dart2js: Merge intercepted names map.

pkg/compiler/lib/src/js_emitter/old_emitter/interceptor_emitter.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.
 
 part of dart2js.js_emitter;
 
 class InterceptorEmitter extends CodeEmitterHelper {
   final Set<String> interceptorInvocationNames = new Set<String>();
 
   void recordMangledNameOfMemberMethod(FunctionElement member, String name) {
@@ skipping 44 matching lines @@
           js('${globalObject}.# = #', [name, function]);
 
       buffer.write(jsAst.prettyPrint(assignment, compiler));
       buffer.write(N);
     }
   }
 
   /**
    * If [JSInvocationMirror._invokeOn] has been compiled, emit all the
    * possible selector names that are intercepted into the
-   * [interceptedNames] top-level variable. The implementation of
+   * [interceptedNames] embedded global. The implementation of
    * [_invokeOn] will use it to determine whether it should call the
    * method with an extra parameter.
    */
-  void emitInterceptedNames(CodeBuffer buffer) {
+  jsAst.ObjectInitializer generateInterceptedNamesSet() {
     // TODO(ahe): We should not generate the list of intercepted names at

[ahe, 2015/01/07 15:31:32]

You may also want to put this on you to-do list, or just remove this to-do.

[floitsch, 2015/01/07 15:48:12]

Changed to a comment.

     // compile time, it can be generated automatically at runtime given
     // subclasses of Interceptor (which can easily be identified).
-    if (!compiler.enabledInvokeOn) return;
-
-    // TODO(ahe): We should roll this into
-    // [emitStaticNonFinalFieldInitializations].
-    String name = backend.namer.getNameOfGlobalField(backend.interceptedNames);
+    if (!compiler.enabledInvokeOn) return null;

[ahe, 2015/01/07 15:31:32]

Or mirrors enabled?

[floitsch, 2015/01/07 15:48:12]

invokeOn is the only one using the data structure.
invokeOn implies reflection.

 
     int index = 0;
-    var invocationNames = interceptorInvocationNames.toList()..sort();
-    List<jsAst.Expression> elements = invocationNames.map(js.string).toList();
-    jsAst.ArrayInitializer array =
-        new jsAst.ArrayInitializer(elements);
-
-    jsAst.Expression assignment =
-        js('${emitter.isolateProperties}.# = #', [name, array]);
-
-    buffer.write(jsAst.prettyPrint(assignment, compiler));
-    buffer.write(N);
+    List<String> invocationNames = interceptorInvocationNames.toList()..sort();
+    List<jsAst.Property> properties =
+        new List<jsAst.Property>(invocationNames.length);
+    for (int i = 0; i < invocationNames.length; i++) {
+      String name = invocationNames[i];
+      properties[i] = new jsAst.Property(js.string(name), js.number(1));

[ahe, 2015/01/07 15:31:32]

Random thought about a potential optimization:

For is-tests, we found that initializing boolean properties to a dummy function
would generate faster accesses.

[floitsch, 2015/01/07 15:48:12]

I thought about it. Here I went for simple and size. (Yes: one could have a
temporary one character variable with a function, but that's more complicated).

+    }
+    return new jsAst.ObjectInitializer(properties, isOneLiner: true);
   }
 
   /**
    * Emit initializer for [mapTypeToInterceptor] data structure used by
    * [findInterceptorForType].  See declaration of [mapTypeToInterceptor] in
    * `interceptors.dart`.
    */
   void emitMapTypeToInterceptor(CodeBuffer buffer) {
     // TODO(sra): Perhaps inject a constant instead?
     CustomElementsAnalysis analysis = backend.customElementsAnalysis;
@@ skipping 46 matching lines @@
     jsAst.ArrayInitializer array = new jsAst.ArrayInitializer(elements);
     String name =
         backend.namer.getNameOfGlobalField(backend.mapTypeToInterceptor);
     jsAst.Expression assignment =
         js('${emitter.isolateProperties}.# = #', [name, array]);
 
     buffer.write(jsAst.prettyPrint(assignment, compiler));
     buffer.write(N);
   }
 }