks_new,"INBLNE")
310# pragma map(inflate_blocks_free,"INBLFR")
311# pragma map(inflate_blocks_reset,"INBLRE")
312# pragma map(inflate_codes_free,"INCOFR")
313# pragma map(inflate_codes,"INCO")
314# pragma map(inflate_fast,"INFA")
315# pragma map(inflate_flush,"INFLU")
316# pragma map(inflate_mask,"INMA")
317# pragma map(inflate_set_dictionary,"INSEDI2")
318# pragma map(inflate_copyright,"INCOPY")
319# pragma map(inflate_trees_bits,"INTRBI")
320# pragma map(inflate_trees_dynamic,"INTRDY")
321# pragma map(inflate_trees_fixed,"INTRFI")
322# pragma map(inflate_trees_free,"INTRFR")
323#endif
324
325#endif /* !ZCONF_H */
326/* --- zconf.h */
327
328#ifndef ZLIB_H
329#define ZLIB_H
330#ifdef __cplusplus
331extern "C" {
332#endif
333
334#define ZLIB_VERSION "1.1.4"
335
336/*
337 The 'zlib' compression library provides in-memory compression and
338 decompression functions, including integrity checks of the uncompressed
339 data. This version of the library supports only one compression method
340 (deflation) but other algorithms will be added later and will have the same
341 stream interface.
342
343 Compression can be done in a single step if the buffers are large
344 enough (for example if an input file is mmap'ed), or can be done by
345 repeated calls of the compression function. In the latter case, the
346 application must provide more input and/or consume the output
347 (providing more output space) before each call.
348
349 The library also supports reading and writing files in gzip (.gz) format
350 with an interface similar to that of stdio.
351
352 The library does not install any signal handler. The decoder checks
353 the consistency of the compressed data, so the library should never
354 crash even in case of corrupted input.
355*/
356
357typedef voidpf (*alloc_func)(voidpf, uInt, uInt);
358typedef void (*free_func)(voidpf, voidpf);
359
360struct internal_state;
361
362typedef struct z_stream_s {
363 Bytef *next_in; /* next input byte */
364 uInt avail_in; /* number of bytes available at next_in */
365 uLong total_in; /* total nb of input bytes read so far */
366
367 Bytef *next_out; /* next output byte should be put there */
368 uInt avail_out; /* remaining free space at next_out */
369 uLong total_out; /* total nb of bytes output so far */
370
371 const char *msg; /* last error message, NULL if no error */
372 struct internal_state FAR *state; /* not visible by applications */
373
374 alloc_func zalloc; /* used to allocate the internal state */
375 free_func zfree; /* used to free the internal state */
376 voidpf opaque; /* private data object passed to zalloc and zfree */
377
378 int data_type; /* best guess about the data type: ascii or binary */
379 uLong adler; /* adler32 value of the uncompressed data */
380 uLong reserved; /* reserved for future use */
381} z_stream;
382
383typedef z_stream FAR *z_streamp;
384
385/*
386 The application must update next_in and avail_in when avail_in has
387 dropped to zero. It must update next_out and avail_out when avail_out
388 has dropped to zero. The application must initialize zalloc, zfree and
389 opaque before calling the init function. All other fields are set by the
390 compression library and must not be updated by the application.
391
392 The opaque value provided by the application will be passed as the first
393 parameter for calls of zalloc and zfree. This can be useful for custom
394 memory management. The compression library attaches no meaning to the
395 opaque value.
396
397 zalloc must return Z_NULL if there is not enough memory for the object.
398 If zlib is used in a multi-threaded application, zalloc and zfree must be
399 thread safe.
400
401 On 16-bit systems, the functions zalloc and zfree must be able to allocate
402 exactly 65536 bytes, but will not be required to allocate more than this
403 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
404 pointers returned by zalloc for objects of exactly 65536 bytes *must*
405 have their offset normalized to zero. The default allocation function
406 provided by this library ensures this (see zutil.c). To reduce memory
407 requirements and avoid any allocation of 64K objects, at the expense of
408 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
409
410 The fields total_in and total_out can be used for statistics or
411 progress reports. After compression, total_in holds the total size of
412 the uncompressed data and may be saved for use in the decompressor
413 (particularly if the decompressor wants to decompress everything in
414 a single step).
415*/
416
417 /* constants */
418
419#define Z_NO_FLUSH 0
420#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
421#define Z_PACKET_FLUSH 2
422#define Z_SYNC_FLUSH 3
423#define Z_FULL_FLUSH 4
424#define Z_FINISH 5
425/* Allowed flush values; see deflate() below for details */
426
427#define Z_OK 0
428#define Z_STREAM_END 1
429#define Z_NEED_DICT 2
430#define Z_ERRNO (-1)
431#define Z_STREAM_ERROR (-2)
432#define Z_DATA_ERROR (-3)
433#define Z_MEM_ERROR (-4)
434#define Z_BUF_ERROR (-5)
435#define Z_VERSION_ERROR (-6)
436/* Return codes for the compression/decompression functions. Negative
437 * values are errors, positive values are used for special but normal events.
438 */
439
440#define Z_NO_COMPRESSION 0
441#define Z_BEST_SPEED 1
442#define Z_BEST_COMPRESSION 9
443#define Z_DEFAULT_COMPRESSION (-1)
444/* compression levels */
445
446#define Z_FILTERED 1
447#define Z_HUFFMAN_ONLY 2
448#define Z_DEFAULT_STRATEGY 0
449/* compression strategy; see deflateInit2() below for details */
450
451#define Z_BINARY 0
452#define Z_ASCII 1
453#define Z_UNKNOWN 2
454/* Possible values of the data_type field */
455
456#define Z_DEFLATED 8
457/* The deflate compression method (the only one supported in this version) */
458
459#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
460
461#define zlib_version zlibVersion()
462/* for compatibility with versions < 1.0.2 */
463
464 /* basic functions */
465
466ZEXTERN const char * ZEXPORT zlibVersion(void);
467/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
468 If the first character differs, the library code actually used is
469 not compatible with the zlib.h header file used by the application.
470 This check is automatically made by deflateInit and inflateInit.
471 */
472
473/*
474ZEXTERN int ZEXPORT deflateInit(z_streamp, int);
475
476 Initializes the internal stream state for compression. The fields
477 zalloc, zfree and opaque must be initialized before by the caller.
478 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
479 use default allocation functions.
480
481 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
482 1 gives best speed, 9 gives best compression, 0 gives no compression at
483 all (the input data is simply copied a block at a time).
484 Z_DEFAULT_COMPRESSION requests a default compromise between speed and
485 compression (currently equivalent to level 6).
486
487 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
488 enough memory, Z_STREAM_ERROR if level is not a valid compression level,
489 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
490 with the version assumed by the caller (ZLIB_VERSION).
491 msg is set to null if there is no error message. deflateInit does not
492 perform any compression: this will be done by deflate().
493*/
494
495
496ZEXTERN int ZEXPORT deflate(z_streamp, int);
497/*
498 deflate compresses as much data as possible, and stops when the input
499 buffer becomes empty or the output buffer becomes full. It may introduce some
500 output latency (reading input without producing any output) except when
501 forced to flush.
502
503 The detailed semantics are as follows. deflate performs one or both of the
504 following actions:
505
506 - Compress more input starting at next_in and update next_in and avail_in
507 accordingly. If not all input can be processed (because there is not
508 enough room in the output buffer), next_in and avail_in are updated and
509 processing will resume at this point for the next call of deflate().
510
511 - Provide more output starting at next_out and update next_out and avail_out
512 accordingly. This action is forced if the parameter flush is non zero.
513 Forcing flush frequently degrades the compression ratio, so this parameter
514 should be set only when necessary (in interactive applications).
515 Some output may be provided even if flush is not set.
516
517 Before the call of deflate(), the application should ensure that at least
518 one of the actions is possible, by providing more input and/or consuming
519 more output, and updating avail_in or avail_out accordingly; avail_out
520 should never be zero before the call. The application can consume the
521 compressed output when it wants, for example when the output buffer is full
522 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
523 and with zero avail_out, it must be called again after making room in the
524 output buffer because there might be more output pending.
525
526 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
527 flushed to the output buffer and the output is aligned on a byte boundary, so
528 that the decompressor can get all input data available so far. (In particular
529 avail_in is zero after the call if enough output space has been provided
530 before the call.) Flushing may degrade compression for some compression
531 algorithms and so it should be used only when necessary.
532
533 If flush is set to Z_FULL_FLUSH, all output is flushed as with
534 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
535 restart from this point if previous compressed data has been damaged or if
536 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
537 the compression.
538
539 If deflate returns with avail_out == 0, this function must be called again
540 with the same value of the flush parameter and more output space (updated
541 avail_out), until the flush is complete (deflate returns with non-zero
542 avail_out).
543
544 If the parameter flush is set to Z_PACKET_FLUSH, the compression
545 block is terminated, and a zero-length stored block is output,
546 omitting the length bytes (the effect of this is that the 3-bit type
547 code 000 for a stored block is output, and the output is then
548 byte-aligned). This is designed for use at the end of a PPP packet.
549
550
551 If the parameter flush is set to Z_FINISH, pending input is processed,
552 pending output is flushed and deflate returns with Z_STREAM_END if there
553 was enough output space; if deflate returns with Z_OK, this function must be
554 called again with Z_FINISH and more output space (updated avail_out) but no
555 more input data, until it returns with Z_STREAM_END or an error. After
556 deflate has returned Z_STREAM_END, the only possible operations on the
557 stream are deflateReset or deflateEnd.
558
559 Z_FINISH can be used immediately after deflateInit if all the compression
560 is to be done in a single step. In this case, avail_out must be at least
561 0.1% larger than avail_in plus 12 bytes. If deflate does not return
562 Z_STREAM_END, then it must be called again as described above.
563
564 deflate() sets strm->adler to the adler32 checksum of all input read
565 so far (that is, total_in bytes).
566
567 deflate() may update data_type if it can make a good guess about
568 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
569 binary. This field is only for information purposes and does not affect
570 the compression algorithm in any manner.
571
572 deflate() returns Z_OK if some progress has been made (more input
573 processed or more output produced), Z_STREAM_END if all input has been
574 consumed and all output has been produced (only when flush is set to
575 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
576 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
577 (for example avail_in or avail_out was zero).
578*/
579
580
581ZEXTERN int ZEXPORT deflateEnd(z_streamp);
582/*
583 All dynamically allocated data structures for this stream are freed.
584 This function discards any unprocessed input and does not flush any
585 pending output.
586
587 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
588 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
589 prematurely (some input or output was discarded). In the error case,
590 msg may be set but then points to a static string (which must not be
591 deallocated).
592*/
593
594
595/*
596ZEXTERN int ZEXPORT inflateInit(z_streamp);
597
598 Initializes the internal stream state for decompression. The fields
599 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
600 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
601 value depends on the compression method), inflateInit determines the
602 compression method from the zlib header and allocates all data structures
603 accordingly; otherwise the allocation will be deferred to the first call of
604 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
605 use default allocation functions.
606
607 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
608 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
609 version assumed by the caller. msg is set to null if there is no error
610 message. inflateInit does not perform any decompression apart from reading
611 the zlib header if present: this will be done by inflate(). (So next_in and
612 avail_in may be modified, but next_out and avail_out are unchanged.)
613*/
614
615
616ZEXTERN int ZEXPORT inflate(z_streamp, int);
617/*
618 inflate decompresses as much data as possible, and stops when the input
619 buffer becomes empty or the output buffer becomes full. It may some
620 introduce some output latency (reading input without producing any output)
621 except when forced to flush.
622
623 The detailed semantics are as follows. inflate performs one or both of the
624 following actions:
625
626 - Decompress more input starting at next_in and update next_in and avail_in
627 accordingly. If not all input can be processed (because there is not
628 enough room in the output buffer), next_in is updated and processing
629 will resume at this point for the next call of inflate().
630
631 - Provide more output starting at next_out and update next_out and avail_out
632 accordingly. inflate() provides as much output as possible, until there
633 is no more input data or no more space in the output buffer (see below
634 about the flush parameter).
635
636 Before the call of inflate(), the application should ensure that at least
637 one of the actions is possible, by providing more input and/or consuming
638 more output, and updating the next_* and avail_* values accordingly.
639 The application can consume the uncompressed output when it wants, for
640 example when the output buffer is full (avail_out == 0), or after each
641 call of inflate(). If inflate returns Z_OK and with zero avail_out, it
642 must be called again after making room in the output buffer because there
643 might be more output pending.
644
645 If the parameter flush is set to Z_SYNC_FLUSH or Z_PACKET_FLUSH,
646 inflate flushes as much output as possible to the output buffer. The
647 flushing behavior of inflate is not specified for values of the flush
648 parameter other than Z_SYNC_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the
649 current implementation actually flushes as much output as possible
650 anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data
651 has been consumed, it is expecting to see the length field of a stored
652 block; if not, it returns Z_DATA_ERROR.
653
654 inflate() should normally be called until it returns Z_STREAM_END or an
655 error. However if all decompression is to be performed in a single step
656 (a single call of inflate), the parameter flush should be set to
657 Z_FINISH. In this case all pending input is processed and all pending
658 output is flushed; avail_out must be large enough to hold all the
659 uncompressed data. (The size of the uncompressed data may have been saved
660 by the compressor for this purpose.) The next operation on this stream must
661 be inflateEnd to deallocate the decompression state. The use of Z_FINISH
662 is never required, but can be used to inform inflate that a faster routine
663 may be used for the single inflate() call.
664
665 If a preset dictionary is needed at this point (see inflateSetDictionary
666 below), inflate sets strm-adler to the adler32 checksum of the
667 dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise
668 it sets strm->adler to the adler32 checksum of all output produced
669 so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or
670 an error code as described below. At the end of the stream, inflate()
671 checks that its computed adler32 checksum is equal to that saved by the
672 compressor and returns Z_STREAM_END only if the checksum is correct.
673
674 inflate() returns Z_OK if some progress has been made (more input processed
675 or more output produced), Z_STREAM_END if the end of the compressed data has
676 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
677 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
678 corrupted (input stream not conforming to the zlib format or incorrect
679 adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent
680 (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not
681 enough memory, Z_BUF_ERROR if no progress is possible or if there was not
682 enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR
683 case, the application may then call inflateSync to look for a good
684 compression block.
685*/
686
687
688ZEXTERN int ZEXPORT inflateEnd(z_streamp);
689/*
690 All dynamically allocated data structures for this stream are freed.
691 This function discards any unprocessed input and does not flush any
692 pending output.
693
694 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
695 was inconsistent. In the error case, msg may be set but then points to a
696 static string (which must not be deallocated).
697*/
698
699 /* Advanced functions */
700
701/*
702 The following functions are needed only in some special applications.
703*/
704
705/*
706ZEXTERN int ZEXPORT deflateInit2(z_streamp, int, int, int, int, int);
707
708 This is another version of deflateInit with more compression options. The
709 fields next_in, zalloc, zfree and opaque must be initialized before by
710 the caller.
711
712 The method parameter is the compression method. It must be Z_DEFLATED in
713 this version of the library.
714
715 The windowBits parameter is the base two logarithm of the window size
716 (the size of the history buffer). It should be in the range 8..15 for this
717 version of the library. Larger values of this parameter result in better
718 compression at the expense of memory usage. The default value is 15 if
719 deflateInit is used instead.
720
721 The memLevel parameter specifies how much memory should be allocated
722 for the internal compression state. memLevel=1 uses minimum memory but
723 is slow and reduces compression ratio; memLevel=9 uses maximum memory
724 for optimal speed. The default value is 8. See zconf.h for total memory
725 usage as a function of windowBits and memLevel.
726
727 The strategy parameter is used to tune the compression algorithm. Use the
728 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
729 filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
730 string match). Filtered data consists mostly of small values with a
731 somewhat random distribution. In this case, the compression algorithm is
732 tuned to compress them better. The effect of Z_FILTERED is to force more
733 Huffman coding and less string matching; it is somewhat intermediate
734 between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
735 the compression ratio but not the correctness of the compressed output even
736 if it is not set appropriately.
737
738 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
739 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
740 method). msg is set to null if there is no error message. deflateInit2 does
741 not perform any compression: this will be done by deflate().
742*/
743
744ZEXTERN int ZEXPORT deflateSetDictionary(z_streamp, const Bytef *, uInt);
745/*
746 Initializes the compression dictionary from the given byte sequence
747 without producing any compressed output. This function must be called
748 immediately after deflateInit, deflateInit2 or deflateReset, before any
749 call of deflate. The compressor and decompressor must use exactly the same
750 dictionary (see inflateSetDictionary).
751
752 The dictionary should consist of strings (byte sequences) that are likely
753 to be encountered later in the data to be compressed, with the most commonly
754 used strings preferably put towards the end of the dictionary. Using a
755 dictionary is most useful when the data to be compressed is short and can be
756 predicted with good accuracy; the data can then be compressed better than
757 with the default empty dictionary.
758
759 Depending on the size of the compression data structures selected by
760 deflateInit or deflateInit2, a part of the dictionary may in effect be
761 discarded, for example if the dictionary is larger than the window size in
762 deflate or deflate2. Thus the strings most likely to be useful should be
763 put at the end of the dictionary, not at the front.
764
765 Upon return of this function, strm->adler is set to the Adler32 value
766 of the dictionary; the decompressor may later use this value to determine
767 which dictionary has been used by the compressor. (The Adler32 value
768 applies to the whole dictionary even if only a subset of the dictionary is
769 actually used by the compressor.)
770
771 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
772 parameter is invalid (such as NULL dictionary) or the stream state is
773 inconsistent (for example if deflate has already been called for this stream
774 or if the compression method is bsort). deflateSetDictionary does not
775 perform any compression: this will be done by deflate().
776*/
777
778ZEXTERN int ZEXPORT deflateCopy(z_streamp, z_streamp);
779/*
780 Sets the destination stream as a complete copy of the source stream.
781
782 This function can be useful when several compression strategies will be
783 tried, for example when there are several ways of pre-processing the input
784 data with a filter. The streams that will be discarded should then be freed
785 by calling deflateEnd. Note that deflateCopy duplicates the internal
786 compression state which can be quite large, so this strategy is slow and
787 can consume lots of memory.
788
789 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
790 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
791 (such as zalloc being NULL). msg is left unchanged in both source and
792 destination.
793*/
794
795extern int inflateIncomp(z_stream *);
796/*
797 This function adds the data at next_in (avail_in bytes) to the output
798 history without performing any output. There must be no pending output,
799 and the decompressor must be expecting to see the start of a block.
800 Calling this function is equivalent to decompressing a stored block
801 containing the data at next_in (except that the data is not output).
802*/
803
804ZEXTERN int ZEXPORT deflateReset(z_streamp);
805/*
806 This function is equivalent to deflateEnd followed by deflateInit,
807 but does not free and reallocate all the internal compression state.
808 The stream will keep the same compression level and any other attributes
809 that may have been set by deflateInit2.
810
811 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
812 stream state was inconsistent (such as zalloc or state being NULL).
813*/
814
815ZEXTERN int ZEXPORT deflateParams(z_streamp, int, int);
816/*
817 Dynamically update the compression level and compression strategy. The
818 interpretation of level and strategy is as in deflateInit2. This can be
819 used to switch between compression and straight copy of the input data, or
820 to switch to a different kind of input data requiring a different
821 strategy. If the compression level is changed, the input available so far
822 is compressed with the old level (and may be flushed); the new level will
823 take effect only at the next call of deflate().
824
825 Before the call of deflateParams, the stream state must be set as for
826 a call of deflate(), since the currently available input may have to
827 be compressed and flushed. In particular, strm->avail_out must be non-zero.
828
829 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
830 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
831 if strm->avail_out was zero.
832*/
833
834ZEXTERN int ZEXPORT deflateOutputPending(z_streamp);
835/*
836 Returns the number of bytes of output which are immediately
837 available from the compressor (i.e. without any further input
838 or flush).
839*/
840
841/*
842ZEXTERN int ZEXPORT inflateInit2(z_streamp, int);
843
844 This is another version of inflateInit with an extra parameter. The
845 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
846 before by the caller.
847
848 The windowBits parameter is the base two logarithm of the maximum window
849 size (the size of the history buffer). It should be in the range 8..15 for
850 this version of the library. The default value is 15 if inflateInit is used
851 instead. If a compressed stream with a larger window size is given as
852 input, inflate() will return with the error code Z_DATA_ERROR instead of
853 trying to allocate a larger window.
854
855 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
856 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
857 memLevel). msg is set to null if there is no error message. inflateInit2
858 does not perform any decompression apart from reading the zlib header if
859 present: this will be done by inflate(). (So next_in and avail_in may be
860 modified, but next_out and avail_out are unchanged.)
861*/
862
863ZEXTERN int ZEXPORT inflateSetDictionary(z_streamp, const Bytef *, uInt);
864/*
865 Initializes the decompression dictionary from the given uncompressed byte
866 sequence. This function must be called immediately after a call of inflate
867 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
868 can be determined from the Adler32 value returned by this call of
869 inflate. The compressor and decompressor must use exactly the same
870 dictionary (see deflateSetDictionary).
871
872 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
873 parameter is invalid (such as NULL dictionary) or the stream state is
874 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
875 expected one (incorrect Adler32 value). inflateSetDictionary does not
876 perform any decompression: this will be done by subsequent calls of
877 inflate().
878*/
879
880ZEXTERN int ZEXPORT inflateSync(z_streamp);
881/*
882 Skips invalid compressed data until a full flush point (see above the
883 description of deflate with Z_FULL_FLUSH) can be found, or until all
884 available input is skipped. No output is provided.
885
886 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
887 if no more input was provided, Z_DATA_ERROR if no flush point has been found,
888 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
889 case, the application may save the current current value of total_in which
890 indicates where valid compressed data was found. In the error case, the
891 application may repeatedly call inflateSync, providing more input each time,
892 until success or end of the input data.
893*/
894
895ZEXTERN int ZEXPORT inflateReset(z_streamp);
896/*
897 This function is equivalent to inflateEnd followed by inflateInit,
898 but does not free and reallocate all the internal decompression state.
899 The stream will keep attributes that may have been set by inflateInit2.
900
901 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
902 stream state was inconsistent (such as zalloc or state being NULL).
903*/
904
905
906 /* utility functions */
907
908/*
909 The following utility functions are implemented on top of the
910 basic stream-oriented functions. To simplify the interface, some
911 default options are assumed (compression level and memory usage,
912 standard memory allocation functions). The source code of these
913 utility functions can easily be modified if you need special options.
914*/
915
916ZEXTERN int ZEXPORT compress(Bytef *, uLongf *, const Bytef *, uLong);
917/*
918 Compresses the source buffer into the destination buffer. sourceLen is
919 the byte length of the source buffer. Upon entry, destLen is the total
920 size of the destination buffer, which must be at least 0.1% larger than
921 sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the
922 compressed buffer.
923 This function can be used to compress a whole file at once if the
924 input file is mmap'ed.
925 compress returns Z_OK if success, Z_MEM_ERROR if there was not
926 enough memory, Z_BUF_ERROR if there was not enough room in the output
927 buffer.
928*/
929
930ZEXTERN int ZEXPORT compress2(Bytef *, uLongf *, const Bytef *,
931 uLong, int);
932/*
933 Compresses the source buffer into the destination buffer. The level
934 parameter has the same meaning as in deflateInit. sourceLen is the byte
935 length of the source buffer. Upon entry, destLen is the total size of the
936 destination buffer, which must be at least 0.1% larger than sourceLen plus
937 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
938
939 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
940 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
941 Z_STREAM_ERROR if the level parameter is invalid.
942*/
943
944ZEXTERN int ZEXPORT uncompress(Bytef *, uLongf *, const Bytef *, uLong);
945/*
946 Decompresses the source buffer into the destination buffer. sourceLen is
947 the byte length of the source buffer. Upon entry, destLen is the total
948 size of the destination buffer, which must be large enough to hold the
949 entire uncompressed data. (The size of the uncompressed data must have
950 been saved previously by the compressor and transmitted to the decompressor
951 by some mechanism outside the scope of this compression library.)
952 Upon exit, destLen is the actual size of the compressed buffer.
953 This function can be used to decompress a whole file at once if the
954 input file is mmap'ed.
955
956 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
957 enough memory, Z_BUF_ERROR if there was not enough room in the output
958 buffer, or Z_DATA_ERROR if the input data was corrupted.
959*/
960
961
962typedef voidp gzFile;
963
964ZEXTERN gzFile ZEXPORT gzopen(const char *, const char *);
965/*
966 Opens a gzip (.gz) file for reading or writing. The mode parameter
967 is as in fopen ("rb" or "wb") but can also include a compression level
968 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
969 Huffman only compression as in "wb1h". (See the description
970 of deflateInit2 for more information about the strategy parameter.)
971
972 gzopen can be used to read a file which is not in gzip format; in this
973 case gzread will directly read from the file without decompression.
974
975 gzopen returns NULL if the file could not be opened or if there was
976 insufficient memory to allocate the (de)compression state; errno
977 can be checked to distinguish the two cases (if errno is zero, the
978 zlib error is Z_MEM_ERROR). */
979
980ZEXTERN gzFile ZEXPORT gzdopen(int, const char *);
981/*
982 gzdopen() associates a gzFile with the file descriptor fd. File
983 descriptors are obtained from calls like open, dup, creat, pipe or
984 fileno (in the file has been previously opened with fopen).
985 The mode parameter is as in gzopen.
986 The next call of gzclose on the returned gzFile will also close the
987 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
988 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
989 gzdopen returns NULL if there was insufficient memory to allocate
990 the (de)compression state.
991*/
992
993ZEXTERN int ZEXPORT gzsetparams(gzFile, int, int);
994/*
995 Dynamically update the compression level or strategy. See the description
996 of deflateInit2 for the meaning of these parameters.
997 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
998 opened for writing.
999*/
1000
1001ZEXTERN int ZEXPORT gzread(gzFile, voidp, unsigned);
1002/*
1003 Reads the given number of uncompressed bytes from the compressed file.
1004 If the input file was not in gzip format, gzread copies the given number
1005 of bytes into the buffer.
1006 gzread returns the number of uncompressed bytes actually read (0 for
1007 end of file, -1 for error). */
1008
1009ZEXTERN int ZEXPORT gzwrite(gzFile, const voidp, unsigned);
1010/*
1011 Writes the given number of uncompressed bytes into the compressed file.
1012 gzwrite returns the number of uncompressed bytes actually written
1013 (0 in case of error).
1014*/
1015
1016ZEXTERN int ZEXPORTVA gzprintf(gzFile, const char *, ...)
1017 __attribute__((__format__(__printf__, 2, 3)));
1018/*
1019 Converts, formats, and writes the args to the compressed file under
1020 control of the format string, as in fprintf. gzprintf returns the number of
1021 uncompressed bytes actually written (0 in case of error).
1022*/
1023
1024ZEXTERN int ZEXPORT gzputs(gzFile, const char *);
1025/*
1026 Writes the given null-terminated string to the compressed file, excluding
1027 the terminating null character.
1028 gzputs returns the number of characters written, or -1 in case of error.
1029*/
1030
1031ZEXTERN char * ZEXPORT gzgets(gzFile, char *, int);
1032/*
1033 Reads bytes from the compressed file until len-1 characters are read, or
1034 a newline character is read and transferred to buf, or an end-of-file
1035 condition is encountered. The string is then terminated with a null
1036 character.
1037 gzgets returns buf, or Z_NULL in case of error.
1038*/
1039
1040ZEXTERN int ZEXPORT gzputc(gzFile, int);
1041/*
1042 Writes c, converted to an unsigned char, into the compressed file.
1043 gzputc returns the value that was written, or -1 in case of error.
1044*/
1045
1046ZEXTERN int ZEXPORT gzgetc(gzFile);
1047/*
1048 Reads one byte from the compressed file. gzgetc returns this byte
1049 or -1 in case of end of file or error.
1050*/
1051
1052ZEXTERN int ZEXPORT gzflush(gzFile, int);
1053/*
1054 Flushes all pending output into the compressed file. The parameter
1055 flush is as in the deflate() function. The return value is the zlib
1056 error number (see function gzerror below). gzflush returns Z_OK if
1057 the flush parameter is Z_FINISH and all output could be flushed.
1058 gzflush should be called only when strictly necessary because it can
1059 degrade compression.
1060
1061*/
1062
1063/*
1064 * NetBSD note:
1065 * "long" gzseek has been there till Oct 1999 (1.4L), which was wrong.
1066 */
1067ZEXTERN z_off_t ZEXPORT gzseek(gzFile, z_off_t, int);
1068/*
1069 Sets the starting position for the next gzread or gzwrite on the
1070 given compressed file. The offset represents a number of bytes in the
1071 uncompressed data stream. The whence parameter is defined as in lseek(2);
1072 the value SEEK_END is not supported.
1073 If the file is opened for reading, this function is emulated but can be
1074 extremely slow. If the file is opened for writing, only forward seeks are
1075 supported; gzseek then compresses a sequence of zeroes up to the new
1076 starting position.
1077
1078 gzseek returns the resulting offset location as measured in bytes from
1079 the beginning of the uncompressed stream, or -1 in case of error, in
1080 particular if the file is opened for writing and the new starting position
1081 would be before the current position.
1082*/
1083
1084ZEXTERN int ZEXPORT gzrewind(gzFile);
1085/*
1086 Rewinds the given file. This function is supported only for reading.
1087
1088 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1089*/
1090
1091/*
1092 * NetBSD note:
1093 * "long" gztell has been there till Oct 1999 (1.4L), which was wrong.
1094 */
1095ZEXTERN z_off_t ZEXPORT gztell(gzFile);
1096/*
1097 Returns the starting position for the next gzread or gzwrite on the
1098 given compressed file. This position represents a number of bytes in the
1099 uncompressed data stream.
1100
1101 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1102*/
1103
1104ZEXTERN int ZEXPORT gzeof(gzFile);
1105/*
1106 Returns 1 when EOF has previously been detected reading the given
1107 input stream, otherwise zero.
1108*/
1109
1110ZEXTERN int ZEXPORT gzclose(gzFile);
1111/*
1112 Flushes all pending output if necessary, closes the compressed file
1113 and deallocates all the (de)compression state. The return value is the zlib
1114 error number (see function gzerror below).
1115*/
1116
1117ZEXTERN const char * ZEXPORT gzerror(gzFile, int *);
1118/*
1119 Returns the error message for the last error which occurred on the
1120 given compressed file. errnum is set to zlib error number. If an
1121 error occurred in the file system and not in the compression library,
1122 errnum is set to Z_ERRNO and the application may consult errno
1123 to get the exact error code.
1124*/
1125
1126 /* checksum functions */
1127
1128/*
1129 These functions are not related to compression but are exported
1130 anyway because they might be useful in applications using the
1131 compression library.
1132*/
1133
1134ZEXTERN uLong ZEXPORT adler32(uLong, const Bytef *, uInt);
1135
1136/*
1137 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1138 return the updated checksum. If buf is NULL, this function returns
1139 the required initial value for the checksum.
1140 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1141 much faster. Usage example:
1142
1143 uLong adler = adler32(0L, Z_NULL, 0);
1144
1145 while (read_buffer(buffer, length) != EOF) {
1146 adler = adler32(adler, buffer, length);
1147 }
1148 if (adler != original_adler) error();
1149*/
1150
1151#ifdef STANDALONE
1152ZEXTERN uLong ZEXPORT crc32(uLong, const Bytef *, uInt);
1153#endif
1154/*
1155 Update a running crc with the bytes buf[0..len-1] and return the updated
1156 crc. If buf is NULL, this function returns the required initial value
1157 for the crc. Pre- and post-conditioning (one's complement) is performed
1158 within this function so it shouldn't be done by the application.
1159 Usage example:
1160
1161 uLong crc = crc32(0L, Z_NULL, 0);
1162
1163 while (read_buffer(buffer, length) != EOF) {
1164 crc = crc32(crc, buffer, length);
1165 }
1166 if (crc != original_crc) error();
1167*/
1168
1169
1170 /* various hacks, don't look :) */
1171
1172/* deflateInit and inflateInit are macros to allow checking the zlib version
1173 * and the compiler's view of z_stream:
1174 */
1175ZEXTERN int ZEXPORT deflateInit_(z_streamp, int, const char *, int);
1176ZEXTERN int ZEXPORT inflateInit_(z_streamp, const char *, int);
1177ZEXTERN int ZEXPORT deflateInit2_(z_streamp, int, int, int, int,
1178 int, const char *, int);
1179ZEXTERN int ZEXPORT inflateInit2_(z_streamp, int, const char *, int);
1180#define deflateInit(strm, level) \
1181 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1182#define inflateInit(strm) \
1183 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1184#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1185 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1186 (strategy), ZLIB_VERSION, sizeof(z_stream))
1187#define inflateInit2(strm, windowBits) \
1188 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1189
1190
1191#if !defined(Z_UTIL_H) && !defined(NO_DUMMY_DECL)
1192 struct internal_state {int dummy;}; /* hack for buggy compilers */
1193#endif
1194
1195ZEXTERN const char * ZEXPORT zError(int);
1196ZEXTERN int ZEXPORT inflateSyncPoint(z_streamp);
1197ZEXTERN const uLongf * ZEXPORT get_crc_table(void);
1198
1199#ifdef __cplusplus
1200}
1201#endif
1202#endif /* !ZLIB_H */
1203
1204#endif /* !_NET_ZLIB_H_ */
1205/* -- zlib.h */