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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 */
* Implementation of the |attributes| property of DOM Core's Element object.
#ifndef nsDOMAttributeMap_h
#define nsDOMAttributeMap_h
#include "mozilla/MemoryReporting.h"
#include "nsCycleCollectionParticipant.h"
#include "nsRefPtrHashtable.h"
#include "nsString.h"
#include "nsWrapperCache.h"
class nsAtom;
class nsINode;
namespace mozilla {
class ErrorResult;
namespace dom {
class Attr;
class DocGroup;
class Document;
class Element;
class NodeInfo;
} // namespace dom
} // namespace mozilla
* Structure used as a key for caching Attrs in nsDOMAttributeMap's
* mAttributeCache.
class nsAttrKey {
* The namespace of the attribute
int32_t mNamespaceID;
* The atom for attribute, stored as void*, to make sure that we only use it
* for the hashcode, and we can never dereference it.
void* mLocalName;
nsAttrKey(int32_t aNs, nsAtom* aName)
: mNamespaceID(aNs), mLocalName(aName) {}
nsAttrKey(const nsAttrKey& aAttr) = default;
* PLDHashEntryHdr implementation for nsAttrKey.
class nsAttrHashKey : public PLDHashEntryHdr {
using KeyType = const nsAttrKey&;
using KeyTypePointer = const nsAttrKey*;
explicit nsAttrHashKey(KeyTypePointer aKey) : mKey(*aKey) {}
nsAttrHashKey(const nsAttrHashKey& aCopy)
: PLDHashEntryHdr{}, mKey(aCopy.mKey) {}
~nsAttrHashKey() = default;
KeyType GetKey() const { return mKey; }
bool KeyEquals(KeyTypePointer aKey) const {
return mKey.mLocalName == aKey->mLocalName &&
mKey.mNamespaceID == aKey->mNamespaceID;
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(KeyTypePointer aKey) {
if (!aKey) return 0;
return mozilla::HashGeneric(aKey->mNamespaceID, aKey->mLocalName);
enum { ALLOW_MEMMOVE = true };
nsAttrKey mKey;
class nsDOMAttributeMap final : public nsISupports, public nsWrapperCache {
using Attr = mozilla::dom::Attr;
using DocGroup = mozilla::dom::DocGroup;
using Document = mozilla::dom::Document;
using Element = mozilla::dom::Element;
using ErrorResult = mozilla::ErrorResult;
explicit nsDOMAttributeMap(Element* aContent);
void DropReference();
Element* GetContent() { return mContent; }
* Called when mContent is moved into a new document.
* Updates the nodeinfos of all owned nodes.
nsresult SetOwnerDocument(Document* aDocument);
* Drop an attribute from the map's cache (does not remove the attribute
* from the node!)
void DropAttribute(int32_t aNamespaceID, nsAtom* aLocalName);
* Returns the number of attribute nodes currently in the map.
* Note: this is just the number of cached attribute nodes, not the number of
* attributes in mContent.
* @return The number of attribute nodes in the map.
uint32_t Count() const;
using AttrCache = nsRefPtrHashtable<nsAttrHashKey, Attr>;
static void BlastSubtreeToPieces(nsINode* aNode);
Element* GetParentObject() const { return mContent; }
virtual JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
DocGroup* GetDocGroup() const;
// WebIDL
Attr* GetNamedItem(const nsAString& aAttrName);
Attr* NamedGetter(const nsAString& aAttrName, bool& aFound);
already_AddRefed<Attr> RemoveNamedItem(mozilla::dom::NodeInfo* aNodeInfo,
ErrorResult& aError);
already_AddRefed<Attr> RemoveNamedItem(const nsAString& aName,
ErrorResult& aError);
Attr* Item(uint32_t aIndex);
Attr* IndexedGetter(uint32_t aIndex, bool& aFound);
uint32_t Length() const;
Attr* GetNamedItemNS(const nsAString& aNamespaceURI,
const nsAString& aLocalName);
already_AddRefed<Attr> SetNamedItemNS(Attr& aNode, ErrorResult& aError);
already_AddRefed<Attr> RemoveNamedItemNS(const nsAString& aNamespaceURI,
const nsAString& aLocalName,
ErrorResult& aError);
void GetSupportedNames(nsTArray<nsString>& aNames);
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
virtual ~nsDOMAttributeMap();
nsCOMPtr<Element> mContent;
* Cache of Attrs.
AttrCache mAttributeCache;
already_AddRefed<mozilla::dom::NodeInfo> GetAttrNodeInfo(
const nsAString& aNamespaceURI, const nsAString& aLocalName);
Attr* GetAttribute(mozilla::dom::NodeInfo* aNodeInfo);
#endif /* nsDOMAttributeMap_h */