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1 | /* uncompr.c -- decompress a memory buffer | |
2 | * Copyright (C) 1995-2003 Jean-loup Gailly. | |
3 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4 | */ | |
5 | ||
6 | /* @(#) $Id$ */ | |
7 | ||
8 | #define ZLIB_INTERNAL | |
9 | #include "zlib.h" | |
10 | ||
11 | /* =========================================================================== | |
12 | Decompresses the source buffer into the destination buffer. sourceLen is | |
13 | the byte length of the source buffer. Upon entry, destLen is the total | |
14 | size of the destination buffer, which must be large enough to hold the | |
15 | entire uncompressed data. (The size of the uncompressed data must have | |
16 | been saved previously by the compressor and transmitted to the decompressor | |
17 | by some mechanism outside the scope of this compression library.) | |
18 | Upon exit, destLen is the actual size of the compressed buffer. | |
19 | This function can be used to decompress a whole file at once if the | |
20 | input file is mmap'ed. | |
21 | ||
22 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not | |
23 | enough memory, Z_BUF_ERROR if there was not enough room in the output | |
24 | buffer, or Z_DATA_ERROR if the input data was corrupted. | |
25 | */ | |
26 | int ZEXPORT uncompress (dest, destLen, source, sourceLen) | |
27 | Bytef *dest; | |
28 | uLongf *destLen; | |
29 | const Bytef *source; | |
30 | uLong sourceLen; | |
31 | { | |
32 | z_stream stream; | |
33 | int err; | |
34 | ||
35 | stream.next_in = (Bytef*)source; | |
36 | stream.avail_in = (uInt)sourceLen; | |
37 | /* Check for source > 64K on 16-bit machine: */ | |
38 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; | |
39 | ||
40 | stream.next_out = dest; | |
41 | stream.avail_out = (uInt)*destLen; | |
42 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; | |
43 | ||
44 | stream.zalloc = (alloc_func)0; | |
45 | stream.zfree = (free_func)0; | |
46 | ||
47 | err = inflateInit(&stream); | |
48 | if (err != Z_OK) return err; | |
49 | ||
50 | err = inflate(&stream, Z_FINISH); | |
51 | if (err != Z_STREAM_END) { | |
52 | inflateEnd(&stream); | |
53 | if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)) | |
54 | return Z_DATA_ERROR; | |
55 | return err; | |
56 | } | |
57 | *destLen = stream.total_out; | |
58 | ||
59 | err = inflateEnd(&stream); | |
60 | return err; | |
61 | } |