Make appendChild/insertBefore faster with active ranges

third_party/WebKit/Source/core/dom/ContainerNode.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
  *
  * 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.
@@ skipping 754 matching lines @@
     childrenContext.resolvedStyle = nullptr;
     childrenContext.clearInvalidation = true;
 
     for (Node* child = firstChild(); child; child = child->nextSibling())
         child->detach(childrenContext);
 
     setChildNeedsStyleRecalc();
     Node::detach(context);
 }
 
+bool ContainerNode::shouldUpdateRangesAfterChildrenChanged(const ChildrenChange& change)
+{
+    return !change.byParser
+        && change.type != TextChanged

[keishi, 2016/06/04 07:02:45]

nit: would the code be easier to understand if it listed the positive matches?

[yosin_UTC9, 2016/06/06 05:21:26]

Done.

+        && change.type != ElementInserted
+        && change.type != NonElementInserted;
+}
+
 void ContainerNode::childrenChanged(const ChildrenChange& change)
 {
     document().incDOMTreeVersion();
-    if (!change.byParser && change.type != TextChanged)
+    if (shouldUpdateRangesAfterChildrenChanged(change))
         document().updateRangesAfterChildrenChanged(this);
     invalidateNodeListCachesInAncestors();
     if (change.isChildInsertion() && !childNeedsStyleRecalc()) {
         setChildNeedsStyleRecalc();
         markAncestorsWithChildNeedsStyleRecalc();
     }
 }
 
 void ContainerNode::cloneChildNodes(ContainerNode *clone)
 {
@@ skipping 598 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace blink