1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/*
* Copyright (C) 2024 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "ZStream.h"
#include <wtf/StdLibExtras.h>
namespace WebCore {
bool ZStream::initializeIfNecessary(Algorithm algorithm, Operation operation)
{
if (m_isInitialized)
return true;
int result = Z_OK;
switch (operation) {
case Operation::Compression:
switch (algorithm) {
// Values chosen here are based off
// https://developer.apple.com/documentation/compression/compression_algorithm/compression_zlib?language=objc
case Algorithm::Deflate:
result = deflateInit2(&m_stream, 5, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);
break;
case Algorithm::Zlib:
result = deflateInit2(&m_stream, 5, Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
break;
case Algorithm::Gzip:
result = deflateInit2(&m_stream, 5, Z_DEFLATED, 15 + 16, 8, Z_DEFAULT_STRATEGY);
break;
}
break;
case Operation::Decompression:
switch (algorithm) {
case Algorithm::Deflate:
result = inflateInit2(&m_stream, -15);
break;
case Algorithm::Zlib:
result = inflateInit2(&m_stream, 15);
break;
case Algorithm::Gzip:
result = inflateInit2(&m_stream, 15 + 16);
break;
}
break;
}
if (result != Z_OK)
return false;
m_isInitialized = true;
return true;
}
ZStream::ZStream()
{
zeroBytes(m_stream);
}
ZStream::~ZStream()
{
if (m_isInitialized)
deflateEnd(&m_stream);
}
}
|
