/work/workdir/UnpackedTarball/zlib/compress.c
Line | Count | Source |
1 | | /* compress.c -- compress a memory buffer |
2 | | * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler |
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 | | Compresses the source buffer into the destination buffer. The level |
13 | | parameter has the same meaning as in deflateInit. sourceLen is the byte |
14 | | length of the source buffer. Upon entry, destLen is the total size of the |
15 | | destination buffer, which must be at least 0.1% larger than sourceLen plus |
16 | | 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
17 | | |
18 | | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
19 | | memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
20 | | Z_STREAM_ERROR if the level parameter is invalid. |
21 | | */ |
22 | | int ZEXPORT compress2(Bytef *dest, uLongf *destLen, const Bytef *source, |
23 | 3.24k | uLong sourceLen, int level) { |
24 | 3.24k | z_stream stream; |
25 | 3.24k | int err; |
26 | 3.24k | const uInt max = (uInt)-1; |
27 | 3.24k | uLong left; |
28 | | |
29 | 3.24k | left = *destLen; |
30 | 3.24k | *destLen = 0; |
31 | | |
32 | 3.24k | stream.zalloc = (alloc_func)0; |
33 | 3.24k | stream.zfree = (free_func)0; |
34 | 3.24k | stream.opaque = (voidpf)0; |
35 | | |
36 | 3.24k | err = deflateInit(&stream, level); |
37 | 3.24k | if (err != Z_OK) return err; |
38 | | |
39 | 3.24k | stream.next_out = dest; |
40 | 3.24k | stream.avail_out = 0; |
41 | 3.24k | stream.next_in = (z_const Bytef *)source; |
42 | 3.24k | stream.avail_in = 0; |
43 | | |
44 | 3.24k | do { |
45 | 3.24k | if (stream.avail_out == 0) { |
46 | 3.24k | stream.avail_out = left > (uLong)max ? max : (uInt)left; |
47 | 3.24k | left -= stream.avail_out; |
48 | 3.24k | } |
49 | 3.24k | if (stream.avail_in == 0) { |
50 | 3.24k | stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen; |
51 | 3.24k | sourceLen -= stream.avail_in; |
52 | 3.24k | } |
53 | 3.24k | err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH); |
54 | 3.24k | } while (err == Z_OK); |
55 | | |
56 | 3.24k | *destLen = stream.total_out; |
57 | 3.24k | deflateEnd(&stream); |
58 | 3.24k | return err == Z_STREAM_END ? Z_OK : err; |
59 | 3.24k | } |
60 | | |
61 | | /* =========================================================================== |
62 | | */ |
63 | | int ZEXPORT compress(Bytef *dest, uLongf *destLen, const Bytef *source, |
64 | 3.24k | uLong sourceLen) { |
65 | 3.24k | return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
66 | 3.24k | } |
67 | | |
68 | | /* =========================================================================== |
69 | | If the default memLevel or windowBits for deflateInit() is changed, then |
70 | | this function needs to be updated. |
71 | | */ |
72 | 0 | uLong ZEXPORT compressBound(uLong sourceLen) { |
73 | 0 | return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
74 | 0 | (sourceLen >> 25) + 13; |
75 | 0 | } |