Raise the loading priority of in-viewport images.

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 14 matching lines @@
 #include "core/rendering/RenderBlock.h"
 
 #include "HTMLNames.h"
 #include "core/accessibility/AXObjectCache.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/events/OverflowEvent.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
+#include "core/fetch/ResourceLoadPriorityOptimizer.h"
 #include "core/frame/Frame.h"
 #include "core/frame/FrameView.h"
 #include "core/page/Page.h"
 #include "core/page/Settings.h"
 #include "core/rendering/FastTextAutosizer.h"
 #include "core/rendering/GraphicsContextAnnotator.h"
 #include "core/rendering/HitTestLocation.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/InlineIterator.h"
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/LayoutRepainter.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderCombineText.h"
 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
 #include "core/rendering/RenderFlexibleBox.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderMarquee.h"
 #include "core/rendering/RenderNamedFlowThread.h"
 #include "core/rendering/RenderRegion.h"
 #include "core/rendering/RenderTableCell.h"
 #include "core/rendering/RenderTextFragment.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/shapes/ShapeOutsideInfo.h"
+#include "core/rendering/style/ContentData.h"
+#include "core/rendering/style/RenderStyle.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/TemporaryChange.h"
 
 using namespace std;
 using namespace WTF;
 using namespace Unicode;
 
@@ skipping 1174 matching lines @@
         return;
 
     // It's safe to check for control clip here, since controls can never be table cells.
     // If we have a lightweight clip, there can never be any overflow from children.
     if (hasControlClip() && m_overflow)
         clearLayoutOverflow();
 
     invalidateBackgroundObscurationStatus();
 }
 
+void RenderBlock::didLayout(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderBox::didLayout(optimizer);
+    updateStyleImageLoadingPriorities(optimizer);
+}
+
+void RenderBlock::didScroll(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderBox::didScroll(optimizer);
+    updateStyleImageLoadingPriorities(optimizer);
+}
+
+void RenderBlock::updateStyleImageLoadingPriorities(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderStyle* blockStyle = style();
+    if (!blockStyle)
+        return;
+
+    Vector<ImageResource*> images;

[shatch, 2013/12/07 03:16:15]

Reorganized this function to grab the images out of the style first, and if
there are none then early exit to avoid having to compute the RenderObject's
bounds and grabbing the view rect. This brought the float tests back to normal.

+
+    for (const FillLayer* layer = blockStyle->backgroundLayers(); layer; layer = layer->next()) {

[shatch, 2013/12/07 03:16:15]

Swapped the ::access<func> for these (::backgroundLayers() and ::maskLayers())
since the access functions can potentially do copies. This brought the ShadowDom
perf test back to normal.

+        if (layer->image()) {
+            ImageResource* img = layer->image()->cachedImage();
+            if (img) {
+                images.append(img);
+            }
+        }
+    }
+    for (const FillLayer* layer = blockStyle->maskLayers(); layer; layer = layer->next()) {
+        if (layer->image()) {
+            ImageResource* imageResource = layer->image()->cachedImage();
+            if (imageResource) {
+                images.append(imageResource);
+            }
+        }
+    }
+    ContentData* contentData = const_cast<ContentData*>(blockStyle->contentData());
+    if (contentData && contentData->isImage()) {
+        ImageContentData* imageContentData = static_cast<ImageContentData*>(contentData);
+        if (imageContentData->image() && imageContentData->image()->cachedImage())
+            images.append(imageContentData->image()->cachedImage());
+    }
+    if (blockStyle->boxReflect()) {
+        if (blockStyle->boxReflect()->mask().image()) {
+            if (blockStyle->boxReflect()->mask().image()->cachedImage()) {
+                images.append(blockStyle->boxReflect()->mask().image()->cachedImage());
+            }
+        }
+    }
+    if (blockStyle->listStyleImage() && blockStyle->listStyleImage()->cachedImage())
+        images.append(blockStyle->listStyleImage()->cachedImage());
+    if (blockStyle->borderImageSource() && blockStyle->borderImageSource()->cachedImage())
+        images.append(blockStyle->borderImageSource()->cachedImage());
+    if (blockStyle->maskBoxImageSource() && blockStyle->maskBoxImageSource()->cachedImage())
+        images.append(blockStyle->maskBoxImageSource()->cachedImage());
+
+    if (images.isEmpty())
+        return;
+
+    const LayoutRect& viewBounds = viewRect();
+    LayoutRect objectBounds = absoluteContentBox();
+    // The object bounds might be empty right now, so intersects will fail since it doesn't deal
+    // with empty rects. Use LayoutRect::contains in that case.
+    bool isVisible;
+    if (!objectBounds.isEmpty())
+        isVisible =  viewBounds.intersects(objectBounds);
+    else
+        isVisible = viewBounds.contains(objectBounds);
+
+    ResourceLoadPriorityOptimizer::VisibilityStatus status = isVisible ?
+        ResourceLoadPriorityOptimizer::Visible : ResourceLoadPriorityOptimizer::NotVisible;
+
+    for (Vector<ImageResource*>::iterator it = images.begin(), end = images.end(); it != end; ++it)
+        optimizer.notifyImageResourceVisibility(*it, status);
+}
+
 void RenderBlock::relayoutShapeDescendantIfMoved(RenderBlock* child, LayoutSize offset)
 {
     LayoutUnit left = isHorizontalWritingMode() ? offset.width() : offset.height();
     if (!left || !child || child->shapeInsideInfo() || !layoutShapeInsideInfo())
         return;
     // Propagate layout markers only up to the child, as we are still in the middle
     // of a layout pass
     child->setNormalChildNeedsLayout(true);
     child->markShapeInsideDescendantsForLayout();
     child->layoutIfNeeded();
@@ skipping 4469 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace WebCore