author Dylan Roeh <>
Tue, 28 Aug 2018 11:35:46 -0500
changeset 481113 31683bdf39d7bcacf8d9bf265fc2365024473fbe
parent 454456 49ae9160211d8b60cdd0ac7d99c80fc4cef15272
child 508163 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1485178 - Only migrate sharedprefs when in Fennec. r=snorp a=ritu

/* -*- 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 "mozilla/dom/Attr.h"
#include "mozilla/ErrorResult.h"
#include "nsCycleCollectionParticipant.h"
#include "nsRefPtrHashtable.h"
#include "nsString.h"
#include "nsWrapperCache.h"

class nsAtom;
class nsIDocument;
namespace mozilla {
namespace dom {
class DocGroup;
} // 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)
    : mNamespaceID(aAttr.mNamespaceID), mLocalName(aAttr.mLocalName) {}

 * PLDHashEntryHdr implementation for nsAttrKey.
class nsAttrHashKey : public PLDHashEntryHdr
  typedef const nsAttrKey& KeyType;
  typedef const nsAttrKey* KeyTypePointer;

  explicit nsAttrHashKey(KeyTypePointer aKey) : mKey(*aKey) {}
  nsAttrHashKey(const nsAttrHashKey& aCopy) : mKey(aCopy.mKey) {}
  ~nsAttrHashKey() {}

  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
  typedef mozilla::dom::Attr Attr;
  typedef mozilla::dom::DocGroup DocGroup;
  typedef mozilla::dom::Element Element;
  typedef mozilla::ErrorResult 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(nsIDocument* 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;

  typedef nsRefPtrHashtable<nsAttrHashKey, Attr> AttrCache;

  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);
  RemoveNamedItem(mozilla::dom::NodeInfo* aNodeInfo, ErrorResult& aError);
  RemoveNamedItem(const nsAString& aName, ErrorResult& aError);

  Attr* Item(uint32_t aIndex);
  Attr* IndexedGetter(uint32_t aIndex, bool& aFound);
  uint32_t Length() const;

  GetNamedItemNS(const nsAString& aNamespaceURI,
                 const nsAString& aLocalName);
  SetNamedItemNS(Attr& aNode, ErrorResult& aError);
  RemoveNamedItemNS(const nsAString& aNamespaceURI, const nsAString& aLocalName,
                    ErrorResult& aError);

  GetSupportedNames(nsTArray<nsString>& aNames);

  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;

  virtual ~nsDOMAttributeMap();

  nsCOMPtr<Element> mContent;

   * Cache of Attrs.
  AttrCache mAttributeCache;

  GetAttrNodeInfo(const nsAString& aNamespaceURI,
                  const nsAString& aLocalName);

  Attr* GetAttribute(mozilla::dom::NodeInfo* aNodeInfo);

// XXX khuey yes this is crazy.  The bindings code needs to see this include,
// but if we pull it in at the top of the file we get a circular include
// problem.
#include "mozilla/dom/Element.h"

#endif /* nsDOMAttributeMap_h */