1/*
2 * Copyright (C) 2008, 2010 Apple Inc. All rights reserved.
3 * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB.  If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 *
20 */
21
22#ifndef NodeListsNodeData_h
23#define NodeListsNodeData_h
24
25#include "core/dom/ChildNodeList.h"
26#include "core/dom/EmptyNodeList.h"
27#include "core/dom/QualifiedName.h"
28#include "core/dom/TagCollection.h"
29#include "core/html/CollectionType.h"
30#include "platform/heap/Handle.h"
31#include "wtf/text/AtomicString.h"
32#include "wtf/text/StringHash.h"
33
34namespace blink {
35
36class NodeListsNodeData FINAL : public NoBaseWillBeGarbageCollectedFinalized<NodeListsNodeData> {
37    WTF_MAKE_NONCOPYABLE(NodeListsNodeData);
38    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
39public:
40    ChildNodeList* childNodeList(ContainerNode& node)
41    {
42        ASSERT_UNUSED(node, !m_childNodeList || node == m_childNodeList->virtualOwnerNode());
43        return toChildNodeList(m_childNodeList);
44    }
45
46    PassRefPtrWillBeRawPtr<ChildNodeList> ensureChildNodeList(ContainerNode& node)
47    {
48        if (m_childNodeList)
49            return toChildNodeList(m_childNodeList);
50        RefPtrWillBeRawPtr<ChildNodeList> list = ChildNodeList::create(node);
51        m_childNodeList = list.get();
52        return list.release();
53    }
54
55    PassRefPtrWillBeRawPtr<EmptyNodeList> ensureEmptyChildNodeList(Node& node)
56    {
57        if (m_childNodeList)
58            return toEmptyNodeList(m_childNodeList);
59        RefPtrWillBeRawPtr<EmptyNodeList> list = EmptyNodeList::create(node);
60        m_childNodeList = list.get();
61        return list.release();
62    }
63
64#if !ENABLE(OILPAN)
65    void removeChildNodeList(ChildNodeList* list)
66    {
67        ASSERT(m_childNodeList == list);
68        if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
69            return;
70        m_childNodeList = nullptr;
71    }
72
73    void removeEmptyChildNodeList(EmptyNodeList* list)
74    {
75        ASSERT(m_childNodeList == list);
76        if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
77            return;
78        m_childNodeList = nullptr;
79    }
80#endif
81
82    struct NodeListAtomicCacheMapEntryHash {
83        static unsigned hash(const std::pair<unsigned char, StringImpl*>& entry)
84        {
85            return DefaultHash<StringImpl*>::Hash::hash(entry.second) + entry.first;
86        }
87        static bool equal(const std::pair<unsigned char, StringImpl*>& a, const std::pair<unsigned char, StringImpl*>& b) { return a == b; }
88        static const bool safeToCompareToEmptyOrDeleted = DefaultHash<StringImpl*>::Hash::safeToCompareToEmptyOrDeleted;
89    };
90
91    // Oilpan: keep a weak reference to the collection objects.
92    // Explicit object unregistration in a non-Oilpan setting
93    // on object destruction is replaced by the garbage collector
94    // clearing out their weak reference.
95    typedef WillBeHeapHashMap<std::pair<unsigned char, StringImpl*>, RawPtrWillBeWeakMember<LiveNodeListBase>, NodeListAtomicCacheMapEntryHash> NodeListAtomicNameCacheMap;
96    typedef WillBeHeapHashMap<QualifiedName, RawPtrWillBeWeakMember<TagCollection> > TagCollectionCacheNS;
97
98    template<typename T>
99    PassRefPtrWillBeRawPtr<T> addCache(ContainerNode& node, CollectionType collectionType, const AtomicString& name)
100    {
101        NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, name), nullptr);
102        if (!result.isNewEntry) {
103#if ENABLE(OILPAN)
104            return static_cast<T*>(result.storedValue->value.get());
105#else
106            return static_cast<T*>(result.storedValue->value);
107#endif
108        }
109
110        RefPtrWillBeRawPtr<T> list = T::create(node, collectionType, name);
111        result.storedValue->value = list.get();
112        return list.release();
113    }
114
115    template<typename T>
116    PassRefPtrWillBeRawPtr<T> addCache(ContainerNode& node, CollectionType collectionType)
117    {
118        NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, starAtom), nullptr);
119        if (!result.isNewEntry) {
120#if ENABLE(OILPAN)
121            return static_cast<T*>(result.storedValue->value.get());
122#else
123            return static_cast<T*>(result.storedValue->value);
124#endif
125        }
126
127        RefPtrWillBeRawPtr<T> list = T::create(node, collectionType);
128        result.storedValue->value = list.get();
129        return list.release();
130    }
131
132    template<typename T>
133    T* cached(CollectionType collectionType)
134    {
135        return static_cast<T*>(m_atomicNameCaches.get(namedNodeListKey(collectionType, starAtom)));
136    }
137
138    PassRefPtrWillBeRawPtr<TagCollection> addCache(ContainerNode& node, const AtomicString& namespaceURI, const AtomicString& localName)
139    {
140        QualifiedName name(nullAtom, localName, namespaceURI);
141        TagCollectionCacheNS::AddResult result = m_tagCollectionCacheNS.add(name, nullptr);
142        if (!result.isNewEntry)
143            return result.storedValue->value;
144
145        RefPtrWillBeRawPtr<TagCollection> list = TagCollection::create(node, namespaceURI, localName);
146        result.storedValue->value = list.get();
147        return list.release();
148    }
149
150#if !ENABLE(OILPAN)
151    void removeCache(LiveNodeListBase* list, CollectionType collectionType, const AtomicString& name = starAtom)
152    {
153        ASSERT(list == m_atomicNameCaches.get(namedNodeListKey(collectionType, name)));
154        if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
155            return;
156        m_atomicNameCaches.remove(namedNodeListKey(collectionType, name));
157    }
158
159    void removeCache(LiveNodeListBase* list, const AtomicString& namespaceURI, const AtomicString& localName)
160    {
161        QualifiedName name(nullAtom, localName, namespaceURI);
162        ASSERT(list == m_tagCollectionCacheNS.get(name));
163        if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
164            return;
165        m_tagCollectionCacheNS.remove(name);
166    }
167#endif
168
169    static PassOwnPtrWillBeRawPtr<NodeListsNodeData> create()
170    {
171        return adoptPtrWillBeNoop(new NodeListsNodeData);
172    }
173
174    void invalidateCaches(const QualifiedName* attrName = 0);
175
176    bool isEmpty() const
177    {
178        return !m_childNodeList && m_atomicNameCaches.isEmpty() && m_tagCollectionCacheNS.isEmpty();
179    }
180
181    void adoptTreeScope()
182    {
183        invalidateCaches();
184    }
185
186    void adoptDocument(Document& oldDocument, Document& newDocument)
187    {
188        ASSERT(oldDocument != newDocument);
189
190        NodeListAtomicNameCacheMap::const_iterator atomicNameCacheEnd = m_atomicNameCaches.end();
191        for (NodeListAtomicNameCacheMap::const_iterator it = m_atomicNameCaches.begin(); it != atomicNameCacheEnd; ++it) {
192            LiveNodeListBase* list = it->value;
193            list->didMoveToDocument(oldDocument, newDocument);
194        }
195
196        TagCollectionCacheNS::const_iterator tagEnd = m_tagCollectionCacheNS.end();
197        for (TagCollectionCacheNS::const_iterator it = m_tagCollectionCacheNS.begin(); it != tagEnd; ++it) {
198            LiveNodeListBase* list = it->value;
199            ASSERT(!list->isRootedAtDocument());
200            list->didMoveToDocument(oldDocument, newDocument);
201        }
202    }
203
204    void trace(Visitor*);
205
206private:
207    NodeListsNodeData()
208        : m_childNodeList(nullptr)
209    { }
210
211    std::pair<unsigned char, StringImpl*> namedNodeListKey(CollectionType type, const AtomicString& name)
212    {
213        // Holding the raw StringImpl is safe because |name| is retained by the NodeList and the NodeList
214        // is reponsible for removing itself from the cache on deletion.
215        return std::pair<unsigned char, StringImpl*>(type, name.impl());
216    }
217
218#if !ENABLE(OILPAN)
219    bool deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node&);
220#endif
221
222    // Can be a ChildNodeList or an EmptyNodeList.
223    RawPtrWillBeWeakMember<NodeList> m_childNodeList;
224    NodeListAtomicNameCacheMap m_atomicNameCaches;
225    TagCollectionCacheNS m_tagCollectionCacheNS;
226};
227
228#if !ENABLE(OILPAN)
229inline bool NodeListsNodeData::deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node& ownerNode)
230{
231    ASSERT(ownerNode.nodeLists() == this);
232    if ((m_childNodeList ? 1 : 0) + m_atomicNameCaches.size() + m_tagCollectionCacheNS.size() != 1)
233        return false;
234    ownerNode.clearNodeLists();
235    return true;
236}
237#endif
238
239template <typename Collection>
240inline PassRefPtrWillBeRawPtr<Collection> ContainerNode::ensureCachedCollection(CollectionType type)
241{
242    return ensureNodeLists().addCache<Collection>(*this, type);
243}
244
245template <typename Collection>
246inline PassRefPtrWillBeRawPtr<Collection> ContainerNode::ensureCachedCollection(CollectionType type, const AtomicString& name)
247{
248    return ensureNodeLists().addCache<Collection>(*this, type, name);
249}
250
251template <typename Collection>
252inline PassRefPtrWillBeRawPtr<Collection> ContainerNode::ensureCachedCollection(CollectionType type, const AtomicString& namespaceURI, const AtomicString& localName)
253{
254    ASSERT_UNUSED(type, type == TagCollectionType);
255    return ensureNodeLists().addCache(*this, namespaceURI, localName);
256}
257
258template <typename Collection>
259inline Collection* ContainerNode::cachedCollection(CollectionType type)
260{
261    NodeListsNodeData* nodeLists = this->nodeLists();
262    return nodeLists ? nodeLists->cached<Collection>(type) : 0;
263}
264
265} // namespace blink
266
267#endif // NodeListsNodeData_h
268