Refactor ResourceLoadPriorityOptimizer to avoid walking render tree

Source/core/rendering/RenderBlock.cpp

Index: Source/core/rendering/RenderBlock.cpp
diff --git a/Source/core/rendering/RenderBlock.cpp b/Source/core/rendering/RenderBlock.cpp
index 38838c1289af1a2f928bb616ffd4224e5833b54c..bb6a4328893c4daac90fbf1c08a14fd7f119b646 100644
--- a/Source/core/rendering/RenderBlock.cpp
+++ b/Source/core/rendering/RenderBlock.cpp
@@ -182,8 +182,11 @@ static void removeBlockFromDescendantAndContainerMaps(RenderBlock* block, Tracke
 
 static void appendImageIfNotNull(Vector<ImageResource*>& imageResources, const StyleImage* styleImage)
 {
-    if (styleImage && styleImage->cachedImage())
-        imageResources.append(styleImage->cachedImage());
+    if (styleImage && styleImage->cachedImage()) {
+        ImageResource* imageResource = styleImage->cachedImage();
+        if (imageResource && !imageResource->isLoaded())
+            imageResources.append(styleImage->cachedImage());
+    }
 }
 
 static void appendLayers(Vector<ImageResource*>& images, const FillLayer* styleLayer)
@@ -193,8 +196,26 @@ static void appendLayers(Vector<ImageResource*>& images, const FillLayer* styleL
     }
 }
 
+static void appendImagesFromStyle(Vector<ImageResource*>& images, RenderStyle* blockStyle)

[esprehn, 2014/01/15 01:27:45]

RenerStyle& blockStyle

[shatch, 2014/01/15 19:28:52]

Done.

+{
+    appendLayers(images, blockStyle->backgroundLayers());
+    appendLayers(images, blockStyle->maskLayers());
+
+    const ContentData* contentData = blockStyle->contentData();
+    if (contentData && contentData->isImage()) {
+        const ImageContentData* imageContentData = static_cast<const ImageContentData*>(contentData);
+        appendImageIfNotNull(images, imageContentData->image());
+    }
+    if (blockStyle->boxReflect())
+        appendImageIfNotNull(images, blockStyle->boxReflect()->mask().image());
+    appendImageIfNotNull(images, blockStyle->listStyleImage());
+    appendImageIfNotNull(images, blockStyle->borderImageSource());
+    appendImageIfNotNull(images, blockStyle->maskBoxImageSource());
+}
+
 RenderBlock::~RenderBlock()
 {
+    resourceLoadPriorityOptimizer()->removeRenderObject(this);
     if (hasColumns())
         gColumnInfoMap->take(this);
     if (gPercentHeightDescendantsMap)
@@ -326,6 +347,15 @@ void RenderBlock::styleDidChange(StyleDifference diff, const RenderStyle* oldSty
     // It's possible for our border/padding to change, but for the overall logical width of the block to
     // end up being the same. We keep track of this change so in layoutBlock, we can know to set relayoutChildren=true.
     m_hasBorderOrPaddingLogicalWidthChanged = oldStyle && diff == StyleDifferenceLayout && needsLayout() && borderOrPaddingLogicalWidthChanged(oldStyle, newStyle);
+
+    // If the style has unloaded images, want to notify the ResourceLoadPriorityOptimizer so that
+    // network priorities can be set.
+    Vector<ImageResource*> images;
+    appendImagesFromStyle(images, newStyle);
+    if (images.isEmpty())
+        resourceLoadPriorityOptimizer()->removeRenderObject(this);

[esprehn, 2014/01/15 01:27:45]

This isn't good, you're going to hit the hash table in the remove() call all the
time, usually we use a bit to avoid this. I'd add a bit for tracking if this
renderer is actually in that hash table.

addRenderObject does renderer->setHasPendingResourceUpdate() or something like
that.
removeRenderObject does:
if (!renderer->hasPendingResourceUpdate())
  return;
m_objects.remove(renderer);
renderer->setHasPendingResourcesUpdate(false);

[shatch, 2014/01/15 19:28:52]

Done.

+    else
+        resourceLoadPriorityOptimizer()->addRenderObject(this);
 }
 
 RenderBlock* RenderBlock::continuationBefore(RenderObject* beforeChild)
@@ -1266,42 +1296,13 @@ void RenderBlock::layout()
     invalidateBackgroundObscurationStatus();
 }
 
-void RenderBlock::didLayout(ResourceLoadPriorityOptimizer& optimizer)
-{
-    RenderBox::didLayout(optimizer);
-    updateStyleImageLoadingPriorities(optimizer);
-}
-
-void RenderBlock::didScroll(ResourceLoadPriorityOptimizer& optimizer)
+bool RenderBlock::updateImageLoadingPriorities()
 {
-    RenderBox::didScroll(optimizer);
-    updateStyleImageLoadingPriorities(optimizer);
-}
-
-void RenderBlock::updateStyleImageLoadingPriorities(ResourceLoadPriorityOptimizer& optimizer)
-{
-    RenderStyle* blockStyle = style();
-    if (!blockStyle)
-        return;
-
     Vector<ImageResource*> images;
-
-    appendLayers(images, blockStyle->backgroundLayers());
-    appendLayers(images, blockStyle->maskLayers());
-
-    const ContentData* contentData = blockStyle->contentData();
-    if (contentData && contentData->isImage()) {
-        const ImageContentData* imageContentData = static_cast<const ImageContentData*>(contentData);
-        appendImageIfNotNull(images, imageContentData->image());
-    }
-    if (blockStyle->boxReflect())
-        appendImageIfNotNull(images, blockStyle->boxReflect()->mask().image());
-    appendImageIfNotNull(images, blockStyle->listStyleImage());
-    appendImageIfNotNull(images, blockStyle->borderImageSource());
-    appendImageIfNotNull(images, blockStyle->maskBoxImageSource());
+    appendImagesFromStyle(images, style());
 
     if (images.isEmpty())
-        return;
+        return false;
 
     LayoutRect viewBounds = viewRect();
     LayoutRect objectBounds = absoluteContentBox();
@@ -1317,7 +1318,9 @@ void RenderBlock::updateStyleImageLoadingPriorities(ResourceLoadPriorityOptimize
         ResourceLoadPriorityOptimizer::Visible : ResourceLoadPriorityOptimizer::NotVisible;
 
     for (Vector<ImageResource*>::iterator it = images.begin(), end = images.end(); it != end; ++it)
-        optimizer.notifyImageResourceVisibility(*it, status);
+        resourceLoadPriorityOptimizer()->notifyImageResourceVisibility(*it, status);
+
+    return true;
 }
 
 void RenderBlock::relayoutShapeDescendantIfMoved(RenderBlock* child, LayoutSize offset)