liblzf/lzf.h

/*
 * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
 *
 * 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.
**
***********************************************************************/

/* API version (major * 256 + minor)
 * major API version gets bumped on incompatible changes.
 * minor API version gets bumped on compatible changes.
 * 1.5 => 1.6: add LZF_MAX_COMPRESSED_SIZE
 */
#define LZF_VERSION 0x0106

/*
 * 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 1 + 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);

/*
 * The maximum out_len that needs to be allocated to make sure
 * any input data can be compressed without overflowing the output
 * buffer, i.e. maximum out_len = LZF_MAX_COMPRESSED_SIZE (in_len).
 * This is useful if you don't want to bother with the case of
 * incompressible data and just want to provide a buffer that is
 * guaranteeed to be big enough.
 * This macro can be used at preprocessing time.
 */
#define LZF_MAX_COMPRESSED_SIZE(n) ((n) * 33 / 32 + 1)

/*
 * 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);

#endif

Revision:	1.17
Committed:	Mon Dec 10 20:46:06 2012 UTC (11 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.16:	+17 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.14	* Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
3	root	1.15	*
4	root	1.1	* Redistribution and use in source and binary forms, with or without modifica-
5			* tion, are permitted provided that the following conditions are met:
6	root	1.15	*
7	root	1.1	* 1. Redistributions of source code must retain the above copyright notice,
8			* this list of conditions and the following disclaimer.
9	root	1.15	*
10	root	1.1	* 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	root	1.15	*
14	root	1.1	* 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	pcg	1.7	*
25			* Alternatively, the contents of this file may be used under the terms of
26	root	1.12	* 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	root	1.1	*/
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	root	1.17	/* API version (major * 256 + minor)
50			* major API version gets bumped on incompatible changes.
51			* minor API version gets bumped on compatible changes.
52			* 1.5 => 1.6: add LZF_MAX_COMPRESSED_SIZE
53			*/
54			#define LZF_VERSION 0x0106
55	root	1.10
56	root	1.1	/*
57			* Compress in_len bytes stored at the memory block starting at
58			* in_data and write the result to out_data, up to a maximum length
59			* of out_len bytes.
60			*
61	root	1.14	* If the output buffer is not large enough or any error occurs return 0,
62			* otherwise return the number of bytes used, which might be considerably
63	root	1.16	* more than in_len (but less than 1 + 104% of the original size), so it
64	root	1.14	* makes sense to always use out_len == in_len - 1), to ensure _some_
65			* compression, and store the data uncompressed otherwise (with a flag, of
66			* course.
67	root	1.1	*
68			* lzf_compress might use different algorithms on different systems and
69	root	1.13	* even different runs, thus might result in different compressed strings
70	root	1.10	* depending on the phase of the moon or similar factors. However, all
71			* these strings are architecture-independent and will result in the
72			* original data when decompressed using lzf_decompress.
73	root	1.1	*
74			* The buffers must not be overlapping.
75			*
76	pcg	1.6	* If the option LZF_STATE_ARG is enabled, an extra argument must be
77	root	1.10	* supplied which is not reflected in this header file. Refer to lzfP.h
78			* and lzf_c.c.
79	pcg	1.5	*
80	root	1.1	*/
81	root	1.15	unsigned int
82	root	1.1	lzf_compress (const void *const in_data, unsigned int in_len,
83			void *out_data, unsigned int out_len);
84
85			/*
86	root	1.17	* The maximum out_len that needs to be allocated to make sure
87			* any input data can be compressed without overflowing the output
88			* buffer, i.e. maximum out_len = LZF_MAX_COMPRESSED_SIZE (in_len).
89			* This is useful if you don't want to bother with the case of
90			* incompressible data and just want to provide a buffer that is
91			* guaranteeed to be big enough.
92			* This macro can be used at preprocessing time.
93			*/
94			#define LZF_MAX_COMPRESSED_SIZE(n) ((n) * 33 / 32 + 1)
95
96			/*
97	root	1.1	* Decompress data compressed with some version of the lzf_compress
98			* function and stored at location in_data and length in_len. The result
99			* will be stored at out_data up to a maximum of out_len characters.
100			*
101	root	1.3	* If the output buffer is not large enough to hold the decompressed
102	root	1.1	* data, a 0 is returned and errno is set to E2BIG. Otherwise the number
103			* of decompressed bytes (i.e. the original length of the data) is
104			* returned.
105			*
106			* If an error in the compressed data is detected, a zero is returned and
107			* errno is set to EINVAL.
108			*
109			* This function is very fast, about as fast as a copying loop.
110			*/
111	root	1.15	unsigned int
112	root	1.1	lzf_decompress (const void *const in_data, unsigned int in_len,
113			void *out_data, unsigned int out_len);
114
115			#endif
116