Changeset 283354 in webkit

Timestamp:

Sep 30, 2021, 6:23:14 PM (5 years ago)

Author:

cathiechen

Message:

[Performance] Optimize RenderLayer::clipCrossesPaintingBoundary
​https://bugs.webkit.org/show_bug.cgi?id=230885

Reviewed by Simon Fraser.

In RenderLayer::clipCrossesPaintingBoundary, to check if the layer and its parent layer are in the same
compositing layer, it calls enclosingCompositingLayerForRepaint() twice, which need to travel up the layer tree.
This patch adds RenderLayer::sharesCompositingLayerForRepaint, to check the repaintTargetForLayer and paintOrderParents.

• rendering/RenderLayer.cpp:

(WebCore::repaintTargetForLayer):
(WebCore::RenderLayer::enclosingCompositingLayerForRepaint const):
(WebCore::RenderLayer::sharesCompositingLayerForRepaint const):
(WebCore::RenderLayer::clipCrossesPaintingBoundary const):

• 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 @@
+2021-09-30  Cathie Chen  <cathiechen@igalia.com>
+
+        [Performance] Optimize RenderLayer::clipCrossesPaintingBoundary
+        https://bugs.webkit.org/show_bug.cgi?id=230885
+
+        Reviewed by Simon Fraser.
+
+        In RenderLayer::clipCrossesPaintingBoundary, to check if the layer and its parent layer are in the same
+        compositing layer, it calls enclosingCompositingLayerForRepaint() twice, which need to travel up the layer tree.
+        This patch adds RenderLayer::sharesCompositingLayerForRepaint, to check the repaintTargetForLayer and paintOrderParents.
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::repaintTargetForLayer):
+        (WebCore::RenderLayer::enclosingCompositingLayerForRepaint const):
+        (WebCore::RenderLayer::sharesCompositingLayerForRepaint const):
+        (WebCore::RenderLayer::clipCrossesPaintingBoundary const):
+        * rendering/RenderLayer.h:
+
 2021-09-30  Simon Fraser  <simon.fraser@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -1921 +1921 @@
 }
 
+static RenderLayer* repaintTargetForLayer(const RenderLayer& layer)
+{
+    if (compositedWithOwnBackingStore(layer))
+        return const_cast<RenderLayer*>(&layer);
+
+    if (layer.paintsIntoProvidedBacking())
+        return layer.backingProviderLayer();
+
+    return nullptr;
+}
+
 RenderLayer* RenderLayer::enclosingCompositingLayerForRepaint(IncludeSelfOrNot includeSelf) const
 {
-    auto repaintTargetForLayer = [](const RenderLayer& layer) -> RenderLayer* {
-        if (compositedWithOwnBackingStore(layer))
-            return const_cast<RenderLayer*>(&layer);
-        
-        if (layer.paintsIntoProvidedBacking())
-            return layer.backingProviderLayer();
-        
-        return nullptr;
-    };
-
     RenderLayer* repaintTarget = nullptr;
     if (includeSelf == IncludeSelf && (repaintTarget = repaintTargetForLayer(*this)))
@@ -1943 +1944 @@
          
     return nullptr;
+}
+
+bool RenderLayer::sharesCompositingLayerForRepaint(const RenderLayer& otherLayer) const
+{
+    if (repaintTargetForLayer(*this))
+        return false;
+
+    const RenderLayer* paintParent = paintOrderParent();
+    if (&otherLayer == paintParent)
+        return true;
+    auto* otherPaintParent = otherLayer.paintOrderParent();
+    return paintParent == otherPaintParent || this == otherPaintParent;
 }
 
@@ -4454 +4467 @@
 bool RenderLayer::clipCrossesPaintingBoundary() const
 {
-    return parent()->enclosingPaginationLayer(IncludeCompositedPaginatedLayers) != enclosingPaginationLayer(IncludeCompositedPaginatedLayers)
-        || parent()->enclosingCompositingLayerForRepaint() != enclosingCompositingLayerForRepaint();
+    auto* parentLayer = parent();
+    if (!sharesCompositingLayerForRepaint(*parentLayer))
+        return true;
+
+    return parentLayer->enclosingPaginationLayer(IncludeCompositedPaginatedLayers) != enclosingPaginationLayer(IncludeCompositedPaginatedLayers);
 }
 

trunk/Source/WebCore/rendering/RenderLayer.h

@@ -588 +588 @@
     RenderLayer* enclosingCompositingLayer(IncludeSelfOrNot = IncludeSelf) const;
     RenderLayer* enclosingCompositingLayerForRepaint(IncludeSelfOrNot = IncludeSelf) const;
+    bool sharesCompositingLayerForRepaint(const RenderLayer& otherLayer) const;
     // Ancestor compositing layer, excluding this.
     RenderLayer* ancestorCompositingLayer() const { return enclosingCompositingLayer(ExcludeSelf); }