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compress.c
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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*/
22int ZEXPORT compress2(dest, destLen, source, sourceLen, level)
23 Bytef *dest;
24 uLongf *destLen;
25 const Bytef *source;
26 uLong sourceLen;
27 int level;
28{
30 int err;
31 const uInt max = (uInt)-1;
32 uLong left;
33
34 left = *destLen;
35 *destLen = 0;
36
37 stream.zalloc = (alloc_func)0;
38 stream.zfree = (free_func)0;
39 stream.opaque = (voidpf)0;
40
42 if (err != Z_OK) return err;
43
44 stream.next_out = dest;
45 stream.avail_out = 0;
46 stream.next_in = (z_const Bytef *)source;
47 stream.avail_in = 0;
48
49 do {
50 if (stream.avail_out == 0) {
51 stream.avail_out = left > (uLong)max ? max : (uInt)left;
52 left -= stream.avail_out;
53 }
54 if (stream.avail_in == 0) {
55 stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
56 sourceLen -= stream.avail_in;
57 }
58 err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
59 } while (err == Z_OK);
60
61 *destLen = stream.total_out;
63 return err == Z_STREAM_END ? Z_OK : err;
64}
65
66/* ===========================================================================
67 */
68int ZEXPORT compress(dest, destLen, source, sourceLen)
69 Bytef *dest;
70 uLongf *destLen;
71 const Bytef *source;
72 uLong sourceLen;
73{
74 return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
75}
76
77/* ===========================================================================
78 If the default memLevel or windowBits for deflateInit() is changed, then
79 this function needs to be updated.
80 */
82 uLong sourceLen;
83{
84 return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
85 (sourceLen >> 25) + 13;
86}
void(* free_func)(voidpf opaque, voidpf address)
Definition: zlib.h:54
unsigned long uLong
Definition: zlib.h:39
voidpf(* alloc_func)(voidpf opaque, uInt items, uInt size)
Definition: zlib.h:53
void FAR * voidpf
Definition: zlib.h:42
#define Z_STREAM_END
Definition: zlib.h:115
#define Z_FINISH
Definition: zlib.h:109
unsigned int uInt
Definition: zlib.h:38
#define Z_OK
Definition: zlib.h:114
#define z_const
Definition: zlib.h:35
int deflate(z_streamp strm, int flush) DECLSPEC_HIDDEN
Definition: deflate.c:815
#define Z_NO_FLUSH
Definition: zlib.h:105
int deflateEnd(z_streamp strm) DECLSPEC_HIDDEN
Definition: deflate.c:1130
Byte FAR Bytef
Definition: zlib.h:41
#define Z_DEFAULT_COMPRESSION
Definition: zlib.h:130
GLint level
Definition: gl.h:1546
GLint left
Definition: glext.h:7726
static char * dest
Definition: rtl.c:135
#define err(...)
#define deflateInit(strm, level)
Definition: zlib.h:1810
uLong ZEXPORT compressBound(uLong sourceLen)
Definition: compress.c:81
int ZEXPORT compress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)
Definition: compress.c:22
int ZEXPORT compress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: compress.c:68
Definition: parse.h:23
#define max(a, b)
Definition: svc.c:63
uLong FAR uLongf
Definition: zconf.h:411
#define ZEXPORT
Definition: zconf.h:386