Implement a Hit Test Cache.

Source/core/layout/HitTestResult.cpp

 /*
  * Copyright (C) 2006, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 83 matching lines @@
 }
 
 HitTestResult::~HitTestResult()
 {
 }
 
 HitTestResult& HitTestResult::operator=(const HitTestResult& other)
 {
     m_hitTestLocation = other.m_hitTestLocation;
     m_hitTestRequest = other.m_hitTestRequest;
+    populateFromCachedResult(other);
+
+    return *this;
+}
+
+bool HitTestResult::equalForCacheability(const HitTestResult& other) const
+{
+    return m_hitTestRequest.equalForCacheability(other.m_hitTestRequest)
+        && m_innerNode == other.innerNode()
+        && m_innerPossiblyPseudoNode == other.innerPossiblyPseudoNode()
+        && m_pointInInnerNodeFrame == other.m_pointInInnerNodeFrame
+        && m_localPoint == other.localPoint()
+        && m_innerURLElement == other.URLElement()
+        && m_scrollbar == other.scrollbar()
+        && m_isOverWidget == other.isOverWidget();
+}
+
+void HitTestResult::cacheValues(const HitTestResult& other)
+{
+    *this = other;
+    m_hitTestRequest = other.m_hitTestRequest.type() & ~HitTestRequest::AvoidCache;
+}
+
+void HitTestResult::populateFromCachedResult(const HitTestResult& other)
+{
     m_innerNode = other.innerNode();
     m_innerPossiblyPseudoNode = other.innerPossiblyPseudoNode();
     m_pointInInnerNodeFrame = other.m_pointInInnerNodeFrame;
     m_localPoint = other.localPoint();
     m_innerURLElement = other.URLElement();
     m_scrollbar = other.scrollbar();
     m_isOverWidget = other.isOverWidget();
+    m_validityRect = other.m_validityRect;
 
     // Only copy the NodeSet in case of list hit test.
     m_listBasedTestResult = adoptPtrWillBeNoop(other.m_listBasedTestResult ? new NodeSet(*other.m_listBasedTestResult) : 0);
-
-    return *this;
 }
 
 DEFINE_TRACE(HitTestResult)
 {
     visitor->trace(m_innerNode);
     visitor->trace(m_innerPossiblyPseudoNode);
     visitor->trace(m_innerURLElement);
     visitor->trace(m_scrollbar);
 #if ENABLE(OILPAN)
     visitor->trace(m_listBasedTestResult);
@@ skipping 86 matching lines @@
 bool HitTestResult::isSelected() const
 {
     if (!m_innerNode)
         return false;
 
     if (LocalFrame* frame = m_innerNode->document().frame())
         return frame->selection().contains(m_hitTestLocation.point());
     return false;
 }
 
+void HitTestResult::setValidityRect(const LayoutRect& rect)
+{
+    ASSERT(!rect.isEmpty());
+    m_validityRect = rect;
+}
+
 String HitTestResult::spellingToolTip(TextDirection& dir) const
 {
     dir = LTR;
     // Return the tool tip string associated with this point, if any. Only markers associated with bad grammar
     // currently supply strings, but maybe someday markers associated with misspelled words will also.
     if (!m_innerNode)
         return String();
 
     DocumentMarker* marker = m_innerNode->document().markers().markerContainingPoint(m_hitTestLocation.point(), DocumentMarker::Grammar);
     if (!marker)
@@ skipping 279 matching lines @@
     else if (isHTMLMapElement(m_innerNode))
         imageMapImageElement = toHTMLMapElement(m_innerNode)->imageElement();
 
     if (!imageMapImageElement)
         return m_innerNode.get();
 
     return imageMapImageElement;
 }
 
 } // namespace blink