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
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/quic/quic_data_reader.h"
using base::StringPiece;
namespace net {
QuicDataReader::QuicDataReader(const char* data, const size_t len)
: data_(data),
len_(len),
pos_(0) {
}
bool QuicDataReader::ReadUInt16(uint16* result) {
// Make sure that we have the whole uint16.
// TODO(rch): use sizeof instead of magic numbers.
// Refactor to use a common Read(void* buffer, size_t len)
// method that will do the memcpy and the advancement of pos_.
if (!CanRead(2)) {
OnFailure();
return false;
}
// Read into result.
memcpy(result, data_ + pos_, 2);
// Iterate.
pos_ += 2;
return true;
}
bool QuicDataReader::ReadUInt32(uint32* result) {
// Make sure that we have the whole uint32.
if (!CanRead(4)) {
OnFailure();
return false;
}
// Read into result.
memcpy(result, data_ + pos_, 4);
// Iterate.
pos_ += 4;
return true;
}
bool QuicDataReader::ReadUInt48(uint64* result) {
uint32 lo;
if (!ReadUInt32(&lo)) {
return false;
}
uint16 hi;
if (!ReadUInt16(&hi)) {
return false;
}
*result = hi;
*result <<= 32;
*result += lo;
return true;
}
bool QuicDataReader::ReadUInt64(uint64* result) {
// Make sure that we have the whole uint64.
if (!CanRead(8)) {
OnFailure();
return false;
}
// Read into result.
memcpy(result, data_ + pos_, 8);
// Iterate.
pos_ += 8;
return true;
}
bool QuicDataReader::ReadUInt128(uint128* result) {
uint64 high_hash;
uint64 low_hash;
if (!ReadUInt64(&low_hash)) {
return false;
}
if (!ReadUInt64(&high_hash)) {
return false;
}
*result = uint128(high_hash, low_hash);
return true;
}
bool QuicDataReader::ReadStringPiece16(StringPiece* result) {
// Read resultant length.
uint16 result_len;
if (!ReadUInt16(&result_len)) {
// OnFailure() already called.
return false;
}
return ReadStringPiece(result, result_len);
}
bool QuicDataReader::ReadBytes(void* result, size_t size) {
// Make sure that we have enough data to read.
if (!CanRead(size)) {
OnFailure();
return false;
}
// Read into result.
memcpy(result, data_ + pos_, size);
// Iterate.
pos_ += size;
return true;
}
bool QuicDataReader::ReadStringPiece(StringPiece* result, size_t size) {
// Make sure that we have enough data to read.
if (!CanRead(size)) {
OnFailure();
return false;
}
// Set result.
result->set(data_ + pos_, size);
// Iterate.
pos_ += size;
return true;
}
StringPiece QuicDataReader::PeekRemainingPayload() {
return StringPiece(data_ + pos_, len_ - pos_);
}
StringPiece QuicDataReader::ReadRemainingPayload() {
StringPiece payload = PeekRemainingPayload();
pos_ = len_;
return payload;
}
bool QuicDataReader::IsDoneReading() const {
return len_ == pos_;
}
size_t QuicDataReader::BytesRemaining() const {
return len_ - pos_;
}
bool QuicDataReader::CanRead(size_t bytes) const {
return bytes <= (len_ - pos_);
}
void QuicDataReader::OnFailure() {
// Set our iterator to the end of the buffer so that further reads fail
// immediately.
pos_ = len_;
}
} // namespace net
|
