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 #include "lzfP.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 * This function formerly had two API variants depending on a
74 * compile-time constant: one took a 64K state structure as an
75 * argument, the other allocated it internally on the stack (yuck).
76 *
77 * We define the stack-unfriendly version in terms of the stack-friendly
78 * one.
79 *
80 */
81 unsigned int
82 lzf_compress_r (const void *const, unsigned int,
83 void *, unsigned int, LZF_STATE);
84
85 static inline int
lzf_compress(const void * const in,unsigned int in_len,void * out,unsigned int out_len)86 lzf_compress (const void *const in, unsigned int in_len,
87 void *out, unsigned int out_len)
88 {
89 LZF_STATE htab;
90
91 return lzf_compress_r(in, in_len, out, out_len, htab);
92 }
93
94 /*
95 * Decompress data compressed with some version of the lzf_compress
96 * function and stored at location in_data and length in_len. The result
97 * will be stored at out_data up to a maximum of out_len characters.
98 *
99 * If the output buffer is not large enough to hold the decompressed
100 * data, a 0 is returned and errno is set to E2BIG. Otherwise the number
101 * of decompressed bytes (i.e. the original length of the data) is
102 * returned.
103 *
104 * If an error in the compressed data is detected, a zero is returned and
105 * errno is set to EINVAL.
106 *
107 * This function is very fast, about as fast as a copying loop.
108 */
109 unsigned int
110 lzf_decompress (const void *const , unsigned int,
111 void *, unsigned int);
112
113 #endif
114
115