/* * Copyright (c) 2000-2008 Marc Alexander Lehmann * * Redistribution and use in source and binary forms, with or without modifica- * tion, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * * Alternatively, the contents of this file may be used under the terms of * the GNU General Public License ("GPL") version 2 or any later version, * in which case the provisions of the GPL are applicable instead of * the above. If you wish to allow the use of your version of this file * only under the terms of the GPL and not to allow others to use your * version of this file under the BSD license, indicate your decision * by deleting the provisions above and replace them with the notice * and other provisions required by the GPL. If you do not delete the * provisions above, a recipient may use your version of this file under * either the BSD or the GPL. */ #ifndef LZF_H #define LZF_H /*********************************************************************** ** ** lzf -- an extremely fast/free compression/decompression-method ** http://liblzf.plan9.de/ ** ** This algorithm is believed to be patent-free. ** ***********************************************************************/ #define LZF_VERSION 0x0105 /* 1.5, API version */ /* * Compress in_len bytes stored at the memory block starting at * in_data and write the result to out_data, up to a maximum length * of out_len bytes. * * If the output buffer is not large enough or any error occurs return 0, * otherwise return the number of bytes used, which might be considerably * more than in_len (but less than 104% of the original size), so it * makes sense to always use out_len == in_len - 1), to ensure _some_ * compression, and store the data uncompressed otherwise (with a flag, of * course. * * lzf_compress might use different algorithms on different systems and * even different runs, thus might result in different compressed strings * depending on the phase of the moon or similar factors. However, all * these strings are architecture-independent and will result in the * original data when decompressed using lzf_decompress. * * The buffers must not be overlapping. * * If the option LZF_STATE_ARG is enabled, an extra argument must be * supplied which is not reflected in this header file. Refer to lzfP.h * and lzf_c.c. * */ unsigned int lzf_compress (const void *const in_data, unsigned int in_len, void *out_data, unsigned int out_len); /* * Decompress data compressed with some version of the lzf_compress * function and stored at location in_data and length in_len. The result * will be stored at out_data up to a maximum of out_len characters. * * If the output buffer is not large enough to hold the decompressed * data, a 0 is returned and errno is set to E2BIG. Otherwise the number * of decompressed bytes (i.e. the original length of the data) is * returned. * * If an error in the compressed data is detected, a zero is returned and * errno is set to EINVAL. * * This function is very fast, about as fast as a copying loop. */ unsigned int lzf_decompress (const void *const in_data, unsigned int in_len, void *out_data, unsigned int out_len); /* * Size of hashtable is (1 << HLOG) * sizeof (char *) * decompression is independent of the hash table size * the difference between 15 and 14 is very small * for small blocks (and 14 is usually a bit faster). * For a low-memory/faster configuration, use HLOG == 13; * For best compression, use 15 or 16 (or more, up to 23). */ #ifndef HLOG # define HLOG 16 #endif /* * Sacrifice very little compression quality in favour of compression speed. * This gives almost the same compression as the default code, and is * (very roughly) 15% faster. This is the preferred mode of operation. */ #ifndef VERY_FAST # define VERY_FAST 1 #endif /* * Sacrifice some more compression quality in favour of compression speed. * (roughly 1-2% worse compression for large blocks and * 9-10% for small, redundant, blocks and >>20% better speed in both cases) * In short: when in need for speed, enable this for binary data, * possibly disable this for text data. */ #ifndef ULTRA_FAST # define ULTRA_FAST 0 #endif /* * Unconditionally aligning does not cost very much, so do it if unsure */ #ifndef STRICT_ALIGN # define STRICT_ALIGN !(defined(__i386) || defined (__amd64)) #endif /* * You may choose to pre-set the hash table (might be faster on some * modern cpus and large (>>64k) blocks, and also makes compression * deterministic/repeatable when the configuration otherwise is the same). */ #ifndef INIT_HTAB # define INIT_HTAB 1 #endif /* * Avoid assigning values to errno variable? for some embedding purposes * (linux kernel for example), this is necessary. NOTE: this breaks * the documentation in lzf.h. */ #ifndef AVOID_ERRNO # define AVOID_ERRNO 0 #endif /* * Wether to pass the LZF_STATE variable as argument, or allocate it * on the stack. For small-stack environments, define this to 1. * NOTE: this breaks the prototype in lzf.h. */ #ifndef LZF_STATE_ARG # define LZF_STATE_ARG 0 #endif /* * Wether to add extra checks for input validity in lzf_decompress * and return EINVAL if the input stream has been corrupted. This * only shields against overflowing the input buffer and will not * detect most corrupted streams. * This check is not normally noticeable on modern hardware * (<1% slowdown), but might slow down older cpus considerably. */ #ifndef CHECK_INPUT # define CHECK_INPUT 1 #endif /*****************************************************************************/ /* nothing should be changed below */ typedef unsigned char u8; typedef const u8 *LZF_STATE[1 << (HLOG)]; #if !STRICT_ALIGN /* for unaligned accesses we need a 16 bit datatype. */ # include # if USHRT_MAX == 65535 typedef unsigned short u16; # elif UINT_MAX == 65535 typedef unsigned int u16; # else # undef STRICT_ALIGN # define STRICT_ALIGN 1 # endif #endif #if ULTRA_FAST # if defined(VERY_FAST) # undef VERY_FAST # endif #endif #if INIT_HTAB # ifdef __cplusplus # include # else # include # endif #endif #endif