Support serialization of WorldImpact

pkg/compiler/lib/src/js_backend/backend_serialization.dart

+// Copyright (c) 2016, 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.
+
+library js_backend.serialization;
+
+import '../common/backend_api.dart' show
+    BackendSerialization;
+import '../elements/elements.dart';
+import '../serialization/serialization.dart' show
+    DeserializerPlugin,
+    ObjectDecoder,
+    ObjectEncoder,
+    SerializerPlugin;
+import '../serialization/keys.dart';
+import 'js_backend.dart';
+
+const String _BACKEND_DATA_TAG = 'jsBackendData';
+
+class JavaScriptBackendSerialization implements BackendSerialization {
+  final JavaScriptBackendSerializer serializer;
+  final JavaScriptBackendDeserializer deserializer;
+
+  JavaScriptBackendSerialization(JavaScriptBackend backend)
+      : serializer = new JavaScriptBackendSerializer(backend),
+        deserializer = new JavaScriptBackendDeserializer(backend);
+}
+
+class JavaScriptBackendSerializer implements SerializerPlugin {
+  final JavaScriptBackend backend;
+
+  JavaScriptBackendSerializer(this.backend);
+
+  @override
+  void onElement(Element element, ObjectEncoder createEncoder(String tag)) {
+    // TODO(johnniwinther): Add more data, e.g. js-interop names, native tags,
+    // etc.
+    String nativeName = backend.nativeData.nativeMemberName[element];
+    if (nativeName != null) {
+      ObjectEncoder encoder = createEncoder(_BACKEND_DATA_TAG);
+      encoder.setString(Key.NAME, nativeName);
+    }
+  }
+}
+
+class JavaScriptBackendDeserializer implements DeserializerPlugin {
+  final JavaScriptBackend backend;
+
+  JavaScriptBackendDeserializer(this.backend);
+
+  @override
+  void onElement(Element element, ObjectDecoder getDecoder(String tag)) {
+    ObjectDecoder decoder = getDecoder(_BACKEND_DATA_TAG);
+    if (decoder != null) {
+      String nativeName = decoder.getString(Key.NAME);
+      backend.nativeData.nativeMemberName[element] = nativeName;
+    }
+  }
+}
+