c62d2810 |
1 | /* compress.c -- compress 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: compress.c,v 1.2 2002/03/13 17:45:56 xodnizel Exp $ */ |
7 | |
8 | #include "zlib.h" |
9 | |
10 | /* =========================================================================== |
11 | Compresses the source buffer into the destination buffer. The level |
12 | parameter has the same meaning as in deflateInit. sourceLen is the byte |
13 | length of the source buffer. Upon entry, destLen is the total size of the |
14 | destination buffer, which must be at least 0.1% larger than sourceLen plus |
15 | 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
16 | |
17 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
18 | memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
19 | Z_STREAM_ERROR if the level parameter is invalid. |
20 | */ |
21 | int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) |
22 | Bytef *dest; |
23 | uLongf *destLen; |
24 | const Bytef *source; |
25 | uLong sourceLen; |
26 | int level; |
27 | { |
28 | z_stream stream; |
29 | int err; |
30 | |
31 | stream.next_in = (Bytef*)source; |
32 | stream.avail_in = (uInt)sourceLen; |
33 | #ifdef MAXSEG_64K |
34 | /* Check for source > 64K on 16-bit machine: */ |
35 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
36 | #endif |
37 | stream.next_out = dest; |
38 | stream.avail_out = (uInt)*destLen; |
39 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
40 | |
41 | stream.zalloc = (alloc_func)0; |
42 | stream.zfree = (free_func)0; |
43 | stream.opaque = (voidpf)0; |
44 | |
45 | err = deflateInit(&stream, level); |
46 | if (err != Z_OK) return err; |
47 | |
48 | err = deflate(&stream, Z_FINISH); |
49 | if (err != Z_STREAM_END) { |
50 | deflateEnd(&stream); |
51 | return err == Z_OK ? Z_BUF_ERROR : err; |
52 | } |
53 | *destLen = stream.total_out; |
54 | |
55 | err = deflateEnd(&stream); |
56 | return err; |
57 | } |
58 | |
59 | /* =========================================================================== |
60 | */ |
61 | int ZEXPORT compress (dest, destLen, source, sourceLen) |
62 | Bytef *dest; |
63 | uLongf *destLen; |
64 | const Bytef *source; |
65 | uLong sourceLen; |
66 | { |
67 | return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
68 | } |