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0001 /*
0002  * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
0003  * 
0004  * Redistribution and use in source and binary forms, with or without modifica-
0005  * tion, are permitted provided that the following conditions are met:
0006  * 
0007  *   1.  Redistributions of source code must retain the above copyright notice,
0008  *       this list of conditions and the following disclaimer.
0009  * 
0010  *   2.  Redistributions in binary form must reproduce the above copyright
0011  *       notice, this list of conditions and the following disclaimer in the
0012  *       documentation and/or other materials provided with the distribution.
0013  * 
0014  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
0015  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
0016  * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
0017  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
0018  * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
0019  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
0020  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
0021  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
0022  * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
0023  * OF THE POSSIBILITY OF SUCH DAMAGE.
0024  *
0025  * Alternatively, the contents of this file may be used under the terms of
0026  * the GNU General Public License ("GPL") version 2 or any later version,
0027  * in which case the provisions of the GPL are applicable instead of
0028  * the above. If you wish to allow the use of your version of this file
0029  * only under the terms of the GPL and not to allow others to use your
0030  * version of this file under the BSD license, indicate your decision
0031  * by deleting the provisions above and replace them with the notice
0032  * and other provisions required by the GPL. If you do not delete the
0033  * provisions above, a recipient may use your version of this file under
0034  * either the BSD or the GPL.
0035  */
0036 
0037 #ifndef LZF_H
0038 #define LZF_H
0039 
0040 /***********************************************************************
0041 **
0042 **  lzf -- an extremely fast/free compression/decompression-method
0043 **  http://liblzf.plan9.de/
0044 **
0045 **  This algorithm is believed to be patent-free.
0046 **
0047 ***********************************************************************/
0048 
0049 #define LZF_VERSION 0x0105 /* 1.5, API version */
0050 
0051 /*
0052  * Compress in_len bytes stored at the memory block starting at
0053  * in_data and write the result to out_data, up to a maximum length
0054  * of out_len bytes.
0055  *
0056  * If the output buffer is not large enough or any error occurs return 0,
0057  * otherwise return the number of bytes used, which might be considerably
0058  * more than in_len (but less than 104% of the original size), so it
0059  * makes sense to always use out_len == in_len - 1), to ensure _some_
0060  * compression, and store the data uncompressed otherwise (with a flag, of
0061  * course.
0062  *
0063  * lzf_compress might use different algorithms on different systems and
0064  * even different runs, thus might result in different compressed strings
0065  * depending on the phase of the moon or similar factors. However, all
0066  * these strings are architecture-independent and will result in the
0067  * original data when decompressed using lzf_decompress.
0068  *
0069  * The buffers must not be overlapping.
0070  *
0071  * If the option LZF_STATE_ARG is enabled, an extra argument must be
0072  * supplied which is not reflected in this header file. Refer to lzfP.h
0073  * and lzf_c.c.
0074  *
0075  */
0076 unsigned int 
0077 lzf_compress (const void *const in_data,  unsigned int in_len,
0078               void             *out_data, unsigned int out_len);
0079 
0080 /*
0081  * Decompress data compressed with some version of the lzf_compress
0082  * function and stored at location in_data and length in_len. The result
0083  * will be stored at out_data up to a maximum of out_len characters.
0084  *
0085  * If the output buffer is not large enough to hold the decompressed
0086  * data, a 0 is returned and errno is set to E2BIG. Otherwise the number
0087  * of decompressed bytes (i.e. the original length of the data) is
0088  * returned.
0089  *
0090  * If an error in the compressed data is detected, a zero is returned and
0091  * errno is set to EINVAL.
0092  *
0093  * This function is very fast, about as fast as a copying loop.
0094  */
0095 unsigned int 
0096 lzf_decompress (const void *const in_data,  unsigned int in_len,
0097                 void             *out_data, unsigned int out_len);
0098 
0099 #endif
0100