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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/*
* Copyright (C) 2010 Google, 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 GOOGLE 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 GOOGLE 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 "core/html/parser/HTMLFormattingElementList.h"
#ifndef NDEBUG
#include <stdio.h>
#endif
namespace WebCore {
// Biblically, Noah's Ark only had room for two of each animal, but in the
// Book of Hixie (aka http://www.whatwg.org/specs/web-apps/current-work/multipage/parsing.html#list-of-active-formatting-elements),
// Noah's Ark of Formatting Elements can fit three of each element.
static const size_t kNoahsArkCapacity = 3;
HTMLFormattingElementList::HTMLFormattingElementList()
{
}
HTMLFormattingElementList::~HTMLFormattingElementList()
{
}
Element* HTMLFormattingElementList::closestElementInScopeWithName(const AtomicString& targetName)
{
for (unsigned i = 1; i <= m_entries.size(); ++i) {
const Entry& entry = m_entries[m_entries.size() - i];
if (entry.isMarker())
return 0;
if (entry.stackItem()->matchesHTMLTag(targetName))
return entry.element();
}
return 0;
}
bool HTMLFormattingElementList::contains(Element* element)
{
return !!find(element);
}
HTMLFormattingElementList::Entry* HTMLFormattingElementList::find(Element* element)
{
size_t index = m_entries.reverseFind(element);
if (index != kNotFound) {
// This is somewhat of a hack, and is why this method can't be const.
return &m_entries[index];
}
return 0;
}
HTMLFormattingElementList::Bookmark HTMLFormattingElementList::bookmarkFor(Element* element)
{
size_t index = m_entries.reverseFind(element);
ASSERT(index != kNotFound);
return Bookmark(&at(index));
}
void HTMLFormattingElementList::swapTo(Element* oldElement, PassRefPtr<HTMLStackItem> newItem, const Bookmark& bookmark)
{
ASSERT(contains(oldElement));
ASSERT(!contains(newItem->element()));
if (!bookmark.hasBeenMoved()) {
ASSERT(bookmark.mark()->element() == oldElement);
bookmark.mark()->replaceElement(newItem);
return;
}
size_t index = bookmark.mark() - first();
ASSERT_WITH_SECURITY_IMPLICATION(index < size());
m_entries.insert(index + 1, newItem);
remove(oldElement);
}
void HTMLFormattingElementList::append(PassRefPtr<HTMLStackItem> item)
{
ensureNoahsArkCondition(item.get());
m_entries.append(item);
}
void HTMLFormattingElementList::remove(Element* element)
{
size_t index = m_entries.reverseFind(element);
if (index != kNotFound)
m_entries.remove(index);
}
void HTMLFormattingElementList::appendMarker()
{
m_entries.append(Entry::MarkerEntry);
}
void HTMLFormattingElementList::clearToLastMarker()
{
// http://www.whatwg.org/specs/web-apps/current-work/multipage/parsing.html#clear-the-list-of-active-formatting-elements-up-to-the-last-marker
while (m_entries.size()) {
bool shouldStop = m_entries.last().isMarker();
m_entries.removeLast();
if (shouldStop)
break;
}
}
void HTMLFormattingElementList::tryToEnsureNoahsArkConditionQuickly(HTMLStackItem* newItem, Vector<HTMLStackItem*>& remainingCandidates)
{
ASSERT(remainingCandidates.isEmpty());
if (m_entries.size() < kNoahsArkCapacity)
return;
// Use a vector with inline capacity to avoid a malloc in the common case
// of a quickly ensuring the condition.
Vector<HTMLStackItem*, 10> candidates;
size_t newItemAttributeCount = newItem->attributes().size();
for (size_t i = m_entries.size(); i; ) {
--i;
Entry& entry = m_entries[i];
if (entry.isMarker())
break;
// Quickly reject obviously non-matching candidates.
HTMLStackItem* candidate = entry.stackItem().get();
if (newItem->localName() != candidate->localName() || newItem->namespaceURI() != candidate->namespaceURI())
continue;
if (candidate->attributes().size() != newItemAttributeCount)
continue;
candidates.append(candidate);
}
if (candidates.size() < kNoahsArkCapacity)
return; // There's room for the new element in the ark. There's no need to copy out the remainingCandidates.
remainingCandidates.append(candidates);
}
void HTMLFormattingElementList::ensureNoahsArkCondition(HTMLStackItem* newItem)
{
Vector<HTMLStackItem*> candidates;
tryToEnsureNoahsArkConditionQuickly(newItem, candidates);
if (candidates.isEmpty())
return;
// We pre-allocate and re-use this second vector to save one malloc per
// attribute that we verify.
Vector<HTMLStackItem*> remainingCandidates;
remainingCandidates.reserveInitialCapacity(candidates.size());
const Vector<Attribute>& attributes = newItem->attributes();
for (size_t i = 0; i < attributes.size(); ++i) {
const Attribute& attribute = attributes[i];
for (size_t j = 0; j < candidates.size(); ++j) {
HTMLStackItem* candidate = candidates[j];
// These properties should already have been checked by tryToEnsureNoahsArkConditionQuickly.
ASSERT(newItem->attributes().size() == candidate->attributes().size());
ASSERT(newItem->localName() == candidate->localName() && newItem->namespaceURI() == candidate->namespaceURI());
Attribute* candidateAttribute = candidate->getAttributeItem(attribute.name());
if (candidateAttribute && candidateAttribute->value() == attribute.value())
remainingCandidates.append(candidate);
}
if (remainingCandidates.size() < kNoahsArkCapacity)
return;
candidates.swap(remainingCandidates);
remainingCandidates.shrink(0);
}
// Inductively, we shouldn't spin this loop very many times. It's possible,
// however, that we wil spin the loop more than once because of how the
// formatting element list gets permuted.
for (size_t i = kNoahsArkCapacity - 1; i < candidates.size(); ++i)
remove(candidates[i]->element());
}
#ifndef NDEBUG
void HTMLFormattingElementList::show()
{
for (unsigned i = 1; i <= m_entries.size(); ++i) {
const Entry& entry = m_entries[m_entries.size() - i];
if (entry.isMarker())
fprintf(stderr, "marker\n");
else
entry.element()->showNode();
}
}
#endif
}
|
