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/cvs/liblzf/lzf_d.c
Revision: 1.3
Committed: Tue Dec 23 04:52:00 2003 UTC (20 years, 4 months ago) by pcg
Content type: text/plain
Branch: MAIN
Changes since 1.2: +13 -8 lines
Log Message:
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File Contents

# User Rev Content
1 root 1.1 /*
2 pcg 1.3 * Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com>
3 root 1.1 *
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     * 3. The name of the author may not be used to endorse or promote products
15     * derived from this software without specific prior written permission.
16     *
17     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18     * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19     * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20     * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21     * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25     * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26     * OF THE POSSIBILITY OF SUCH DAMAGE.
27     */
28    
29 pcg 1.3 #include "lzfP.h"
30 root 1.1
31 pcg 1.3 #if AVOID_ERRNO
32     # define SET_ERRNO(n)
33     #else
34     # include <errno.h>
35     # define SET_ERRNO(n) errno = (n)
36     #endif
37 root 1.1
38     unsigned int
39     lzf_decompress (const void *const in_data, unsigned int in_len,
40     void *out_data, unsigned int out_len)
41     {
42 pcg 1.3 u8 const *ip = (const u8 *)in_data;
43     u8 *op = (u8 *)out_data;
44 root 1.1 u8 const *const in_end = ip + in_len;
45     u8 *const out_end = op + out_len;
46    
47     do
48     {
49     unsigned int ctrl = *ip++;
50    
51     if (ctrl < (1 << 5)) /* literal run */
52     {
53     ctrl++;
54    
55     if (op + ctrl > out_end)
56     {
57 pcg 1.3 SET_ERRNO (E2BIG);
58 root 1.1 return 0;
59     }
60    
61     #if USE_MEMCPY
62     memcpy (op, ip, ctrl);
63     op += ctrl;
64     ip += ctrl;
65     #else
66     do
67     *op++ = *ip++;
68     while (--ctrl);
69     #endif
70     }
71     else /* back reference */
72     {
73     unsigned int len = ctrl >> 5;
74    
75     u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
76    
77     if (len == 7)
78     len += *ip++;
79    
80     ref -= *ip++;
81    
82     if (op + len + 2 > out_end)
83     {
84 pcg 1.3 SET_ERRNO (E2BIG);
85 root 1.1 return 0;
86     }
87    
88     if (ref < (u8 *)out_data)
89     {
90 pcg 1.3 SET_ERRNO (EINVAL);
91 root 1.1 return 0;
92     }
93    
94     *op++ = *ref++;
95     *op++ = *ref++;
96    
97     do
98     *op++ = *ref++;
99     while (--len);
100     }
101     }
102     while (op < out_end && ip < in_end);
103    
104     return op - (u8 *)out_data;
105     }
106