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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* Copyright (c) 2013, Opera Software ASA. 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.
* 3. Neither the name of Opera Software ASA nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR 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 "VTTScanner.h"
#include <wtf/text/StringToIntegerConversion.h>
namespace WebCore {
VTTScanner::VTTScanner(const String& line)
: m_source(line)
, m_is8Bit(line.is8Bit())
{
if (m_is8Bit)
m_data.characters8 = line.span8();
else
m_data.characters16 = line.span16();
}
bool VTTScanner::scan(char c)
{
if (!match(c))
return false;
advance();
return true;
}
bool VTTScanner::scan(std::span<const LChar> characters)
{
auto matchLength = m_is8Bit ? m_data.characters8.size() : m_data.characters16.size();
if (matchLength < characters.size())
return false;
bool matched;
if (m_is8Bit)
matched = equal(m_data.characters8.first(characters.size()), characters);
else
matched = equal(m_data.characters16.first(characters.size()), characters);
if (matched)
advance(characters.size());
return matched;
}
bool VTTScanner::scanRun(const Run& run, const String& toMatch)
{
ASSERT(run.start() == position());
ASSERT(run.start() <= end());
ASSERT(run.end() >= run.start());
ASSERT(run.end() <= end());
size_t matchLength = run.length();
if (toMatch.length() > matchLength)
return false;
bool matched;
if (m_is8Bit)
matched = equal(toMatch.impl(), m_data.characters8.first(matchLength));
else
matched = equal(toMatch.impl(), m_data.characters16.first(matchLength));
if (matched)
advance(run.length());
return matched;
}
void VTTScanner::skipRun(const Run& run)
{
ASSERT(run.start() <= end());
ASSERT(run.end() >= run.start());
ASSERT(run.end() <= end());
seekTo(run.end());
}
String VTTScanner::extractString(const Run& run)
{
ASSERT(run.start() == position());
ASSERT(run.start() <= end());
ASSERT(run.end() >= run.start());
ASSERT(run.end() <= end());
String s;
if (m_is8Bit)
s = run.span8();
else
s = run.span16();
advance(run.length());
return s;
}
String VTTScanner::restOfInputAsString()
{
return extractString(m_is8Bit ? Run { m_data.characters8 } : Run { m_data.characters16 });
}
unsigned VTTScanner::scanDigits(unsigned& number)
{
Run runOfDigits = collectWhile<isASCIIDigit>();
if (runOfDigits.isEmpty()) {
number = 0;
return 0;
}
StringView string;
unsigned numDigits = runOfDigits.length();
if (m_is8Bit)
string = m_data.characters8.first(numDigits);
else
string = m_data.characters16.first(numDigits);
// Since these are ASCII digits, the only failure mode is overflow, so use the maximum unsigned value.
number = parseInteger<unsigned>(string).value_or(std::numeric_limits<unsigned>::max());
// Consume the digits.
advance(runOfDigits.length());
return numDigits;
}
bool VTTScanner::scanFloat(float& number, bool* isNegative)
{
bool negative = scan('-');
Run integerRun = collectWhile<isASCIIDigit>();
advance(integerRun.length());
Run decimalRun = createRun(position(), position());
if (scan('.')) {
decimalRun = collectWhile<isASCIIDigit>();
advance(decimalRun.length());
}
// At least one digit required.
if (integerRun.isEmpty() && decimalRun.isEmpty()) {
// Restore to starting position.
seekTo(integerRun.start());
return false;
}
Run floatRun = createRun(integerRun.start(), position());
bool validNumber;
if (m_is8Bit)
number = charactersToFloat(floatRun.span8(), &validNumber);
else
number = charactersToFloat(floatRun.span16(), &validNumber);
if (!validNumber)
number = std::numeric_limits<float>::max();
else if (negative)
number = -number;
if (isNegative)
*isNegative = negative;
return true;
}
auto VTTScanner::createRun(Position start, Position end) const -> Run
{
if (m_is8Bit) {
auto span8 = m_source.span8();
auto* start8 = static_cast<const LChar*>(start);
auto* end8 = static_cast<const LChar*>(end);
RELEASE_ASSERT(start8 >= span8.data());
return Run { span8.subspan(start8 - span8.data(), end8 - start8) };
}
auto span16 = m_source.span16();
auto* start16 = static_cast<const UChar*>(start);
auto* end16 = static_cast<const UChar*>(end);
RELEASE_ASSERT(start16 >= span16.data());
return Run { span16.subspan(start16 - span16.data(), end16 - start16) };
}
}
|
