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      1 /*
      2  * Copyright (C) 2008, 2010 Apple Inc. All rights reserved.
      3  * Copyright (C) 2008 David Smith <catfish.man (at) 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 NodeRareData_h
     23 #define NodeRareData_h
     24 
     25 #include "core/dom/ChildNodeList.h"
     26 #include "core/dom/LiveNodeList.h"
     27 #include "core/dom/MutationObserverRegistration.h"
     28 #include "core/dom/QualifiedName.h"
     29 #include "core/dom/TagNodeList.h"
     30 #include "core/page/Page.h"
     31 #include "wtf/HashSet.h"
     32 #include "wtf/OwnPtr.h"
     33 #include "wtf/PassOwnPtr.h"
     34 #include "wtf/text/AtomicString.h"
     35 #include "wtf/text/StringHash.h"
     36 
     37 namespace WebCore {
     38 
     39 class LabelsNodeList;
     40 class RadioNodeList;
     41 class TreeScope;
     42 
     43 class NodeListsNodeData {
     44     WTF_MAKE_NONCOPYABLE(NodeListsNodeData); WTF_MAKE_FAST_ALLOCATED;
     45 public:
     46     void clearChildNodeListCache()
     47     {
     48         if (m_childNodeList)
     49             m_childNodeList->invalidateCache();
     50     }
     51 
     52     PassRefPtr<ChildNodeList> ensureChildNodeList(Node* node)
     53     {
     54         if (m_childNodeList)
     55             return m_childNodeList;
     56         RefPtr<ChildNodeList> list = ChildNodeList::create(node);
     57         m_childNodeList = list.get();
     58         return list.release();
     59     }
     60 
     61     void removeChildNodeList(ChildNodeList* list)
     62     {
     63         ASSERT(m_childNodeList = list);
     64         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
     65             return;
     66         m_childNodeList = 0;
     67     }
     68 
     69     template <typename StringType>
     70     struct NodeListCacheMapEntryHash {
     71         static unsigned hash(const std::pair<unsigned char, StringType>& entry)
     72         {
     73             return DefaultHash<StringType>::Hash::hash(entry.second) + entry.first;
     74         }
     75         static bool equal(const std::pair<unsigned char, StringType>& a, const std::pair<unsigned char, StringType>& b) { return a == b; }
     76         static const bool safeToCompareToEmptyOrDeleted = DefaultHash<StringType>::Hash::safeToCompareToEmptyOrDeleted;
     77     };
     78 
     79     typedef HashMap<std::pair<unsigned char, AtomicString>, LiveNodeListBase*, NodeListCacheMapEntryHash<AtomicString> > NodeListAtomicNameCacheMap;
     80     typedef HashMap<std::pair<unsigned char, String>, LiveNodeListBase*, NodeListCacheMapEntryHash<String> > NodeListNameCacheMap;
     81     typedef HashMap<QualifiedName, TagNodeList*> TagNodeListCacheNS;
     82 
     83     template<typename T>
     84     PassRefPtr<T> addCacheWithAtomicName(Node* node, CollectionType collectionType, const AtomicString& name)
     85     {
     86         NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, name), 0);
     87         if (!result.isNewEntry)
     88             return static_cast<T*>(result.iterator->value);
     89 
     90         RefPtr<T> list = T::create(node, collectionType, name);
     91         result.iterator->value = list.get();
     92         return list.release();
     93     }
     94 
     95     // FIXME: This function should be renamed since it doesn't have an atomic name.
     96     template<typename T>
     97     PassRefPtr<T> addCacheWithAtomicName(Node* node, CollectionType collectionType)
     98     {
     99         NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, starAtom), 0);
    100         if (!result.isNewEntry)
    101             return static_cast<T*>(result.iterator->value);
    102 
    103         RefPtr<T> list = T::create(node, collectionType);
    104         result.iterator->value = list.get();
    105         return list.release();
    106     }
    107 
    108     template<typename T>
    109     T* cacheWithAtomicName(CollectionType collectionType)
    110     {
    111         return static_cast<T*>(m_atomicNameCaches.get(namedNodeListKey(collectionType, starAtom)));
    112     }
    113 
    114     template<typename T>
    115     PassRefPtr<T> addCacheWithName(Node* node, CollectionType collectionType, const String& name)
    116     {
    117         NodeListNameCacheMap::AddResult result = m_nameCaches.add(namedNodeListKey(collectionType, name), 0);
    118         if (!result.isNewEntry)
    119             return static_cast<T*>(result.iterator->value);
    120 
    121         RefPtr<T> list = T::create(node, name);
    122         result.iterator->value = list.get();
    123         return list.release();
    124     }
    125 
    126     PassRefPtr<TagNodeList> addCacheWithQualifiedName(Node* node, const AtomicString& namespaceURI, const AtomicString& localName)
    127     {
    128         QualifiedName name(nullAtom, localName, namespaceURI);
    129         TagNodeListCacheNS::AddResult result = m_tagNodeListCacheNS.add(name, 0);
    130         if (!result.isNewEntry)
    131             return result.iterator->value;
    132 
    133         RefPtr<TagNodeList> list = TagNodeList::create(node, namespaceURI, localName);
    134         result.iterator->value = list.get();
    135         return list.release();
    136     }
    137 
    138     void removeCacheWithAtomicName(LiveNodeListBase* list, CollectionType collectionType, const AtomicString& name = starAtom)
    139     {
    140         ASSERT(list == m_atomicNameCaches.get(namedNodeListKey(collectionType, name)));
    141         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
    142             return;
    143         m_atomicNameCaches.remove(namedNodeListKey(collectionType, name));
    144     }
    145 
    146     void removeCacheWithName(LiveNodeListBase* list, CollectionType collectionType, const String& name)
    147     {
    148         ASSERT(list == m_nameCaches.get(namedNodeListKey(collectionType, name)));
    149         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
    150             return;
    151         m_nameCaches.remove(namedNodeListKey(collectionType, name));
    152     }
    153 
    154     void removeCacheWithQualifiedName(LiveNodeList* list, const AtomicString& namespaceURI, const AtomicString& localName)
    155     {
    156         QualifiedName name(nullAtom, localName, namespaceURI);
    157         ASSERT(list == m_tagNodeListCacheNS.get(name));
    158         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
    159             return;
    160         m_tagNodeListCacheNS.remove(name);
    161     }
    162 
    163     static PassOwnPtr<NodeListsNodeData> create()
    164     {
    165         return adoptPtr(new NodeListsNodeData);
    166     }
    167 
    168     void invalidateCaches(const QualifiedName* attrName = 0);
    169     bool isEmpty() const
    170     {
    171         return m_atomicNameCaches.isEmpty() && m_nameCaches.isEmpty() && m_tagNodeListCacheNS.isEmpty();
    172     }
    173 
    174     void adoptTreeScope()
    175     {
    176         invalidateCaches();
    177     }
    178 
    179     void adoptDocument(Document* oldDocument, Document* newDocument)
    180     {
    181         invalidateCaches();
    182 
    183         if (oldDocument != newDocument) {
    184             NodeListAtomicNameCacheMap::const_iterator atomicNameCacheEnd = m_atomicNameCaches.end();
    185             for (NodeListAtomicNameCacheMap::const_iterator it = m_atomicNameCaches.begin(); it != atomicNameCacheEnd; ++it) {
    186                 LiveNodeListBase* list = it->value;
    187                 oldDocument->unregisterNodeList(list);
    188                 newDocument->registerNodeList(list);
    189             }
    190 
    191             NodeListNameCacheMap::const_iterator nameCacheEnd = m_nameCaches.end();
    192             for (NodeListNameCacheMap::const_iterator it = m_nameCaches.begin(); it != nameCacheEnd; ++it) {
    193                 LiveNodeListBase* list = it->value;
    194                 oldDocument->unregisterNodeList(list);
    195                 newDocument->registerNodeList(list);
    196             }
    197 
    198             TagNodeListCacheNS::const_iterator tagEnd = m_tagNodeListCacheNS.end();
    199             for (TagNodeListCacheNS::const_iterator it = m_tagNodeListCacheNS.begin(); it != tagEnd; ++it) {
    200                 LiveNodeListBase* list = it->value;
    201                 ASSERT(!list->isRootedAtDocument());
    202                 oldDocument->unregisterNodeList(list);
    203                 newDocument->registerNodeList(list);
    204             }
    205         }
    206     }
    207 
    208 private:
    209     NodeListsNodeData()
    210         : m_childNodeList(0)
    211     { }
    212 
    213     std::pair<unsigned char, AtomicString> namedNodeListKey(CollectionType type, const AtomicString& name)
    214     {
    215         return std::pair<unsigned char, AtomicString>(type, name);
    216     }
    217 
    218     std::pair<unsigned char, String> namedNodeListKey(CollectionType type, const String& name)
    219     {
    220         return std::pair<unsigned char, String>(type, name);
    221     }
    222 
    223     bool deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node*);
    224 
    225     // FIXME: m_childNodeList should be merged into m_atomicNameCaches or at least be shared with HTMLCollection returned by Element::children
    226     // but it's tricky because invalidateCaches shouldn't invalidate this cache and adoptTreeScope shouldn't call registerNodeList or unregisterNodeList.
    227     ChildNodeList* m_childNodeList;
    228     NodeListAtomicNameCacheMap m_atomicNameCaches;
    229     NodeListNameCacheMap m_nameCaches;
    230     TagNodeListCacheNS m_tagNodeListCacheNS;
    231 };
    232 
    233 class NodeMutationObserverData {
    234     WTF_MAKE_NONCOPYABLE(NodeMutationObserverData); WTF_MAKE_FAST_ALLOCATED;
    235 public:
    236     Vector<OwnPtr<MutationObserverRegistration> > registry;
    237     HashSet<MutationObserverRegistration*> transientRegistry;
    238 
    239     static PassOwnPtr<NodeMutationObserverData> create() { return adoptPtr(new NodeMutationObserverData); }
    240 
    241 private:
    242     NodeMutationObserverData() { }
    243 };
    244 
    245 class NodeRareData : public NodeRareDataBase {
    246     WTF_MAKE_NONCOPYABLE(NodeRareData); WTF_MAKE_FAST_ALLOCATED;
    247 public:
    248     static PassOwnPtr<NodeRareData> create(RenderObject* renderer) { return adoptPtr(new NodeRareData(renderer)); }
    249 
    250     void clearNodeLists() { m_nodeLists.clear(); }
    251     NodeListsNodeData* nodeLists() const { return m_nodeLists.get(); }
    252     NodeListsNodeData* ensureNodeLists()
    253     {
    254         if (!m_nodeLists)
    255             m_nodeLists = NodeListsNodeData::create();
    256         return m_nodeLists.get();
    257     }
    258 
    259     NodeMutationObserverData* mutationObserverData() { return m_mutationObserverData.get(); }
    260     NodeMutationObserverData* ensureMutationObserverData()
    261     {
    262         if (!m_mutationObserverData)
    263             m_mutationObserverData = NodeMutationObserverData::create();
    264         return m_mutationObserverData.get();
    265     }
    266 
    267     unsigned connectedSubframeCount() const { return m_connectedFrameCount; }
    268     void incrementConnectedSubframeCount(unsigned amount)
    269     {
    270         m_connectedFrameCount += amount;
    271     }
    272     void decrementConnectedSubframeCount(unsigned amount)
    273     {
    274         ASSERT(m_connectedFrameCount);
    275         ASSERT(amount <= m_connectedFrameCount);
    276         m_connectedFrameCount -= amount;
    277     }
    278 
    279 protected:
    280     NodeRareData(RenderObject* renderer)
    281         : NodeRareDataBase(renderer)
    282         , m_connectedFrameCount(0)
    283     { }
    284 
    285 private:
    286     unsigned m_connectedFrameCount : 10; // Must fit Page::maxNumberOfFrames.
    287 
    288     OwnPtr<NodeListsNodeData> m_nodeLists;
    289     OwnPtr<NodeMutationObserverData> m_mutationObserverData;
    290 };
    291 
    292 inline bool NodeListsNodeData::deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node* ownerNode)
    293 {
    294     ASSERT(ownerNode);
    295     ASSERT(ownerNode->nodeLists() == this);
    296     if ((m_childNodeList ? 1 : 0) + m_atomicNameCaches.size() + m_nameCaches.size() + m_tagNodeListCacheNS.size() != 1)
    297         return false;
    298     ownerNode->clearNodeLists();
    299     return true;
    300 }
    301 
    302 // Ensure the 10 bits reserved for the m_connectedFrameCount cannot overflow
    303 COMPILE_ASSERT(Page::maxNumberOfFrames < 1024, Frame_limit_should_fit_in_rare_data_count);
    304 
    305 } // namespace WebCore
    306 
    307 #endif // NodeRareData_h
    308