Subtree caching implementation in blink-core

Source/core/layout/LayoutObject.cpp

Index: Source/core/layout/LayoutObject.cpp
diff --git a/Source/core/layout/LayoutObject.cpp b/Source/core/layout/LayoutObject.cpp
index fb0062c7711f8310c7700117e88d6e360ffe14e5..0969c25548316aaaa0ab283065f1134249558b8c 100644
--- a/Source/core/layout/LayoutObject.cpp
+++ b/Source/core/layout/LayoutObject.cpp
@@ -1165,7 +1165,21 @@ void LayoutObject::invalidatePaintUsingContainer(const LayoutBoxModelObject& pai
     }
 }
 
-void LayoutObject::invalidateDisplayItemClient(const DisplayItemClientWrapper& displayItemClient) const
+void LayoutObject::invalidateDisplayItemClient(const NonLayoutObjectDisplayItemClientWrapper& displayItemClient)
+{
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+        setChildNeedsRepaint();
+    invalidateDisplayItemClientInternal(displayItemClient);
+}
+
+void LayoutObject::invalidateDisplayItemClient(LayoutObject& object)
+{
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+        object.setNeedsRepaint();
+    invalidateDisplayItemClientInternal(object);
+}
+
+void LayoutObject::invalidateDisplayItemClientInternal(const DisplayItemClientWrapper& displayItemClient)
 {
     if (!RuntimeEnabledFeatures::slimmingPaintEnabled())
         return;
@@ -1179,12 +1193,70 @@ void LayoutObject::invalidateDisplayItemClient(const DisplayItemClientWrapper& d
     }
 }
 
-void LayoutObject::invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer) const
+void LayoutObject::invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer)
 {
     ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+        setNeedsRepaint();
     paintInvalidationContainer.invalidateDisplayItemClientOnBacking(*this);
 }
 
+void LayoutObject::setNeedsRepaint()
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    ASSERT(document().lifecycle().state() <= DocumentLifecycle::InPaintInvalidation);
+
+    if (!selfNeedsRepaint()) {
+        m_bitfields.setSelfNeedsRepaint(true);
+        markContainerChainForChildNeedsRepaint();
+    }
+}
+
+void LayoutObject::setChildNeedsRepaint()
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    ASSERT(document().lifecycle().state() <= DocumentLifecycle::InPaintInvalidation);
+
+    if (!childNeedsRepaint()) {
+        m_bitfields.setChildNeedsRepaint(true);
+        markContainerChainForChildNeedsRepaint();
+    }
+}
+
+void LayoutObject::markContainerChainForChildNeedsRepaint()
+{
+    // TODO(wangxianzhu): This should be "markPaintContainerChainForChildNeedsRepaint"
+    // (which returns the painting container instead of positioning container for fixed-pos)
+    // when we remove DeprecatedPaintLayer. Currently DeprecatedPaintLayer paints fixed-pos
+    // object which is not fully controlled by normal LayoutBlock subtree repaint flags.
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    for (LayoutObject* container = this->containerCrossingFrameBoundaries(); container && !container->childNeedsRepaint(); container = container->containerCrossingFrameBoundaries())
+        container->m_bitfields.setChildNeedsRepaint(true);
+}
+
+void LayoutObject::clearRepaintFlagsRecursively()
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    ASSERT(document().lifecycle().state() == DocumentLifecycle::InPaintForSlimmingPaintV2);
+
+    m_bitfields.setSelfNeedsRepaint(false);
+
+    if (!m_bitfields.childNeedsRepaint())
+        return;
+
+    clearRepaintFlagsOfSubtrees();
+    m_bitfields.setChildNeedsRepaint(false);
+}
+
+void LayoutObject::clearRepaintFlagsOfSubtrees()
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    for (LayoutObject* child = slowFirstChild(); child; child = child->nextSibling()) {
+        if (!child->isOutOfFlowPositioned())
+            child->clearRepaintFlagsRecursively();
+    }
+}
+
 LayoutRect LayoutObject::boundsRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* paintInvalidationState) const
 {
     if (!paintInvalidationContainer)
@@ -1192,7 +1264,7 @@ LayoutRect LayoutObject::boundsRectForPaintInvalidation(const LayoutBoxModelObje
     return DeprecatedPaintLayer::computePaintInvalidationRect(this, paintInvalidationContainer->layer(), paintInvalidationState);
 }
 
-const LayoutBoxModelObject* LayoutObject::invalidatePaintRectangleInternal(const LayoutRect& r) const
+const LayoutBoxModelObject* LayoutObject::invalidatePaintRectangleInternal(const LayoutRect& r)
 {
     RELEASE_ASSERT(isRooted());
 
@@ -1210,7 +1282,7 @@ const LayoutBoxModelObject* LayoutObject::invalidatePaintRectangleInternal(const
     return &paintInvalidationContainer;
 }
 
-void LayoutObject::invalidatePaintRectangle(const LayoutRect& r) const
+void LayoutObject::invalidatePaintRectangle(const LayoutRect& r)
 {
     if (const LayoutBoxModelObject* paintInvalidationContainer = invalidatePaintRectangleInternal(r)) {
         if (RuntimeEnabledFeatures::slimmingPaintEnabled())
@@ -3273,7 +3345,7 @@ void traverseNonCompositingDescendants(LayoutObject& object, const LayoutObjectT
 
 } // unnamed namespace
 
-void LayoutObject::invalidateDisplayItemClientForNonCompositingDescendantsOf(const LayoutObject& object) const
+void LayoutObject::invalidateDisplayItemClientForNonCompositingDescendantsOf(LayoutObject& object)
 {
     ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());