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Revision: 1.32
Committed: Tue Nov 12 12:46:28 2024 UTC (5 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: HEAD
Changes since 1.31: +3 -2 lines
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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 * Unaligned accesses are not safe even on x86, so disable by default.
81 */
82 #ifndef STRICT_ALIGN
83 # define STRICT_ALIGN 0 /* was: # !(defined(__i386) || defined (__amd64)) */
84 #endif
85
86 /*
87 * You may choose to pre-set the hash table (might be faster on some
88 * modern cpus and large (>>64k) blocks, and also makes compression
89 * deterministic/repeatable when the configuration otherwise is the same).
90 */
91 #ifndef INIT_HTAB
92 # define INIT_HTAB 1
93 #endif
94
95 /*
96 * Avoid assigning values to errno variable? for some embedding purposes
97 * (linux kernel for example), this is necessary. NOTE: this breaks
98 * the documentation in lzf.h. Avoiding errno has no speed impact.
99 */
100 #ifndef AVOID_ERRNO
101 # define AVOID_ERRNO 0
102 #endif
103
104 /*
105 * Whether to pass the LZF_STATE variable as argument, or allocate it
106 * on the stack. For small-stack environments, define this to 1.
107 * NOTE: this breaks the prototype in lzf.h.
108 */
109 #ifndef LZF_STATE_ARG
110 # define LZF_STATE_ARG 0
111 #endif
112
113 /*
114 * Whether to add extra checks for input validity in lzf_decompress
115 * and return EINVAL if the input stream has been corrupted. This
116 * only shields against overflowing the input buffer and will not
117 * detect most corrupted streams.
118 * This check is not normally noticeable on modern hardware
119 * (<1% slowdown), but might slow down older cpus considerably.
120 */
121 #ifndef CHECK_INPUT
122 # define CHECK_INPUT 1
123 #endif
124
125 /*
126 * Whether the target CPU has a slow multiplication. This affects
127 * the default hash function for the compressor, and enables a slightly
128 * worse hash function that needs only shifts.
129 */
130 #ifndef MULTIPLICATION_IS_SLOW
131 # define MULTIPLICATION_IS_SLOW 0
132 #endif
133
134 /*
135 * If defined, then this data type will be used for storing offsets.
136 * This can be useful if you want to use a huge hashtable, want to
137 * conserve memory, or both, and your data fits into e.g. 64kb.
138 * If instead you want to compress data > 4GB, then it's better to
139 * to "#define LZF_USE_OFFSETS 0" instead.
140 */
141 /*#define LZF_HSLOT unsigned short*/
142
143 /*
144 * Whether to store pointers or offsets inside the hash table. On
145 * 64 bit architetcures, pointers take up twice as much space,
146 * and might also be slower. Default is to autodetect.
147 */
148 /*#define LZF_USE_OFFSETS autodetect */
149
150 /*
151 * Whether to optimise code for size, at the expense of speed. Use
152 * this when you are extremely tight on memory, perhaps in combination
153 * with AVOID_ERRNO 1 and CHECK_INPUT 0.
154 */
155 #ifndef OPTIMISE_SIZE
156 # ifdef __OPTIMIZE_SIZE__
157 # define OPTIMISE_SIZE 1
158 # else
159 # define OPTIMISE_SIZE 0
160 # endif
161 #endif
162
163 /*****************************************************************************/
164 /* nothing should be changed below */
165
166 #ifdef __cplusplus
167 # include <cstring>
168 # include <climits>
169 using namespace std;
170 #else
171 # include <string.h>
172 # include <limits.h>
173 #endif
174
175 #if ULTRA_FAST
176 # undef VERY_FAST
177 #endif
178
179 #ifndef LZF_USE_OFFSETS
180 # ifdef _WIN32
181 # define LZF_USE_OFFSETS defined(_M_X64)
182 # else
183 # if __cplusplus > 199711L
184 # include <cstdint>
185 # else
186 # include <stdint.h>
187 # endif
188 # define LZF_USE_OFFSETS (UINTPTR_MAX > 0xffffffffU)
189 # endif
190 #endif
191
192 typedef unsigned char u8;
193
194 #ifdef LZF_HSLOT
195 # define LZF_HSLOT_BIAS ((const u8 *)in_data)
196 #else
197 # if LZF_USE_OFFSETS
198 # define LZF_HSLOT_BIAS ((const u8 *)in_data)
199 typedef unsigned int LZF_HSLOT;
200 # else
201 # define LZF_HSLOT_BIAS 0
202 typedef const u8 *LZF_HSLOT;
203 # endif
204 #endif
205
206 #if USHRT_MAX == 65535
207 typedef unsigned short u16;
208 #elif UINT_MAX == 65535
209 typedef unsigned int u16;
210 #else
211 # undef STRICT_ALIGN
212 # define STRICT_ALIGN 1
213 #endif
214
215 #define LZF_MAX_LIT (1 << 5)
216 #define LZF_MAX_OFF (1 << 13)
217 #define LZF_MAX_REF ((1 << 8) + (1 << 3))
218
219 typedef LZF_HSLOT LZF_STATE[1 << (HLOG)];
220
221 typedef struct
222 {
223 const u8 *first [1 << (6+8)]; /* most recent occurance of a match */
224 u16 prev [LZF_MAX_OFF]; /* how many bytes to go backwards for the next match */
225 } LZF_STATE_BEST[1];
226
227 #endif
228