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/cvs/liblzf/lzf_d.c
Revision: 1.16
Committed: Mon Feb 23 23:46:10 2015 UTC (9 years, 4 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: HEAD
Changes since 1.15: +11 -2 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * Copyright (c) 2000-2010 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 #include "lzfP.h"
38
39 #if AVOID_ERRNO
40 # define SET_ERRNO(n)
41 #else
42 # include <errno.h>
43 # define SET_ERRNO(n) errno = (n)
44 #endif
45
46 #if USE_REP_MOVSB /* small win on amd, big loss on intel */
47 #if (__i386 || __amd64) && __GNUC__ >= 3
48 # define lzf_movsb(dst, src, len) \
49 asm ("rep movsb" \
50 : "=D" (dst), "=S" (src), "=c" (len) \
51 : "0" (dst), "1" (src), "2" (len));
52 #endif
53 #endif
54
55 unsigned int
56 lzf_decompress (const void *const in_data, unsigned int in_len,
57 void *out_data, unsigned int out_len)
58 {
59 u8 const *ip = (const u8 *)in_data;
60 u8 *op = (u8 *)out_data;
61 u8 const *const in_end = ip + in_len;
62 u8 *const out_end = op + out_len;
63
64 do
65 {
66 unsigned int ctrl = *ip++;
67
68 if (ctrl < (1 << 5)) /* literal run */
69 {
70 ctrl++;
71
72 if (op + ctrl > out_end)
73 {
74 SET_ERRNO (E2BIG);
75 return 0;
76 }
77
78 #if CHECK_INPUT
79 if (ip + ctrl > in_end)
80 {
81 SET_ERRNO (EINVAL);
82 return 0;
83 }
84 #endif
85
86 #ifdef lzf_movsb
87 lzf_movsb (op, ip, ctrl);
88 #elif OPTIMISE_SIZE
89 while (ctrl--)
90 *op++ = *ip++;
91 #else
92 switch (ctrl)
93 {
94 case 32: *op++ = *ip++; case 31: *op++ = *ip++; case 30: *op++ = *ip++; case 29: *op++ = *ip++;
95 case 28: *op++ = *ip++; case 27: *op++ = *ip++; case 26: *op++ = *ip++; case 25: *op++ = *ip++;
96 case 24: *op++ = *ip++; case 23: *op++ = *ip++; case 22: *op++ = *ip++; case 21: *op++ = *ip++;
97 case 20: *op++ = *ip++; case 19: *op++ = *ip++; case 18: *op++ = *ip++; case 17: *op++ = *ip++;
98 case 16: *op++ = *ip++; case 15: *op++ = *ip++; case 14: *op++ = *ip++; case 13: *op++ = *ip++;
99 case 12: *op++ = *ip++; case 11: *op++ = *ip++; case 10: *op++ = *ip++; case 9: *op++ = *ip++;
100 case 8: *op++ = *ip++; case 7: *op++ = *ip++; case 6: *op++ = *ip++; case 5: *op++ = *ip++;
101 case 4: *op++ = *ip++; case 3: *op++ = *ip++; case 2: *op++ = *ip++; case 1: *op++ = *ip++;
102 }
103 #endif
104 }
105 else /* back reference */
106 {
107 unsigned int len = ctrl >> 5;
108
109 u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
110
111 #if CHECK_INPUT
112 if (ip >= in_end)
113 {
114 SET_ERRNO (EINVAL);
115 return 0;
116 }
117 #endif
118 if (len == 7)
119 {
120 len += *ip++;
121 #if CHECK_INPUT
122 if (ip >= in_end)
123 {
124 SET_ERRNO (EINVAL);
125 return 0;
126 }
127 #endif
128 }
129
130 ref -= *ip++;
131
132 if (op + len + 2 > out_end)
133 {
134 SET_ERRNO (E2BIG);
135 return 0;
136 }
137
138 if (ref < (u8 *)out_data)
139 {
140 SET_ERRNO (EINVAL);
141 return 0;
142 }
143
144 #ifdef lzf_movsb
145 len += 2;
146 lzf_movsb (op, ref, len);
147 #elif OPTIMISE_SIZE
148 len += 2;
149
150 do
151 *op++ = *ref++;
152 while (--len);
153 #else
154 switch (len)
155 {
156 default:
157 len += 2;
158
159 if (op >= ref + len)
160 {
161 /* disjunct areas */
162 memcpy (op, ref, len);
163 op += len;
164 }
165 else
166 {
167 /* overlapping, use octet by octet copying */
168 do
169 *op++ = *ref++;
170 while (--len);
171 }
172
173 break;
174
175 case 9: *op++ = *ref++;
176 case 8: *op++ = *ref++;
177 case 7: *op++ = *ref++;
178 case 6: *op++ = *ref++;
179 case 5: *op++ = *ref++;
180 case 4: *op++ = *ref++;
181 case 3: *op++ = *ref++;
182 case 2: *op++ = *ref++;
183 case 1: *op++ = *ref++;
184 case 0: *op++ = *ref++; /* two octets more */
185 *op++ = *ref++;
186 }
187 #endif
188 }
189 }
190 while (ip < in_end);
191
192 return op - (u8 *)out_data;
193 }
194