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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  */
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