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uncompr.c
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1 /* uncompr.c -- decompress a memory buffer
2  * Copyright (C) 1995-2003, 2010, 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  Decompresses the source buffer into the destination buffer. *sourceLen is
13  the byte length of the source buffer. Upon entry, *destLen is the total size
14  of the destination buffer, which must be large enough to hold the entire
15  uncompressed data. (The size of the uncompressed data must have been saved
16  previously by the compressor and transmitted to the decompressor by some
17  mechanism outside the scope of this compression library.) Upon exit,
18  *destLen is the size of the decompressed data and *sourceLen is the number
19  of source bytes consumed. Upon return, source + *sourceLen points to the
20  first unused input byte.
21 
22  uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
23  memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
24  Z_DATA_ERROR if the input data was corrupted, including if the input data is
25  an incomplete zlib stream.
26 */
27 int ZEXPORT uncompress2 (dest, destLen, source, sourceLen)
28  Bytef *dest;
29  uLongf *destLen;
30  const Bytef *source;
31  uLong *sourceLen;
32 {
34  int err;
35  const uInt max = (uInt)-1;
36  uLong len, left;
37  Byte buf[1]; /* for detection of incomplete stream when *destLen == 0 */
38 
39  len = *sourceLen;
40  if (*destLen) {
41  left = *destLen;
42  *destLen = 0;
43  }
44  else {
45  left = 1;
46  dest = buf;
47  }
48 
49  stream.next_in = (z_const Bytef *)source;
50  stream.avail_in = 0;
51  stream.zalloc = (alloc_func)0;
52  stream.zfree = (free_func)0;
53  stream.opaque = (voidpf)0;
54 
56  if (err != Z_OK) return err;
57 
58  stream.next_out = dest;
59  stream.avail_out = 0;
60 
61  do {
62  if (stream.avail_out == 0) {
63  stream.avail_out = left > (uLong)max ? max : (uInt)left;
64  left -= stream.avail_out;
65  }
66  if (stream.avail_in == 0) {
67  stream.avail_in = len > (uLong)max ? max : (uInt)len;
68  len -= stream.avail_in;
69  }
71  } while (err == Z_OK);
72 
73  *sourceLen -= len + stream.avail_in;
74  if (dest != buf)
75  *destLen = stream.total_out;
76  else if (stream.total_out && err == Z_BUF_ERROR)
77  left = 1;
78 
80  return err == Z_STREAM_END ? Z_OK :
82  err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
83  err;
84 }
85 
86 int ZEXPORT uncompress (dest, destLen, source, sourceLen)
87  Bytef *dest;
88  uLongf *destLen;
89  const Bytef *source;
90  uLong sourceLen;
91 {
92  return uncompress2(dest, destLen, source, &sourceLen);
93 }
#define max(a, b)
Definition: svc.c:63
void FAR * voidpf
Definition: zlib.h:42
GLenum GLuint GLenum GLsizei const GLchar * buf
Definition: glext.h:7751
int ZEXPORT uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: uncompr.c:86
#define Z_OK
Definition: zlib.h:114
int ZEXPORT uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong *sourceLen)
Definition: uncompr.c:27
unsigned long uLong
Definition: zlib.h:39
#define Z_STREAM_END
Definition: zlib.h:115
void(* free_func)(voidpf opaque, voidpf address)
Definition: zlib.h:54
GLint left
Definition: glext.h:7726
int inflateEnd(z_streamp strm)
Definition: inflate.c:1910
Definition: parse.h:22
GLuint GLuint stream
Definition: glext.h:7522
GLenum GLsizei len
Definition: glext.h:6722
#define err(...)
uLong FAR uLongf
Definition: zconf.h:405
unsigned int uInt
Definition: zlib.h:38
GLsizei GLsizei GLchar * source
Definition: glext.h:6048
#define Z_BUF_ERROR
Definition: zlib.h:121
#define Z_NEED_DICT
Definition: zlib.h:116
Byte FAR Bytef
Definition: zlib.h:41
unsigned char Byte
Definition: zlib.h:37
#define z_const
Definition: zlib.h:35
voidpf(* alloc_func)(voidpf opaque, uInt items, uInt size)
Definition: zlib.h:53
#define Z_DATA_ERROR
Definition: zlib.h:119
#define Z_NO_FLUSH
Definition: zlib.h:105
int inflate(z_streamp strm, int flush)
Definition: inflate.c:1257
static char * dest
Definition: rtl.c:135
#define inflateInit(strm)
Definition: zlib.h:1795
#define ZEXPORT
Definition: zconf.h:380