Changeset 238583 in webkit

Timestamp:

Nov 27, 2018, 3:46:18 PM (6 years ago)

Author:

Simon Fraser

Message:

Avoid triggering compositing updates when only the root layer is composited
​https://bugs.webkit.org/show_bug.cgi?id=191813

Reviewed by Zalan Bujtas.

If we know that the only composited layer is the root, we can avoid triggering deep
compositing updates sometimes, for example when layout changes size or position,
or when z-order lists change.

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::addChild):
(WebCore::RenderLayer::removeChild):
(WebCore::RenderLayer::updateLayerPosition):
(WebCore::RenderLayer::scrollTo):
(WebCore::RenderLayer::updateCompositingLayersAfterScroll):
(WebCore::outputPaintOrderTreeRecursive):

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::updateBackingAndHierarchy): Consult the layer.hasCompositingDescendant()
flag to cut off descendants traversal when possible.
(WebCore::RenderLayerCompositor::layerStyleChanged):

Location:

trunk

Files:

• LayoutTests/platform/ios-wk2/TestExpectations (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayer.cpp (modified) (7 diffs)
• Source/WebCore/rendering/RenderLayerCompositor.cpp (modified) (4 diffs)

trunk/LayoutTests/platform/ios-wk2/TestExpectations

@@ -1125 +1125 @@
 svg/animations/mozilla/animateMotion-mpath-pathLength-1.svg [ ImageOnlyFailure ]
 
+webkit.org/b/192045 css3/filters/blur-filter-page-scroll-parents.html
+webkit.org/b/192045 css3/filters/blur-filter-page-scroll-self.html
+webkit.org/b/192045 css3/filters/blur-filter-page-scroll.html
+
 webkit.org/b/159379 fast/history/page-cache-webdatabase-pending-transaction.html [ Pass Failure ]
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2018-11-27  Simon Fraser  <simon.fraser@apple.com>
+
+        Avoid triggering compositing updates when only the root layer is composited
+        https://bugs.webkit.org/show_bug.cgi?id=191813
+
+        Reviewed by Zalan Bujtas.
+
+        If we know that the only composited layer is the root, we can avoid triggering deep
+        compositing updates sometimes, for example when layout changes size or position,
+        or when z-order lists change.
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::addChild):
+        (WebCore::RenderLayer::removeChild):
+        (WebCore::RenderLayer::updateLayerPosition):
+        (WebCore::RenderLayer::scrollTo):
+        (WebCore::RenderLayer::updateCompositingLayersAfterScroll):
+        (WebCore::outputPaintOrderTreeRecursive):
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::updateBackingAndHierarchy): Consult the layer.hasCompositingDescendant()
+        flag to cut off descendants traversal when possible.
+        (WebCore::RenderLayerCompositor::layerStyleChanged):
+
 2018-11-27  Eric Carlson  <eric.carlson@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -406 +406 @@
         setAncestorChainHasSelfPaintingLayerDescendant();
 
-    if (compositor().usesCompositing())
+    if (compositor().hasContentCompositingLayers())
         setDescendantsNeedCompositingRequirementsTraversal();
 
@@ -452 +452 @@
         dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
 
-    if (compositor().usesCompositing())
+    if (compositor().hasContentCompositingLayers())
         setDescendantsNeedCompositingRequirementsTraversal();
 
@@ -1578 +1578 @@
     setLocation(localPoint);
     
-    if (positionOrOffsetChanged && compositor().usesCompositing()) {
+    if (positionOrOffsetChanged && compositor().hasContentCompositingLayers()) {
         if (isComposited())
             setNeedsCompositingGeometryUpdate();
@@ -2431 +2431 @@
 
     bool requiresRepaint = true;
-    if (compositor().usesCompositing() && usesCompositedScrolling()) {
+    if (usesCompositedScrolling()) {
         setNeedsCompositingGeometryUpdate();
         setDescendantsNeedUpdateBackingAndHierarchyTraversal();
@@ -2581 +2581 @@
 void RenderLayer::updateCompositingLayersAfterScroll()
 {
-    if (compositor().usesCompositing()) {
+    if (compositor().hasContentCompositingLayers()) {
         // Our stacking container is guaranteed to contain all of our descendants that may need
         // repositioning, so update compositing layers from there.
@@ -6644 +6644 @@
 {
     stream.nextLine();
-    stream << "(S)tacking Context, (N)ormal flow only, (O)verflow clip, (A)lpha (opacity or mask), has (B)lend mode, (I)solates blending, (T)ransform-ish, (F)ilter, Fi(X)ed position, (C)omposited\n"
+    stream << "(S)tacking Context, (N)ormal flow only, (O)verflow clip, (A)lpha (opacity or mask), has (B)lend mode, (I)solates blending, (T)ransform-ish, (F)ilter, Fi(X)ed position, (C)omposited, (c)omposited descendant\n"
         "Dirty (z)-lists, Dirty (n)ormal flow lists\n"
         "Descendant needs overlap (t)raversal, Descendant needs (b)acking or hierarchy update, All descendants need (r)equirements traversal, All (s)ubsequent layers need requirements traversal, All descendants need (h)ierarchy traversal\n"
@@ -6671 +6671 @@
     stream << (layer.renderer().isFixedPositioned() ? "X" : "-");
     stream << (layer.isComposited() ? "C" : "-");
+    stream << (layer.hasCompositingDescendant() ? "c" : "-");
 
     stream << " ";

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -1171 +1171 @@
     Vector<Ref<GraphicsLayer>> layerChildren;
     auto& childList = layerBacking ? layerChildren : childLayersOfEnclosingLayer;
-    // FIXME: why the !layerBacking check?
-    bool requireDescendantTraversal = !layerBacking || layer.needsCompositingLayerConnection() || layer.hasDescendantNeedingUpdateBackingOrHierarchyTraversal() || !updateLevel.isEmpty();
+
+    bool requireDescendantTraversal = layer.hasDescendantNeedingUpdateBackingOrHierarchyTraversal()
+        || (layer.hasCompositingDescendant() && (!layerBacking || layer.needsCompositingLayerConnection() || !updateLevel.isEmpty()));
 
 #if !ASSERT_DISABLED
@@ -1178 +1179 @@
 #endif
     
+    auto appendForegroundLayerIfNecessary = [&] () {
+        // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
+        if (layer.negativeZOrderLayers().size()) {
+            if (layerBacking && layerBacking->foregroundLayer())
+                childList.append(*layerBacking->foregroundLayer());
+        }
+    };
+
     if (requireDescendantTraversal) {
         for (auto* renderLayer : layer.negativeZOrderLayers())
             updateBackingAndHierarchy(*renderLayer, childList, updateLevel, depth + 1);
 
-            // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
-        if (layer.negativeZOrderLayers().size()) {
-            if (layerBacking && layerBacking->foregroundLayer())
-                childList.append(*layerBacking->foregroundLayer());
-        }
+        appendForegroundLayerIfNecessary();
 
         for (auto* renderLayer : layer.normalFlowLayers())
@@ -1193 +1198 @@
         for (auto* renderLayer : layer.positiveZOrderLayers())
             updateBackingAndHierarchy(*renderLayer, childList, updateLevel, depth + 1);
-    }
+    } else
+        appendForegroundLayerIfNecessary();
 
     if (layerBacking) {
@@ -1371 +1377 @@
         layer.setNeedsPostLayoutCompositingUpdate();
 
-    if (diff >= StyleDifference::LayoutPositionedMovementOnly && usesCompositing()) {
+    if (diff >= StyleDifference::LayoutPositionedMovementOnly && hasContentCompositingLayers()) {
         layer.setNeedsPostLayoutCompositingUpdate();
         layer.setNeedsCompositingGeometryUpdate();