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diff --git a/dom/base/NodeInfo.h b/dom/base/NodeInfo.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Class that represents a prefix/namespace/localName triple; a single
+ * nodeinfo is shared by all elements in a document that have that
+ * prefix, namespace, and localName.
+ *
+ * nsNodeInfoManagers are internal objects that manage a list of
+ * NodeInfos, every document object should hold a strong reference to
+ * a nsNodeInfoManager and every NodeInfo also holds a strong reference
+ * to their owning manager. When a NodeInfo is no longer used it will
+ * automatically remove itself from its owner manager, and when all
+ * NodeInfos have been removed from a nsNodeInfoManager and all external
+ * references are released the nsNodeInfoManager deletes itself.
+ */
+
+#ifndef mozilla_dom_NodeInfo_h___
+#define mozilla_dom_NodeInfo_h___
+
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/dom/NameSpaceConstants.h"
+#include "nsString.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+#include "nsAtom.h"
+#include "nsHashKeys.h"
+
+class nsNodeInfoManager;
+
+namespace mozilla::dom {
+
+class Document;
+
+class NodeInfo final {
+ public:
+ NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(NodeInfo)
+ NS_DECL_CYCLE_COLLECTION_SKIPPABLE_NATIVE_CLASS_WITH_CUSTOM_DELETE(NodeInfo)
+
+ /*
+ * Get the name from this node as a string, this does not include the prefix.
+ *
+ * For the HTML element "<body>" this will return "body" and for the XML
+ * element "<html:body>" this will return "body".
+ */
+ void GetName(nsAString& aName) const;
+
+ /*
+ * Get the name from this node as an atom, this does not include the prefix.
+ * This function never returns a null atom.
+ *
+ * For the HTML element "<body>" this will return the "body" atom and for
+ * the XML element "<html:body>" this will return the "body" atom.
+ */
+ nsAtom* NameAtom() const { return mInner.mName; }
+
+ /*
+ * Get the qualified name from this node as a string, the qualified name
+ * includes the prefix, if one exists.
+ *
+ * For the HTML element "<body>" this will return "body" and for the XML
+ * element "<html:body>" this will return "html:body".
+ */
+ const nsString& QualifiedName() const { return mQualifiedName; }
+
+ /*
+ * Returns the node's nodeName as defined in DOM Core
+ */
+ const nsString& NodeName() const { return mNodeName; }
+
+ /*
+ * Returns the node's localName as defined in DOM Core
+ */
+ const nsString& LocalName() const { return mLocalName; }
+
+ /*
+ * Get the prefix from this node as a string.
+ *
+ * For the HTML element "<body>" this will return a null string and for
+ * the XML element "<html:body>" this will return the string "html".
+ */
+ void GetPrefix(nsAString& aPrefix) const;
+
+ /*
+ * Get the prefix from this node as an atom.
+ *
+ * For the HTML element "<body>" this will return a null atom and for
+ * the XML element "<html:body>" this will return the "html" atom.
+ */
+ nsAtom* GetPrefixAtom() const { return mInner.mPrefix; }
+
+ /*
+ * Get the namespace URI for a node, if the node has a namespace URI.
+ */
+ void GetNamespaceURI(nsAString& aNameSpaceURI) const;
+
+ /*
+ * Get the namespace ID for a node if the node has a namespace, if not this
+ * returns kNameSpaceID_None.
+ */
+ int32_t NamespaceID() const { return mInner.mNamespaceID; }
+
+ /*
+ * Get the nodetype for the node. Returns the values specified in Node
+ * for Node.nodeType
+ */
+ uint16_t NodeType() const { return mInner.mNodeType; }
+
+ /*
+ * Get the extra name, used by PIs and DocTypes, for the node.
+ */
+ nsAtom* GetExtraName() const { return mInner.mExtraName; }
+
+ /**
+ * Get the owning node info manager. Only to be used inside Gecko, you can't
+ * really do anything with the pointer outside Gecko anyway.
+ */
+ nsNodeInfoManager* NodeInfoManager() const { return mOwnerManager; }
+
+ /*
+ * Utility functions that can be used to check if a nodeinfo holds a specific
+ * name, name and prefix, name and prefix and namespace ID, or just
+ * namespace ID.
+ */
+ inline bool Equals(NodeInfo* aNodeInfo) const;
+
+ bool NameAndNamespaceEquals(NodeInfo* aNodeInfo) const;
+
+ bool Equals(const nsAtom* aNameAtom) const {
+ return mInner.mName == aNameAtom;
+ }
+
+ bool Equals(const nsAtom* aNameAtom, const nsAtom* aPrefixAtom) const {
+ return (mInner.mName == aNameAtom) && (mInner.mPrefix == aPrefixAtom);
+ }
+
+ bool Equals(const nsAtom* aNameAtom, int32_t aNamespaceID) const {
+ return ((mInner.mName == aNameAtom) &&
+ (mInner.mNamespaceID == aNamespaceID));
+ }
+
+ bool Equals(const nsAtom* aNameAtom, const nsAtom* aPrefixAtom,
+ int32_t aNamespaceID) const {
+ return ((mInner.mName == aNameAtom) && (mInner.mPrefix == aPrefixAtom) &&
+ (mInner.mNamespaceID == aNamespaceID));
+ }
+
+ bool NamespaceEquals(int32_t aNamespaceID) const {
+ return mInner.mNamespaceID == aNamespaceID;
+ }
+
+ inline bool Equals(const nsAString& aName) const;
+
+ inline bool Equals(const nsAString& aName, const nsAString& aPrefix) const;
+
+ inline bool Equals(const nsAString& aName, int32_t aNamespaceID) const;
+
+ inline bool Equals(const nsAString& aName, const nsAString& aPrefix,
+ int32_t aNamespaceID) const;
+
+ bool NamespaceEquals(const nsAString& aNamespaceURI) const;
+
+ inline bool QualifiedNameEquals(const nsAtom* aNameAtom) const;
+
+ bool QualifiedNameEquals(const nsAString& aQualifiedName) const {
+ return mQualifiedName == aQualifiedName;
+ }
+
+ /*
+ * Retrieve a pointer to the document that owns this node info.
+ */
+ Document* GetDocument() const { return mDocument; }
+
+ private:
+ NodeInfo() = delete;
+ NodeInfo(const NodeInfo& aOther) = delete;
+
+ // NodeInfo is only constructed by nsNodeInfoManager which is a friend class.
+ // aName and aOwnerManager may not be null.
+ NodeInfo(nsAtom* aName, nsAtom* aPrefix, int32_t aNamespaceID,
+ uint16_t aNodeType, nsAtom* aExtraName,
+ nsNodeInfoManager* aOwnerManager);
+
+ ~NodeInfo();
+
+ public:
+ bool CanSkip();
+
+ /**
+ * This method gets called by the cycle collector when it's time to delete
+ * this object.
+ */
+ void DeleteCycleCollectable();
+
+ protected:
+ /*
+ * NodeInfoInner is used for two things:
+ *
+ * 1. as a member in nsNodeInfo for holding the name, prefix and
+ * namespace ID
+ * 2. as the hash key in the hash table in nsNodeInfoManager
+ *
+ * NodeInfoInner does not do any kind of reference counting,
+ * that's up to the user of this class. Since NodeInfoInner is
+ * typically used as a member of NodeInfo, the hash table doesn't
+ * need to delete the keys. When the value (NodeInfo) is deleted
+ * the key is automatically deleted.
+ */
+
+ class NodeInfoInner {
+ public:
+ NodeInfoInner()
+ : mName(nullptr),
+ mPrefix(nullptr),
+ mNamespaceID(kNameSpaceID_Unknown),
+ mNodeType(0),
+ mNameString(nullptr),
+ mExtraName(nullptr),
+ mHash() {}
+ NodeInfoInner(nsAtom* aName, nsAtom* aPrefix, int32_t aNamespaceID,
+ uint16_t aNodeType, nsAtom* aExtraName)
+ : mName(aName),
+ mPrefix(aPrefix),
+ mNamespaceID(aNamespaceID),
+ mNodeType(aNodeType),
+ mNameString(nullptr),
+ mExtraName(aExtraName),
+ mHash() {}
+ NodeInfoInner(const nsAString& aTmpName, nsAtom* aPrefix,
+ int32_t aNamespaceID, uint16_t aNodeType)
+ : mName(nullptr),
+ mPrefix(aPrefix),
+ mNamespaceID(aNamespaceID),
+ mNodeType(aNodeType),
+ mNameString(&aTmpName),
+ mExtraName(nullptr),
+ mHash() {}
+
+ bool operator==(const NodeInfoInner& aOther) const {
+ if (mPrefix != aOther.mPrefix || mNamespaceID != aOther.mNamespaceID ||
+ mNodeType != aOther.mNodeType || mExtraName != aOther.mExtraName) {
+ return false;
+ }
+
+ if (mName) {
+ if (aOther.mName) {
+ return mName == aOther.mName;
+ }
+ return mName->Equals(*(aOther.mNameString));
+ }
+
+ if (aOther.mName) {
+ return aOther.mName->Equals(*(mNameString));
+ }
+
+ return mNameString->Equals(*(aOther.mNameString));
+ }
+
+ uint32_t Hash() const {
+ if (!mHash) {
+ mHash.emplace(mName ? mName->hash()
+ : mozilla::HashString(*mNameString));
+ }
+ return mHash.value();
+ }
+
+ nsAtom* const MOZ_OWNING_REF mName;
+ nsAtom* MOZ_OWNING_REF mPrefix;
+ int32_t mNamespaceID;
+ uint16_t mNodeType; // As defined by Node.nodeType
+ const nsAString* const mNameString;
+ nsAtom* MOZ_OWNING_REF mExtraName; // Only used by PIs and DocTypes
+ mutable mozilla::Maybe<const uint32_t> mHash;
+ };
+
+ // nsNodeInfoManager needs to pass mInner to the hash table.
+ friend class ::nsNodeInfoManager;
+
+ // This is a non-owning reference, but it's safe since it's set to nullptr
+ // by nsNodeInfoManager::DropDocumentReference when the document is destroyed.
+ Document* MOZ_NON_OWNING_REF mDocument; // Cache of mOwnerManager->mDocument
+
+ NodeInfoInner mInner;
+
+ RefPtr<nsNodeInfoManager> mOwnerManager;
+
+ /*
+ * Members for various functions of mName+mPrefix that we can be
+ * asked to compute.
+ */
+
+ // Qualified name
+ nsString mQualifiedName;
+
+ // nodeName for the node.
+ nsString mNodeName;
+
+ // localName for the node. This is either equal to mInner.mName, or a
+ // void string, depending on mInner.mNodeType.
+ nsString mLocalName;
+};
+
+} // namespace mozilla::dom
+
+#endif /* mozilla_dom_NodeInfo_h___ */