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/cvs/liblzf/lzf_d.c
Revision: 1.1
Committed: Sun Jun 9 22:41:34 2002 UTC (21 years, 11 months ago) by root
Content type: text/plain
Branch: MAIN
Log Message:
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# User Rev Content
1 root 1.1 /*
2     * Copyright (c) 2000 Marc Alexander Lehmann <pcg@goof.com>
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     * 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     #include <errno.h>
30    
31     #include "lzfP.h"
32    
33     unsigned int
34     lzf_decompress (const void *const in_data, unsigned int in_len,
35     void *out_data, unsigned int out_len)
36     {
37     u8 const *ip = in_data;
38     u8 *op = out_data;
39     u8 const *const in_end = ip + in_len;
40     u8 *const out_end = op + out_len;
41    
42     do
43     {
44     unsigned int ctrl = *ip++;
45    
46     if (ctrl < (1 << 5)) /* literal run */
47     {
48     ctrl++;
49    
50     if (op + ctrl > out_end)
51     {
52     errno = E2BIG;
53     return 0;
54     }
55    
56     #if USE_MEMCPY
57     memcpy (op, ip, ctrl);
58     op += ctrl;
59     ip += ctrl;
60     #else
61     do
62     *op++ = *ip++;
63     while (--ctrl);
64     #endif
65     }
66     else /* back reference */
67     {
68     unsigned int len = ctrl >> 5;
69    
70     u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
71    
72     if (len == 7)
73     len += *ip++;
74    
75     ref -= *ip++;
76    
77     if (op + len + 2 > out_end)
78     {
79     errno = E2BIG;
80     return 0;
81     }
82    
83     if (ref < (u8 *)out_data)
84     {
85     errno = EINVAL;
86     return 0;
87     }
88    
89     *op++ = *ref++;
90     *op++ = *ref++;
91    
92     do
93     *op++ = *ref++;
94     while (--len);
95     }
96     }
97     while (op < out_end && ip < in_end);
98    
99     return op - (u8 *)out_data;
100     }
101