Schedule image resource downloads by decreasing visual impact - Blink Side

Source/core/fetch/ResourceLoadPriorityOptimizer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 ResourceLoadPriorityOptimizer* ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()
 {
     DEFINE_STATIC_LOCAL(ResourceLoadPriorityOptimizer, s_renderLoadOptimizer, ());
     return &s_renderLoadOptimizer;
 }
 
-ResourceLoadPriorityOptimizer::ResourceAndVisibility::ResourceAndVisibility(ImageResource* image, VisibilityStatus v)
+ResourceLoadPriorityOptimizer::ResourceAndVisibility::ResourceAndVisibility(ImageResource* image, VisibilityStatus v, uint32_t s)
     : imageResource(image)
     , status(v)
+    , screenArea(s)
 {
 }
 
 ResourceLoadPriorityOptimizer::ResourceAndVisibility::~ResourceAndVisibility()
 {
 }
 
 ResourceLoadPriorityOptimizer::ResourceLoadPriorityOptimizer()
 {
 }
@@ skipping 34 matching lines @@
     updateImageResourcesWithLoadPriority();
 }
 
 void ResourceLoadPriorityOptimizer::updateImageResourcesWithLoadPriority()
 {
     for (ImageResourceMap::iterator it = m_imageResources.begin(); it != m_imageResources.end(); ++it) {
         ResourceLoadPriority priority = it->value->status == Visible ?
             ResourceLoadPriorityLow : ResourceLoadPriorityVeryLow;
 
         if (priority != it->value->imageResource->resourceRequest().priority()) {
-            it->value->imageResource->resourceRequest().setPriority(priority);
-            it->value->imageResource->didChangePriority(priority);
+            it->value->imageResource->resourceRequest().setPriority(priority, it->value->screenArea);
+            it->value->imageResource->didChangePriority(priority, it->value->screenArea);
         }
     }
     m_imageResources.clear();
 }
 
-void ResourceLoadPriorityOptimizer::notifyImageResourceVisibility(ImageResource* img, VisibilityStatus status)
+void ResourceLoadPriorityOptimizer::notifyImageResourceVisibility(ImageResource* img, VisibilityStatus status, const LayoutRect& screenRect)
 {
     if (!img || img->isLoaded())
         return;
 
-    ImageResourceMap::AddResult result = m_imageResources.add(img->identifier(), adoptPtr(new ResourceAndVisibility(img, status)));
-    if (!result.isNewEntry && status == Visible)
+    int screenArea = 0;
+    if (!screenRect.isEmpty() && status == Visible)
+        screenArea += static_cast<uint32_t>(screenRect.width() * screenRect.height());
+
+    ImageResourceMap::AddResult result = m_imageResources.add(img->identifier(), adoptPtr(new ResourceAndVisibility(img, status, screenArea)));
+    if (!result.isNewEntry && status == Visible) {
         result.iterator->value->status = status;
+        result.iterator->value->screenArea = status;
+    }
 }
 
 }