analysis server performance measurement driver first cut

pkg/analysis_server/test/integration/integration_tests.dart

 // Copyright (c) 2014, 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 test.integration.analysis;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
@@ skipping 410 matching lines @@
    * test.
    */
   bool _receivedBadDataFromServer = false;
 
   /**
    * Stopwatch that we use to generate timing information for debug output.
    */
   Stopwatch _time = new Stopwatch();
 
   /**
+   * The [currentElapseTime] at which the last communication was received from the server
+   * or `null` if no communication has been received.
+   */
+  double lastCommunicationTime;
+
+  /**
+   * The current elapse time (seconds) since the server was started.
+   */
+  double get currentElapseTime => _time.elapsedTicks / _time.frequency;
+
+  /**
    * Future that completes when the server process exits.
    */
   Future<int> get exitCode => _process.exitCode;
 
   /**
    * Print out any messages exchanged with the server.  If some messages have
    * already been exchanged with the server, they are printed out immediately.
    */
   void debugStdio() {
     if (_debuggingStdio) {
@@ skipping 40 matching lines @@
 
   /**
    * Start listening to output from the server, and deliver notifications to
    * [notificationProcessor].
    */
   void listenToOutput(NotificationProcessor notificationProcessor) {
     _process.stdout
         .transform((new Utf8Codec()).decoder)
         .transform(new LineSplitter())
         .listen((String line) {
+      lastCommunicationTime = currentElapseTime;
       String trimmedLine = line.trim();
       _recordStdio('RECV: $trimmedLine');
       var message;
       try {
         message = JSON.decoder.convert(trimmedLine);
       } catch (exception) {
         _badDataFromServer();
         return;
       }
       expect(message, isMap);
@@ skipping 122 matching lines @@
     new Future.delayed(new Duration(seconds: 1), expectAsync(() {
       fail('Bad data received from server');
     }));
   }
 
   /**
    * Record a message that was exchanged with the server, and print it out if
    * [debugStdio] has been called.
    */
   void _recordStdio(String line) {
-    double elapsedTime = _time.elapsedTicks / _time.frequency;
+    double elapsedTime = currentElapseTime;
     line = "$elapsedTime: $line";
     if (_debuggingStdio) {
       print(line);
     }
     _recordedStdio.add(line);
   }
 }
 
 /**
  * Matcher that matches a list of objects, each of which satisfies the given
@@ skipping 200 matching lines @@
   void populateMismatches(item, List<MismatchDescriber> mismatches);
 
   /**
    * Create a [MismatchDescriber] describing a mismatch with a simple string.
    */
   MismatchDescriber simpleDescription(String description) =>
       (Description mismatchDescription) {
     mismatchDescription.add(description);
   };
 }