1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 * (C) 1999 Antti Koivisto (koivisto@kde.org)
4 * Copyright (C) 2003-2017 Apple Inc. All rights reserved.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public License
17 * along with this library; see the file COPYING.LIB. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 *
21 */
22
23#pragma once
24
25#include "CollectionIndexCache.h"
26#include "HTMLNames.h"
27#include "LiveNodeList.h"
28#include <wtf/HashMap.h>
29
30namespace WebCore {
31
32class Element;
33
34class CollectionNamedElementCache {
35 WTF_MAKE_FAST_ALLOCATED;
36public:
37 const Vector<Element*>* findElementsWithId(const AtomicString& id) const;
38 const Vector<Element*>* findElementsWithName(const AtomicString& name) const;
39 const Vector<AtomicString>& propertyNames() const { return m_propertyNames; }
40
41 void appendToIdCache(const AtomicString& id, Element&);
42 void appendToNameCache(const AtomicString& name, Element&);
43 void didPopulate();
44
45 size_t memoryCost() const;
46
47private:
48 typedef HashMap<AtomicStringImpl*, Vector<Element*>> StringToElementsMap;
49
50 const Vector<Element*>* find(const StringToElementsMap&, const AtomicString& key) const;
51 void append(StringToElementsMap&, const AtomicString& key, Element&);
52
53 StringToElementsMap m_idMap;
54 StringToElementsMap m_nameMap;
55 Vector<AtomicString> m_propertyNames;
56
57#if !ASSERT_DISABLED
58 bool m_didPopulate { false };
59#endif
60};
61
62// HTMLCollection subclasses NodeList to maintain legacy ObjC API compatibility.
63class HTMLCollection : public NodeList {
64 WTF_MAKE_ISO_ALLOCATED(HTMLCollection);
65public:
66 virtual ~HTMLCollection();
67
68 // DOM API
69 Element* item(unsigned index) const override = 0; // Tighten return type from NodeList::item().
70 virtual Element* namedItem(const AtomicString& name) const = 0;
71 const Vector<AtomicString>& supportedPropertyNames();
72 bool isSupportedPropertyName(const String& name);
73
74 // Non-DOM API
75 Vector<Ref<Element>> namedItems(const AtomicString& name) const;
76 size_t memoryCost() const override;
77
78 bool isRootedAtDocument() const;
79 NodeListInvalidationType invalidationType() const;
80 CollectionType type() const;
81 ContainerNode& ownerNode() const;
82 ContainerNode& rootNode() const;
83 void invalidateCacheForAttribute(const QualifiedName& attributeName);
84 virtual void invalidateCacheForDocument(Document&);
85 void invalidateCache() { invalidateCacheForDocument(document()); }
86
87 bool hasNamedElementCache() const;
88
89protected:
90 HTMLCollection(ContainerNode& base, CollectionType);
91
92 virtual void updateNamedElementCache() const;
93 WEBCORE_EXPORT Element* namedItemSlow(const AtomicString& name) const;
94
95 void setNamedItemCache(std::unique_ptr<CollectionNamedElementCache>) const;
96 const CollectionNamedElementCache& namedItemCaches() const;
97
98 Document& document() const;
99
100 void invalidateNamedElementCache(Document&) const;
101
102 enum RootType { IsRootedAtNode, IsRootedAtDocument };
103 static RootType rootTypeFromCollectionType(CollectionType);
104
105 mutable Lock m_namedElementCacheAssignmentLock;
106
107 const unsigned m_collectionType : 5; // CollectionType
108 const unsigned m_invalidationType : 4; // NodeListInvalidationType
109 const unsigned m_rootType : 1; // RootType
110
111 Ref<ContainerNode> m_ownerNode;
112
113 mutable std::unique_ptr<CollectionNamedElementCache> m_namedElementCache;
114};
115
116inline ContainerNode& HTMLCollection::rootNode() const
117{
118 if (isRootedAtDocument() && ownerNode().isConnected())
119 return ownerNode().document();
120
121 return ownerNode();
122}
123
124inline const Vector<Element*>* CollectionNamedElementCache::findElementsWithId(const AtomicString& id) const
125{
126 return find(m_idMap, id);
127}
128
129inline const Vector<Element*>* CollectionNamedElementCache::findElementsWithName(const AtomicString& name) const
130{
131 return find(m_nameMap, name);
132}
133
134inline void CollectionNamedElementCache::appendToIdCache(const AtomicString& id, Element& element)
135{
136 append(m_idMap, id, element);
137}
138
139inline void CollectionNamedElementCache::appendToNameCache(const AtomicString& name, Element& element)
140{
141 append(m_nameMap, name, element);
142}
143
144inline size_t CollectionNamedElementCache::memoryCost() const
145{
146 // memoryCost() may be invoked concurrently from a GC thread, and we need to be careful about what data we access here and how.
147 // It is safe to access m_idMap.size(), m_nameMap.size(), and m_propertyNames.size() because they don't chase pointers.
148 return (m_idMap.size() + m_nameMap.size()) * sizeof(Element*) + m_propertyNames.size() * sizeof(AtomicString);
149}
150
151inline void CollectionNamedElementCache::didPopulate()
152{
153#if !ASSERT_DISABLED
154 m_didPopulate = true;
155#endif
156 if (size_t cost = memoryCost())
157 reportExtraMemoryAllocatedForCollectionIndexCache(cost);
158}
159
160inline const Vector<Element*>* CollectionNamedElementCache::find(const StringToElementsMap& map, const AtomicString& key) const
161{
162 ASSERT(m_didPopulate);
163 auto it = map.find(key.impl());
164 return it != map.end() ? &it->value : nullptr;
165}
166
167inline void CollectionNamedElementCache::append(StringToElementsMap& map, const AtomicString& key, Element& element)
168{
169 if (!m_idMap.contains(key.impl()) && !m_nameMap.contains(key.impl()))
170 m_propertyNames.append(key);
171 map.add(key.impl(), Vector<Element*>()).iterator->value.append(&element);
172}
173
174inline size_t HTMLCollection::memoryCost() const
175{
176 // memoryCost() may be invoked concurrently from a GC thread, and we need to be careful about what data we access here and how.
177 // Hence, we need to guard m_namedElementCache from being replaced while accessing it.
178 auto locker = holdLock(m_namedElementCacheAssignmentLock);
179 return m_namedElementCache ? m_namedElementCache->memoryCost() : 0;
180}
181
182inline bool HTMLCollection::isRootedAtDocument() const
183{
184 return m_rootType == IsRootedAtDocument;
185}
186
187inline NodeListInvalidationType HTMLCollection::invalidationType() const
188{
189 return static_cast<NodeListInvalidationType>(m_invalidationType);
190}
191
192inline CollectionType HTMLCollection::type() const
193{
194 return static_cast<CollectionType>(m_collectionType);
195}
196
197inline ContainerNode& HTMLCollection::ownerNode() const
198{
199 return m_ownerNode;
200}
201
202inline Document& HTMLCollection::document() const
203{
204 return m_ownerNode->document();
205}
206
207inline void HTMLCollection::invalidateCacheForAttribute(const QualifiedName& attributeName)
208{
209 if (shouldInvalidateTypeOnAttributeChange(invalidationType(), attributeName))
210 invalidateCache();
211 else if (hasNamedElementCache() && (attributeName == HTMLNames::idAttr || attributeName == HTMLNames::nameAttr))
212 invalidateNamedElementCache(document());
213}
214
215inline bool HTMLCollection::hasNamedElementCache() const
216{
217 return !!m_namedElementCache;
218}
219
220inline void HTMLCollection::setNamedItemCache(std::unique_ptr<CollectionNamedElementCache> cache) const
221{
222 ASSERT(cache);
223 ASSERT(!m_namedElementCache);
224 cache->didPopulate();
225 {
226 auto locker = holdLock(m_namedElementCacheAssignmentLock);
227 m_namedElementCache = WTFMove(cache);
228 }
229 document().collectionCachedIdNameMap(*this);
230}
231
232inline const CollectionNamedElementCache& HTMLCollection::namedItemCaches() const
233{
234 ASSERT(!!m_namedElementCache);
235 return *m_namedElementCache;
236}
237
238} // namespace WebCore
239
240#define SPECIALIZE_TYPE_TRAITS_HTMLCOLLECTION(ClassName, Type) \
241SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::ClassName) \
242 static bool isType(const WebCore::HTMLCollection& collection) { return collection.type() == WebCore::Type; } \
243SPECIALIZE_TYPE_TRAITS_END()
244