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
|
/*
* Copyright (C) 2008-2021 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,
* 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 "StorageMap.h"
#include <wtf/CheckedArithmetic.h>
#include <wtf/SetForScope.h>
#include <wtf/TZoneMallocInlines.h>
namespace WebCore {
WTF_MAKE_TZONE_ALLOCATED_IMPL(StorageMap);
StorageMap::StorageMap(unsigned quota)
: m_impl(Impl::create())
, m_quotaSize(quota) // quota measured in bytes
{
}
void StorageMap::invalidateIterator()
{
m_impl->iterator = m_impl->map.end();
m_impl->iteratorIndex = UINT_MAX;
}
void StorageMap::setIteratorToIndex(unsigned index)
{
// FIXME: Once we have bidirectional iterators for HashMap we can be more intelligent about this.
// The requested index will be closest to begin(), our current iterator, or end(), and we
// can take the shortest route.
// Until that mechanism is available, we'll always increment our iterator from begin() or current.
if (m_impl->iteratorIndex == index)
return;
if (index < m_impl->iteratorIndex) {
m_impl->iteratorIndex = 0;
m_impl->iterator = m_impl->map.begin();
ASSERT(m_impl->iterator != m_impl->map.end());
}
while (m_impl->iteratorIndex < index) {
++m_impl->iteratorIndex;
++m_impl->iterator;
ASSERT(m_impl->iterator != m_impl->map.end());
}
}
unsigned StorageMap::length() const
{
return m_impl->map.size();
}
String StorageMap::key(unsigned index)
{
if (index >= length())
return String();
setIteratorToIndex(index);
return m_impl->iterator->key;
}
String StorageMap::getItem(const String& key) const
{
return m_impl->map.get(key);
}
void StorageMap::setItem(const String& key, const String& value, String& oldValue, bool& quotaException)
{
ASSERT(!value.isNull());
quotaException = false;
CheckedUint32 newSize = m_impl->currentSize;
auto iter = m_impl->map.find(key);
if (iter != m_impl->map.end()) {
oldValue = iter->value;
newSize -= oldValue.sizeInBytes();
} else {
oldValue = nullString();
newSize += key.sizeInBytes();
}
newSize += value.sizeInBytes();
if (m_quotaSize != noQuota && (newSize.hasOverflowed() || newSize > m_quotaSize)) {
quotaException = true;
return;
}
// Implement copy-on-write semantics.
if (m_impl->refCount() > 1)
m_impl = m_impl->copy();
m_impl->map.set(key, value);
m_impl->currentSize = newSize;
invalidateIterator();
}
void StorageMap::setItemIgnoringQuota(const String& key, const String& value)
{
SetForScope quotaSizeChange(m_quotaSize, noQuota);
String oldValue;
bool quotaException;
setItem(key, value, oldValue, quotaException);
ASSERT(!quotaException);
}
void StorageMap::removeItem(const String& key, String& oldValue)
{
oldValue = nullString();
CheckedUint32 newSize = m_impl->currentSize;
auto iter = m_impl->map.find(key);
if (iter == m_impl->map.end())
return;
oldValue = iter->value;
newSize = newSize - iter->key.sizeInBytes() - oldValue.sizeInBytes();
if (m_impl->hasOneRef())
m_impl->map.remove(iter);
else {
// Implement copy-on-write semantics.
m_impl = m_impl->copy();
m_impl->map.remove(key);
}
m_impl->currentSize = newSize;
invalidateIterator();
}
void StorageMap::clear()
{
if (m_impl->refCount() > 1 && length()) {
m_impl = Impl::create();
return;
}
m_impl->map.clear();
m_impl->currentSize = 0;
invalidateIterator();
}
bool StorageMap::contains(const String& key) const
{
return m_impl->map.contains(key);
}
void StorageMap::importItems(HashMap<String, String>&& items)
{
RELEASE_ASSERT(m_impl->map.isEmpty());
RELEASE_ASSERT(!m_impl->currentSize);
CheckedUint32 newSize;
for (auto& [key, value] : items) {
newSize += key.sizeInBytes();
newSize += value.sizeInBytes();
}
m_impl->map = WTFMove(items);
m_impl->currentSize = newSize;
}
Ref<StorageMap::Impl> StorageMap::Impl::copy() const
{
auto copy = Impl::create();
copy->map = map;
copy->currentSize = currentSize;
return copy;
}
}
|
