1/*
2 * Copyright (C) 2010, 2011, 2014 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include <wtf/persistence/PersistentDecoder.h>
28
29#include <wtf/persistence/PersistentEncoder.h>
30
31namespace WTF {
32namespace Persistence {
33
34Decoder::Decoder(const uint8_t* buffer, size_t bufferSize)
35 : m_buffer(buffer)
36 , m_bufferPosition(buffer)
37 , m_bufferEnd(buffer + bufferSize)
38{
39}
40
41Decoder::~Decoder()
42{
43}
44
45bool Decoder::bufferIsLargeEnoughToContain(size_t size) const
46{
47 return size <= static_cast<size_t>(m_bufferEnd - m_bufferPosition);
48}
49
50bool Decoder::decodeFixedLengthData(uint8_t* data, size_t size)
51{
52 if (!bufferIsLargeEnoughToContain(size))
53 return false;
54
55 memcpy(data, m_bufferPosition, size);
56 m_bufferPosition += size;
57
58 Encoder::updateChecksumForData(m_sha1, data, size);
59 return true;
60}
61
62template<typename Type>
63bool Decoder::decodeNumber(Type& value)
64{
65 if (!bufferIsLargeEnoughToContain(sizeof(value)))
66 return false;
67
68 memcpy(&value, m_bufferPosition, sizeof(value));
69 m_bufferPosition += sizeof(Type);
70
71 Encoder::updateChecksumForNumber(m_sha1, value);
72 return true;
73}
74
75bool Decoder::decode(bool& result)
76{
77 return decodeNumber(result);
78}
79
80bool Decoder::decode(uint8_t& result)
81{
82 return decodeNumber(result);
83}
84
85bool Decoder::decode(uint16_t& result)
86{
87 return decodeNumber(result);
88}
89
90bool Decoder::decode(uint32_t& result)
91{
92 return decodeNumber(result);
93}
94
95bool Decoder::decode(uint64_t& result)
96{
97 return decodeNumber(result);
98}
99
100bool Decoder::decode(int32_t& result)
101{
102 return decodeNumber(result);
103}
104
105bool Decoder::decode(int64_t& result)
106{
107 return decodeNumber(result);
108}
109
110bool Decoder::decode(float& result)
111{
112 return decodeNumber(result);
113}
114
115bool Decoder::decode(double& result)
116{
117 return decodeNumber(result);
118}
119
120bool Decoder::verifyChecksum()
121{
122 SHA1::Digest computedHash;
123 m_sha1.computeHash(computedHash);
124
125 SHA1::Digest savedHash;
126 if (!decodeFixedLengthData(savedHash.data(), sizeof(savedHash)))
127 return false;
128
129 return computedHash == savedHash;
130}
131
132}
133}
134