Bug 1055821 - Add layer construction logging. r=mattwoodrow

--HG--
extra : rebase_source : 318ea4b96780830fd5665fc0b0cd610b67392113

gfx/layers/Layers.cpp

@@ -1320,6 +1320,13 @@ Layer::Dump(std::stringstream& aStream, const char* aPrefix, bool aDumpHtml)
     mask->Dump(aStream, pfx.get(), aDumpHtml);
   }
 
+#ifdef MOZ_DUMP_PAINTING
+  for (size_t i = 0; i < mExtraDumpInfo.Length(); i++) {
+    const nsCString& str = mExtraDumpInfo[i];
+    aStream << aPrefix << "  Info:\n" << str.get();
+  }
+#endif
+
   if (Layer* kid = GetFirstChild()) {
     nsAutoCString pfx(aPrefix);
     pfx += "  ";

gfx/layers/Layers.h

@@ -1504,6 +1504,26 @@ public:
 
   RenderTargetRect TransformRectToRenderTarget(const LayerIntRect& aRect);
 
+  /**
+   * Add debugging information to the layer dump.
+   */
+  void AddExtraDumpInfo(const nsACString& aStr)
+  {
+#ifdef MOZ_DUMP_PAINTING
+    mExtraDumpInfo.AppendElement(aStr);
+#endif
+  }
+
+  /**
+   * Clear debugging information. Useful for recycling.
+   */
+  void ClearExtraDumpInfo()
+  {
+#ifdef MOZ_DUMP_PAINTING
+     mExtraDumpInfo.Clear();
+#endif
+  }
+
 protected:
   Layer(LayerManager* aManager, void* aImplData);
 
@@ -1606,6 +1626,9 @@ protected:
   // This is empty unless this is a scrollable ContainerLayer and the
   // apz.printtree pref is turned on.
   std::string mContentDescription;
+#ifdef MOZ_DUMP_PAINTING
+  nsTArray<nsCString> mExtraDumpInfo;
+#endif
 };
 
 /**

layout/base/FrameLayerBuilder.cpp

@@ -370,6 +370,20 @@ public:
     return mFixedPosFrameForLayerData != nullptr;
   }
 
+#ifdef MOZ_DUMP_PAINTING
+
+  /**
+   * Keep track of important decisions for debugging.
+   */
+  nsAutoCString mLog;
+
+  #define FLB_LOG_THEBES_DECISION(tld, ...) \
+          tld->mLog.AppendPrintf("\t\t\t\t"); \
+          tld->mLog.AppendPrintf(__VA_ARGS__);
+#else
+  #define FLB_LOG_THEBES_DECISION(...)
+#endif
+
   /**
    * The region of visible content in the layer, relative to the
    * container layer (which is at the snapped top-left of the display
@@ -501,6 +515,7 @@ private:
    * as infinite, and all display items should be considered 'above' this layer.
    */
   bool mAllDrawingAbove;
+
 };
 
 struct NewLayerEntry {
@@ -1455,6 +1470,7 @@ ContainerState::CreateOrRecycleColorLayer(ThebesLayer *aThebes)
   nsRefPtr<ColorLayer> layer = data->mColorLayer;
   if (layer) {
     layer->SetMaskLayer(nullptr);
+    layer->ClearExtraDumpInfo();
   } else {
     // Create a new layer
     layer = mManager->CreateColorLayer();
@@ -1478,6 +1494,7 @@ ContainerState::CreateOrRecycleImageLayer(ThebesLayer *aThebes)
   nsRefPtr<ImageLayer> layer = data->mImageLayer;
   if (layer) {
     layer->SetMaskLayer(nullptr);
+    layer->ClearExtraDumpInfo();
   } else {
     // Create a new layer
     layer = mManager->CreateImageLayer();
@@ -1499,6 +1516,7 @@ ContainerState::CreateOrRecycleMaskImageLayerFor(Layer* aLayer)
   nsRefPtr<ImageLayer> result = mRecycledMaskImageLayers.Get(aLayer);
   if (result) {
     mRecycledMaskImageLayers.Remove(aLayer);
+    aLayer->ClearExtraDumpInfo();
     // XXX if we use clip on mask layers, null it out here
   } else {
     // Create a new layer
@@ -1601,6 +1619,7 @@ ContainerState::CreateOrRecycleThebesLayer(const nsIFrame* aAnimatedGeometryRoot
       // Clear clip rect and mask layer so we don't accidentally stay clipped.
       // We will reapply any necessary clipping.
       layer->SetMaskLayer(nullptr);
+      layer->ClearExtraDumpInfo();
 
       data = static_cast<ThebesDisplayItemLayerUserData*>
           (layer->GetUserData(&gThebesDisplayItemLayerUserData));
@@ -2049,6 +2068,12 @@ ContainerState::PopThebesLayerData()
   NewLayerEntry* newLayerEntry = &mNewChildLayers[data->mNewChildLayersIndex];
   nsRefPtr<Layer> layer;
   nsRefPtr<ImageContainer> imageContainer = data->CanOptimizeImageLayer(mBuilder);
+
+  FLB_LOG_THEBES_DECISION(data, "Selecting layer for tld=%p\n", data);
+  FLB_LOG_THEBES_DECISION(data, "  Solid=%i, hasImage=%i, canOptimizeAwayThebes=%i\n",
+          data->mIsSolidColorInVisibleRegion, !!imageContainer,
+          CanOptimizeAwayThebesLayer(data, mLayerBuilder));
+
   if ((data->mIsSolidColorInVisibleRegion || imageContainer) &&
       CanOptimizeAwayThebesLayer(data, mLayerBuilder)) {
     NS_ASSERTION(!(data->mIsSolidColorInVisibleRegion && imageContainer),
@@ -2069,6 +2094,7 @@ ContainerState::PopThebesLayerData()
       layer = imageLayer;
       mLayerBuilder->StoreOptimizedLayerForFrame(data->mImage,
                                                  imageLayer);
+      FLB_LOG_THEBES_DECISION(data, "  Selected image layer=%p\n", layer.get());
     } else {
       nsRefPtr<ColorLayer> colorLayer = CreateOrRecycleColorLayer(data->mLayer);
       colorLayer->SetColor(data->mSolidColor);
@@ -2082,6 +2108,7 @@ ContainerState::PopThebesLayerData()
       colorLayer->SetBounds(visibleRect);
 
       layer = colorLayer;
+      FLB_LOG_THEBES_DECISION(data, "  Selected color layer=%p\n", layer.get());
     }
 
     NS_ASSERTION(FindIndexOfLayerIn(mNewChildLayers, layer) < 0,
@@ -2106,6 +2133,7 @@ ContainerState::PopThebesLayerData()
     layer = data->mLayer;
     imageContainer = nullptr;
     layer->SetClipRect(nullptr);
+    FLB_LOG_THEBES_DECISION(data, "  Selected thebes layer=%p\n", layer.get());
   }
 
   if (mLayerBuilder->IsBuildingRetainedLayers()) {
@@ -2122,6 +2150,10 @@ ContainerState::PopThebesLayerData()
     SetOuterVisibleRegionForLayer(layer, data->mVisibleRegion);
   }
 
+#ifdef MOZ_DUMP_PAINTING
+  layer->AddExtraDumpInfo(nsCString(data->mLog));
+#endif
+
   nsIntRegion transparentRegion;
   transparentRegion.Sub(data->mVisibleRegion, data->mOpaqueRegion);
   bool isOpaque = transparentRegion.IsEmpty();
@@ -2276,6 +2308,8 @@ ThebesLayerData::Accumulate(ContainerState* aState,
                             const nsIntRect& aDrawRect,
                             const DisplayItemClip& aClip)
 {
+  FLB_LOG_THEBES_DECISION(this, "Accumulating dp=%s(%p), f=%p against tld=%p\n", aItem->Name(), aItem, aItem->Frame(), this);
+
   if (aState->mBuilder->NeedToForceTransparentSurfaceForItem(aItem)) {
     mForceTransparentSurface = true;
   }
@@ -2292,7 +2326,9 @@ ThebesLayerData::Accumulate(ContainerState* aState,
   if (mVisibleRegion.IsEmpty() &&
       aItem->SupportsOptimizingToImage()) {
     mImage = static_cast<nsDisplayImageContainer*>(aItem);
-  } else {
+    FLB_LOG_THEBES_DECISION(this, "  Tracking image\n");
+  } else if (mImage) {
+    FLB_LOG_THEBES_DECISION(this, "  No longer tracking image\n");
     mImage = nullptr;
   }
   bool clipMatches = mItemClip == aClip;
@@ -2327,6 +2363,7 @@ ThebesLayerData::Accumulate(ContainerState* aState,
       nsRect bounds = aItem->GetBounds(aState->mBuilder, &snap);
       if (!aState->ScaleToInsidePixels(bounds, snap).Contains(aVisibleRect)) {
         isUniform = false;
+        FLB_LOG_THEBES_DECISION(this, "  Display item does not cover the visible rect\n");
       }
     }
     if (isUniform) {
@@ -2340,9 +2377,11 @@ ThebesLayerData::Accumulate(ContainerState* aState,
         // we can just blend the colors together
         mSolidColor = NS_ComposeColors(mSolidColor, uniformColor);
       } else {
+        FLB_LOG_THEBES_DECISION(this, "  Layer not a solid color: Can't blend colors togethers\n");
         mIsSolidColorInVisibleRegion = false;
       }
     } else {
+      FLB_LOG_THEBES_DECISION(this, "  Layer is not a solid color: Display item is not uniform over the visible bound\n");
       mIsSolidColorInVisibleRegion = false;
     }