c62d2810 |
1 | /* uncompr.c -- decompress a memory buffer |
2 | * Copyright (C) 1995-2002 Jean-loup Gailly. |
3 | * For conditions of distribution and use, see copyright notice in zlib.h |
4 | */ |
5 | |
6 | /* @(#) $Id: uncompr.c,v 1.2 2002/03/13 17:45:56 xodnizel Exp $ */ |
7 | |
8 | #include "zlib.h" |
9 | |
10 | /* =========================================================================== |
11 | Decompresses the source buffer into the destination buffer. sourceLen is |
12 | the byte length of the source buffer. Upon entry, destLen is the total |
13 | size of the destination buffer, which must be large enough to hold the |
14 | entire uncompressed data. (The size of the uncompressed data must have |
15 | been saved previously by the compressor and transmitted to the decompressor |
16 | by some mechanism outside the scope of this compression library.) |
17 | Upon exit, destLen is the actual size of the compressed buffer. |
18 | This function can be used to decompress a whole file at once if the |
19 | input file is mmap'ed. |
20 | |
21 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not |
22 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
23 | buffer, or Z_DATA_ERROR if the input data was corrupted. |
24 | */ |
25 | int ZEXPORT uncompress (dest, destLen, source, sourceLen) |
26 | Bytef *dest; |
27 | uLongf *destLen; |
28 | const Bytef *source; |
29 | uLong sourceLen; |
30 | { |
31 | z_stream stream; |
32 | int err; |
33 | |
34 | stream.next_in = (Bytef*)source; |
35 | stream.avail_in = (uInt)sourceLen; |
36 | /* Check for source > 64K on 16-bit machine: */ |
37 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
38 | |
39 | stream.next_out = dest; |
40 | stream.avail_out = (uInt)*destLen; |
41 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
42 | |
43 | stream.zalloc = (alloc_func)0; |
44 | stream.zfree = (free_func)0; |
45 | |
46 | err = inflateInit(&stream); |
47 | if (err != Z_OK) return err; |
48 | |
49 | err = inflate(&stream, Z_FINISH); |
50 | if (err != Z_STREAM_END) { |
51 | inflateEnd(&stream); |
52 | return err == Z_OK ? Z_BUF_ERROR : err; |
53 | } |
54 | *destLen = stream.total_out; |
55 | |
56 | err = inflateEnd(&stream); |
57 | return err; |
58 | } |