Introduced support for external services registration in the ServiceProtocol

sdk/lib/vmservice/client.dart

Index: sdk/lib/vmservice/client.dart
diff --git a/sdk/lib/vmservice/client.dart b/sdk/lib/vmservice/client.dart
index 4eb7460a60a2645f4ba4c22edb4f59e97d280e77..3f99607a64c22c7fd9f30b8f80bc6a79d42faad5 100644
--- a/sdk/lib/vmservice/client.dart
+++ b/sdk/lib/vmservice/client.dart
@@ -4,12 +4,27 @@
 
 part of dart._vmservice;
 
+typedef void ClientServiceHandle(Message response);
+
 // A service client.
 abstract class Client {
   final VMService service;
   final bool sendEvents;
+
+  /// A set streamIds which describes the streams the client is connected to
   final Set<String> streams = new Set<String>();
 
+  /// Services registered and their aliases
+  /// key: service
+  /// value: alias
+  final Map<String, String> services = new Map<String, String>();
+
+  /// Callbacks registered for service invocations set to the client
+  /// key: RPC id used for the request
+  /// value: callback that should be invoked
+  final Map<String, ClientServiceHandle> serviceHandles =
+      new Map<String, ClientServiceHandle>();
+
   Client(this.service, {bool sendEvents: true}) : this.sendEvents = sendEvents {
     service._addClient(this);
   }
@@ -22,18 +37,23 @@ abstract class Client {
     service._removeClient(this);
   }
 
-  /// Call to process a message. Response will be posted with 'seq'.
-  void onMessage(var seq, Message message) {
-    try {
-      // Send message to service.
-      service.route(message).then((response) {
-        // Call post when the response arrives.
-        post(response);
-      });
-    } catch (e, st) {
-      message.setErrorResponse(kInternalError, 'Unexpected exception:$e\n$st');
-      post(message.response);
-    }
+  /// Call to process a request. Response will be posted with 'seq'.
+  void onRequest(Message message) {
+    // In JSON-RPC 2.0 messages with and id are Request and must be answered
+    // http://www.jsonrpc.org/specification#notification
+    service.routeRequest(message).then((response) => post(response));
+  }
+
+  void onResponse(Message message) {
+    service.routeResponse(message);
+  }
+
+  /// Call to process a notification. Response will not be posted.
+  void onNotification(Message message) {
+    // In JSON-RPC 2.0 messages without an id are Notification
+    // and should not be answered
+    // http://www.jsonrpc.org/specification#notification
+    service.routeRequest(message);
   }
 
   // Sends a result to the client.  Implemented in subclasses.