nataraid(4): Add devstat support.
[dragonfly.git] / sys / net / zlib.h
CommitLineData
984263bc 1/* $FreeBSD: src/sys/net/zlib.h,v 1.7.2.1 2002/07/31 14:13:05 rwatson Exp $ */
1bd40720 2/* $DragonFly: src/sys/net/zlib.h,v 1.5 2006/05/20 02:42:08 dillon Exp $ */
984263bc
MD
3
4/*
5 * This file is derived from zlib.h and zconf.h from the zlib-1.0.4
6 * distribution by Jean-loup Gailly and Mark Adler, with some additions
7 * by Paul Mackerras to aid in implementing Deflate compression and
8 * decompression for PPP packets.
9 */
10
11/*
12 * ==FILEVERSION 971127==
13 *
14 * This marker is used by the Linux installation script to determine
15 * whether an up-to-date version of this file is already installed.
16 */
17
18
19/* +++ zlib.h */
20/* zlib.h -- interface of the 'zlib' general purpose compression library
21 version 1.0.4, Jul 24th, 1996.
22
23 Copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler
24
25 This software is provided 'as-is', without any express or implied
26 warranty. In no event will the authors be held liable for any damages
27 arising from the use of this software.
28
29 Permission is granted to anyone to use this software for any purpose,
30 including commercial applications, and to alter it and redistribute it
31 freely, subject to the following restrictions:
32
33 1. The origin of this software must not be misrepresented; you must not
34 claim that you wrote the original software. If you use this software
35 in a product, an acknowledgment in the product documentation would be
36 appreciated but is not required.
37 2. Altered source versions must be plainly marked as such, and must not be
38 misrepresented as being the original software.
39 3. This notice may not be removed or altered from any source distribution.
40
41 Jean-loup Gailly Mark Adler
42 gzip@prep.ai.mit.edu madler@alumni.caltech.edu
43
44
45 The data format used by the zlib library is described by RFCs (Request for
46 Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
47 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
48*/
49
1bd40720
MD
50#ifndef _NET_ZLIB_H_
51#define _NET_ZLIB_H_
984263bc
MD
52
53#ifdef __cplusplus
54extern "C" {
55#endif
56
57
58/* +++ zconf.h */
59/* zconf.h -- configuration of the zlib compression library
60 * Copyright (C) 1995-1996 Jean-loup Gailly.
61 * For conditions of distribution and use, see copyright notice in zlib.h
62 */
63
64/* From: zconf.h,v 1.20 1996/07/02 15:09:28 me Exp $ */
65
66#ifndef _ZCONF_H
67#define _ZCONF_H
68
69/*
70 * If you *really* need a unique prefix for all types and library functions,
71 * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
72 */
73#ifdef Z_PREFIX
74# define deflateInit_ z_deflateInit_
75# define deflate z_deflate
76# define deflateEnd z_deflateEnd
f23061d4 77# define inflateInit_ z_inflateInit_
984263bc
MD
78# define inflate z_inflate
79# define inflateEnd z_inflateEnd
80# define deflateInit2_ z_deflateInit2_
81# define deflateSetDictionary z_deflateSetDictionary
82# define deflateCopy z_deflateCopy
83# define deflateReset z_deflateReset
84# define deflateParams z_deflateParams
85# define inflateInit2_ z_inflateInit2_
86# define inflateSetDictionary z_inflateSetDictionary
87# define inflateSync z_inflateSync
88# define inflateReset z_inflateReset
89# define compress z_compress
90# define uncompress z_uncompress
91# define adler32 z_adler32
92#if 0
93# define crc32 z_crc32
94# define get_crc_table z_get_crc_table
95#endif
96
97# define Byte z_Byte
98# define uInt z_uInt
99# define uLong z_uLong
100# define Bytef z_Bytef
101# define charf z_charf
102# define intf z_intf
103# define uIntf z_uIntf
104# define uLongf z_uLongf
105# define voidpf z_voidpf
106# define voidp z_voidp
107#endif
108
109#if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32)
110# define WIN32
111#endif
112#if defined(__GNUC__) || defined(WIN32) || defined(__386__) || defined(i386)
113# ifndef __32BIT__
114# define __32BIT__
115# endif
116#endif
117#if defined(__MSDOS__) && !defined(MSDOS)
118# define MSDOS
119#endif
120
121/*
122 * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
123 * than 64k bytes at a time (needed on systems with 16-bit int).
124 */
125#if defined(MSDOS) && !defined(__32BIT__)
126# define MAXSEG_64K
127#endif
128#ifdef MSDOS
129# define UNALIGNED_OK
130#endif
131
132#if (defined(MSDOS) || defined(_WINDOWS) || defined(WIN32)) && !defined(STDC)
133# define STDC
134#endif
135#if (defined(__STDC__) || defined(__cplusplus)) && !defined(STDC)
136# define STDC
137#endif
138
139#ifndef STDC
140# ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
141# define const
142# endif
143#endif
144
145/* Some Mac compilers merge all .h files incorrectly: */
146#if defined(__MWERKS__) || defined(applec) ||defined(THINK_C) ||defined(__SC__)
147# define NO_DUMMY_DECL
148#endif
149
150/* Maximum value for memLevel in deflateInit2 */
151#ifndef MAX_MEM_LEVEL
152# ifdef MAXSEG_64K
153# define MAX_MEM_LEVEL 8
154# else
155# define MAX_MEM_LEVEL 9
156# endif
157#endif
158
159/* Maximum value for windowBits in deflateInit2 and inflateInit2 */
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 OF /* function prototypes */
180# ifdef STDC
181# define OF(args) args
182# else
183# define OF(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#ifndef FAR
209# define FAR
210#endif
211
212typedef unsigned char Byte; /* 8 bits */
213typedef unsigned int uInt; /* 16 bits or more */
214typedef unsigned long uLong; /* 32 bits or more */
215
216#if defined(__BORLANDC__) && defined(SMALL_MEDIUM)
217 /* Borland C/C++ ignores FAR inside typedef */
218# define Bytef Byte FAR
219#else
220 typedef Byte FAR Bytef;
221#endif
222typedef char FAR charf;
223typedef int FAR intf;
224typedef uInt FAR uIntf;
225typedef uLong FAR uLongf;
226
227#ifdef STDC
228 typedef void FAR *voidpf;
229 typedef void *voidp;
230#else
231 typedef Byte FAR *voidpf;
232 typedef Byte *voidp;
233#endif
234
235
236/* Compile with -DZLIB_DLL for Windows DLL support */
237#if (defined(_WINDOWS) || defined(WINDOWS)) && defined(ZLIB_DLL)
238# include <windows.h>
239# define EXPORT WINAPI
240#else
241# define EXPORT
242#endif
243
244#endif /* _ZCONF_H */
245/* --- zconf.h */
246
247#define ZLIB_VERSION "1.0.4P"
248
249/*
250 The 'zlib' compression library provides in-memory compression and
251 decompression functions, including integrity checks of the uncompressed
252 data. This version of the library supports only one compression method
253 (deflation) but other algorithms may be added later and will have the same
254 stream interface.
255
256 For compression the application must provide the output buffer and
257 may optionally provide the input buffer for optimization. For decompression,
258 the application must provide the input buffer and may optionally provide
259 the output buffer for optimization.
260
261 Compression can be done in a single step if the buffers are large
262 enough (for example if an input file is mmap'ed), or can be done by
263 repeated calls of the compression function. In the latter case, the
264 application must provide more input and/or consume the output
265 (providing more output space) before each call.
266
267 The library does not install any signal handler. It is recommended to
268 add at least a handler for SIGSEGV when decompressing; the library checks
269 the consistency of the input data whenever possible but may go nuts
270 for some forms of corrupted input.
271*/
272
273typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
274typedef void (*free_func) OF((voidpf opaque, voidpf address));
275
276struct internal_state;
277
278typedef struct z_stream_s {
279 Bytef *next_in; /* next input byte */
280 uInt avail_in; /* number of bytes available at next_in */
281 uLong total_in; /* total nb of input bytes read so far */
282
283 Bytef *next_out; /* next output byte should be put there */
284 uInt avail_out; /* remaining free space at next_out */
285 uLong total_out; /* total nb of bytes output so far */
286
287 const char *msg; /* last error message, NULL if no error */
288 struct internal_state FAR *state; /* not visible by applications */
289
290 alloc_func zalloc; /* used to allocate the internal state */
291 free_func zfree; /* used to free the internal state */
292 voidpf opaque; /* private data object passed to zalloc and zfree */
293
294 int data_type; /* best guess about the data type: ascii or binary */
295 uLong adler; /* adler32 value of the uncompressed data */
296 uLong reserved; /* reserved for future use */
297} z_stream;
298
299typedef z_stream FAR *z_streamp;
300
301/*
302 The application must update next_in and avail_in when avail_in has
303 dropped to zero. It must update next_out and avail_out when avail_out
304 has dropped to zero. The application must initialize zalloc, zfree and
305 opaque before calling the init function. All other fields are set by the
306 compression library and must not be updated by the application.
307
308 The opaque value provided by the application will be passed as the first
309 parameter for calls of zalloc and zfree. This can be useful for custom
310 memory management. The compression library attaches no meaning to the
311 opaque value.
312
313 zalloc must return Z_NULL if there is not enough memory for the object.
314 On 16-bit systems, the functions zalloc and zfree must be able to allocate
315 exactly 65536 bytes, but will not be required to allocate more than this
316 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
317 pointers returned by zalloc for objects of exactly 65536 bytes *must*
318 have their offset normalized to zero. The default allocation function
319 provided by this library ensures this (see zutil.c). To reduce memory
320 requirements and avoid any allocation of 64K objects, at the expense of
321 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
322
323 The fields total_in and total_out can be used for statistics or
324 progress reports. After compression, total_in holds the total size of
325 the uncompressed data and may be saved for use in the decompressor
326 (particularly if the decompressor wants to decompress everything in
327 a single step).
328*/
329
330 /* constants */
331
332#define Z_NO_FLUSH 0
333#define Z_PARTIAL_FLUSH 1
334#define Z_PACKET_FLUSH 2
335#define Z_SYNC_FLUSH 3
336#define Z_FULL_FLUSH 4
337#define Z_FINISH 5
338/* Allowed flush values; see deflate() below for details */
339
340#define Z_OK 0
341#define Z_STREAM_END 1
342#define Z_NEED_DICT 2
343#define Z_ERRNO (-1)
344#define Z_STREAM_ERROR (-2)
345#define Z_DATA_ERROR (-3)
346#define Z_MEM_ERROR (-4)
347#define Z_BUF_ERROR (-5)
348#define Z_VERSION_ERROR (-6)
349/* Return codes for the compression/decompression functions. Negative
350 * values are errors, positive values are used for special but normal events.
351 */
352
353#define Z_NO_COMPRESSION 0
354#define Z_BEST_SPEED 1
355#define Z_BEST_COMPRESSION 9
356#define Z_DEFAULT_COMPRESSION (-1)
357/* compression levels */
358
359#define Z_FILTERED 1
360#define Z_HUFFMAN_ONLY 2
361#define Z_DEFAULT_STRATEGY 0
362/* compression strategy; see deflateInit2() below for details */
363
364#define Z_BINARY 0
365#define Z_ASCII 1
366#define Z_UNKNOWN 2
367/* Possible values of the data_type field */
368
369#define Z_DEFLATED 8
370/* The deflate compression method (the only one supported in this version) */
371
372#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
373
374#define zlib_version zlibVersion()
375/* for compatibility with versions < 1.0.2 */
376
377 /* basic functions */
378
379extern const char * EXPORT zlibVersion OF((void));
380/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
381 If the first character differs, the library code actually used is
382 not compatible with the zlib.h header file used by the application.
383 This check is automatically made by deflateInit and inflateInit.
384 */
385
386/*
387extern int EXPORT deflateInit OF((z_streamp strm, int level));
388
389 Initializes the internal stream state for compression. The fields
390 zalloc, zfree and opaque must be initialized before by the caller.
391 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
392 use default allocation functions.
393
394 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
395 1 gives best speed, 9 gives best compression, 0 gives no compression at
396 all (the input data is simply copied a block at a time).
397 Z_DEFAULT_COMPRESSION requests a default compromise between speed and
398 compression (currently equivalent to level 6).
399
400 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
401 enough memory, Z_STREAM_ERROR if level is not a valid compression level,
402 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
403 with the version assumed by the caller (ZLIB_VERSION).
404 msg is set to null if there is no error message. deflateInit does not
405 perform any compression: this will be done by deflate().
406*/
407
408
409extern int EXPORT deflate OF((z_streamp strm, int flush));
410/*
411 Performs one or both of the following actions:
412
413 - Compress more input starting at next_in and update next_in and avail_in
414 accordingly. If not all input can be processed (because there is not
415 enough room in the output buffer), next_in and avail_in are updated and
416 processing will resume at this point for the next call of deflate().
417
418 - Provide more output starting at next_out and update next_out and avail_out
419 accordingly. This action is forced if the parameter flush is non zero.
420 Forcing flush frequently degrades the compression ratio, so this parameter
421 should be set only when necessary (in interactive applications).
422 Some output may be provided even if flush is not set.
423
424 Before the call of deflate(), the application should ensure that at least
425 one of the actions is possible, by providing more input and/or consuming
426 more output, and updating avail_in or avail_out accordingly; avail_out
427 should never be zero before the call. The application can consume the
428 compressed output when it wants, for example when the output buffer is full
429 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
430 and with zero avail_out, it must be called again after making room in the
431 output buffer because there might be more output pending.
432
433 If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression
434 block is terminated and flushed to the output buffer so that the
435 decompressor can get all input data available so far. For method 9, a future
436 variant on method 8, the current block will be flushed but not terminated.
437 Z_SYNC_FLUSH has the same effect as partial flush except that the compressed
438 output is byte aligned (the compressor can clear its internal bit buffer)
439 and the current block is always terminated; this can be useful if the
440 compressor has to be restarted from scratch after an interruption (in which
441 case the internal state of the compressor may be lost).
442 If flush is set to Z_FULL_FLUSH, the compression block is terminated, a
443 special marker is output and the compression dictionary is discarded; this
444 is useful to allow the decompressor to synchronize if one compressed block
445 has been damaged (see inflateSync below). Flushing degrades compression and
446 so should be used only when necessary. Using Z_FULL_FLUSH too often can
447 seriously degrade the compression. If deflate returns with avail_out == 0,
448 this function must be called again with the same value of the flush
449 parameter and more output space (updated avail_out), until the flush is
450 complete (deflate returns with non-zero avail_out).
451
452 If the parameter flush is set to Z_PACKET_FLUSH, the compression
453 block is terminated, and a zero-length stored block is output,
454 omitting the length bytes (the effect of this is that the 3-bit type
455 code 000 for a stored block is output, and the output is then
456 byte-aligned). This is designed for use at the end of a PPP packet.
457
458 If the parameter flush is set to Z_FINISH, pending input is processed,
459 pending output is flushed and deflate returns with Z_STREAM_END if there
460 was enough output space; if deflate returns with Z_OK, this function must be
461 called again with Z_FINISH and more output space (updated avail_out) but no
462 more input data, until it returns with Z_STREAM_END or an error. After
463 deflate has returned Z_STREAM_END, the only possible operations on the
464 stream are deflateReset or deflateEnd.
465
466 Z_FINISH can be used immediately after deflateInit if all the compression
467 is to be done in a single step. In this case, avail_out must be at least
468 0.1% larger than avail_in plus 12 bytes. If deflate does not return
469 Z_STREAM_END, then it must be called again as described above.
470
471 deflate() may update data_type if it can make a good guess about
472 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
473 binary. This field is only for information purposes and does not affect
474 the compression algorithm in any manner.
475
476 deflate() returns Z_OK if some progress has been made (more input
477 processed or more output produced), Z_STREAM_END if all input has been
478 consumed and all output has been produced (only when flush is set to
479 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
480 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible.
481*/
482
483
484extern int EXPORT deflateEnd OF((z_streamp strm));
485/*
486 All dynamically allocated data structures for this stream are freed.
487 This function discards any unprocessed input and does not flush any
488 pending output.
489
490 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
491 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
492 prematurely (some input or output was discarded). In the error case,
493 msg may be set but then points to a static string (which must not be
494 deallocated).
495*/
496
497
498/*
499extern int EXPORT inflateInit OF((z_streamp strm));
500
501 Initializes the internal stream state for decompression. The fields
502 zalloc, zfree and opaque must be initialized before by the caller. If
503 zalloc and zfree are set to Z_NULL, inflateInit updates them to use default
504 allocation functions.
505
506 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
507 enough memory, Z_VERSION_ERROR if the zlib library version is incompatible
508 with the version assumed by the caller. msg is set to null if there is no
509 error message. inflateInit does not perform any decompression: this will be
510 done by inflate().
511*/
512
9a7f3897 513#if (defined(__DragonFly__) || defined(__FreeBSD__)) && defined(_KERNEL)
984263bc
MD
514#define inflate inflate_ppp /* FreeBSD already has an inflate :-( */
515#endif
516
517extern int EXPORT inflate OF((z_streamp strm, int flush));
518/*
519 Performs one or both of the following actions:
520
521 - Decompress more input starting at next_in and update next_in and avail_in
522 accordingly. If not all input can be processed (because there is not
523 enough room in the output buffer), next_in is updated and processing
524 will resume at this point for the next call of inflate().
525
526 - Provide more output starting at next_out and update next_out and avail_out
527 accordingly. inflate() provides as much output as possible, until there
528 is no more input data or no more space in the output buffer (see below
529 about the flush parameter).
530
531 Before the call of inflate(), the application should ensure that at least
532 one of the actions is possible, by providing more input and/or consuming
533 more output, and updating the next_* and avail_* values accordingly.
534 The application can consume the uncompressed output when it wants, for
535 example when the output buffer is full (avail_out == 0), or after each
536 call of inflate(). If inflate returns Z_OK and with zero avail_out, it
537 must be called again after making room in the output buffer because there
538 might be more output pending.
539
540 If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH,
541 inflate flushes as much output as possible to the output buffer. The
542 flushing behavior of inflate is not specified for values of the flush
543 parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the
544 current implementation actually flushes as much output as possible
545 anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data
546 has been consumed, it is expecting to see the length field of a stored
547 block; if not, it returns Z_DATA_ERROR.
548
549 inflate() should normally be called until it returns Z_STREAM_END or an
550 error. However if all decompression is to be performed in a single step
551 (a single call of inflate), the parameter flush should be set to
552 Z_FINISH. In this case all pending input is processed and all pending
553 output is flushed; avail_out must be large enough to hold all the
554 uncompressed data. (The size of the uncompressed data may have been saved
555 by the compressor for this purpose.) The next operation on this stream must
556 be inflateEnd to deallocate the decompression state. The use of Z_FINISH
557 is never required, but can be used to inform inflate that a faster routine
558 may be used for the single inflate() call.
559
560 inflate() returns Z_OK if some progress has been made (more input
561 processed or more output produced), Z_STREAM_END if the end of the
562 compressed data has been reached and all uncompressed output has been
563 produced, Z_NEED_DICT if a preset dictionary is needed at this point (see
564 inflateSetDictionary below), Z_DATA_ERROR if the input data was corrupted,
565 Z_STREAM_ERROR if the stream structure was inconsistent (for example if
566 next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
567 Z_BUF_ERROR if no progress is possible or if there was not enough room in
568 the output buffer when Z_FINISH is used. In the Z_DATA_ERROR case, the
569 application may then call inflateSync to look for a good compression block.
570 In the Z_NEED_DICT case, strm->adler is set to the Adler32 value of the
571 dictionary chosen by the compressor.
572*/
573
574
575extern int EXPORT inflateEnd OF((z_streamp strm));
576/*
577 All dynamically allocated data structures for this stream are freed.
578 This function discards any unprocessed input and does not flush any
579 pending output.
580
581 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
582 was inconsistent. In the error case, msg may be set but then points to a
583 static string (which must not be deallocated).
584*/
585
586 /* Advanced functions */
587
588/*
589 The following functions are needed only in some special applications.
590*/
591
592/*
593extern int EXPORT deflateInit2 OF((z_streamp strm,
594 int level,
595 int method,
596 int windowBits,
597 int memLevel,
598 int strategy));
599
600 This is another version of deflateInit with more compression options. The
601 fields next_in, zalloc, zfree and opaque must be initialized before by
602 the caller.
603
604 The method parameter is the compression method. It must be Z_DEFLATED in
605 this version of the library. (Method 9 will allow a 64K history buffer and
606 partial block flushes.)
607
608 The windowBits parameter is the base two logarithm of the window size
609 (the size of the history buffer). It should be in the range 8..15 for this
610 version of the library (the value 16 will be allowed for method 9). Larger
611 values of this parameter result in better compression at the expense of
612 memory usage. The default value is 15 if deflateInit is used instead.
613
614 The memLevel parameter specifies how much memory should be allocated
615 for the internal compression state. memLevel=1 uses minimum memory but
616 is slow and reduces compression ratio; memLevel=9 uses maximum memory
617 for optimal speed. The default value is 8. See zconf.h for total memory
618 usage as a function of windowBits and memLevel.
619
620 The strategy parameter is used to tune the compression algorithm. Use the
621 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
622 filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
623 string match). Filtered data consists mostly of small values with a
624 somewhat random distribution. In this case, the compression algorithm is
625 tuned to compress them better. The effect of Z_FILTERED is to force more
626 Huffman coding and less string matching; it is somewhat intermediate
627 between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
628 the compression ratio but not the correctness of the compressed output even
629 if it is not set appropriately.
630
631 If next_in is not null, the library will use this buffer to hold also
632 some history information; the buffer must either hold the entire input
633 data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in
634 is null, the library will allocate its own history buffer (and leave next_in
635 null). next_out need not be provided here but must be provided by the
636 application for the next call of deflate().
637
638 If the history buffer is provided by the application, next_in must
639 must never be changed by the application since the compressor maintains
640 information inside this buffer from call to call; the application
641 must provide more input only by increasing avail_in. next_in is always
642 reset by the library in this case.
643
644 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
645 not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
646 an invalid method). msg is set to null if there is no error message.
647 deflateInit2 does not perform any compression: this will be done by
648 deflate().
649*/
650
651extern int EXPORT deflateSetDictionary OF((z_streamp strm,
652 const Bytef *dictionary,
653 uInt dictLength));
654/*
655 Initializes the compression dictionary (history buffer) from the given
656 byte sequence without producing any compressed output. This function must
657 be called immediately after deflateInit or deflateInit2, before any call
658 of deflate. The compressor and decompressor must use exactly the same
659 dictionary (see inflateSetDictionary).
660 The dictionary should consist of strings (byte sequences) that are likely
661 to be encountered later in the data to be compressed, with the most commonly
662 used strings preferably put towards the end of the dictionary. Using a
663 dictionary is most useful when the data to be compressed is short and
664 can be predicted with good accuracy; the data can then be compressed better
665 than with the default empty dictionary. In this version of the library,
666 only the last 32K bytes of the dictionary are used.
667 Upon return of this function, strm->adler is set to the Adler32 value
668 of the dictionary; the decompressor may later use this value to determine
669 which dictionary has been used by the compressor. (The Adler32 value
670 applies to the whole dictionary even if only a subset of the dictionary is
671 actually used by the compressor.)
672
673 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
674 parameter is invalid (such as NULL dictionary) or the stream state
675 is inconsistent (for example if deflate has already been called for this
676 stream). deflateSetDictionary does not perform any compression: this will
677 be done by deflate().
678*/
679
680extern int EXPORT deflateCopy OF((z_streamp dest,
681 z_streamp source));
682/*
683 Sets the destination stream as a complete copy of the source stream. If
684 the source stream is using an application-supplied history buffer, a new
685 buffer is allocated for the destination stream. The compressed output
686 buffer is always application-supplied. It's the responsibility of the
687 application to provide the correct values of next_out and avail_out for the
688 next call of deflate.
689
690 This function can be useful when several compression strategies will be
691 tried, for example when there are several ways of pre-processing the input
692 data with a filter. The streams that will be discarded should then be freed
693 by calling deflateEnd. Note that deflateCopy duplicates the internal
694 compression state which can be quite large, so this strategy is slow and
695 can consume lots of memory.
696
697 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
698 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
699 (such as zalloc being NULL). msg is left unchanged in both source and
700 destination.
701*/
702
703extern int EXPORT deflateReset OF((z_streamp strm));
704/*
705 This function is equivalent to deflateEnd followed by deflateInit,
706 but does not free and reallocate all the internal compression state.
707 The stream will keep the same compression level and any other attributes
708 that may have been set by deflateInit2.
709
710 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
711 stream state was inconsistent (such as zalloc or state being NULL).
712*/
713
714extern int EXPORT deflateParams OF((z_streamp strm, int level, int strategy));
715/*
716 Dynamically update the compression level and compression strategy.
717 This can be used to switch between compression and straight copy of
718 the input data, or to switch to a different kind of input data requiring
719 a different strategy. If the compression level is changed, the input
720 available so far is compressed with the old level (and may be flushed);
721 the new level will take effect only at the next call of deflate().
722
723 Before the call of deflateParams, the stream state must be set as for
724 a call of deflate(), since the currently available input may have to
725 be compressed and flushed. In particular, strm->avail_out must be non-zero.
726
727 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
728 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
729 if strm->avail_out was zero.
730*/
731
732extern int EXPORT deflateOutputPending OF((z_streamp strm));
733/*
734 Returns the number of bytes of output which are immediately
735 available from the compressor (i.e. without any further input
736 or flush).
737*/
738
739/*
740extern int EXPORT inflateInit2 OF((z_streamp strm,
741 int windowBits));
742
743 This is another version of inflateInit with more compression options. The
744 fields next_out, zalloc, zfree and opaque must be initialized before by
745 the caller.
746
747 The windowBits parameter is the base two logarithm of the maximum window
748 size (the size of the history buffer). It should be in the range 8..15 for
749 this version of the library (the value 16 will be allowed soon). The
750 default value is 15 if inflateInit is used instead. If a compressed stream
751 with a larger window size is given as input, inflate() will return with
752 the error code Z_DATA_ERROR instead of trying to allocate a larger window.
753
754 If next_out is not null, the library will use this buffer for the history
755 buffer; the buffer must either be large enough to hold the entire output
756 data, or have at least 1<<windowBits bytes. If next_out is null, the
757 library will allocate its own buffer (and leave next_out null). next_in
758 need not be provided here but must be provided by the application for the
759 next call of inflate().
760
761 If the history buffer is provided by the application, next_out must
762 never be changed by the application since the decompressor maintains
763 history information inside this buffer from call to call; the application
764 can only reset next_out to the beginning of the history buffer when
765 avail_out is zero and all output has been consumed.
766
767 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
768 not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
769 windowBits < 8). msg is set to null if there is no error message.
770 inflateInit2 does not perform any decompression: this will be done by
771 inflate().
772*/
773
774extern int EXPORT inflateSetDictionary OF((z_streamp strm,
775 const Bytef *dictionary,
776 uInt dictLength));
777/*
778 Initializes the decompression dictionary (history buffer) from the given
779 uncompressed byte sequence. This function must be called immediately after
780 a call of inflate if this call returned Z_NEED_DICT. The dictionary chosen
781 by the compressor can be determined from the Adler32 value returned by this
782 call of inflate. The compressor and decompressor must use exactly the same
783 dictionary (see deflateSetDictionary).
784
785 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
786 parameter is invalid (such as NULL dictionary) or the stream state is
787 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
788 expected one (incorrect Adler32 value). inflateSetDictionary does not
789 perform any decompression: this will be done by subsequent calls of
790 inflate().
791*/
792
793extern int EXPORT inflateSync OF((z_streamp strm));
794/*
795 Skips invalid compressed data until the special marker (see deflate()
796 above) can be found, or until all available input is skipped. No output
797 is provided.
798
799 inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR
800 if no more input was provided, Z_DATA_ERROR if no marker has been found,
801 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
802 case, the application may save the current current value of total_in which
803 indicates where valid compressed data was found. In the error case, the
804 application may repeatedly call inflateSync, providing more input each time,
805 until success or end of the input data.
806*/
807
808extern int EXPORT inflateReset OF((z_streamp strm));
809/*
810 This function is equivalent to inflateEnd followed by inflateInit,
811 but does not free and reallocate all the internal decompression state.
812 The stream will keep attributes that may have been set by inflateInit2.
813
814 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
815 stream state was inconsistent (such as zalloc or state being NULL).
816*/
817
818extern int inflateIncomp OF((z_stream *strm));
819/*
820 This function adds the data at next_in (avail_in bytes) to the output
821 history without performing any output. There must be no pending output,
822 and the decompressor must be expecting to see the start of a block.
823 Calling this function is equivalent to decompressing a stored block
824 containing the data at next_in (except that the data is not output).
825*/
826
827 /* utility functions */
828
829/*
830 The following utility functions are implemented on top of the
831 basic stream-oriented functions. To simplify the interface, some
832 default options are assumed (compression level, window size,
833 standard memory allocation functions). The source code of these
834 utility functions can easily be modified if you need special options.
835*/
836
837extern int EXPORT compress OF((Bytef *dest, uLongf *destLen,
838 const Bytef *source, uLong sourceLen));
839/*
840 Compresses the source buffer into the destination buffer. sourceLen is
841 the byte length of the source buffer. Upon entry, destLen is the total
842 size of the destination buffer, which must be at least 0.1% larger than
843 sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the
844 compressed buffer.
845 This function can be used to compress a whole file at once if the
846 input file is mmap'ed.
847 compress returns Z_OK if success, Z_MEM_ERROR if there was not
848 enough memory, Z_BUF_ERROR if there was not enough room in the output
849 buffer.
850*/
851
852extern int EXPORT uncompress OF((Bytef *dest, uLongf *destLen,
853 const Bytef *source, uLong sourceLen));
854/*
855 Decompresses the source buffer into the destination buffer. sourceLen is
856 the byte length of the source buffer. Upon entry, destLen is the total
857 size of the destination buffer, which must be large enough to hold the
858 entire uncompressed data. (The size of the uncompressed data must have
859 been saved previously by the compressor and transmitted to the decompressor
860 by some mechanism outside the scope of this compression library.)
861 Upon exit, destLen is the actual size of the compressed buffer.
862 This function can be used to decompress a whole file at once if the
863 input file is mmap'ed.
864
865 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
866 enough memory, Z_BUF_ERROR if there was not enough room in the output
867 buffer, or Z_DATA_ERROR if the input data was corrupted.
868*/
869
870
871typedef voidp gzFile;
872
873extern gzFile EXPORT gzopen OF((const char *path, const char *mode));
874/*
875 Opens a gzip (.gz) file for reading or writing. The mode parameter
876 is as in fopen ("rb" or "wb") but can also include a compression level
877 ("wb9"). gzopen can be used to read a file which is not in gzip format;
878 in this case gzread will directly read from the file without decompression.
879 gzopen returns NULL if the file could not be opened or if there was
880 insufficient memory to allocate the (de)compression state; errno
881 can be checked to distinguish the two cases (if errno is zero, the
882 zlib error is Z_MEM_ERROR).
883*/
884
885extern gzFile EXPORT gzdopen OF((int fd, const char *mode));
886/*
887 gzdopen() associates a gzFile with the file descriptor fd. File
888 descriptors are obtained from calls like open, dup, creat, pipe or
889 fileno (in the file has been previously opened with fopen).
890 The mode parameter is as in gzopen.
891 The next call of gzclose on the returned gzFile will also close the
892 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
893 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
894 gzdopen returns NULL if there was insufficient memory to allocate
895 the (de)compression state.
896*/
897
898extern int EXPORT gzread OF((gzFile file, voidp buf, unsigned len));
899/*
900 Reads the given number of uncompressed bytes from the compressed file.
901 If the input file was not in gzip format, gzread copies the given number
902 of bytes into the buffer.
903 gzread returns the number of uncompressed bytes actually read (0 for
904 end of file, -1 for error). */
905
906extern int EXPORT gzwrite OF((gzFile file, const voidp buf, unsigned len));
907/*
908 Writes the given number of uncompressed bytes into the compressed file.
909 gzwrite returns the number of uncompressed bytes actually written
910 (0 in case of error).
911*/
912
913extern int EXPORT gzflush OF((gzFile file, int flush));
914/*
915 Flushes all pending output into the compressed file. The parameter
916 flush is as in the deflate() function. The return value is the zlib
917 error number (see function gzerror below). gzflush returns Z_OK if
918 the flush parameter is Z_FINISH and all output could be flushed.
919 gzflush should be called only when strictly necessary because it can
920 degrade compression.
921*/
922
923extern int EXPORT gzclose OF((gzFile file));
924/*
925 Flushes all pending output if necessary, closes the compressed file
926 and deallocates all the (de)compression state. The return value is the zlib
927 error number (see function gzerror below).
928*/
929
930extern const char * EXPORT gzerror OF((gzFile file, int *errnum));
931/*
932 Returns the error message for the last error which occurred on the
933 given compressed file. errnum is set to zlib error number. If an
934 error occurred in the file system and not in the compression library,
935 errnum is set to Z_ERRNO and the application may consult errno
936 to get the exact error code.
937*/
938
939 /* checksum functions */
940
941/*
942 These functions are not related to compression but are exported
943 anyway because they might be useful in applications using the
944 compression library.
945*/
946
947extern uLong EXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
948
949/*
950 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
951 return the updated checksum. If buf is NULL, this function returns
952 the required initial value for the checksum.
953 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
954 much faster. Usage example:
955
956 uLong adler = adler32(0L, Z_NULL, 0);
957
958 while (read_buffer(buffer, length) != EOF) {
959 adler = adler32(adler, buffer, length);
960 }
961 if (adler != original_adler) error();
962*/
963
964#if 0
965extern uLong EXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
966/*
967 Update a running crc with the bytes buf[0..len-1] and return the updated
968 crc. If buf is NULL, this function returns the required initial value
969 for the crc. Pre- and post-conditioning (one's complement) is performed
970 within this function so it shouldn't be done by the application.
971 Usage example:
972
973 uLong crc = crc32(0L, Z_NULL, 0);
974
975 while (read_buffer(buffer, length) != EOF) {
976 crc = crc32(crc, buffer, length);
977 }
978 if (crc != original_crc) error();
979*/
980#endif
981
982
983 /* various hacks, don't look :) */
984
985/* deflateInit and inflateInit are macros to allow checking the zlib version
986 * and the compiler's view of z_stream:
987 */
988extern int EXPORT deflateInit_ OF((z_streamp strm, int level,
989 const char *version, int stream_size));
990extern int EXPORT inflateInit_ OF((z_streamp strm,
991 const char *version, int stream_size));
992extern int EXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
993 int windowBits, int memLevel, int strategy,
994 const char *version, int stream_size));
995extern int EXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
996 const char *version, int stream_size));
997#define deflateInit(strm, level) \
998 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
999#define inflateInit(strm) \
1000 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1001#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1002 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1003 (strategy), ZLIB_VERSION, sizeof(z_stream))
1004#define inflateInit2(strm, windowBits) \
1005 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1006
1007#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
1008 struct internal_state {int dummy;}; /* hack for buggy compilers */
1009#endif
1010
1011uLongf *get_crc_table OF((void)); /* can be used by asm versions of crc32() */
1012
1013#ifdef __cplusplus
1014}
1015#endif
1016
1bd40720 1017#endif /* _NET_ZLIB_H_ */
984263bc 1018/* --- zlib.h */