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Diffstat (limited to 'compress.c')
-rw-r--r-- | compress.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/compress.c b/compress.c new file mode 100644 index 0000000..8edcb2a --- /dev/null +++ b/compress.c | |||
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1 | /* compress.c -- compress a memory buffer | ||
2 | * Copyright (C) 1995 Jean-loup Gailly. | ||
3 | * For conditions of distribution and use, see copyright notice in zlib.h | ||
4 | */ | ||
5 | |||
6 | /* $Id: compress.c,v 1.4 1995/04/10 15:52:04 jloup Exp $ */ | ||
7 | |||
8 | #include "zlib.h" | ||
9 | |||
10 | /* =========================================================================== | ||
11 | Compresses 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 at least 0.1% larger than | ||
14 | sourceLen plus 8 bytes. Upon exit, destLen is the actual size of the | ||
15 | compressed buffer. | ||
16 | This function can be used to compress a whole file at once if the | ||
17 | input file is mmap'ed. | ||
18 | compress returns Z_OK if success, Z_MEM_ERROR if there was not | ||
19 | enough memory, Z_BUF_ERROR if there was not enough room in the output | ||
20 | buffer. | ||
21 | */ | ||
22 | int compress (dest, destLen, source, sourceLen) | ||
23 | Byte *dest; | ||
24 | uLong *destLen; | ||
25 | Byte *source; | ||
26 | uLong sourceLen; | ||
27 | { | ||
28 | z_stream stream; | ||
29 | int err; | ||
30 | |||
31 | stream.next_in = source; | ||
32 | stream.avail_in = (uInt)sourceLen; | ||
33 | /* Check for source > 64K on 16-bit machine: */ | ||
34 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; | ||
35 | |||
36 | stream.next_out = dest; | ||
37 | stream.avail_out = (uInt)*destLen; | ||
38 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; | ||
39 | |||
40 | stream.zalloc = (alloc_func)0; | ||
41 | stream.zfree = (free_func)0; | ||
42 | |||
43 | err = deflateInit(&stream, Z_DEFAULT_COMPRESSION); | ||
44 | if (err != Z_OK) return err; | ||
45 | |||
46 | err = deflate(&stream, Z_FINISH); | ||
47 | if (err != Z_OK) { | ||
48 | deflateEnd(&stream); | ||
49 | return err; | ||
50 | } | ||
51 | *destLen = stream.total_out; | ||
52 | |||
53 | err = deflateEnd(&stream); | ||
54 | return err; | ||
55 | } | ||