1a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 2*f33b325aSWolfgang Denk * This file is derived from zlib.h and zconf.h from the zlib-0.95 3a31e091aSJean-Christophe PLAGNIOL-VILLARD * distribution by Jean-loup Gailly and Mark Adler, with some additions 4a31e091aSJean-Christophe PLAGNIOL-VILLARD * by Paul Mackerras to aid in implementing Deflate compression and 5a31e091aSJean-Christophe PLAGNIOL-VILLARD * decompression for PPP packets. 6a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 7a31e091aSJean-Christophe PLAGNIOL-VILLARD 8a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 9a31e091aSJean-Christophe PLAGNIOL-VILLARD * ==FILEVERSION 960122== 10a31e091aSJean-Christophe PLAGNIOL-VILLARD * 11a31e091aSJean-Christophe PLAGNIOL-VILLARD * This marker is used by the Linux installation script to determine 12a31e091aSJean-Christophe PLAGNIOL-VILLARD * whether an up-to-date version of this file is already installed. 13a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 14a31e091aSJean-Christophe PLAGNIOL-VILLARD 15a31e091aSJean-Christophe PLAGNIOL-VILLARD /* zlib.h -- interface of the 'zlib' general purpose compression library 16*f33b325aSWolfgang Denk version 0.95, Aug 16th, 1995. 17a31e091aSJean-Christophe PLAGNIOL-VILLARD 18*f33b325aSWolfgang Denk Copyright (C) 1995 Jean-loup Gailly and Mark Adler 19a31e091aSJean-Christophe PLAGNIOL-VILLARD 20a31e091aSJean-Christophe PLAGNIOL-VILLARD This software is provided 'as-is', without any express or implied 21a31e091aSJean-Christophe PLAGNIOL-VILLARD warranty. In no event will the authors be held liable for any damages 22a31e091aSJean-Christophe PLAGNIOL-VILLARD arising from the use of this software. 23a31e091aSJean-Christophe PLAGNIOL-VILLARD 24a31e091aSJean-Christophe PLAGNIOL-VILLARD Permission is granted to anyone to use this software for any purpose, 25a31e091aSJean-Christophe PLAGNIOL-VILLARD including commercial applications, and to alter it and redistribute it 26a31e091aSJean-Christophe PLAGNIOL-VILLARD freely, subject to the following restrictions: 27a31e091aSJean-Christophe PLAGNIOL-VILLARD 28a31e091aSJean-Christophe PLAGNIOL-VILLARD 1. The origin of this software must not be misrepresented; you must not 29a31e091aSJean-Christophe PLAGNIOL-VILLARD claim that you wrote the original software. If you use this software 30a31e091aSJean-Christophe PLAGNIOL-VILLARD in a product, an acknowledgment in the product documentation would be 31a31e091aSJean-Christophe PLAGNIOL-VILLARD appreciated but is not required. 32a31e091aSJean-Christophe PLAGNIOL-VILLARD 2. Altered source versions must be plainly marked as such, and must not be 33a31e091aSJean-Christophe PLAGNIOL-VILLARD misrepresented as being the original software. 34a31e091aSJean-Christophe PLAGNIOL-VILLARD 3. This notice may not be removed or altered from any source distribution. 35a31e091aSJean-Christophe PLAGNIOL-VILLARD 36a31e091aSJean-Christophe PLAGNIOL-VILLARD Jean-loup Gailly Mark Adler 37*f33b325aSWolfgang Denk gzip@prep.ai.mit.edu madler@alumni.caltech.edu 38a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 39a31e091aSJean-Christophe PLAGNIOL-VILLARD 40*f33b325aSWolfgang Denk #ifndef _ZLIB_H 41*f33b325aSWolfgang Denk #define _ZLIB_H 42a31e091aSJean-Christophe PLAGNIOL-VILLARD 43a31e091aSJean-Christophe PLAGNIOL-VILLARD /* #include "zconf.h" */ /* included directly here */ 44*f33b325aSWolfgang Denk 45a31e091aSJean-Christophe PLAGNIOL-VILLARD /* zconf.h -- configuration of the zlib compression library 46*f33b325aSWolfgang Denk * Copyright (C) 1995 Jean-loup Gailly. 47a31e091aSJean-Christophe PLAGNIOL-VILLARD * For conditions of distribution and use, see copyright notice in zlib.h 48a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 49a31e091aSJean-Christophe PLAGNIOL-VILLARD 50*f33b325aSWolfgang Denk /* From: zconf.h,v 1.12 1995/05/03 17:27:12 jloup Exp */ 51*f33b325aSWolfgang Denk 52a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 53*f33b325aSWolfgang Denk The library does not install any signal handler. It is recommended to 54*f33b325aSWolfgang Denk add at least a handler for SIGSEGV when decompressing; the library checks 55*f33b325aSWolfgang Denk the consistency of the input data whenever possible but may go nuts 56*f33b325aSWolfgang Denk for some forms of corrupted input. 57a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 58a31e091aSJean-Christophe PLAGNIOL-VILLARD 59a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 60a31e091aSJean-Christophe PLAGNIOL-VILLARD * Compile with -DMAXSEG_64K if the alloc function cannot allocate more 61a31e091aSJean-Christophe PLAGNIOL-VILLARD * than 64k bytes at a time (needed on systems with 16-bit int). 62*f33b325aSWolfgang Denk * Compile with -DUNALIGNED_OK if it is OK to access shorts or ints 63*f33b325aSWolfgang Denk * at addresses which are not a multiple of their size. 64*f33b325aSWolfgang Denk * Under DOS, -DFAR=far or -DFAR=__far may be needed. 65a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 66b201171fSGiuseppe CONDORELLI 67b201171fSGiuseppe CONDORELLI #ifndef STDC 68*f33b325aSWolfgang Denk # if defined(MSDOS) || defined(__STDC__) || defined(__cplusplus) 69*f33b325aSWolfgang Denk # define STDC 70b201171fSGiuseppe CONDORELLI # endif 71b201171fSGiuseppe CONDORELLI #endif 72b201171fSGiuseppe CONDORELLI 73*f33b325aSWolfgang Denk #ifdef __MWERKS__ /* Metrowerks CodeWarrior declares fileno() in unix.h */ 74*f33b325aSWolfgang Denk # include <unix.h> 75a31e091aSJean-Christophe PLAGNIOL-VILLARD #endif 76a31e091aSJean-Christophe PLAGNIOL-VILLARD 77a31e091aSJean-Christophe PLAGNIOL-VILLARD /* Maximum value for memLevel in deflateInit2 */ 78a31e091aSJean-Christophe PLAGNIOL-VILLARD #ifndef MAX_MEM_LEVEL 79a31e091aSJean-Christophe PLAGNIOL-VILLARD # ifdef MAXSEG_64K 80a31e091aSJean-Christophe PLAGNIOL-VILLARD # define MAX_MEM_LEVEL 8 81a31e091aSJean-Christophe PLAGNIOL-VILLARD # else 82a31e091aSJean-Christophe PLAGNIOL-VILLARD # define MAX_MEM_LEVEL 9 83a31e091aSJean-Christophe PLAGNIOL-VILLARD # endif 84a31e091aSJean-Christophe PLAGNIOL-VILLARD #endif 85a31e091aSJean-Christophe PLAGNIOL-VILLARD 86*f33b325aSWolfgang Denk #ifndef FAR 87*f33b325aSWolfgang Denk # define FAR 88*f33b325aSWolfgang Denk #endif 89*f33b325aSWolfgang Denk 90*f33b325aSWolfgang Denk /* Maximum value for windowBits in deflateInit2 and inflateInit2 */ 91a31e091aSJean-Christophe PLAGNIOL-VILLARD #ifndef MAX_WBITS 92a31e091aSJean-Christophe PLAGNIOL-VILLARD # define MAX_WBITS 15 /* 32K LZ77 window */ 93a31e091aSJean-Christophe PLAGNIOL-VILLARD #endif 94a31e091aSJean-Christophe PLAGNIOL-VILLARD 95a31e091aSJean-Christophe PLAGNIOL-VILLARD /* The memory requirements for deflate are (in bytes): 96*f33b325aSWolfgang Denk 1 << (windowBits+2) + 1 << (memLevel+9) 97a31e091aSJean-Christophe PLAGNIOL-VILLARD that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) 98a31e091aSJean-Christophe PLAGNIOL-VILLARD plus a few kilobytes for small objects. For example, if you want to reduce 99a31e091aSJean-Christophe PLAGNIOL-VILLARD the default memory requirements from 256K to 128K, compile with 100a31e091aSJean-Christophe PLAGNIOL-VILLARD make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" 101a31e091aSJean-Christophe PLAGNIOL-VILLARD Of course this will generally degrade compression (there's no free lunch). 102a31e091aSJean-Christophe PLAGNIOL-VILLARD 103a31e091aSJean-Christophe PLAGNIOL-VILLARD The memory requirements for inflate are (in bytes) 1 << windowBits 104a31e091aSJean-Christophe PLAGNIOL-VILLARD that is, 32K for windowBits=15 (default value) plus a few kilobytes 105a31e091aSJean-Christophe PLAGNIOL-VILLARD for small objects. 106a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 107a31e091aSJean-Christophe PLAGNIOL-VILLARD 108a31e091aSJean-Christophe PLAGNIOL-VILLARD /* Type declarations */ 109a31e091aSJean-Christophe PLAGNIOL-VILLARD 110a31e091aSJean-Christophe PLAGNIOL-VILLARD #ifndef OF /* function prototypes */ 111a31e091aSJean-Christophe PLAGNIOL-VILLARD # ifdef STDC 112a31e091aSJean-Christophe PLAGNIOL-VILLARD # define OF(args) args 113a31e091aSJean-Christophe PLAGNIOL-VILLARD # else 114a31e091aSJean-Christophe PLAGNIOL-VILLARD # define OF(args) () 115a31e091aSJean-Christophe PLAGNIOL-VILLARD # endif 116a31e091aSJean-Christophe PLAGNIOL-VILLARD #endif 117a31e091aSJean-Christophe PLAGNIOL-VILLARD 118a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef unsigned char Byte; /* 8 bits */ 119a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef unsigned int uInt; /* 16 bits or more */ 120a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef unsigned long uLong; /* 32 bits or more */ 121a31e091aSJean-Christophe PLAGNIOL-VILLARD 122a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef Byte FAR Bytef; 123a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef char FAR charf; 124a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef int FAR intf; 125a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef uInt FAR uIntf; 126a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef uLong FAR uLongf; 127a31e091aSJean-Christophe PLAGNIOL-VILLARD 128a31e091aSJean-Christophe PLAGNIOL-VILLARD #ifdef STDC 129a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef void FAR *voidpf; 130a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef void *voidp; 131a31e091aSJean-Christophe PLAGNIOL-VILLARD #else 132a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef Byte FAR *voidpf; 133a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef Byte *voidp; 134a31e091aSJean-Christophe PLAGNIOL-VILLARD #endif 135a31e091aSJean-Christophe PLAGNIOL-VILLARD 136*f33b325aSWolfgang Denk /* end of original zconf.h */ 137a31e091aSJean-Christophe PLAGNIOL-VILLARD 138*f33b325aSWolfgang Denk #define ZLIB_VERSION "0.95P" 139a31e091aSJean-Christophe PLAGNIOL-VILLARD 140a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 141a31e091aSJean-Christophe PLAGNIOL-VILLARD The 'zlib' compression library provides in-memory compression and 142a31e091aSJean-Christophe PLAGNIOL-VILLARD decompression functions, including integrity checks of the uncompressed 143a31e091aSJean-Christophe PLAGNIOL-VILLARD data. This version of the library supports only one compression method 144*f33b325aSWolfgang Denk (deflation) but other algorithms may be added later and will have the same 145a31e091aSJean-Christophe PLAGNIOL-VILLARD stream interface. 146a31e091aSJean-Christophe PLAGNIOL-VILLARD 147*f33b325aSWolfgang Denk For compression the application must provide the output buffer and 148*f33b325aSWolfgang Denk may optionally provide the input buffer for optimization. For decompression, 149*f33b325aSWolfgang Denk the application must provide the input buffer and may optionally provide 150*f33b325aSWolfgang Denk the output buffer for optimization. 151*f33b325aSWolfgang Denk 152a31e091aSJean-Christophe PLAGNIOL-VILLARD Compression can be done in a single step if the buffers are large 153a31e091aSJean-Christophe PLAGNIOL-VILLARD enough (for example if an input file is mmap'ed), or can be done by 154a31e091aSJean-Christophe PLAGNIOL-VILLARD repeated calls of the compression function. In the latter case, the 155a31e091aSJean-Christophe PLAGNIOL-VILLARD application must provide more input and/or consume the output 156a31e091aSJean-Christophe PLAGNIOL-VILLARD (providing more output space) before each call. 157a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 158a31e091aSJean-Christophe PLAGNIOL-VILLARD 159a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 160*f33b325aSWolfgang Denk typedef void (*free_func) OF((voidpf opaque, voidpf address, uInt nbytes)); 161*f33b325aSWolfgang Denk 162a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef void (*cb_func) OF((Bytef *buf, uInt len)); 163a31e091aSJean-Christophe PLAGNIOL-VILLARD 164a31e091aSJean-Christophe PLAGNIOL-VILLARD struct internal_state; 165a31e091aSJean-Christophe PLAGNIOL-VILLARD 166a31e091aSJean-Christophe PLAGNIOL-VILLARD typedef struct z_stream_s { 167a31e091aSJean-Christophe PLAGNIOL-VILLARD Bytef *next_in; /* next input byte */ 168a31e091aSJean-Christophe PLAGNIOL-VILLARD uInt avail_in; /* number of bytes available at next_in */ 169a31e091aSJean-Christophe PLAGNIOL-VILLARD uLong total_in; /* total nb of input bytes read so far */ 170*f33b325aSWolfgang Denk 171a31e091aSJean-Christophe PLAGNIOL-VILLARD Bytef *next_out; /* next output byte should be put there */ 172a31e091aSJean-Christophe PLAGNIOL-VILLARD uInt avail_out; /* remaining free space at next_out */ 173a31e091aSJean-Christophe PLAGNIOL-VILLARD uLong total_out; /* total nb of bytes output so far */ 174*f33b325aSWolfgang Denk 175a31e091aSJean-Christophe PLAGNIOL-VILLARD char *msg; /* last error message, NULL if no error */ 176a31e091aSJean-Christophe PLAGNIOL-VILLARD struct internal_state FAR *state; /* not visible by applications */ 177*f33b325aSWolfgang Denk 178a31e091aSJean-Christophe PLAGNIOL-VILLARD alloc_func zalloc; /* used to allocate the internal state */ 179a31e091aSJean-Christophe PLAGNIOL-VILLARD free_func zfree; /* used to free the internal state */ 180*f33b325aSWolfgang Denk voidp opaque; /* private data object passed to zalloc and zfree */ 181*f33b325aSWolfgang Denk 182*f33b325aSWolfgang Denk Byte data_type; /* best guess about the data type: ascii or binary */ 183*f33b325aSWolfgang Denk 184a31e091aSJean-Christophe PLAGNIOL-VILLARD cb_func outcb; /* called regularly just before blocks of output */ 185*f33b325aSWolfgang Denk 186a31e091aSJean-Christophe PLAGNIOL-VILLARD } z_stream; 187a31e091aSJean-Christophe PLAGNIOL-VILLARD 188a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 189*f33b325aSWolfgang Denk The application must update next_in and avail_in when avail_in has 190*f33b325aSWolfgang Denk dropped to zero. It must update next_out and avail_out when avail_out 191*f33b325aSWolfgang Denk has dropped to zero. The application must initialize zalloc, zfree and 192*f33b325aSWolfgang Denk opaque before calling the init function. All other fields are set by the 193*f33b325aSWolfgang Denk compression library and must not be updated by the application. 194b201171fSGiuseppe CONDORELLI 195*f33b325aSWolfgang Denk The opaque value provided by the application will be passed as the first 196*f33b325aSWolfgang Denk parameter for calls of zalloc and zfree. This can be useful for custom 197*f33b325aSWolfgang Denk memory management. The compression library attaches no meaning to the 198*f33b325aSWolfgang Denk opaque value. 199*f33b325aSWolfgang Denk 200*f33b325aSWolfgang Denk zalloc must return Z_NULL if there is not enough memory for the object. 201*f33b325aSWolfgang Denk On 16-bit systems, the functions zalloc and zfree must be able to allocate 202*f33b325aSWolfgang Denk exactly 65536 bytes, but will not be required to allocate more than this 203*f33b325aSWolfgang Denk if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 204*f33b325aSWolfgang Denk pointers returned by zalloc for objects of exactly 65536 bytes *must* 205*f33b325aSWolfgang Denk have their offset normalized to zero. The default allocation function 206*f33b325aSWolfgang Denk provided by this library ensures this (see zutil.c). To reduce memory 207*f33b325aSWolfgang Denk requirements and avoid any allocation of 64K objects, at the expense of 208*f33b325aSWolfgang Denk compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 209*f33b325aSWolfgang Denk 210*f33b325aSWolfgang Denk The fields total_in and total_out can be used for statistics or 211*f33b325aSWolfgang Denk progress reports. After compression, total_in holds the total size of 212*f33b325aSWolfgang Denk the uncompressed data and may be saved for use in the decompressor 213*f33b325aSWolfgang Denk (particularly if the decompressor wants to decompress everything in 214*f33b325aSWolfgang Denk a single step). 215*f33b325aSWolfgang Denk */ 216a31e091aSJean-Christophe PLAGNIOL-VILLARD 217a31e091aSJean-Christophe PLAGNIOL-VILLARD /* constants */ 218*f33b325aSWolfgang Denk 219a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_NO_FLUSH 0 220*f33b325aSWolfgang Denk #define Z_PARTIAL_FLUSH 1 221*f33b325aSWolfgang Denk #define Z_FULL_FLUSH 2 222*f33b325aSWolfgang Denk #define Z_SYNC_FLUSH 3 /* experimental: partial_flush + byte align */ 223a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_FINISH 4 224*f33b325aSWolfgang Denk #define Z_PACKET_FLUSH 5 225*f33b325aSWolfgang Denk /* See deflate() below for the usage of these constants */ 226a31e091aSJean-Christophe PLAGNIOL-VILLARD 227a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_OK 0 228a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_STREAM_END 1 229a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_ERRNO (-1) 230a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_STREAM_ERROR (-2) 231a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_DATA_ERROR (-3) 232a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_MEM_ERROR (-4) 233a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_BUF_ERROR (-5) 234*f33b325aSWolfgang Denk /* error codes for the compression/decompression functions */ 235a31e091aSJean-Christophe PLAGNIOL-VILLARD 236a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_BEST_SPEED 1 237a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_BEST_COMPRESSION 9 238a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_DEFAULT_COMPRESSION (-1) 239a31e091aSJean-Christophe PLAGNIOL-VILLARD /* compression levels */ 240a31e091aSJean-Christophe PLAGNIOL-VILLARD 241a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_FILTERED 1 242a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_HUFFMAN_ONLY 2 243a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_DEFAULT_STRATEGY 0 244a31e091aSJean-Christophe PLAGNIOL-VILLARD 245a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_BINARY 0 246*f33b325aSWolfgang Denk #define Z_ASCII 1 247a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_UNKNOWN 2 248*f33b325aSWolfgang Denk /* Used to set the data_type field */ 249a31e091aSJean-Christophe PLAGNIOL-VILLARD 250a31e091aSJean-Christophe PLAGNIOL-VILLARD #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 251a31e091aSJean-Christophe PLAGNIOL-VILLARD 252*f33b325aSWolfgang Denk extern char *zlib_version; 253*f33b325aSWolfgang Denk /* The application can compare zlib_version and ZLIB_VERSION for consistency. 254b201171fSGiuseppe CONDORELLI If the first character differs, the library code actually used is 255b201171fSGiuseppe CONDORELLI not compatible with the zlib.h header file used by the application. 256a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 257a31e091aSJean-Christophe PLAGNIOL-VILLARD 258*f33b325aSWolfgang Denk /* basic functions */ 259a31e091aSJean-Christophe PLAGNIOL-VILLARD 260*f33b325aSWolfgang Denk extern int inflateInit OF((z_stream *strm)); 261a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 262*f33b325aSWolfgang Denk Initializes the internal stream state for decompression. The fields 263*f33b325aSWolfgang Denk zalloc and zfree must be initialized before by the caller. If zalloc and 264*f33b325aSWolfgang Denk zfree are set to Z_NULL, inflateInit updates them to use default allocation 265*f33b325aSWolfgang Denk functions. 266b201171fSGiuseppe CONDORELLI 267*f33b325aSWolfgang Denk inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 268*f33b325aSWolfgang Denk enough memory. msg is set to null if there is no error message. 269*f33b325aSWolfgang Denk inflateInit does not perform any decompression: this will be done by 270*f33b325aSWolfgang Denk inflate(). 271*f33b325aSWolfgang Denk */ 272*f33b325aSWolfgang Denk 273*f33b325aSWolfgang Denk 274*f33b325aSWolfgang Denk extern int inflate OF((z_stream *strm, int flush)); 275*f33b325aSWolfgang Denk /* 276*f33b325aSWolfgang Denk Performs one or both of the following actions: 277a31e091aSJean-Christophe PLAGNIOL-VILLARD 278a31e091aSJean-Christophe PLAGNIOL-VILLARD - Decompress more input starting at next_in and update next_in and avail_in 279a31e091aSJean-Christophe PLAGNIOL-VILLARD accordingly. If not all input can be processed (because there is not 280a31e091aSJean-Christophe PLAGNIOL-VILLARD enough room in the output buffer), next_in is updated and processing 281a31e091aSJean-Christophe PLAGNIOL-VILLARD will resume at this point for the next call of inflate(). 282a31e091aSJean-Christophe PLAGNIOL-VILLARD 283a31e091aSJean-Christophe PLAGNIOL-VILLARD - Provide more output starting at next_out and update next_out and avail_out 284*f33b325aSWolfgang Denk accordingly. inflate() always provides as much output as possible 285*f33b325aSWolfgang Denk (until there is no more input data or no more space in the output buffer). 286a31e091aSJean-Christophe PLAGNIOL-VILLARD 287a31e091aSJean-Christophe PLAGNIOL-VILLARD Before the call of inflate(), the application should ensure that at least 288a31e091aSJean-Christophe PLAGNIOL-VILLARD one of the actions is possible, by providing more input and/or consuming 289a31e091aSJean-Christophe PLAGNIOL-VILLARD more output, and updating the next_* and avail_* values accordingly. 290a31e091aSJean-Christophe PLAGNIOL-VILLARD The application can consume the uncompressed output when it wants, for 291a31e091aSJean-Christophe PLAGNIOL-VILLARD example when the output buffer is full (avail_out == 0), or after each 292*f33b325aSWolfgang Denk call of inflate(). 293a31e091aSJean-Christophe PLAGNIOL-VILLARD 294*f33b325aSWolfgang Denk If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH, 295*f33b325aSWolfgang Denk inflate flushes as much output as possible to the output buffer. The 296*f33b325aSWolfgang Denk flushing behavior of inflate is not specified for values of the flush 297*f33b325aSWolfgang Denk parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the 298*f33b325aSWolfgang Denk current implementation actually flushes as much output as possible 299*f33b325aSWolfgang Denk anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data 300*f33b325aSWolfgang Denk has been consumed, it is expecting to see the length field of a stored 301*f33b325aSWolfgang Denk block; if not, it returns Z_DATA_ERROR. 302a31e091aSJean-Christophe PLAGNIOL-VILLARD 303a31e091aSJean-Christophe PLAGNIOL-VILLARD inflate() should normally be called until it returns Z_STREAM_END or an 304a31e091aSJean-Christophe PLAGNIOL-VILLARD error. However if all decompression is to be performed in a single step 305a31e091aSJean-Christophe PLAGNIOL-VILLARD (a single call of inflate), the parameter flush should be set to 306a31e091aSJean-Christophe PLAGNIOL-VILLARD Z_FINISH. In this case all pending input is processed and all pending 307a31e091aSJean-Christophe PLAGNIOL-VILLARD output is flushed; avail_out must be large enough to hold all the 308a31e091aSJean-Christophe PLAGNIOL-VILLARD uncompressed data. (The size of the uncompressed data may have been saved 309a31e091aSJean-Christophe PLAGNIOL-VILLARD by the compressor for this purpose.) The next operation on this stream must 310a31e091aSJean-Christophe PLAGNIOL-VILLARD be inflateEnd to deallocate the decompression state. The use of Z_FINISH 311*f33b325aSWolfgang Denk is never required, but can be used to inform inflate that a faster routine 312a31e091aSJean-Christophe PLAGNIOL-VILLARD may be used for the single inflate() call. 313a31e091aSJean-Christophe PLAGNIOL-VILLARD 314*f33b325aSWolfgang Denk inflate() returns Z_OK if some progress has been made (more input 315*f33b325aSWolfgang Denk processed or more output produced), Z_STREAM_END if the end of the 316*f33b325aSWolfgang Denk compressed data has been reached and all uncompressed output has been 317*f33b325aSWolfgang Denk produced, Z_DATA_ERROR if the input data was corrupted, Z_STREAM_ERROR if 318*f33b325aSWolfgang Denk the stream structure was inconsistent (for example if next_in or next_out 319*f33b325aSWolfgang Denk was NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no 320*f33b325aSWolfgang Denk progress is possible or if there was not enough room in the output buffer 321*f33b325aSWolfgang Denk when Z_FINISH is used. In the Z_DATA_ERROR case, the application may then 322*f33b325aSWolfgang Denk call inflateSync to look for a good compression block. */ 323a31e091aSJean-Christophe PLAGNIOL-VILLARD 324a31e091aSJean-Christophe PLAGNIOL-VILLARD 325*f33b325aSWolfgang Denk extern int inflateEnd OF((z_stream *strm)); 326a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 327a31e091aSJean-Christophe PLAGNIOL-VILLARD All dynamically allocated data structures for this stream are freed. 328a31e091aSJean-Christophe PLAGNIOL-VILLARD This function discards any unprocessed input and does not flush any 329a31e091aSJean-Christophe PLAGNIOL-VILLARD pending output. 330a31e091aSJean-Christophe PLAGNIOL-VILLARD 331a31e091aSJean-Christophe PLAGNIOL-VILLARD inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 332a31e091aSJean-Christophe PLAGNIOL-VILLARD was inconsistent. In the error case, msg may be set but then points to a 333a31e091aSJean-Christophe PLAGNIOL-VILLARD static string (which must not be deallocated). 334a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 335a31e091aSJean-Christophe PLAGNIOL-VILLARD 336*f33b325aSWolfgang Denk /* advanced functions */ 337a31e091aSJean-Christophe PLAGNIOL-VILLARD 338*f33b325aSWolfgang Denk extern int inflateInit2 OF((z_stream *strm, 339*f33b325aSWolfgang Denk int windowBits)); 340a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 341*f33b325aSWolfgang Denk This is another version of inflateInit with more compression options. The 342*f33b325aSWolfgang Denk fields next_out, zalloc and zfree must be initialized before by the caller. 343*f33b325aSWolfgang Denk 344*f33b325aSWolfgang Denk The windowBits parameter is the base two logarithm of the maximum window 345*f33b325aSWolfgang Denk size (the size of the history buffer). It should be in the range 8..15 for 346*f33b325aSWolfgang Denk this version of the library (the value 16 will be allowed soon). The 347*f33b325aSWolfgang Denk default value is 15 if inflateInit is used instead. If a compressed stream 348*f33b325aSWolfgang Denk with a larger window size is given as input, inflate() will return with 349*f33b325aSWolfgang Denk the error code Z_DATA_ERROR instead of trying to allocate a larger window. 350*f33b325aSWolfgang Denk 351*f33b325aSWolfgang Denk If next_out is not null, the library will use this buffer for the history 352*f33b325aSWolfgang Denk buffer; the buffer must either be large enough to hold the entire output 353*f33b325aSWolfgang Denk data, or have at least 1<<windowBits bytes. If next_out is null, the 354*f33b325aSWolfgang Denk library will allocate its own buffer (and leave next_out null). next_in 355*f33b325aSWolfgang Denk need not be provided here but must be provided by the application for the 356*f33b325aSWolfgang Denk next call of inflate(). 357*f33b325aSWolfgang Denk 358*f33b325aSWolfgang Denk If the history buffer is provided by the application, next_out must 359*f33b325aSWolfgang Denk never be changed by the application since the decompressor maintains 360*f33b325aSWolfgang Denk history information inside this buffer from call to call; the application 361*f33b325aSWolfgang Denk can only reset next_out to the beginning of the history buffer when 362*f33b325aSWolfgang Denk avail_out is zero and all output has been consumed. 363*f33b325aSWolfgang Denk 364*f33b325aSWolfgang Denk inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was 365*f33b325aSWolfgang Denk not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as 366*f33b325aSWolfgang Denk windowBits < 8). msg is set to null if there is no error message. 367*f33b325aSWolfgang Denk inflateInit2 does not perform any decompression: this will be done by 368*f33b325aSWolfgang Denk inflate(). 369a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 370a31e091aSJean-Christophe PLAGNIOL-VILLARD 371*f33b325aSWolfgang Denk extern int inflateSync OF((z_stream *strm)); 372*f33b325aSWolfgang Denk /* 373*f33b325aSWolfgang Denk Skips invalid compressed data until the special marker (see deflate() 374*f33b325aSWolfgang Denk above) can be found, or until all available input is skipped. No output 375*f33b325aSWolfgang Denk is provided. 376*f33b325aSWolfgang Denk 377*f33b325aSWolfgang Denk inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR 378*f33b325aSWolfgang Denk if no more input was provided, Z_DATA_ERROR if no marker has been found, 379*f33b325aSWolfgang Denk or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 380*f33b325aSWolfgang Denk case, the application may save the current current value of total_in which 381*f33b325aSWolfgang Denk indicates where valid compressed data was found. In the error case, the 382*f33b325aSWolfgang Denk application may repeatedly call inflateSync, providing more input each time, 383*f33b325aSWolfgang Denk until success or end of the input data. 384*f33b325aSWolfgang Denk */ 385*f33b325aSWolfgang Denk 386*f33b325aSWolfgang Denk extern int inflateReset OF((z_stream *strm)); 387*f33b325aSWolfgang Denk /* 388*f33b325aSWolfgang Denk This function is equivalent to inflateEnd followed by inflateInit, 389*f33b325aSWolfgang Denk but does not free and reallocate all the internal decompression state. 390*f33b325aSWolfgang Denk The stream will keep attributes that may have been set by inflateInit2. 391*f33b325aSWolfgang Denk 392*f33b325aSWolfgang Denk inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 393*f33b325aSWolfgang Denk stream state was inconsistent (such as zalloc or state being NULL). 394*f33b325aSWolfgang Denk */ 395*f33b325aSWolfgang Denk 396*f33b325aSWolfgang Denk extern int inflateIncomp OF((z_stream *strm)); 397*f33b325aSWolfgang Denk /* 398*f33b325aSWolfgang Denk This function adds the data at next_in (avail_in bytes) to the output 399*f33b325aSWolfgang Denk history without performing any output. There must be no pending output, 400*f33b325aSWolfgang Denk and the decompressor must be expecting to see the start of a block. 401*f33b325aSWolfgang Denk Calling this function is equivalent to decompressing a stored block 402*f33b325aSWolfgang Denk containing the data at next_in (except that the data is not output). 403*f33b325aSWolfgang Denk */ 404*f33b325aSWolfgang Denk 405*f33b325aSWolfgang Denk /* checksum functions */ 406*f33b325aSWolfgang Denk 407*f33b325aSWolfgang Denk /* 408*f33b325aSWolfgang Denk This function is not related to compression but is exported 409*f33b325aSWolfgang Denk anyway because it might be useful in applications using the 410*f33b325aSWolfgang Denk compression library. 411*f33b325aSWolfgang Denk */ 412*f33b325aSWolfgang Denk 413*f33b325aSWolfgang Denk extern uLong adler32 OF((uLong adler, Bytef *buf, uInt len)); 414*f33b325aSWolfgang Denk 415a31e091aSJean-Christophe PLAGNIOL-VILLARD /* 416a31e091aSJean-Christophe PLAGNIOL-VILLARD Update a running Adler-32 checksum with the bytes buf[0..len-1] and 417a31e091aSJean-Christophe PLAGNIOL-VILLARD return the updated checksum. If buf is NULL, this function returns 418a31e091aSJean-Christophe PLAGNIOL-VILLARD the required initial value for the checksum. 419a31e091aSJean-Christophe PLAGNIOL-VILLARD An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 420a31e091aSJean-Christophe PLAGNIOL-VILLARD much faster. Usage example: 421a31e091aSJean-Christophe PLAGNIOL-VILLARD 422a31e091aSJean-Christophe PLAGNIOL-VILLARD uLong adler = adler32(0L, Z_NULL, 0); 423a31e091aSJean-Christophe PLAGNIOL-VILLARD 424a31e091aSJean-Christophe PLAGNIOL-VILLARD while (read_buffer(buffer, length) != EOF) { 425a31e091aSJean-Christophe PLAGNIOL-VILLARD adler = adler32(adler, buffer, length); 426a31e091aSJean-Christophe PLAGNIOL-VILLARD } 427a31e091aSJean-Christophe PLAGNIOL-VILLARD if (adler != original_adler) error(); 428a31e091aSJean-Christophe PLAGNIOL-VILLARD */ 429a31e091aSJean-Christophe PLAGNIOL-VILLARD 430*f33b325aSWolfgang Denk #ifndef _Z_UTIL_H 431a31e091aSJean-Christophe PLAGNIOL-VILLARD struct internal_state {int dummy;}; /* hack for buggy compilers */ 432a31e091aSJean-Christophe PLAGNIOL-VILLARD #endif 433a31e091aSJean-Christophe PLAGNIOL-VILLARD 434*f33b325aSWolfgang Denk #endif /* _ZLIB_H */ 435