analysis server performance measurement driver first cut

pkg/analysis_server/test/performance/driver.dart

+library server.driver;
+
+import 'dart:async';
+
+import 'package:logging/logging.dart';
+
+import '../integration/integration_test_methods.dart';
+import '../integration/integration_tests.dart';
+import 'operation.dart';
+
+/**
+ * [Driver] launches and manages an instance of analysis server,
+ * reads a stream of operations, sends requests to analysis server
+ * based upon those operations, and evaluates the results.
+ */
+class Driver extends IntegrationTestMixin {
+  /**
+   * The amount of time to give the server to respond to a shutdown request
+   * before forcibly terminating it.
+   */
+  static const Duration SHUTDOWN_TIMEOUT = const Duration(seconds: 5);
+  
+  final Logger logger;
+
+  /**
+   * A flag indicating whether the server is running.
+   */
+  bool running = false;
+
+  @override
+  Server server;
+
+  /**
+   * The results collected while running analysis server.
+   */
+  final Results results = new Results();
+
+  /**
+   * The [Completer] for [runComplete].
+   */
+  Completer<Results> _runCompleter = new Completer<Results>();
+
+  Driver(this.logger);
+
+  /**
+   * Return a [Future] that completes with the [Results] of running
+   * the analysis server once all operations have been performed.
+   */
+  Future<Results> get runComplete => _runCompleter.future;
+
+  /**
+   * Perform the given operation.
+   * Return a [Future] that completes when the next operation can be performed,
+   * or `null` if the next operation can be performed immediately
+   */
+  Future perform(Operation op) {
+    return op.perform(this);
+  }
+
+  /**
+   * Send a command to the server.  An 'id' will be automatically assigned.
+   * The returned [Future] will be completed when the server acknowledges the
+   * command with a response.  If the server acknowledges the command with a
+   * normal (non-error) response, the future will be completed with the 'result'
+   * field from the response.  If the server acknowledges the command with an
+   * error response, the future will be completed with an error.
+   */
+  Future send(String method, Map<String, dynamic> params) {
+    return server.send(method, params);
+  }
+
+  /**
+   * Launch the analysis server.
+   * Return a [Future] that completes when analysis server has started.
+   */
+  Future startServer() async {
+    logger.log(Level.FINE, 'starting server');
+    initializeInttestMixin();
+    server = new Server();
+    Completer serverConnected = new Completer();
+    onServerConnected.listen((_) {
+      logger.log(Level.FINE, 'connected to server');
+      serverConnected.complete();
+    });
+    running = true;
+    return server.start(/*profileServer: true*/).then((params) {
+      server.listenToOutput(dispatchNotification);
+      server.exitCode.then((_) {
+        logger.log(Level.FINE, 'server stopped');
+        running = false;
+        _resultsReady();
+      });
+      return serverConnected.future;
+    });
+  }
+
+  /**
+   * Shutdown the analysis server if it is running.
+   */
+  Future stopServer() async {
+    if (running) {
+      logger.log(Level.FINE, 'requesting server shutdown');
+      // Give the server a short time to comply with the shutdown request; if it
+      // doesn't exit, then forcibly terminate it.
+      sendServerShutdown();
+      await server.exitCode.timeout(SHUTDOWN_TIMEOUT, onTimeout: () {
+        return server.kill();
+      });
+    }
+    _resultsReady();
+  }
+
+  /**
+   * If not already complete, signal the completer with the collected results.
+   */
+  void _resultsReady() {
+    if (!_runCompleter.isCompleted) {
+      _runCompleter.complete(results);
+    }
+  }
+}
+
+/**
+ * [Results] contains information gathered by [Driver]
+ * while running the analysis server
+ */
+class Results {
+  Map<String, Measurement> measurements = new Map<String, Measurement>();
+
+  /**
+   * Display results on stdout.
+   */
+  void printResults() {
+    print('==================================================================');
+    print('Results:');
+    for (String tag in measurements.keys.toList()..sort()) {
+      measurements[tag].printResults();
+    }
+  }
+
+  /**
+   * Record the elapsed time for the given operation.
+   */
+  void record(String tag, Duration elapsed) {
+    Measurement measurement = measurements[tag];
+    if (measurement == null) {
+      measurement = new Measurement(tag);
+      measurements[tag] = measurement;
+    }
+    measurement.record(elapsed);
+  }
+}
+
+/**
+ * [Measurement] tracks elapsed time for a given operation.
+ */
+class Measurement {
+  final String tag;
+  final List<Duration> elapsedTimes = new List<Duration>();
+  
+  Measurement(this.tag);
+
+  void record(Duration elapsed) {
+    elapsedTimes.add(elapsed);
+  }
+
+  void printResults() {
+    if (elapsedTimes.length == 0) {
+      return;
+    }
+    print('=== $tag');
+    for (Duration elapsed in elapsedTimes) {
+      print(elapsed);
+    }
+  }
+}