compress.c
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1 /* compress.c -- compress a memory buffer
2  * Copyright (C) 1995-2003 Jean-loup Gailly.
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 (dest, destLen, source, sourceLen, level)
23  Bytef *dest;
24  uLongf *destLen;
25  const Bytef *source;
26  uLong sourceLen;
27  int level;
28 {
29  z_stream stream;
30  int err;
31 
32  stream.next_in = (Bytef*)source;
33  stream.avail_in = (uInt)sourceLen;
34 #ifdef MAXSEG_64K
35  /* Check for source > 64K on 16-bit machine: */
36  if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
37 #endif
38  stream.next_out = dest;
39  stream.avail_out = (uInt)*destLen;
40  if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
41 
42  stream.zalloc = (alloc_func)0;
43  stream.zfree = (free_func)0;
44  stream.opaque = (voidpf)0;
45 
46  err = deflateInit(&stream, level);
47  if (err != Z_OK) return err;
48 
49  err = deflate(&stream, Z_FINISH);
50  if (err != Z_STREAM_END) {
51  deflateEnd(&stream);
52  return err == Z_OK ? Z_BUF_ERROR : err;
53  }
54  *destLen = stream.total_out;
55 
56  err = deflateEnd(&stream);
57  return err;
58 }
59 
60 /* ===========================================================================
61  */
62 int ZEXPORT compress (dest, destLen, source, sourceLen)
63  Bytef *dest;
64  uLongf *destLen;
65  const Bytef *source;
66  uLong sourceLen;
67 {
68  return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
69 }
70 
71 /* ===========================================================================
72  If the default memLevel or windowBits for deflateInit() is changed, then
73  this function needs to be updated.
74  */
76  uLong sourceLen;
77 {
78  return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
79 }
uLong ZEXPORT compressBound(uLong sourceLen)
Definition: compress.c:75
Byte FAR * voidpf
Definition: zconf.h:283
Bytef * next_in
Definition: zlib.h:83
uInt avail_in
Definition: zlib.h:84
unsigned long uLong
Definition: zconf.h:264
int ZEXPORT deflateEnd(z_streamp strm)
Definition: deflate.c:859
Byte FAR Bytef
Definition: zconf.h:270
voidpf opaque
Definition: zlib.h:96
free_func zfree
Definition: zlib.h:95
#define Z_FINISH
Definition: zlib.h:166
#define Z_STREAM_END
Definition: zlib.h:171
int ZEXPORT compress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)
Definition: compress.c:22
alloc_func zalloc
Definition: zlib.h:94
Bytef * next_out
Definition: zlib.h:87
int ZEXPORT deflate(z_streamp strm, int flush)
Definition: deflate.c:552
uLong total_out
Definition: zlib.h:89
uLong FAR uLongf
Definition: zconf.h:275
int ZEXPORT compress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: compress.c:62
int level
Definition: png.h:1926
#define Z_BUF_ERROR
Definition: zlib.h:177
#define deflateInit(strm, level)
Definition: zlib.h:1331
uInt avail_out
Definition: zlib.h:88
#define Z_OK
Definition: zlib.h:170
#define ZEXPORT
Definition: zconf.h:250
#define Z_DEFAULT_COMPRESSION
Definition: zlib.h:186
unsigned int uInt
Definition: zconf.h:263


openhrp3
Author(s): AIST, General Robotix Inc., Nakamura Lab of Dept. of Mechano Informatics at University of Tokyo
autogenerated on Thu Sep 8 2022 02:24:02