Build Observatory as part of runtime

runtime/bin/vmservice/observatory/lib/tracer.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.
-
-library tracer;
-
-import 'dart:async';
-
-import 'package:logging/logging.dart';
-import 'package:observe/observe.dart';
-
-_deepCopy(src) {
-  if (src is Map) {
-    var dest = {};
-    src.forEach((key, val) {
-        dest[key] = _deepCopy(val);
-    });
-    return dest;
-  } else if (src is List) {
-    var dest = [];
-    src.forEach((val) {
-        dest.add(_deepCopy(val));
-    });
-    return dest;
-  } else {
-    return src;
-  }
-}
-
-class TraceEvent {
-  TraceEvent.msg(this._time, this.message, Map originalMap) {
-    map = _deepCopy(originalMap);
-  }
-
-  String get timeStamp => "T+${_time}us";
-
-  String toString() {
-    return "[${timeStamp}] ${message}";
-  }
-
-  int _time;
-  String message;
-  Map map;
-}
-
-class Tracer extends Observable {
-  // The current global tracer.
-  static Tracer get current => _current;
-
-  static Tracer _current;
-
-  static void start() {
-    if (_current == null) {
-      _current = new Tracer();
-    }
-  }
-  static void stop() {
-    if (_current != null) {
-      _current.cancel();
-      _current = null;
-    }
-  }
-  
-  // The tracer subscribes to all logging events.
-  StreamSubscription loggerSub = null;
-
-  // The start time for the current request.
-  Stopwatch _time;
-
-  // A list of all tracing events for thre current request.
-  ObservableList<TraceEvent> events = new ObservableList<TraceEvent>();
-
-  Tracer() {
-    _time = new Stopwatch();
-    _time.start();
-    loggerSub = Logger.root.onRecord.listen((LogRecord rec) {
-        // Echo all log messages to the trace.
-        trace('${rec.level.name}: ${rec.message}');
-      });
-    reset();
-  }
-
-  void cancel() {
-    loggerSub.cancel();
-  }
-
-  void reset() {
-    _time.reset();
-    events.clear();
-  }
-
-  TraceEvent trace(String message, {Map map: null}) {
-    var event = new TraceEvent.msg(_time.elapsedMicroseconds, message, map);
-    events.add(event);
-    return event;
-  } 
-}