Changeset 196666 in webkit

Timestamp:

Feb 16, 2016 3:24:14 PM (8 years ago)

Author:

Simon Fraser

Message:

Every RenderLayer should not have to remove itself from the scrollableArea set
​https://bugs.webkit.org/show_bug.cgi?id=154311

Reviewed by Zalan Bujtas.

A subset of RenderLayers are are scrollable, and get registered on the FrameView,
but we pay the cost of a hash lookup for removal on every RenderLayer, which is a waste.

Store a bit that tells RenderLayer that it's in the set and needs to be removed.

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::RenderLayer):
(WebCore::RenderLayer::~RenderLayer):
(WebCore::RenderLayer::calculateClipRects):

• rendering/RenderLayer.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderLayer.cpp (modified) (3 diffs)
• rendering/RenderLayer.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2016-02-16  Simon Fraser  <simon.fraser@apple.com>
+
+        Every RenderLayer should not have to remove itself from the scrollableArea set
+        https://bugs.webkit.org/show_bug.cgi?id=154311
+
+        Reviewed by Zalan Bujtas.
+
+        A subset of RenderLayers are are scrollable, and get registered on the FrameView,
+        but we pay the cost of a hash lookup for removal on every RenderLayer, which is a waste.
+        
+        Store a bit that tells RenderLayer that it's in the set and needs to be removed.
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::RenderLayer):
+        (WebCore::RenderLayer::~RenderLayer):
+        (WebCore::RenderLayer::calculateClipRects):
+        * rendering/RenderLayer.h:
+
 2016-02-16  Daniel Bates  <dabates@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -281 +281 @@
     , m_visibleDescendantStatusDirty(false)
     , m_hasVisibleDescendant(false)
+    , m_registeredScrollableArea(false)
     , m_3DTransformedDescendantStatusDirty(true)
     , m_has3DTransformedDescendant(false)
@@ -346 +347 @@
         renderer().frame().eventHandler().resizeLayerDestroyed();
 
-    renderer().view().frameView().removeScrollableArea(this);
+    ASSERT(m_registeredScrollableArea == renderer().view().frameView().containsScrollableArea(this));
+
+    if (m_registeredScrollableArea)
+        renderer().view().frameView().removeScrollableArea(this);
 
     if (!renderer().documentBeingDestroyed()) {
@@ -6731 +6735 @@
     bool isScrollable = hasOverflow && isVisibleToHitTest;
     bool addedOrRemoved = false;
-    if (isScrollable)
-        addedOrRemoved = frameView.addScrollableArea(this);
-    else
+    
+    ASSERT(m_registeredScrollableArea == frameView.containsScrollableArea(this));
+    
+    if (isScrollable) {
+        if (!m_registeredScrollableArea) {
+            addedOrRemoved = frameView.addScrollableArea(this);
+            m_registeredScrollableArea = true;
+        }
+    } else if (m_registeredScrollableArea) {
         addedOrRemoved = frameView.removeScrollableArea(this);
+        m_registeredScrollableArea = false;
+    }
     
     if (addedOrRemoved)

trunk/Source/WebCore/rendering/RenderLayer.h

@@ -1039 +1039 @@
     bool m_visibleDescendantStatusDirty : 1;
     bool m_hasVisibleDescendant : 1;
+    bool m_registeredScrollableArea : 1;
 
     bool m_3DTransformedDescendantStatusDirty : 1;