dom/base/nsNodeInfoManager.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /*
   8  * A class for handing out nodeinfos and ensuring sharing of them as needed.
   9  */
  10
  11 #ifndef nsNodeInfoManager_h___
  12 #define nsNodeInfoManager_h___
  13
  14 #include "mozilla/Attributes.h"  // for final
  15 #include "mozilla/dom/NodeInfo.h"
  16 #include "mozilla/dom/DOMArena.h"
  17 #include "mozilla/MruCache.h"
  18 #include "nsCOMPtr.h"                      // for member
  19 #include "nsCycleCollectionParticipant.h"  // for NS_DECL_CYCLE_*
  20 #include "nsTHashMap.h"
  21 #include "nsStringFwd.h"
  22
  23 class nsAtom;
  24 class nsIPrincipal;
  25 class nsWindowSizes;
  26 template <class T>
  27 struct already_AddRefed;
  28
  29 namespace mozilla::dom {
  30 class Document;
  31 }  // namespace mozilla::dom
  32
  33 class nsNodeInfoManager final {
  34  private:
  35   ~nsNodeInfoManager();
  36
  37  public:
  38   explicit nsNodeInfoManager(mozilla::dom::Document* aDocument,
  39                              nsIPrincipal* aPrincipal);
  40
  41   NS_DECL_CYCLE_COLLECTION_SKIPPABLE_NATIVE_CLASS(nsNodeInfoManager)
  42
  43   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(nsNodeInfoManager)
  44
  45   /**
  46    * Release the reference to the document, this will be called when
  47    * the document is going away.
  48    */
  49   void DropDocumentReference();
  50
  51   /**
  52    * Methods for creating nodeinfo's from atoms and/or strings.
  53    */
  54   already_AddRefed<mozilla::dom::NodeInfo> GetNodeInfo(
  55       nsAtom* aName, nsAtom* aPrefix, int32_t aNamespaceID, uint16_t aNodeType,
  56       nsAtom* aExtraName = nullptr);
  57   nsresult GetNodeInfo(const nsAString& aName, nsAtom* aPrefix,
  58                        int32_t aNamespaceID, uint16_t aNodeType,
  59                        mozilla::dom::NodeInfo** aNodeInfo);
  60   nsresult GetNodeInfo(const nsAString& aName, nsAtom* aPrefix,
  61                        const nsAString& aNamespaceURI, uint16_t aNodeType,
  62                        mozilla::dom::NodeInfo** aNodeInfo);
  63
  64   /**
  65    * Returns the nodeinfo for text nodes. Can return null if OOM.
  66    */
  67   already_AddRefed<mozilla::dom::NodeInfo> GetTextNodeInfo();
  68
  69   /**
  70    * Returns the nodeinfo for comment nodes. Can return null if OOM.
  71    */
  72   already_AddRefed<mozilla::dom::NodeInfo> GetCommentNodeInfo();
  73
  74   /**
  75    * Returns the nodeinfo for the document node. Can return null if OOM.
  76    */
  77   already_AddRefed<mozilla::dom::NodeInfo> GetDocumentNodeInfo();
  78
  79   /**
  80    * Retrieve a pointer to the document that owns this node info
  81    * manager.
  82    */
  83   mozilla::dom::Document* GetDocument() const { return mDocument; }
  84
  85   /**
  86    * Gets the principal of the document this nodeinfo manager belongs to.
  87    */
  88   nsIPrincipal* DocumentPrincipal() const {
  89     NS_ASSERTION(mPrincipal, "How'd that happen?");
  90     return mPrincipal;
  91   }
  92
  93   void RemoveNodeInfo(mozilla::dom::NodeInfo* aNodeInfo);
  94
  95   /**
  96    * Returns true if SVG nodes in this document have real SVG semantics.
  97    */
  98   bool SVGEnabled() {
  99     return mSVGEnabled.valueOrFrom([this] { return InternalSVGEnabled(); });
 100   }
 101
 102   /**
 103    * Returns true if MathML nodes in this document have real MathML semantics.
 104    */
 105   bool MathMLEnabled() {
 106     return mMathMLEnabled.valueOrFrom(
 107         [this] { return InternalMathMLEnabled(); });
 108   }
 109
 110   mozilla::dom::DOMArena* GetArenaAllocator() { return mArena; }
 111   void SetArenaAllocator(mozilla::dom::DOMArena* aArena);
 112
 113   void* Allocate(size_t aSize);
 114
 115   void Free(void* aPtr) { free(aPtr); }
 116
 117   bool HasAllocated() { return mHasAllocated; }
 118
 119   void AddSizeOfIncludingThis(nsWindowSizes& aSizes) const;
 120
 121  protected:
 122   friend class mozilla::dom::Document;
 123   friend class nsXULPrototypeDocument;
 124
 125   /**
 126    * Sets the principal of the document this nodeinfo manager belongs to.
 127    */
 128   void SetDocumentPrincipal(nsIPrincipal* aPrincipal);
 129
 130  private:
 131   bool InternalSVGEnabled();
 132   bool InternalMathMLEnabled();
 133
 134   class NodeInfoInnerKey
 135       : public nsPtrHashKey<mozilla::dom::NodeInfo::NodeInfoInner> {
 136    public:
 137     explicit NodeInfoInnerKey(KeyTypePointer aKey) : nsPtrHashKey(aKey) {}
 138     NodeInfoInnerKey(NodeInfoInnerKey&&) = default;
 139     ~NodeInfoInnerKey() = default;
 140     bool KeyEquals(KeyTypePointer aKey) const { return *mKey == *aKey; }
 141     static PLDHashNumber HashKey(KeyTypePointer aKey) { return aKey->Hash(); }
 142   };
 143
 144   struct NodeInfoCache
 145       : public mozilla::MruCache<mozilla::dom::NodeInfo::NodeInfoInner,
 146                                  mozilla::dom::NodeInfo*, NodeInfoCache> {
 147     static mozilla::HashNumber Hash(
 148         const mozilla::dom::NodeInfo::NodeInfoInner& aKey) {
 149       return aKey.Hash();
 150     }
 151     static bool Match(const mozilla::dom::NodeInfo::NodeInfoInner& aKey,
 152                       const mozilla::dom::NodeInfo* aVal) {
 153       return aKey == aVal->mInner;
 154     }
 155   };
 156
 157   nsTHashMap<NodeInfoInnerKey, mozilla::dom::NodeInfo*> mNodeInfoHash;
 158   mozilla::dom::Document* MOZ_NON_OWNING_REF mDocument;  // WEAK
 159   uint32_t mNonDocumentNodeInfos;
 160
 161   // Note: it's important that mPrincipal is declared before mDefaultPrincipal,
 162   // since the latter is initialized to the value of the former in the
 163   // constructor's init list:
 164   nsCOMPtr<nsIPrincipal> mPrincipal;         // Never null
 165   nsCOMPtr<nsIPrincipal> mDefaultPrincipal;  // Never null
 166
 167   mozilla::dom::NodeInfo* MOZ_NON_OWNING_REF
 168       mTextNodeInfo;  // WEAK to avoid circular ownership
 169   mozilla::dom::NodeInfo* MOZ_NON_OWNING_REF
 170       mCommentNodeInfo;  // WEAK to avoid circular ownership
 171   mozilla::dom::NodeInfo* MOZ_NON_OWNING_REF
 172       mDocumentNodeInfo;  // WEAK to avoid circular ownership
 173   NodeInfoCache mRecentlyUsedNodeInfos;
 174   mozilla::Maybe<bool> mSVGEnabled;     // Lazily initialized.
 175   mozilla::Maybe<bool> mMathMLEnabled;  // Lazily initialized.
 176
 177   // For dom_arena_allocator_enabled
 178   RefPtr<mozilla::dom::DOMArena> mArena;
 179   bool mHasAllocated = false;
 180 };
 181
 182 #endif /* nsNodeInfoManager_h___ */