1 | /* |
1 | /* |
2 | * Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de> |
2 | * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de> |
3 | * |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without modifica- |
4 | * Redistribution and use in source and binary forms, with or without modifica- |
5 | * tion, are permitted provided that the following conditions are met: |
5 | * tion, are permitted provided that the following conditions are met: |
6 | * |
6 | * |
7 | * 1. Redistributions of source code must retain the above copyright notice, |
7 | * 1. Redistributions of source code must retain the above copyright notice, |
8 | * this list of conditions and the following disclaimer. |
8 | * this list of conditions and the following disclaimer. |
9 | * |
9 | * |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
11 | * notice, this list of conditions and the following disclaimer in the |
11 | * notice, this list of conditions and the following disclaimer in the |
12 | * documentation and/or other materials provided with the distribution. |
12 | * documentation and/or other materials provided with the distribution. |
13 | * |
13 | * |
14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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- |
15 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- |
16 | * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
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- |
17 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- |
18 | * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
18 | * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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44 | ** |
44 | ** |
45 | ** This algorithm is believed to be patent-free. |
45 | ** This algorithm is believed to be patent-free. |
46 | ** |
46 | ** |
47 | ***********************************************************************/ |
47 | ***********************************************************************/ |
48 | |
48 | |
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49 | /* API version (major * 256 + minor) |
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50 | * major API version gets bumped on incompatible changes. |
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51 | * minor API version gets bumped on compatible changes. |
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52 | * 1.5 => 1.6: add LZF_MAX_COMPRESSED_SIZE |
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53 | */ |
49 | #define LZF_VERSION 0x0105 /* 1.5 */ |
54 | #define LZF_VERSION 0x0106 |
50 | |
55 | |
51 | /* |
56 | /* |
52 | * Compress in_len bytes stored at the memory block starting at |
57 | * 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 |
58 | * in_data and write the result to out_data, up to a maximum length |
54 | * of out_len bytes. |
59 | * of out_len bytes. |
55 | * |
60 | * |
56 | * If the output buffer is not large enough or any error occurs |
61 | * If the output buffer is not large enough or any error occurs return 0, |
57 | * return 0, otherwise return the number of bytes used (which might |
62 | * otherwise return the number of bytes used, which might be considerably |
58 | * be considerably larger than in_len, so it makes sense to always |
63 | * more than in_len (but less than 1 + 104% of the original size), so it |
59 | * use out_len == in_len - 1), to ensure _some_ compression, and store |
64 | * makes sense to always use out_len == in_len - 1), to ensure _some_ |
60 | * the data uncompressed otherwise. |
65 | * compression, and store the data uncompressed otherwise (with a flag, of |
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66 | * course. |
61 | * |
67 | * |
62 | * lzf_compress might use different algorithms on different systems and |
68 | * lzf_compress might use different algorithms on different systems and |
63 | * even different runs, thus might result in different compressed strings |
69 | * even different runs, thus might result in different compressed strings |
64 | * depending on the phase of the moon or similar factors. However, all |
70 | * depending on the phase of the moon or similar factors. However, all |
65 | * these strings are architecture-independent and will result in the |
71 | * these strings are architecture-independent and will result in the |
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70 | * If the option LZF_STATE_ARG is enabled, an extra argument must be |
76 | * If the option LZF_STATE_ARG is enabled, an extra argument must be |
71 | * supplied which is not reflected in this header file. Refer to lzfP.h |
77 | * supplied which is not reflected in this header file. Refer to lzfP.h |
72 | * and lzf_c.c. |
78 | * and lzf_c.c. |
73 | * |
79 | * |
74 | */ |
80 | */ |
75 | unsigned int |
81 | unsigned int |
76 | lzf_compress (const void *const in_data, unsigned int in_len, |
82 | lzf_compress (const void *const in_data, unsigned int in_len, |
77 | void *out_data, unsigned int out_len); |
83 | void *out_data, unsigned int out_len); |
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84 | |
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85 | /* |
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86 | * The maximum out_len that needs to be allocated to make sure |
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87 | * any input data can be compressed without overflowing the output |
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88 | * buffer, i.e. maximum out_len = LZF_MAX_COMPRESSED_SIZE (in_len). |
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89 | * This is useful if you don't want to bother with the case of |
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90 | * incompressible data and just want to provide a buffer that is |
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91 | * guaranteeed to be big enough. |
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92 | * This macro can be used at preprocessing time. |
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93 | */ |
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94 | #define LZF_MAX_COMPRESSED_SIZE(n) ((n) * 33 / 32 + 1) |
78 | |
95 | |
79 | /* |
96 | /* |
80 | * Decompress data compressed with some version of the lzf_compress |
97 | * Decompress data compressed with some version of the lzf_compress |
81 | * function and stored at location in_data and length in_len. The result |
98 | * function and stored at location in_data and length in_len. The result |
82 | * will be stored at out_data up to a maximum of out_len characters. |
99 | * will be stored at out_data up to a maximum of out_len characters. |
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89 | * If an error in the compressed data is detected, a zero is returned and |
106 | * If an error in the compressed data is detected, a zero is returned and |
90 | * errno is set to EINVAL. |
107 | * errno is set to EINVAL. |
91 | * |
108 | * |
92 | * This function is very fast, about as fast as a copying loop. |
109 | * This function is very fast, about as fast as a copying loop. |
93 | */ |
110 | */ |
94 | unsigned int |
111 | unsigned int |
95 | lzf_decompress (const void *const in_data, unsigned int in_len, |
112 | lzf_decompress (const void *const in_data, unsigned int in_len, |
96 | void *out_data, unsigned int out_len); |
113 | void *out_data, unsigned int out_len); |
97 | |
114 | |
98 | #endif |
115 | #endif |
99 | |
116 | |