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      1 /*
      2  * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp (at) 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  */
     76 unsigned int
     77 lzf_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  */
     95 unsigned int
     96 lzf_decompress (const void *const in_data,  unsigned int in_len,
     97                 void             *out_data, unsigned int out_len);
     98 
     99 #endif
    100 
    101