Backout changeset 90ab708bab8b (bug 539356) because of performance and correctness regressions

layout/base/FrameLayerBuilder.cpp

@@ -89,7 +89,8 @@ public:
     mLayerBuilder(aLayerBuilder),
     mContainerFrame(aContainerFrame), mContainerLayer(aContainerLayer),
     mParameters(aParameters),
-    mNextFreeRecycledThebesLayer(0)
+    mNextFreeRecycledThebesLayer(0), mNextFreeRecycledColorLayer(0),
+    mNextFreeRecycledImageLayer(0)
   {
     nsPresContext* presContext = aContainerFrame->PresContext();
     mAppUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
@@ -298,12 +299,12 @@ protected:
    * Grab the next recyclable ColorLayer, or create one if there are no
    * more recyclable ColorLayers.
    */
-  already_AddRefed<ColorLayer> CreateOrRecycleColorLayer(ThebesLayer* aThebes);
+  already_AddRefed<ColorLayer> CreateOrRecycleColorLayer();
   /**
    * Grab the next recyclable ImageLayer, or create one if there are no
    * more recyclable ImageLayers.
    */
-  already_AddRefed<ImageLayer> CreateOrRecycleImageLayer(ThebesLayer* aThebes);
+  already_AddRefed<ImageLayer> CreateOrRecycleImageLayer();
   /**
    * Grab a recyclable ImageLayer for use as a mask layer for aLayer (that is a
    * mask layer which has been used for aLayer before), or create one if such
@@ -395,9 +396,13 @@ protected:
   typedef nsAutoTArray<nsRefPtr<Layer>,1> AutoLayersArray;
   AutoLayersArray                  mNewChildLayers;
   nsTArray<nsRefPtr<ThebesLayer> > mRecycledThebesLayers;
+  nsTArray<nsRefPtr<ColorLayer> >  mRecycledColorLayers;
+  nsTArray<nsRefPtr<ImageLayer> >  mRecycledImageLayers;
   nsDataHashtable<nsPtrHashKey<Layer>, nsRefPtr<ImageLayer> >
     mRecycledMaskImageLayers;
   PRUint32                         mNextFreeRecycledThebesLayer;
+  PRUint32                         mNextFreeRecycledColorLayer;
+  PRUint32                         mNextFreeRecycledImageLayer;
   nscoord                          mAppUnitsPerDevPixel;
   bool                             mSnappingEnabled;
 };
@@ -433,9 +438,6 @@ public:
   gfxPoint mActiveScrolledRootPosition;
 
   nsIntRegion mRegionToInvalidate;
-
-  nsRefPtr<ColorLayer> mColorLayer;
-  nsRefPtr<ImageLayer> mImageLayer;
 };
 
 /*
@@ -950,12 +952,15 @@ FrameLayerBuilder::GetInactiveLayerManagerFor(nsDisplayItem* aItem)
 }
 
 already_AddRefed<ColorLayer>
-ContainerState::CreateOrRecycleColorLayer(ThebesLayer *aThebes)
+ContainerState::CreateOrRecycleColorLayer()
 {
-  ThebesDisplayItemLayerUserData* data = 
-      static_cast<ThebesDisplayItemLayerUserData*>(aThebes->GetUserData(&gThebesDisplayItemLayerUserData));
-  nsRefPtr<ColorLayer> layer = data->mColorLayer;
-  if (layer) {
+  nsRefPtr<ColorLayer> layer;
+  if (mNextFreeRecycledColorLayer < mRecycledColorLayers.Length()) {
+    // Recycle a layer
+    layer = mRecycledColorLayers[mNextFreeRecycledColorLayer];
+    ++mNextFreeRecycledColorLayer;
+    // Clear clip rect and mask layer so we don't accidentally stay clipped.
+    // We will reapply any necessary clipping.
     layer->SetClipRect(nsnull);
     layer->SetMaskLayer(nsnull);
   } else {
@@ -964,22 +969,21 @@ ContainerState::CreateOrRecycleColorLayer(ThebesLayer *aThebes)
     if (!layer)
       return nsnull;
     // Mark this layer as being used for Thebes-painting display items
-    data->mColorLayer = layer;
     layer->SetUserData(&gColorLayerUserData, nsnull);
-    
-    // Remove other layer types we might have stored for this ThebesLayer
-    data->mImageLayer = nsnull;
   }
   return layer.forget();
 }
 
 already_AddRefed<ImageLayer>
-ContainerState::CreateOrRecycleImageLayer(ThebesLayer *aThebes)
+ContainerState::CreateOrRecycleImageLayer()
 {
-  ThebesDisplayItemLayerUserData* data = 
-      static_cast<ThebesDisplayItemLayerUserData*>(aThebes->GetUserData(&gThebesDisplayItemLayerUserData));
-  nsRefPtr<ImageLayer> layer = data->mImageLayer;
-  if (layer) {
+  nsRefPtr<ImageLayer> layer;
+  if (mNextFreeRecycledImageLayer < mRecycledImageLayers.Length()) {
+    // Recycle a layer
+    layer = mRecycledImageLayers[mNextFreeRecycledImageLayer];
+    ++mNextFreeRecycledImageLayer;
+    // Clear clip rect and mask layer so we don't accidentally stay clipped.
+    // We will reapply any necessary clipping.
     layer->SetClipRect(nsnull);
     layer->SetMaskLayer(nsnull);
   } else {
@@ -988,11 +992,7 @@ ContainerState::CreateOrRecycleImageLayer(ThebesLayer *aThebes)
     if (!layer)
       return nsnull;
     // Mark this layer as being used for Thebes-painting display items
-    data->mImageLayer = layer;
     layer->SetUserData(&gImageLayerUserData, nsnull);
-
-    // Remove other layer types we might have stored for this ThebesLayer
-    data->mColorLayer = nsnull;
   }
   return layer.forget();
 }
@@ -1315,7 +1315,7 @@ ContainerState::PopThebesLayerData()
     NS_ASSERTION(!(data->mIsSolidColorInVisibleRegion && imageContainer),
                  "Can't be a solid color as well as an image!");
     if (imageContainer) {
-      nsRefPtr<ImageLayer> imageLayer = CreateOrRecycleImageLayer(data->mLayer);
+      nsRefPtr<ImageLayer> imageLayer = CreateOrRecycleImageLayer();
       imageLayer->SetContainer(imageContainer);
       data->mImage->ConfigureLayer(imageLayer);
       // The layer's current transform is applied first, then the result is scaled.
@@ -1328,7 +1328,7 @@ ContainerState::PopThebesLayerData()
       }
       layer = imageLayer;
     } else {
-      nsRefPtr<ColorLayer> colorLayer = CreateOrRecycleColorLayer(data->mLayer);
+      nsRefPtr<ColorLayer> colorLayer = CreateOrRecycleColorLayer();
       colorLayer->SetIsFixedPosition(data->mLayer->GetIsFixedPosition());
       colorLayer->SetColor(data->mSolidColor);
 
@@ -2179,7 +2179,11 @@ ContainerState::CollectOldLayers()
        layer = layer->GetNextSibling()) {
     NS_ASSERTION(!layer->HasUserData(&gMaskLayerUserData),
                  "Mask layer in layer tree; could not be recycled.");
-    if (layer->HasUserData(&gThebesDisplayItemLayerUserData)) {
+    if (layer->HasUserData(&gColorLayerUserData)) {
+      mRecycledColorLayers.AppendElement(static_cast<ColorLayer*>(layer));
+    } else if (layer->HasUserData(&gImageLayerUserData)) {
+      mRecycledImageLayers.AppendElement(static_cast<ImageLayer*>(layer));
+    } else if (layer->HasUserData(&gThebesDisplayItemLayerUserData)) {
       NS_ASSERTION(layer->AsThebesLayer(), "Wrong layer type");
       mRecycledThebesLayers.AppendElement(static_cast<ThebesLayer*>(layer));
     }