Ruby: ext/zlib/zlib-1.2.13/uncompr.c Source File

Ruby 3.0.5p211 (2022-11-24 revision ba5cf0f7c52d4d35cc6a173c89eda98ceffa2dcf)

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{
33 z_stream stream;
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
55 err = inflateInit(&stream);
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 }
70 err = inflate(&stream, Z_NO_FLUSH);
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
79 inflateEnd(&stream);
80 return err == Z_STREAM_END ? Z_OK :
81 err == Z_NEED_DICT ? Z_DATA_ERROR :
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}
max
int max
Definition: enough.c:225
len
uint8_t len
Definition: escape.c:17
inflate
int ZEXPORT inflate(z_streamp strm, int flush)
Definition: inflate.c:625
inflateEnd
int ZEXPORT inflateEnd(z_streamp strm)
Definition: inflate.c:1304
stream
voidpf stream
Definition: ioapi.h:138
buf
voidpf void * buf
Definition: ioapi.h:138
z_stream_s
Definition: zlib.h:86
uncompress
int ZEXPORT uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: uncompr.c:86
uncompress2
int ZEXPORT uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong *sourceLen)
Definition: uncompr.c:27
err
int err
Definition: win32.c:142
uLongf
uLong FAR uLongf
Definition: zconf.h:411
uLong
unsigned long uLong
Definition: zconf.h:400
ZEXPORT
#define ZEXPORT
Definition: zconf.h:386
voidpf
void FAR * voidpf
Definition: zconf.h:415
uInt
unsigned int uInt
Definition: zconf.h:399
z_const
#define z_const
Definition: zconf.h:240
Byte
unsigned char Byte
Definition: zconf.h:397
Bytef
Byte FAR Bytef
Definition: zconf.h:406
zlib.h
Z_NEED_DICT
#define Z_NEED_DICT
Definition: zlib.h:179
Z_BUF_ERROR
#define Z_BUF_ERROR
Definition: zlib.h:184
Z_STREAM_END
#define Z_STREAM_END
Definition: zlib.h:178
Z_OK
#define Z_OK
Definition: zlib.h:177
Z_DATA_ERROR
#define Z_DATA_ERROR
Definition: zlib.h:182
Z_NO_FLUSH
#define Z_NO_FLUSH
Definition: zlib.h:168
inflateInit
#define inflateInit(strm)
Definition: zlib.h:1812