1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de> 5 * 6 * Redistribution and use in source and binary forms, with or without modifica- 7 * tion, are permitted provided that the following conditions are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 18 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 20 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 24 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 25 * OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * Alternatively, the contents of this file may be used under the terms of 28 * the GNU General Public License ("GPL") version 2 or any later version, 29 * in which case the provisions of the GPL are applicable instead of 30 * the above. If you wish to allow the use of your version of this file 31 * only under the terms of the GPL and not to allow others to use your 32 * version of this file under the BSD license, indicate your decision 33 * by deleting the provisions above and replace them with the notice 34 * and other provisions required by the GPL. If you do not delete the 35 * provisions above, a recipient may use your version of this file under 36 * either the BSD or the GPL. 37 */ 38 39#ifndef LZF_H 40#define LZF_H 41 42/*********************************************************************** 43** 44** lzf -- an extremely fast/free compression/decompression-method 45** http://liblzf.plan9.de/ 46** 47** This algorithm is believed to be patent-free. 48** 49***********************************************************************/ 50 51#define LZF_VERSION 0x0105 /* 1.5, API version */ 52 53/* 54 * Compress in_len bytes stored at the memory block starting at 55 * in_data and write the result to out_data, up to a maximum length 56 * of out_len bytes. 57 * 58 * If the output buffer is not large enough or any error occurs return 0, 59 * otherwise return the number of bytes used, which might be considerably 60 * more than in_len (but less than 104% of the original size), so it 61 * makes sense to always use out_len == in_len - 1), to ensure _some_ 62 * compression, and store the data uncompressed otherwise (with a flag, of 63 * course. 64 * 65 * lzf_compress might use different algorithms on different systems and 66 * even different runs, thus might result in different compressed strings 67 * depending on the phase of the moon or similar factors. However, all 68 * these strings are architecture-independent and will result in the 69 * original data when decompressed using lzf_decompress. 70 * 71 * The buffers must not be overlapping. 72 * 73 * If the option LZF_STATE_ARG is enabled, an extra argument must be 74 * supplied which is not reflected in this header file. Refer to lzfP.h 75 * and lzf_c.c. 76 * 77 */ 78unsigned int 79lzf_compress (const void *const in_data, unsigned int in_len, 80 void *out_data, unsigned int out_len); 81 82/* 83 * Decompress data compressed with some version of the lzf_compress 84 * function and stored at location in_data and length in_len. The result 85 * will be stored at out_data up to a maximum of out_len characters. 86 * 87 * If the output buffer is not large enough to hold the decompressed 88 * data, a 0 is returned and errno is set to E2BIG. Otherwise the number 89 * of decompressed bytes (i.e. the original length of the data) is 90 * returned. 91 * 92 * If an error in the compressed data is detected, a zero is returned and 93 * errno is set to EINVAL. 94 * 95 * This function is very fast, about as fast as a copying loop. 96 */ 97unsigned int 98lzf_decompress (const void *const in_data, unsigned int in_len, 99 void *out_data, unsigned int out_len); 100 101/* 102 * Size of hashtable is (1 << HLOG) * sizeof (char *) 103 * decompression is independent of the hash table size 104 * the difference between 15 and 14 is very small 105 * for small blocks (and 14 is usually a bit faster). 106 * For a low-memory/faster configuration, use HLOG == 13; 107 * For best compression, use 15 or 16 (or more, up to 23). 108 */ 109#ifndef HLOG 110# define HLOG 16 111#endif 112 113/* 114 * Sacrifice very little compression quality in favour of compression speed. 115 * This gives almost the same compression as the default code, and is 116 * (very roughly) 15% faster. This is the preferred mode of operation. 117 */ 118#ifndef VERY_FAST 119# define VERY_FAST 1 120#endif 121 122/* 123 * Sacrifice some more compression quality in favour of compression speed. 124 * (roughly 1-2% worse compression for large blocks and 125 * 9-10% for small, redundant, blocks and >>20% better speed in both cases) 126 * In short: when in need for speed, enable this for binary data, 127 * possibly disable this for text data. 128 */ 129#ifndef ULTRA_FAST 130# define ULTRA_FAST 0 131#endif 132 133/* 134 * Unconditionally aligning does not cost very much, so do it if unsure 135 */ 136#ifndef STRICT_ALIGN 137# if !(defined(__i386) || defined (__amd64)) 138# define STRICT_ALIGN 1 139# else 140# define STRICT_ALIGN 0 141# endif 142#endif 143 144/* 145 * You may choose to pre-set the hash table (might be faster on some 146 * modern cpus and large (>>64k) blocks, and also makes compression 147 * deterministic/repeatable when the configuration otherwise is the same). 148 */ 149#ifndef INIT_HTAB 150# define INIT_HTAB 1 151#endif 152 153/* 154 * Avoid assigning values to errno variable? for some embedding purposes 155 * (linux kernel for example), this is necessary. NOTE: this breaks 156 * the documentation in lzf.h. 157 */ 158#ifndef AVOID_ERRNO 159# define AVOID_ERRNO 0 160#endif 161 162/* 163 * Wether to pass the LZF_STATE variable as argument, or allocate it 164 * on the stack. For small-stack environments, define this to 1. 165 * NOTE: this breaks the prototype in lzf.h. 166 */ 167#ifndef LZF_STATE_ARG 168# define LZF_STATE_ARG 0 169#endif 170 171/* 172 * Wether to add extra checks for input validity in lzf_decompress 173 * and return EINVAL if the input stream has been corrupted. This 174 * only shields against overflowing the input buffer and will not 175 * detect most corrupted streams. 176 * This check is not normally noticeable on modern hardware 177 * (<1% slowdown), but might slow down older cpus considerably. 178 */ 179#ifndef CHECK_INPUT 180# define CHECK_INPUT 1 181#endif 182 183/*****************************************************************************/ 184/* nothing should be changed below */ 185 186typedef unsigned char u8; 187 188typedef const u8 *LZF_STATE[1 << (HLOG)]; 189 190#if !STRICT_ALIGN 191/* for unaligned accesses we need a 16 bit datatype. */ 192# include <limits.h> 193# if USHRT_MAX == 65535 194 typedef unsigned short u16; 195# elif UINT_MAX == 65535 196 typedef unsigned int u16; 197# else 198# undef STRICT_ALIGN 199# define STRICT_ALIGN 1 200# endif 201#endif 202 203#if ULTRA_FAST 204# if defined(VERY_FAST) 205# undef VERY_FAST 206# endif 207#endif 208 209#if INIT_HTAB 210# ifdef __cplusplus 211# include <cstring> 212# else 213# include <string.h> 214# endif 215#endif 216 217#endif 218