Optimization for patch file generation

sdk/lib/js/dartium/js_dartium.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Support for interoperating with JavaScript.
  *
  * This library provides access to JavaScript objects from Dart, allowing
  * Dart code to get and set properties, and call methods of JavaScript objects
  * and invoke JavaScript functions. The library takes care of converting
@@ skipping 293 matching lines @@
       var uri = library.uri;
       // make sure the annotation is from package://js
       if (uri.scheme == 'package' && uri.path == 'js/js.dart') {
         return true;
       }
     }
   }
   return false;
 }
 
-bool _hasJsName(mirrors.DeclarationMirror mirror) => _getJsName(mirror) != null;
+bool _hasJsName(mirrors.DeclarationMirror mirror) {
+  if (_atJsType != null) {
+    for (var annotation in mirror.metadata) {
+      if (annotation.type.reflectedType == _atJsType) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
 
 var _domNameType;
 
 bool hasDomName(mirrors.DeclarationMirror mirror) {
   var location = mirror.location;
   if (location == null || location.sourceUri.scheme != 'dart') return false;
   for (var annotation in mirror.metadata) {
     if (mirrors.MirrorSystem.getName(annotation.type.simpleName) == "DomName") {
       // We can't make sure the annotation is in dart: as Dartium believes it
       // is file://dart/sdk/lib/html/html_common/metadata.dart
@@ skipping 302 matching lines @@
 const ${_UNDEFINED_VAR} = const Object();
 
 ${sb}
 """);
     }
 }
 
 // Remember the @JS type to compare annotation type.
 var _atJsType = -1;
 
-/**
- * Generates part files defining source code for JSObjectImpl, all DOM classes
- * classes. This codegen  is needed so that type checks for all registered
- * JavaScript interop classes pass.
- * If genCachedPatches is true then the patch files don't exist this is a special
- * signal to generate and emit the patches to stdout to be captured and put into
- * the file sdk/lib/js/dartium/cached_patches.dart
- */
-List<String> _generateInteropPatchFiles(List<String> libraryPaths, genCachedPatches) {
+void setupJsTypeCache() {
   // Cache the @JS Type.
   if (_atJsType == -1) {
     var uri = new Uri(scheme: "package", path: "js/js.dart");
     var jsLibrary = mirrors.currentMirrorSystem().libraries[uri];
     if (jsLibrary != null) {
       // @ JS used somewhere.
       var jsDeclaration = jsLibrary.declarations[new Symbol("JS")];
       _atJsType = jsDeclaration.reflectedType;
     } else {
       // @ JS not used in any library.
       _atJsType = null;
     }
   }
+}
+
+/**
+ * Generates part files defining source code for JSObjectImpl, all DOM classes
+ * classes. This codegen  is needed so that type checks for all registered
+ * JavaScript interop classes pass.
+ * If genCachedPatches is true then the patch files don't exist this is a special
+ * signal to generate and emit the patches to stdout to be captured and put into
+ * the file sdk/lib/js/dartium/cached_patches.dart
+ */
+List<String> _generateInteropPatchFiles(List<String> libraryPaths, genCachedPatches) {
+  // Cache the @JS Type.
+  if (_atJsType == -1) setupJsTypeCache();
 
   var ret = _generateExternalMethods(libraryPaths, genCachedPatches ? false : true);
   var libraryPrefixes = new Map<mirrors.LibraryMirror, String>();
   var prefixNames = new Set<String>();
   var sb = new StringBuffer();
 
   var implements = <String>[];
   var implementsArray = <String>[];
   var implementsDom = <String>[];
   var listMirror = mirrors.reflectType(List);
@@ skipping 875 matching lines @@
     if (ret == null) {
       // TODO(jacobr): we could optimize this.
       ret = JSFunction._createWithThis(f);
       _interopCaptureThisExpando[f] = ret;
     }
     return ret;
   }
 }
 
 debugPrint(_) {}