third_party/WebKit/Source/core/fetch/ResourceLoadPriorityOptimizer.h

   1 /*
   2  * Copyright (C) 2013 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef ResourceLoadPriorityOptimizer_h
  32 #define ResourceLoadPriorityOptimizer_h
  33
  34 #include "core/fetch/ImageResource.h"
  35 #include "core/fetch/ResourcePtr.h"
  36 #include "platform/geometry/LayoutRect.h"
  37
  38 #include "wtf/HashMap.h"
  39 #include "wtf/HashSet.h"
  40 #include "wtf/OwnPtr.h"
  41
  42 namespace blink {
  43
  44 class ResourceLoadPriorityOptimizer {
  45     WTF_MAKE_FAST_ALLOCATED(ResourceLoadPriorityOptimizer);
  46     WTF_MAKE_NONCOPYABLE(ResourceLoadPriorityOptimizer);
  47 public:
  48     enum VisibilityStatus {
  49         NotVisible,
  50         Visible,
  51     };
  52     void notifyImageResourceVisibility(ImageResource*, VisibilityStatus, const LayoutRect&);
  53     void updateAllImageResourcePriorities();
  54     void addLayoutObject(LayoutObject*);
  55     void removeLayoutObject(LayoutObject*);
  56
  57     static ResourceLoadPriorityOptimizer* resourceLoadPriorityOptimizer();
  58
  59 private:
  60     ResourceLoadPriorityOptimizer();
  61     ~ResourceLoadPriorityOptimizer();
  62
  63     void updateImageResourcesWithLoadPriority();
  64
  65     struct ResourceAndVisibility {
  66         ResourceAndVisibility(ImageResource*, VisibilityStatus, uint32_t);
  67         ~ResourceAndVisibility();
  68         ResourcePtr<ImageResource> imageResource;
  69         VisibilityStatus status;
  70         int screenArea;
  71     };
  72
  73     typedef HashMap<unsigned long, OwnPtr<ResourceAndVisibility>, WTF::IntHash<unsigned>, WTF::UnsignedWithZeroKeyHashTraits<unsigned>> ImageResourceMap;
  74     ImageResourceMap m_imageResources;
  75
  76     typedef HashSet<LayoutObject*> LayoutObjectSet;
  77     LayoutObjectSet m_objects;
  78 };
  79
  80 }
  81
  82 #endif