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Revision: 1.31
Committed: Mon Jun 29 23:34:41 2015 UTC (8 years, 10 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: HEAD
Changes since 1.30: +15 -5 lines
Log Message:
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File Contents

# Content
1 /*
2 * Copyright (c) 2000-2007 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 LZFP_h
38 #define LZFP_h
39
40 #define STANDALONE 1 /* at the moment, this is ok. */
41
42 #ifndef STANDALONE
43 # include "lzf.h"
44 #endif
45
46 /*
47 * Size of hashtable is (1 << HLOG) * sizeof (char *)
48 * decompression is independent of the hash table size
49 * the difference between 15 and 14 is very small
50 * for small blocks (and 14 is usually a bit faster).
51 * For a low-memory/faster configuration, use HLOG == 13;
52 * For best compression, use 15 or 16 (or more, up to 22).
53 */
54 #ifndef HLOG
55 # define HLOG 16
56 #endif
57
58 /*
59 * Sacrifice very little compression quality in favour of compression speed.
60 * This gives almost the same compression as the default code, and is
61 * (very roughly) 15% faster. This is the preferred mode of operation.
62 */
63 #ifndef VERY_FAST
64 # define VERY_FAST 1
65 #endif
66
67 /*
68 * Sacrifice some more compression quality in favour of compression speed.
69 * (roughly 1-2% worse compression for large blocks and
70 * 9-10% for small, redundant, blocks and >>20% better speed in both cases)
71 * In short: when in need for speed, enable this for binary data,
72 * possibly disable this for text data.
73 */
74 #ifndef ULTRA_FAST
75 # define ULTRA_FAST 0
76 #endif
77
78 /*
79 * Unconditionally aligning does not cost very much, so do it if unsure
80 */
81 #ifndef STRICT_ALIGN
82 # define STRICT_ALIGN !(defined(__i386) || defined (__amd64))
83 #endif
84
85 /*
86 * You may choose to pre-set the hash table (might be faster on some
87 * modern cpus and large (>>64k) blocks, and also makes compression
88 * deterministic/repeatable when the configuration otherwise is the same).
89 */
90 #ifndef INIT_HTAB
91 # define INIT_HTAB 1
92 #endif
93
94 /*
95 * Avoid assigning values to errno variable? for some embedding purposes
96 * (linux kernel for example), this is necessary. NOTE: this breaks
97 * the documentation in lzf.h. Avoiding errno has no speed impact.
98 */
99 #ifndef AVOID_ERRNO
100 # define AVOID_ERRNO 0
101 #endif
102
103 /*
104 * Whether to pass the LZF_STATE variable as argument, or allocate it
105 * on the stack. For small-stack environments, define this to 1.
106 * NOTE: this breaks the prototype in lzf.h.
107 */
108 #ifndef LZF_STATE_ARG
109 # define LZF_STATE_ARG 0
110 #endif
111
112 /*
113 * Whether to add extra checks for input validity in lzf_decompress
114 * and return EINVAL if the input stream has been corrupted. This
115 * only shields against overflowing the input buffer and will not
116 * detect most corrupted streams.
117 * This check is not normally noticeable on modern hardware
118 * (<1% slowdown), but might slow down older cpus considerably.
119 */
120 #ifndef CHECK_INPUT
121 # define CHECK_INPUT 1
122 #endif
123
124 /*
125 * Whether the target CPU has a slow multiplication. This affects
126 * the default hash function for the compressor, and enables a slightly
127 * worse hash function that needs only shifts.
128 */
129 #ifndef MULTIPLICATION_IS_SLOW
130 # define MULTIPLICATION_IS_SLOW 0
131 #endif
132
133 /*
134 * If defined, then this data type will be used for storing offsets.
135 * This can be useful if you want to use a huge hashtable, want to
136 * conserve memory, or both, and your data fits into e.g. 64kb.
137 * If instead you want to compress data > 4GB, then it's better to
138 * to "#define LZF_USE_OFFSETS 0" instead.
139 */
140 /*#define LZF_HSLOT unsigned short*/
141
142 /*
143 * Whether to store pointers or offsets inside the hash table. On
144 * 64 bit architetcures, pointers take up twice as much space,
145 * and might also be slower. Default is to autodetect.
146 */
147 /*#define LZF_USE_OFFSETS autodetect */
148
149 /*
150 * Whether to optimise code for size, at the expense of speed. Use
151 * this when you are extremely tight on memory, perhaps in combination
152 * with AVOID_ERRNO 1 and CHECK_INPUT 0.
153 */
154 #ifndef OPTIMISE_SIZE
155 # ifdef __OPTIMIZE_SIZE__
156 # define OPTIMISE_SIZE 1
157 # else
158 # define OPTIMISE_SIZE 0
159 # endif
160 #endif
161
162 /*****************************************************************************/
163 /* nothing should be changed below */
164
165 #ifdef __cplusplus
166 # include <cstring>
167 # include <climits>
168 using namespace std;
169 #else
170 # include <string.h>
171 # include <limits.h>
172 #endif
173
174 #if ULTRA_FAST
175 # undef VERY_FAST
176 #endif
177
178 #ifndef LZF_USE_OFFSETS
179 # ifdef _WIN32
180 # define LZF_USE_OFFSETS defined(_M_X64)
181 # else
182 # if __cplusplus > 199711L
183 # include <cstdint>
184 # else
185 # include <stdint.h>
186 # endif
187 # define LZF_USE_OFFSETS (UINTPTR_MAX > 0xffffffffU)
188 # endif
189 #endif
190
191 typedef unsigned char u8;
192
193 #ifdef LZF_HSLOT
194 # define LZF_HSLOT_BIAS ((const u8 *)in_data)
195 #else
196 # if LZF_USE_OFFSETS
197 # define LZF_HSLOT_BIAS ((const u8 *)in_data)
198 typedef unsigned int LZF_HSLOT;
199 # else
200 # define LZF_HSLOT_BIAS 0
201 typedef const u8 *LZF_HSLOT;
202 # endif
203 #endif
204
205 #if USHRT_MAX == 65535
206 typedef unsigned short u16;
207 #elif UINT_MAX == 65535
208 typedef unsigned int u16;
209 #else
210 # undef STRICT_ALIGN
211 # define STRICT_ALIGN 1
212 #endif
213
214 #define LZF_MAX_LIT (1 << 5)
215 #define LZF_MAX_OFF (1 << 13)
216 #define LZF_MAX_REF ((1 << 8) + (1 << 3))
217
218 typedef LZF_HSLOT LZF_STATE[1 << (HLOG)];
219
220 typedef struct
221 {
222 const u8 *first [1 << (6+8)]; /* most recent occurance of a match */
223 u16 prev [LZF_MAX_OFF]; /* how many bytes to go backwards for the next match */
224 } LZF_STATE_BEST[1];
225
226 #endif
227