Bug 655084 - Remove nsWeakFrame's from editor scripts and the nsTextInputListener to improve perf on pages with lots of text widgets. r=ehsan

content/html/content/src/nsTextEditorState.cpp

@@ -84,7 +84,6 @@ public:
   RestoreSelectionState(nsTextEditorState *aState, nsTextControlFrame *aFrame,
                         PRInt32 aStart, PRInt32 aEnd)
     : mFrame(aFrame),
-      mWeakFrame(aFrame),
       mStart(aStart),
       mEnd(aEnd),
       mTextEditorState(aState)
@@ -92,19 +91,24 @@ public:
   }
 
   NS_IMETHOD Run() {
-    if (mWeakFrame.IsAlive()) {
+    if (mFrame) {
       // SetSelectionRange leads to Selection::AddRange which flushes Layout -
       // need to block script to avoid nested PrepareEditor calls (bug 642800).
       nsAutoScriptBlocker scriptBlocker;
       mFrame->SetSelectionRange(mStart, mEnd);
       mTextEditorState->HideSelectionIfBlurred();
     }
+    mTextEditorState->FinishedRestoringSelection();
     return NS_OK;
   }
 
+  // Let the text editor tell us we're no longer relevant - avoids use of nsWeakFrame
+  void Revoke() {
+    mFrame = nsnull;
+  }
+
 private:
   nsTextControlFrame* mFrame;
-  nsWeakFrame mWeakFrame;
   PRInt32 mStart;
   PRInt32 mEnd;
   nsTextEditorState* mTextEditorState;
@@ -645,7 +649,7 @@ protected:
 
 protected:
 
-  nsWeakFrame mFrame;
+  nsIFrame* mFrame;
 
   nsITextControlElement* const mTxtCtrlElement;
 
@@ -673,7 +677,8 @@ protected:
  */
 
 nsTextInputListener::nsTextInputListener(nsITextControlElement* aTxtCtrlElement)
-: mTxtCtrlElement(aTxtCtrlElement)
+: mFrame(nsnull)
+, mTxtCtrlElement(aTxtCtrlElement)
 , mSelectionWasCollapsed(PR_TRUE)
 , mHadUndoItems(PR_FALSE)
 , mHadRedoItems(PR_FALSE)
@@ -703,7 +708,9 @@ NS_IMETHODIMP
 nsTextInputListener::NotifySelectionChanged(nsIDOMDocument* aDoc, nsISelection* aSel, PRInt16 aReason)
 {
   PRBool collapsed;
-  if (!mFrame.IsAlive() || !aDoc || !aSel || NS_FAILED(aSel->GetIsCollapsed(&collapsed)))
+  nsWeakFrame weakFrame = mFrame;
+
+  if (!aDoc || !aSel || NS_FAILED(aSel->GetIsCollapsed(&collapsed)))
     return NS_OK;
 
   // Fire the select event
@@ -748,7 +755,7 @@ nsTextInputListener::NotifySelectionChanged(nsIDOMDocument* aDoc, nsISelection*
   
   mSelectionWasCollapsed = collapsed;
 
-  if (!mFrame.IsAlive() || !nsContentUtils::IsFocusedContent(mFrame->GetContent()))
+  if (!weakFrame.IsAlive() || !nsContentUtils::IsFocusedContent(mFrame->GetContent()))
     return NS_OK;
 
   return UpdateTextInputCommands(NS_LITERAL_STRING("select"));
@@ -799,7 +806,6 @@ DoCommandCallback(const char *aCommand, void *aData)
 NS_IMETHODIMP
 nsTextInputListener::KeyDown(nsIDOMEvent *aDOMEvent)
 {
-  NS_ENSURE_STATE(mFrame.IsAlive());
   nsCOMPtr<nsIDOMKeyEvent> keyEvent(do_QueryInterface(aDOMEvent));
   NS_ENSURE_TRUE(keyEvent, NS_ERROR_INVALID_ARG);
 
@@ -818,7 +824,6 @@ nsTextInputListener::KeyDown(nsIDOMEvent *aDOMEvent)
 NS_IMETHODIMP
 nsTextInputListener::KeyPress(nsIDOMEvent *aDOMEvent)
 {
-  NS_ENSURE_STATE(mFrame.IsAlive());
   nsCOMPtr<nsIDOMKeyEvent> keyEvent(do_QueryInterface(aDOMEvent));
   NS_ENSURE_TRUE(keyEvent, NS_ERROR_INVALID_ARG);
 
@@ -837,7 +842,6 @@ nsTextInputListener::KeyPress(nsIDOMEvent *aDOMEvent)
 NS_IMETHODIMP
 nsTextInputListener::KeyUp(nsIDOMEvent *aDOMEvent)
 {
-  NS_ENSURE_STATE(mFrame.IsAlive());
   nsCOMPtr<nsIDOMKeyEvent> keyEvent(do_QueryInterface(aDOMEvent));
   NS_ENSURE_TRUE(keyEvent, NS_ERROR_INVALID_ARG);
 
@@ -859,8 +863,9 @@ nsTextInputListener::KeyUp(nsIDOMEvent *aDOMEvent)
 NS_IMETHODIMP
 nsTextInputListener::EditAction()
 {
-  NS_ENSURE_STATE(mFrame.IsAlive());
-  nsITextControlFrame* frameBase = do_QueryFrame(mFrame.GetFrame());
+  nsWeakFrame weakFrame = mFrame;
+
+  nsITextControlFrame* frameBase = do_QueryFrame(mFrame);
   nsTextControlFrame* frame = static_cast<nsTextControlFrame*> (frameBase);
   NS_ASSERTION(frame, "Where is our frame?");
   //
@@ -887,7 +892,7 @@ nsTextInputListener::EditAction()
     mHadRedoItems = numRedoItems != 0;
   }
 
-  if (!mFrame.IsAlive()) {
+  if (!weakFrame.IsAlive()) {
     return NS_OK;
   }
 
@@ -916,8 +921,6 @@ nsTextInputListener::EditAction()
 nsresult
 nsTextInputListener::UpdateTextInputCommands(const nsAString& commandsToUpdate)
 {
-  NS_ENSURE_STATE(mFrame.IsAlive());
-
   nsIContent* content = mFrame->GetContent();
   NS_ENSURE_TRUE(content, NS_ERROR_FAILURE);
   
@@ -967,6 +970,7 @@ nsTextInputListener::GetKeyBindings()
 
 nsTextEditorState::nsTextEditorState(nsITextControlElement* aOwningElement)
   : mTextCtrlElement(aOwningElement),
+    mRestoringSelection(nsnull),
     mBoundFrame(nsnull),
     mTextListener(nsnull),
     mEditorInitialized(PR_FALSE),
@@ -1385,8 +1389,13 @@ nsTextEditorState::PrepareEditor(const nsAString *aValue)
 
   // Restore our selection after being bound to a new frame
   if (mSelState) {
-    nsContentUtils::AddScriptRunner(new RestoreSelectionState(this, mBoundFrame, mSelState->mStart, mSelState->mEnd));
-    mSelState = nsnull;
+    if (mRestoringSelection) // paranoia
+      mRestoringSelection->Revoke();
+    mRestoringSelection = new RestoreSelectionState(this, mBoundFrame, mSelState->mStart, mSelState->mEnd);
+    if (mRestoringSelection) {
+      nsContentUtils::AddScriptRunner(mRestoringSelection);
+      mSelState = nsnull;
+    }
   }
 
   return rv;
@@ -1419,6 +1428,11 @@ nsTextEditorState::UnbindFromFrame(nsTextControlFrame* aFrame)
   nsAutoString value;
   GetValue(value, PR_TRUE);
 
+  if (mRestoringSelection) {
+    mRestoringSelection->Revoke();
+    mRestoringSelection = nsnull;
+  }
+
   // Save our selection state if needed.
   // Note that nsTextControlFrame::GetSelectionRange attempts to initialize the
   // editor before grabbing the range, and because this is not an acceptable

content/html/content/src/nsTextEditorState.h

@@ -140,6 +140,8 @@ struct SelectionState;
  *     frame is bound to the text editor state object.
  */
 
+class RestoreSelectionState;
+
 class nsTextEditorState {
 public:
   explicit nsTextEditorState(nsITextControlElement* aOwningElement);
@@ -213,6 +215,8 @@ public:
   void HideSelectionIfBlurred();
 
 private:
+  friend class RestoreSelectionState;
+
   // not copy constructible
   nsTextEditorState(const nsTextEditorState&);
   // not assignable
@@ -225,6 +229,8 @@ private:
   void DestroyEditor();
   void Clear();
 
+  void FinishedRestoringSelection() { mRestoringSelection = nsnull; }
+
   class InitializationGuard {
   public:
     explicit InitializationGuard(nsTextEditorState& aState) :
@@ -253,6 +259,7 @@ private:
   nsITextControlElement* const mTextCtrlElement;
   nsRefPtr<nsTextInputSelectionImpl> mSelCon;
   nsAutoPtr<SelectionState> mSelState;
+  RestoreSelectionState* mRestoringSelection;
   nsCOMPtr<nsIEditor> mEditor;
   nsCOMPtr<nsIContent> mRootNode;
   nsCOMPtr<nsIContent> mPlaceholderDiv;

layout/forms/nsTextControlFrame.cpp

@@ -201,6 +201,12 @@ nsTextControlFrame::DestroyFrom(nsIFrame* aDestructRoot)
 {
   mScrollEvent.Revoke();
 
+  EditorInitializer* initializer = (EditorInitializer*) Properties().Get(TextControlInitializer());
+  if (initializer) {
+    initializer->Revoke();
+    Properties().Delete(TextControlInitializer());
+  }
+
   // Unbind the text editor state object from the frame.  The editor will live
   // on, but things like controllers will be released.
   nsCOMPtr<nsITextControlElement> txtCtrl = do_QueryInterface(GetContent());
@@ -445,10 +451,17 @@ nsTextControlFrame::CreateAnonymousContent(nsTArray<ContentInfo>& aElements)
   if (initEagerly) {
     NS_ASSERTION(!nsContentUtils::IsSafeToRunScript(),
                  "Someone forgot a script blocker?");
-
-    if (!nsContentUtils::AddScriptRunner(new EditorInitializer(this))) {
+    EditorInitializer* initializer = (EditorInitializer*) Properties().Get(TextControlInitializer());
+    if (initializer) {
+      initializer->Revoke();
+    }
+    initializer = new EditorInitializer(this);
+    if (!nsContentUtils::AddScriptRunner(initializer)) {
+      initializer->Revoke(); // paranoia
+      delete initializer;
       return NS_ERROR_OUT_OF_MEMORY;
     }
+    Properties().Set(TextControlInitializer(),initializer);
   }
 
   return NS_OK;

layout/forms/nsTextControlFrame.h

@@ -180,6 +180,11 @@ public:
 
   NS_DECL_QUERYFRAME
 
+  // Temp reference to scriptrunner
+  // We could make these auto-Revoking via the "delete" entry for safety
+  NS_DECLARE_FRAME_PROPERTY(TextControlInitializer, nsnull)
+
+
 public: //for methods who access nsTextControlFrame directly
   void FireOnInput(PRBool aTrusted);
   void SetValueChanged(PRBool aValueChanged);
@@ -286,23 +291,27 @@ protected:
   class EditorInitializer : public nsRunnable {
   public:
     EditorInitializer(nsTextControlFrame* aFrame) :
-      mWeakFrame(aFrame),
       mFrame(aFrame) {}
 
     NS_IMETHOD Run() {
-      if (mWeakFrame) {
+      if (mFrame) {
         nsCOMPtr<nsIPresShell> shell =
-          mWeakFrame.GetFrame()->PresContext()->GetPresShell();
+          mFrame->PresContext()->GetPresShell();
         PRBool observes = shell->ObservesNativeAnonMutationsForPrint();
         shell->ObserveNativeAnonMutationsForPrint(PR_TRUE);
         mFrame->EnsureEditorInitialized();
         shell->ObserveNativeAnonMutationsForPrint(observes);
+        mFrame->FinishedInitializer();
       }
       return NS_OK;
     }
 
+    // avoids use of nsWeakFrame
+    void Revoke() {
+      mFrame = nsnull;
+    }
+
   private:
-    nsWeakFrame mWeakFrame;
     nsTextControlFrame* mFrame;
   };
 
@@ -388,6 +397,10 @@ private:
    */
   nsresult GetRootNodeAndInitializeEditor(nsIDOMElement **aRootElement);
 
+  void FinishedInitializer() {
+    Properties().Delete(TextControlInitializer());
+  }
+
 private:
   // these packed bools could instead use the high order bits on mState, saving 4 bytes 
   PRPackedBool mUseEditor;