From 63c229c7f7dab901e650fb1c8b155d2bc006ca30 Mon Sep 17 00:00:00 2001
From: James deBoer <james@huronbox.com>
Date: Mon, 31 Mar 2014 15:56:24 -0700
Subject: [PATCH] feat(metadata extractor): Cache the fieldMetadataExtractor
 for greater performance

Dartium tests run in 7.6s; down from 18.2s.
dart2js on Chrome runs in 2m instead of 3m
---
 lib/core/registry_dynamic.dart | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/core/registry_dynamic.dart b/lib/core/registry_dynamic.dart
index f0a76ddfd..bea0b4972 100644
--- a/lib/core/registry_dynamic.dart
+++ b/lib/core/registry_dynamic.dart
@@ -3,6 +3,8 @@ library angular.core_dynamic;
 import 'dart:mirrors';
 import 'package:angular/core/module_internal.dart';
 
+var _fieldMetadataCache = new Map<Type, Map<String, AttrFieldAnnotation>>();
+
 class DynamicMetadataExtractor implements MetadataExtractor {
   final _fieldAnnotations = [
         reflectType(NgAttr),
@@ -51,6 +53,10 @@ class DynamicMetadataExtractor implements MetadataExtractor {
 
 
   Map<String, AttrFieldAnnotation> fieldMetadataExtractor(Type type) {
+    return _fieldMetadataCache.putIfAbsent(type, () => _fieldMetadataExtractor(type));
+  }
+
+  Map<String, AttrFieldAnnotation> _fieldMetadataExtractor(Type type) {
     ClassMirror cm = reflectType(type);
     final fields = <String, AttrFieldAnnotation>{};
     cm.declarations.forEach((Symbol name, DeclarationMirror decl) {