Source/WebCore/dom/NodeRareData.h - external/github.com/WebKit/webkit - Git at Google

 /*
  * Copyright (C) 2008-2025 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <[email protected]>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */

 #pragma once

 #include "ChildNodeList.h"
 #include "CommonAtomStrings.h"
 #include "HTMLCollection.h"
 #include "HTMLSlotElement.h"
 #include "MutationObserverRegistration.h"
 #include "QualifiedName.h"
 #include "TagCollection.h"
 #include <new>
 #include <wtf/HashSet.h>
 #include <wtf/NoVirtualDestructorBase.h>
 #include <wtf/StdLibExtras.h>
 #include <wtf/TZoneMalloc.h>
 #include <wtf/WeakHashSet.h>

 namespace WebCore {

 class LabelsNodeList;
 class LiveNodeList;
 class NameNodeList;
 class RadioNodeList;

 template<typename ListType> struct NodeListTypeIdentifier;

 DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(NodeListsNodeData);
 class NodeListsNodeData {
     WTF_MAKE_NONCOPYABLE(NodeListsNodeData);
     WTF_DEPRECATED_MAKE_STRUCT_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(NodeListsNodeData, NodeListsNodeData);
 public:
     NodeListsNodeData() = default;

     void clearChildNodeListCache()
     {
         if (m_childNodeList)
             m_childNodeList->invalidateCache();
     }

     Ref<ChildNodeList> ensureChildNodeList(ContainerNode& node)
     {
         ASSERT(!m_emptyChildNodeList);
         if (m_childNodeList)
             return *m_childNodeList;
         Ref list = ChildNodeList::create(node);
         m_childNodeList = list.ptr();
         return list;
     }

     void removeChildNodeList(ChildNodeList* list)
     {
         ASSERT(m_childNodeList == list);
         Ref ownerNode = list->ownerNode();
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(ownerNode))
             return;
         m_childNodeList = nullptr;
     }

     Ref<EmptyNodeList> ensureEmptyChildNodeList(Node& node)
     {
         ASSERT(!m_childNodeList);
         if (m_emptyChildNodeList)
             return *m_emptyChildNodeList;
         Ref list = EmptyNodeList::create(node);
         m_emptyChildNodeList = list.ptr();
         return list;
     }

     void removeEmptyChildNodeList(EmptyNodeList* list)
     {
         ASSERT(m_emptyChildNodeList == list);
         Ref ownerNode = list->ownerNode();
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(ownerNode))
             return;
         m_emptyChildNodeList = nullptr;
     }

     struct NodeListCacheMapEntryHash {
         static unsigned hash(const std::pair<unsigned char, AtomString>& entry)
         {
             return DefaultHash<AtomString>::hash(entry.second) + entry.first;
         }
         static bool equal(const std::pair<unsigned char, AtomString>& a, const std::pair<unsigned char, AtomString>& b) { return a.first == b.first && DefaultHash<AtomString>::equal(a.second, b.second); }
         static const bool safeToCompareToEmptyOrDeleted = DefaultHash<AtomString>::safeToCompareToEmptyOrDeleted;
     };

     using NodeListCacheMap = HashMap<std::pair<unsigned char, AtomString>, LiveNodeList*, NodeListCacheMapEntryHash>;
     using CollectionCacheMap = HashMap<std::pair<std::underlying_type_t<CollectionType>, AtomString>, HTMLCollection*, NodeListCacheMapEntryHash>;
     using TagCollectionNSCache = HashMap<QualifiedName, TagCollectionNS*>;

     template<typename T, typename ContainerType>
     ALWAYS_INLINE Ref<T> addCacheWithAtomName(ContainerType& container, const AtomString& name)
     {
         auto result = m_atomNameCaches.fastAdd(namedNodeListKey<T>(name), nullptr);
         if (!result.isNewEntry)
             return static_cast<T&>(*result.iterator->value);

         Ref list = T::create(container, name);
         result.iterator->value = list.ptr();
         return list;
     }

     ALWAYS_INLINE Ref<TagCollectionNS> addCachedTagCollectionNS(ContainerNode& node, const AtomString& namespaceURI, const AtomString& localName)
     {
         auto result = m_tagCollectionNSCache.fastAdd(QualifiedName { nullAtom(), localName, namespaceURI }, nullptr);
         if (!result.isNewEntry)
             return *result.iterator->value;

         Ref list = TagCollectionNS::create(node, namespaceURI, localName);
         result.iterator->value = list.ptr();
         return list;
     }

     template<typename T, typename ContainerType>
     ALWAYS_INLINE Ref<T> addCachedCollection(ContainerType& container, CollectionType collectionType, const AtomString& name)
     {
         auto result = m_cachedCollections.fastAdd(namedCollectionKey(collectionType, name), nullptr);
         if (!result.isNewEntry)
             return static_cast<T&>(*result.iterator->value);

         Ref list = T::create(container, collectionType, name);
         result.iterator->value = list.ptr();
         return list;
     }

     template<typename T, typename ContainerType>
     ALWAYS_INLINE Ref<T> addCachedCollection(ContainerType& container, CollectionType collectionType)
     {
         auto result = m_cachedCollections.fastAdd(namedCollectionKey(collectionType, starAtom()), nullptr);
         if (!result.isNewEntry)
             return static_cast<T&>(*result.iterator->value);

         Ref list = T::create(container, collectionType);
         result.iterator->value = list.ptr();
         return list;
     }

     template<typename T>
     T* cachedCollection(CollectionType collectionType)
     {
         return static_cast<T*>(m_cachedCollections.get(namedCollectionKey(collectionType, starAtom())));
     }

     template<typename NodeListType>
     void removeCacheWithAtomName(NodeListType& list, const AtomString& name)
     {
         ASSERT(&list == m_atomNameCaches.get(namedNodeListKey<NodeListType>(name)));
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list.ownerNode()))
             return;
         m_atomNameCaches.remove(namedNodeListKey<NodeListType>(name));
     }

     void removeCachedTagCollectionNS(HTMLCollection& collection, const AtomString& namespaceURI, const AtomString& localName)
     {
         QualifiedName name(nullAtom(), localName, namespaceURI);
         ASSERT(&collection == m_tagCollectionNSCache.get(name));
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(collection.ownerNode()))
             return;
         m_tagCollectionNSCache.remove(name);
     }

     inline void removeCachedCollection(HTMLCollection*, const AtomString& = starAtom());

     void invalidateCaches();
     void invalidateCachesForAttribute(const QualifiedName& attrName);

     void adoptTreeScope()
     {
         invalidateCaches();
     }

     inline void adoptDocument(Document& oldDocument, Document& newDocument);

 private:
     std::pair<std::underlying_type_t<CollectionType>, AtomString> namedCollectionKey(CollectionType type, const AtomString& name)
     {
         return std::pair<std::underlying_type_t<CollectionType>, AtomString>(static_cast<std::underlying_type_t<CollectionType>>(type), name);
     }

     template<typename NodeListType>
     std::pair<unsigned char, AtomString> namedNodeListKey(const AtomString& name)
     {
         return std::pair<unsigned char, AtomString>(NodeListTypeIdentifier<NodeListType>::value(), name);
     }

     bool deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node&);

     // These two are currently mutually exclusive and could be unioned. Not very important as this class is large anyway.
     SingleThreadWeakPtr<ChildNodeList> m_childNodeList;
     SingleThreadWeakPtr<EmptyNodeList> m_emptyChildNodeList;

     NodeListCacheMap m_atomNameCaches;
     TagCollectionNSCache m_tagCollectionNSCache;
     CollectionCacheMap m_cachedCollections;
 };

 class NodeMutationObserverData {
     WTF_MAKE_TZONE_ALLOCATED(NodeMutationObserverData);
     WTF_MAKE_NONCOPYABLE(NodeMutationObserverData);
 public:
     Vector<std::unique_ptr<MutationObserverRegistration>> registry;
     WeakHashSet<MutationObserverRegistration> transientRegistry;

     NodeMutationObserverData() = default;
 };

 DECLARE_COMPACT_ALLOCATOR_WITH_HEAP_IDENTIFIER(NodeRareData);
 class NodeRareData : public NoVirtualDestructorBase {
     WTF_MAKE_NONCOPYABLE(NodeRareData);
     WTF_DEPRECATED_MAKE_STRUCT_FAST_COMPACT_ALLOCATED_WITH_HEAP_IDENTIFIER(NodeRareData, NodeRareData);
 public:
 #if defined(DUMP_NODE_STATISTICS) && DUMP_NODE_STATISTICS
     enum class UseType : uint32_t {
         TabIndex = 1 << 0,
         ChildIndex = 1 << 1,
         NodeList = 1 << 2,
         MutationObserver = 1 << 3,
         ManuallyAssignedSlot = 1 << 4,
         ScrollingPosition = 1 << 5,
         ComputedStyle = 1 << 6,
         EffectiveLang = 1 << 7,
         Dataset = 1 << 8,
         ClassList = 1 << 9,
         ShadowRoot = 1 << 10,
         CustomElementReactionQueue = 1 << 11,
         CustomElementDefaultARIA = 1 << 12,
         FormAssociatedCustomElement = 1 << 13,
         AttributeMap = 1 << 14,
         InteractionObserver = 1 << 15,
         ResizeObserver = 1 << 16,
         Animations = 1 << 17,
         PseudoElements = 1 << 18,
         AttributeStyleMap = 1 << 19,
         ComputedStyleMap = 1 << 20,
         PartList = 1 << 21,
         PartNames = 1 << 22,
         Nonce = 1 << 23,
         ExplicitlySetAttrElementsMap = 1 << 24,
         Popover = 1 << 25,
         DisplayContentsOrNoneStyle = 1 << 26,
         CustomStateSet = 1 << 27,
         UserInfo = 1 << 28,
         InvokedPopover = 1 << 29,
     };
 #endif

     enum class Type { Element, Node };

     NodeRareData(Type type = Type::Node)
         : m_isElementRareData(type == Type::Element)
     {
     }

     bool isElementRareData() const { return m_isElementRareData; }

     void clearNodeLists() { m_nodeLists = nullptr; }
     NodeListsNodeData* nodeLists() const { return m_nodeLists.get(); }
     NodeListsNodeData& ensureNodeLists()
     {
         if (!m_nodeLists)
             m_nodeLists = makeUnique<NodeListsNodeData>();
         return *m_nodeLists;
     }

     NodeMutationObserverData* mutationObserverDataIfExists() { return m_mutationObserverData.get(); }
     NodeMutationObserverData& mutationObserverData()
     {
         if (!m_mutationObserverData)
             m_mutationObserverData = makeUnique<NodeMutationObserverData>();
         return *m_mutationObserverData;
     }

     // https://html.spec.whatwg.org/multipage/scripting.html#manually-assigned-nodes
     HTMLSlotElement* manuallyAssignedSlot() { return m_manuallyAssignedSlot.get(); }
     void setManuallyAssignedSlot(HTMLSlotElement* slot) { m_manuallyAssignedSlot = slot; }

     bool hasEverPaintedImages() const { return m_hasEverPaintedImages; }
     void setHasEverPaintedImages(bool hasEverPaintedImages) { m_hasEverPaintedImages = hasEverPaintedImages; }

 #if DUMP_NODE_STATISTICS
     OptionSet<UseType> useTypes() const
     {
         OptionSet<UseType> result;
         if (m_nodeLists)
             result.add(UseType::NodeList);
         if (m_mutationObserverData)
             result.add(UseType::MutationObserver);
         if (m_manuallyAssignedSlot)
             result.add(UseType::ManuallyAssignedSlot);
         return result;
     }
 #endif

     void operator delete(NodeRareData*, std::destroying_delete_t);

 private:
     std::unique_ptr<NodeListsNodeData> m_nodeLists;
     std::unique_ptr<NodeMutationObserverData> m_mutationObserverData;
     WeakPtr<HTMLSlotElement, WeakPtrImplWithEventTargetData> m_manuallyAssignedSlot;
     bool m_isElementRareData;
     bool m_hasEverPaintedImages { false }; // Keep last for better bit packing with ElementRareData.
 };

 template<> struct NodeListTypeIdentifier<NameNodeList> {
     static constexpr unsigned char value() { return 0; }
 };

 template<> struct NodeListTypeIdentifier<RadioNodeList> {
     static constexpr unsigned char value() { return 1; }
 };

 template<> struct NodeListTypeIdentifier<LabelsNodeList> {
     static constexpr unsigned char value() { return 2; }
 };

 inline bool NodeListsNodeData::deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node& ownerNode)
 {
     ASSERT(ownerNode.nodeLists() == this);
     size_t listsCount = (m_childNodeList ? 1 : 0)
         + (m_emptyChildNodeList ? 1 : 0)
         + m_atomNameCaches.size()
         + m_tagCollectionNSCache.size()
         + m_cachedCollections.size();
     if (listsCount != 1)
         return false;
     ownerNode.clearNodeLists();
     return true;
 }

 inline NodeRareData& Node::ensureRareData()
 {
     if (!hasRareData())
         materializeRareData();
     return *rareData();
 }

 } // namespace WebCore
	/*
	* Copyright (C) 2008-2025 Apple Inc. All rights reserved.
	* Copyright (C) 2008 David Smith <[email protected]>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public License
	* along with this library; see the file COPYING.LIB. If not, write to
	* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*
	*/

	#pragma once

	#include "ChildNodeList.h"
	#include "CommonAtomStrings.h"
	#include "HTMLCollection.h"
	#include "HTMLSlotElement.h"
	#include "MutationObserverRegistration.h"
	#include "QualifiedName.h"
	#include "TagCollection.h"
	#include <new>
	#include <wtf/HashSet.h>
	#include <wtf/NoVirtualDestructorBase.h>
	#include <wtf/StdLibExtras.h>
	#include <wtf/TZoneMalloc.h>
	#include <wtf/WeakHashSet.h>

	namespace WebCore {

	class LabelsNodeList;
	class LiveNodeList;
	class NameNodeList;
	class RadioNodeList;

	template<typename ListType> struct NodeListTypeIdentifier;

	DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(NodeListsNodeData);
	class NodeListsNodeData {
	WTF_MAKE_NONCOPYABLE(NodeListsNodeData);
	WTF_DEPRECATED_MAKE_STRUCT_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(NodeListsNodeData, NodeListsNodeData);
	public:
	NodeListsNodeData() = default;

	void clearChildNodeListCache()
	{
	if (m_childNodeList)
	m_childNodeList->invalidateCache();
	}

	Ref<ChildNodeList> ensureChildNodeList(ContainerNode& node)
	{
	ASSERT(!m_emptyChildNodeList);
	if (m_childNodeList)
	return *m_childNodeList;
	Ref list = ChildNodeList::create(node);
	m_childNodeList = list.ptr();
	return list;
	}

	void removeChildNodeList(ChildNodeList* list)
	{
	ASSERT(m_childNodeList == list);
	Ref ownerNode = list->ownerNode();
	if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(ownerNode))
	return;
	m_childNodeList = nullptr;
	}

	Ref<EmptyNodeList> ensureEmptyChildNodeList(Node& node)
	{
	ASSERT(!m_childNodeList);
	if (m_emptyChildNodeList)
	return *m_emptyChildNodeList;
	Ref list = EmptyNodeList::create(node);
	m_emptyChildNodeList = list.ptr();
	return list;
	}

	void removeEmptyChildNodeList(EmptyNodeList* list)
	{
	ASSERT(m_emptyChildNodeList == list);
	Ref ownerNode = list->ownerNode();
	if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(ownerNode))
	return;
	m_emptyChildNodeList = nullptr;
	}

	struct NodeListCacheMapEntryHash {
	static unsigned hash(const std::pair<unsigned char, AtomString>& entry)
	{
	return DefaultHash<AtomString>::hash(entry.second) + entry.first;
	}
	static bool equal(const std::pair<unsigned char, AtomString>& a, const std::pair<unsigned char, AtomString>& b) { return a.first == b.first && DefaultHash<AtomString>::equal(a.second, b.second); }
	static const bool safeToCompareToEmptyOrDeleted = DefaultHash<AtomString>::safeToCompareToEmptyOrDeleted;
	};

	using NodeListCacheMap = HashMap<std::pair<unsigned char, AtomString>, LiveNodeList*, NodeListCacheMapEntryHash>;
	using CollectionCacheMap = HashMap<std::pair<std::underlying_type_t<CollectionType>, AtomString>, HTMLCollection*, NodeListCacheMapEntryHash>;
	using TagCollectionNSCache = HashMap<QualifiedName, TagCollectionNS*>;

	template<typename T, typename ContainerType>
	ALWAYS_INLINE Ref<T> addCacheWithAtomName(ContainerType& container, const AtomString& name)
	{
	auto result = m_atomNameCaches.fastAdd(namedNodeListKey<T>(name), nullptr);
	if (!result.isNewEntry)
	return static_cast<T&>(*result.iterator->value);

	Ref list = T::create(container, name);
	result.iterator->value = list.ptr();
	return list;
	}

	ALWAYS_INLINE Ref<TagCollectionNS> addCachedTagCollectionNS(ContainerNode& node, const AtomString& namespaceURI, const AtomString& localName)
	{
	auto result = m_tagCollectionNSCache.fastAdd(QualifiedName { nullAtom(), localName, namespaceURI }, nullptr);
	if (!result.isNewEntry)
	return *result.iterator->value;

	Ref list = TagCollectionNS::create(node, namespaceURI, localName);
	result.iterator->value = list.ptr();
	return list;
	}

	template<typename T, typename ContainerType>
	ALWAYS_INLINE Ref<T> addCachedCollection(ContainerType& container, CollectionType collectionType, const AtomString& name)
	{
	auto result = m_cachedCollections.fastAdd(namedCollectionKey(collectionType, name), nullptr);
	if (!result.isNewEntry)
	return static_cast<T&>(*result.iterator->value);

	Ref list = T::create(container, collectionType, name);
	result.iterator->value = list.ptr();
	return list;
	}

	template<typename T, typename ContainerType>
	ALWAYS_INLINE Ref<T> addCachedCollection(ContainerType& container, CollectionType collectionType)
	{
	auto result = m_cachedCollections.fastAdd(namedCollectionKey(collectionType, starAtom()), nullptr);
	if (!result.isNewEntry)
	return static_cast<T&>(*result.iterator->value);

	Ref list = T::create(container, collectionType);
	result.iterator->value = list.ptr();
	return list;
	}

	template<typename T>
	T* cachedCollection(CollectionType collectionType)
	{
	return static_cast<T*>(m_cachedCollections.get(namedCollectionKey(collectionType, starAtom())));
	}

	template<typename NodeListType>
	void removeCacheWithAtomName(NodeListType& list, const AtomString& name)
	{
	ASSERT(&list == m_atomNameCaches.get(namedNodeListKey<NodeListType>(name)));
	if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list.ownerNode()))
	return;
	m_atomNameCaches.remove(namedNodeListKey<NodeListType>(name));
	}

	void removeCachedTagCollectionNS(HTMLCollection& collection, const AtomString& namespaceURI, const AtomString& localName)
	{
	QualifiedName name(nullAtom(), localName, namespaceURI);
	ASSERT(&collection == m_tagCollectionNSCache.get(name));
	if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(collection.ownerNode()))
	return;
	m_tagCollectionNSCache.remove(name);
	}

	inline void removeCachedCollection(HTMLCollection*, const AtomString& = starAtom());

	void invalidateCaches();
	void invalidateCachesForAttribute(const QualifiedName& attrName);

	void adoptTreeScope()
	{
	invalidateCaches();
	}

	inline void adoptDocument(Document& oldDocument, Document& newDocument);

	private:
	std::pair<std::underlying_type_t<CollectionType>, AtomString> namedCollectionKey(CollectionType type, const AtomString& name)
	{
	return std::pair<std::underlying_type_t<CollectionType>, AtomString>(static_cast<std::underlying_type_t<CollectionType>>(type), name);
	}

	template<typename NodeListType>
	std::pair<unsigned char, AtomString> namedNodeListKey(const AtomString& name)
	{
	return std::pair<unsigned char, AtomString>(NodeListTypeIdentifier<NodeListType>::value(), name);
	}

	bool deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node&);

	// These two are currently mutually exclusive and could be unioned. Not very important as this class is large anyway.
	SingleThreadWeakPtr<ChildNodeList> m_childNodeList;
	SingleThreadWeakPtr<EmptyNodeList> m_emptyChildNodeList;

	NodeListCacheMap m_atomNameCaches;
	TagCollectionNSCache m_tagCollectionNSCache;
	CollectionCacheMap m_cachedCollections;
	};

	class NodeMutationObserverData {
	WTF_MAKE_TZONE_ALLOCATED(NodeMutationObserverData);
	WTF_MAKE_NONCOPYABLE(NodeMutationObserverData);
	public:
	Vector<std::unique_ptr<MutationObserverRegistration>> registry;
	WeakHashSet<MutationObserverRegistration> transientRegistry;

	NodeMutationObserverData() = default;
	};

	DECLARE_COMPACT_ALLOCATOR_WITH_HEAP_IDENTIFIER(NodeRareData);
	class NodeRareData : public NoVirtualDestructorBase {
	WTF_MAKE_NONCOPYABLE(NodeRareData);
	WTF_DEPRECATED_MAKE_STRUCT_FAST_COMPACT_ALLOCATED_WITH_HEAP_IDENTIFIER(NodeRareData, NodeRareData);
	public:
	#if defined(DUMP_NODE_STATISTICS) && DUMP_NODE_STATISTICS
	enum class UseType : uint32_t {
	TabIndex = 1 << 0,
	ChildIndex = 1 << 1,
	NodeList = 1 << 2,
	MutationObserver = 1 << 3,
	ManuallyAssignedSlot = 1 << 4,
	ScrollingPosition = 1 << 5,
	ComputedStyle = 1 << 6,
	EffectiveLang = 1 << 7,
	Dataset = 1 << 8,
	ClassList = 1 << 9,
	ShadowRoot = 1 << 10,
	CustomElementReactionQueue = 1 << 11,
	CustomElementDefaultARIA = 1 << 12,
	FormAssociatedCustomElement = 1 << 13,
	AttributeMap = 1 << 14,
	InteractionObserver = 1 << 15,
	ResizeObserver = 1 << 16,
	Animations = 1 << 17,
	PseudoElements = 1 << 18,
	AttributeStyleMap = 1 << 19,
	ComputedStyleMap = 1 << 20,
	PartList = 1 << 21,
	PartNames = 1 << 22,
	Nonce = 1 << 23,
	ExplicitlySetAttrElementsMap = 1 << 24,
	Popover = 1 << 25,
	DisplayContentsOrNoneStyle = 1 << 26,
	CustomStateSet = 1 << 27,
	UserInfo = 1 << 28,
	InvokedPopover = 1 << 29,
	};
	#endif

	enum class Type { Element, Node };

	NodeRareData(Type type = Type::Node)
	: m_isElementRareData(type == Type::Element)
	{
	}

	bool isElementRareData() const { return m_isElementRareData; }

	void clearNodeLists() { m_nodeLists = nullptr; }
	NodeListsNodeData* nodeLists() const { return m_nodeLists.get(); }
	NodeListsNodeData& ensureNodeLists()
	{
	if (!m_nodeLists)
	m_nodeLists = makeUnique<NodeListsNodeData>();
	return *m_nodeLists;
	}

	NodeMutationObserverData* mutationObserverDataIfExists() { return m_mutationObserverData.get(); }
	NodeMutationObserverData& mutationObserverData()
	{
	if (!m_mutationObserverData)
	m_mutationObserverData = makeUnique<NodeMutationObserverData>();
	return *m_mutationObserverData;
	}

	// https://html.spec.whatwg.org/multipage/scripting.html#manually-assigned-nodes
	HTMLSlotElement* manuallyAssignedSlot() { return m_manuallyAssignedSlot.get(); }
	void setManuallyAssignedSlot(HTMLSlotElement* slot) { m_manuallyAssignedSlot = slot; }

	bool hasEverPaintedImages() const { return m_hasEverPaintedImages; }
	void setHasEverPaintedImages(bool hasEverPaintedImages) { m_hasEverPaintedImages = hasEverPaintedImages; }

	#if DUMP_NODE_STATISTICS
	OptionSet<UseType> useTypes() const
	{
	OptionSet<UseType> result;
	if (m_nodeLists)
	result.add(UseType::NodeList);
	if (m_mutationObserverData)
	result.add(UseType::MutationObserver);
	if (m_manuallyAssignedSlot)
	result.add(UseType::ManuallyAssignedSlot);
	return result;
	}
	#endif

	void operator delete(NodeRareData*, std::destroying_delete_t);

	private:
	std::unique_ptr<NodeListsNodeData> m_nodeLists;
	std::unique_ptr<NodeMutationObserverData> m_mutationObserverData;
	WeakPtr<HTMLSlotElement, WeakPtrImplWithEventTargetData> m_manuallyAssignedSlot;
	bool m_isElementRareData;
	bool m_hasEverPaintedImages { false }; // Keep last for better bit packing with ElementRareData.
	};

	template<> struct NodeListTypeIdentifier<NameNodeList> {
	static constexpr unsigned char value() { return 0; }
	};

	template<> struct NodeListTypeIdentifier<RadioNodeList> {
	static constexpr unsigned char value() { return 1; }
	};

	template<> struct NodeListTypeIdentifier<LabelsNodeList> {
	static constexpr unsigned char value() { return 2; }
	};

	inline bool NodeListsNodeData::deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node& ownerNode)
	{
	ASSERT(ownerNode.nodeLists() == this);
	size_t listsCount = (m_childNodeList ? 1 : 0)
	+ (m_emptyChildNodeList ? 1 : 0)
	+ m_atomNameCaches.size()
	+ m_tagCollectionNSCache.size()
	+ m_cachedCollections.size();
	if (listsCount != 1)
	return false;
	ownerNode.clearNodeLists();
	return true;
	}

	inline NodeRareData& Node::ensureRareData()
	{
	if (!hasRareData())
	materializeRareData();
	return *rareData();
	}

	} // namespace WebCore