1/* 2 * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de> 3 * 4 * Redistribution and use in source and binary forms, with or without modifica- 5 * tion, are permitted provided that the following conditions are met: 6 * 7 * 1. Redistributions of source code must retain the above copyright notice, 8 * this list of conditions and the following disclaimer. 9 * 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 16 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 17 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 18 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 20 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 21 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 22 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 23 * OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 * Alternatively, the contents of this file may be used under the terms of 26 * the GNU General Public License ("GPL") version 2 or any later version, 27 * in which case the provisions of the GPL are applicable instead of 28 * the above. If you wish to allow the use of your version of this file 29 * only under the terms of the GPL and not to allow others to use your 30 * version of this file under the BSD license, indicate your decision 31 * by deleting the provisions above and replace them with the notice 32 * and other provisions required by the GPL. If you do not delete the 33 * provisions above, a recipient may use your version of this file under 34 * either the BSD or the GPL. 35 */ 36 37#ifndef LZF_H 38#define LZF_H 39 40/*********************************************************************** 41** 42** lzf -- an extremely fast/free compression/decompression-method 43** http://liblzf.plan9.de/ 44** 45** This algorithm is believed to be patent-free. 46** 47***********************************************************************/ 48 49#define LZF_VERSION 0x0105 /* 1.5, API version */ 50 51/* 52 * Compress in_len bytes stored at the memory block starting at 53 * in_data and write the result to out_data, up to a maximum length 54 * of out_len bytes. 55 * 56 * If the output buffer is not large enough or any error occurs return 0, 57 * otherwise return the number of bytes used, which might be considerably 58 * more than in_len (but less than 104% of the original size), so it 59 * makes sense to always use out_len == in_len - 1), to ensure _some_ 60 * compression, and store the data uncompressed otherwise (with a flag, of 61 * course. 62 * 63 * lzf_compress might use different algorithms on different systems and 64 * even different runs, thus might result in different compressed strings 65 * depending on the phase of the moon or similar factors. However, all 66 * these strings are architecture-independent and will result in the 67 * original data when decompressed using lzf_decompress. 68 * 69 * The buffers must not be overlapping. 70 * 71 * If the option LZF_STATE_ARG is enabled, an extra argument must be 72 * supplied which is not reflected in this header file. Refer to lzfP.h 73 * and lzf_c.c. 74 * 75 */ 76unsigned int 77lzf_compress (const void *const in_data, unsigned int in_len, 78 void *out_data, unsigned int out_len); 79 80/* 81 * Decompress data compressed with some version of the lzf_compress 82 * function and stored at location in_data and length in_len. The result 83 * will be stored at out_data up to a maximum of out_len characters. 84 * 85 * If the output buffer is not large enough to hold the decompressed 86 * data, a 0 is returned and errno is set to E2BIG. Otherwise the number 87 * of decompressed bytes (i.e. the original length of the data) is 88 * returned. 89 * 90 * If an error in the compressed data is detected, a zero is returned and 91 * errno is set to EINVAL. 92 * 93 * This function is very fast, about as fast as a copying loop. 94 */ 95unsigned int 96lzf_decompress (const void *const in_data, unsigned int in_len, 97 void *out_data, unsigned int out_len); 98 99/* 100 * Size of hashtable is (1 << HLOG) * sizeof (char *) 101 * decompression is independent of the hash table size 102 * the difference between 15 and 14 is very small 103 * for small blocks (and 14 is usually a bit faster). 104 * For a low-memory/faster configuration, use HLOG == 13; 105 * For best compression, use 15 or 16 (or more, up to 23). 106 */ 107#ifndef HLOG 108# define HLOG 16 109#endif 110 111/* 112 * Sacrifice very little compression quality in favour of compression speed. 113 * This gives almost the same compression as the default code, and is 114 * (very roughly) 15% faster. This is the preferred mode of operation. 115 */ 116#ifndef VERY_FAST 117# define VERY_FAST 1 118#endif 119 120/* 121 * Sacrifice some more compression quality in favour of compression speed. 122 * (roughly 1-2% worse compression for large blocks and 123 * 9-10% for small, redundant, blocks and >>20% better speed in both cases) 124 * In short: when in need for speed, enable this for binary data, 125 * possibly disable this for text data. 126 */ 127#ifndef ULTRA_FAST 128# define ULTRA_FAST 0 129#endif 130 131/* 132 * Unconditionally aligning does not cost very much, so do it if unsure 133 */ 134#ifndef STRICT_ALIGN 135# if !(defined(__i386) || defined (__amd64)) 136# define STRICT_ALIGN 1 137# else 138# define STRICT_ALIGN 0 139# endif 140#endif 141 142/* 143 * You may choose to pre-set the hash table (might be faster on some 144 * modern cpus and large (>>64k) blocks, and also makes compression 145 * deterministic/repeatable when the configuration otherwise is the same). 146 */ 147#ifndef INIT_HTAB 148# define INIT_HTAB 1 149#endif 150 151/* 152 * Avoid assigning values to errno variable? for some embedding purposes 153 * (linux kernel for example), this is necessary. NOTE: this breaks 154 * the documentation in lzf.h. 155 */ 156#ifndef AVOID_ERRNO 157# define AVOID_ERRNO 0 158#endif 159 160/* 161 * Wether to pass the LZF_STATE variable as argument, or allocate it 162 * on the stack. For small-stack environments, define this to 1. 163 * NOTE: this breaks the prototype in lzf.h. 164 */ 165#ifndef LZF_STATE_ARG 166# define LZF_STATE_ARG 0 167#endif 168 169/* 170 * Wether to add extra checks for input validity in lzf_decompress 171 * and return EINVAL if the input stream has been corrupted. This 172 * only shields against overflowing the input buffer and will not 173 * detect most corrupted streams. 174 * This check is not normally noticeable on modern hardware 175 * (<1% slowdown), but might slow down older cpus considerably. 176 */ 177#ifndef CHECK_INPUT 178# define CHECK_INPUT 1 179#endif 180 181/*****************************************************************************/ 182/* nothing should be changed below */ 183 184typedef unsigned char u8; 185 186typedef const u8 *LZF_STATE[1 << (HLOG)]; 187 188#if !STRICT_ALIGN 189/* for unaligned accesses we need a 16 bit datatype. */ 190# include <limits.h> 191# if USHRT_MAX == 65535 192 typedef unsigned short u16; 193# elif UINT_MAX == 65535 194 typedef unsigned int u16; 195# else 196# undef STRICT_ALIGN 197# define STRICT_ALIGN 1 198# endif 199#endif 200 201#if ULTRA_FAST 202# if defined(VERY_FAST) 203# undef VERY_FAST 204# endif 205#endif 206 207#if INIT_HTAB 208# ifdef __cplusplus 209# include <cstring> 210# else 211# include <string.h> 212# endif 213#endif 214 215#endif 216