Speeding up Node.nodes.addAll

tools/dom/templates/html/impl/impl_Node.darttemplate

Index: tools/dom/templates/html/impl/impl_Node.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_Node.darttemplate b/tools/dom/templates/html/impl/impl_Node.darttemplate
index c312f77c61818217c1cef7636329563e549c827f..307cd0cea96e329577874641d1b269bf174c973d 100644
--- a/tools/dom/templates/html/impl/impl_Node.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Node.darttemplate
@@ -70,7 +70,13 @@ $endif
 
   void addAll(Iterable<Node> iterable) {
     if (iterable is _ChildNodeListLazy) {

[Siggi Cherem (dart-lang), 2013/02/28 19:43:32]

is it worth doing this also for other types like List<Node>?

[blois, 2013/02/28 20:45:58]

The optimized loop requires that it be a browser node list as it relies on the
behavior of the items getting automatically removed from the other list.

The general for..in loop could potentially be optimized to avoid the generation
of an iterator for lists, but I'd prefer to delay a change like that until we
have prescriptive guidance around List iterating.

[Siggi Cherem (dart-lang), 2013/03/01 00:05:28]

I see, thanks! - somehow the [0] below didn't sink in =).

-      iterable = new List.from(iterable);
+      if (iterable._this != _this) {

[sra1, 2013/03/01 01:17:59]

if (!identical(iterable._this, _this))

+        // Optimized route for copying between nodes.
+        for (var i = 0, len = iterable.length; i < len; ++i) {
+          _this.$dom_appendChild(iterable[0]);

[sra1, 2013/03/01 01:17:59]

iterable.first should be slightly faster.

[sra1, 2013/03/01 01:28:46]

or, better, iterable._this.$dom_firstChild

+        }
+      }
+      return;
     }
     for (Node node in iterable) {
       _this.$dom_appendChild(node);