NodeInfo.h
/* -*- 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 "nsAutoPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/dom/NameSpaceConstants.h"
#include "nsStringGlue.h"
#include "mozilla/Attributes.h"
#include "nsIAtom.h"
class nsIDocument;
class nsNodeInfoManager;
namespace mozilla {
namespace dom {
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.
*/
nsIAtom* 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.
*/
nsIAtom* 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 nsIDOMNode
* for nsIDOMNode.nodeType
*/
uint16_t NodeType() const
{
return mInner.mNodeType;
}
/*
* Get the extra name, used by PIs and DocTypes, for the node.
*/
nsIAtom* 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(nsIAtom* aNameAtom) const
{
return mInner.mName == aNameAtom;
}
bool Equals(nsIAtom* aNameAtom, nsIAtom* aPrefixAtom) const
{
return (mInner.mName == aNameAtom) && (mInner.mPrefix == aPrefixAtom);
}
bool Equals(nsIAtom* aNameAtom, int32_t aNamespaceID) const
{
return ((mInner.mName == aNameAtom) &&
(mInner.mNamespaceID == aNamespaceID));
}
bool Equals(nsIAtom* aNameAtom, nsIAtom* 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(nsIAtom* aNameAtom) const;
bool QualifiedNameEquals(const nsAString& aQualifiedName) const
{
return mQualifiedName == aQualifiedName;
}
/*
* Retrieve a pointer to the document that owns this node info.
*/
nsIDocument* 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(nsIAtom* aName, nsIAtom* aPrefix, int32_t aNamespaceID,
uint16_t aNodeType, nsIAtom* 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)
{
}
NodeInfoInner(nsIAtom *aName, nsIAtom *aPrefix, int32_t aNamespaceID,
uint16_t aNodeType, nsIAtom* aExtraName)
: mName(aName), mPrefix(aPrefix), mNamespaceID(aNamespaceID),
mNodeType(aNodeType), mNameString(nullptr), mExtraName(aExtraName)
{
}
NodeInfoInner(const nsAString& aTmpName, nsIAtom *aPrefix,
int32_t aNamespaceID, uint16_t aNodeType)
: mName(nullptr), mPrefix(aPrefix), mNamespaceID(aNamespaceID),
mNodeType(aNodeType), mNameString(&aTmpName), mExtraName(nullptr)
{
}
nsCOMPtr<nsIAtom> mName;
nsCOMPtr<nsIAtom> mPrefix;
int32_t mNamespaceID;
uint16_t mNodeType; // As defined by nsIDOMNode.nodeType
const nsAString* mNameString;
nsCOMPtr<nsIAtom> mExtraName; // Only used by PIs and DocTypes
};
// 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.
nsIDocument* MOZ_NON_OWNING_REF mDocument; // Cache of mOwnerManager->mDocument
NodeInfoInner mInner;
nsRefPtr<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 dom
} // namespace mozilla
#endif /* mozilla_dom_NodeInfo_h___ */
