Revert "Build Observatory with runtime"

runtime/observatory/lib/src/service/object.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.
-
-part of service;
-
-/// A [ServiceObject] is an object known to the VM service and is tied
-/// to an owning [Isolate].
-abstract class ServiceObject extends Observable {
-  static int LexicalSortName(ServiceObject o1, ServiceObject o2) {
-    return o1.name.compareTo(o2.name);
-  }
-
-  List removeDuplicatesAndSortLexical(List<ServiceObject> list) {
-    return list.toSet().toList()..sort(LexicalSortName);
-  }
-
-  /// The owner of this [ServiceObject].  This can be an [Isolate], a
-  /// [VM], or null.
-  @reflectable ServiceObjectOwner get owner => _owner;
-  ServiceObjectOwner _owner;
-
-  /// The [VM] which owns this [ServiceObject].
-  @reflectable VM get vm => _owner.vm;
-
-  /// The [Isolate] which owns this [ServiceObject].  May be null.
-  @reflectable Isolate get isolate => _owner.isolate;
-
-  /// The id of this object.
-  @reflectable String get id => _id;
-  String _id;
-
-  /// The user-level type of this object.
-  @reflectable String get type => _type;
-  String _type;
-
-  /// The vm type of this object.
-  @reflectable String get vmType => _vmType;
-  String _vmType;
-
-  static bool _isInstanceType(String type) {
-    switch (type) {
-      case 'BoundedType':
-      case 'Instance':
-      case 'List':
-      case 'String':
-      case 'Type':
-      case 'TypeParameter':
-      case 'TypeRef':
-      case 'bool':
-      case 'double':
-      case 'int':
-      case 'null':
-        return true;
-      default:
-        return false;
-    }
-  }
-
-  static bool _isTypeType(String type) {
-    switch (type) {
-      case 'BoundedType':
-      case 'Type':
-      case 'TypeParameter':
-      case 'TypeRef':
-        return true;
-      default:
-        return false;
-    }
-  }
-
-  bool get isAbstractType => _isTypeType(type);
-  bool get isBool => type == 'bool';
-  bool get isContext => type == 'Context';
-  bool get isDouble => type == 'double';
-  bool get isError => type == 'Error';
-  bool get isInstance => _isInstanceType(type);
-  bool get isInt => type == 'int';
-  bool get isList => type == 'List';
-  bool get isNull => type == 'null';
-  bool get isSentinel => type == 'Sentinel';
-  bool get isString => type == 'String';
-
-  // Kinds of Instance.
-  bool get isMirrorReference => vmType == 'MirrorReference';
-  bool get isWeakProperty => vmType == 'WeakProperty';
-  bool get isClosure => false;
-  bool get isPlainInstance {
-    return (type == 'Instance' &&
-            !isMirrorReference && !isWeakProperty && !isClosure);
-  }
-
-  /// The complete service url of this object.
-  @reflectable String get link => _owner.relativeLink(_id);
-
-  /// Has this object been fully loaded?
-  bool get loaded => _loaded;
-  bool _loaded = false;
-  // TODO(turnidge): Make loaded observable and get rid of loading
-  // from Isolate.
-
-  /// Is this object cacheable?  That is, is it impossible for the [id]
-  /// of this object to change?
-  bool get canCache => false;
-
-  /// Is this object immutable after it is [loaded]?
-  bool get immutable => false;
-
-  @observable String name;
-  @observable String vmName;
-
-  /// Creates an empty [ServiceObject].
-  ServiceObject._empty(this._owner);
-
-  /// Creates a [ServiceObject] initialized from [map].
-  factory ServiceObject._fromMap(ServiceObjectOwner owner,
-                                 ObservableMap map) {
-    if (map == null) {
-      return null;
-    }
-    if (!_isServiceMap(map)) {
-      Logger.root.severe('Malformed service object: $map');
-    }
-    assert(_isServiceMap(map));
-    var type = _stripRef(map['type']);
-    var vmType = map['_vmType'] != null ? _stripRef(map['_vmType']) : type;
-    var obj = null;
-    assert(type != 'VM');
-    switch (type) {
-      case 'Class':
-        obj = new Class._empty(owner);
-        break;
-      case 'Code':
-        obj = new Code._empty(owner);
-        break;
-      case 'Context':
-        obj = new Context._empty(owner);
-        break;
-      case 'Counter':
-        obj = new ServiceMetric._empty(owner);
-        break;
-      case 'Error':
-        obj = new DartError._empty(owner);
-        break;
-      case 'Field':
-        obj = new Field._empty(owner);
-        break;
-      case 'Function':
-        obj = new ServiceFunction._empty(owner);
-        break;
-      case 'Gauge':
-        obj = new ServiceMetric._empty(owner);
-        break;
-      case 'Isolate':
-        obj = new Isolate._empty(owner.vm);
-        break;
-      case 'Library':
-        obj = new Library._empty(owner);
-        break;
-      case 'Object':
-        switch (vmType) {
-          case 'PcDescriptors':
-            obj = new PcDescriptors._empty(owner);
-            break;
-          case 'LocalVarDescriptors':
-            obj = new LocalVarDescriptors._empty(owner);
-            break;
-          case 'TokenStream':
-            obj = new TokenStream._empty(owner);
-            break;
-        }
-        break;
-      case 'ServiceError':
-        obj = new ServiceError._empty(owner);
-        break;
-      case 'ServiceEvent':
-        obj = new ServiceEvent._empty(owner);
-        break;
-      case 'ServiceException':
-        obj = new ServiceException._empty(owner);
-        break;
-      case 'Script':
-        obj = new Script._empty(owner);
-        break;
-      case 'Socket':
-        obj = new Socket._empty(owner);
-        break;
-      default:
-        if (_isInstanceType(type) ||
-            type == 'Sentinel') {  // TODO(rmacnak): Separate this out.
-          obj = new Instance._empty(owner);
-        }
-        break;
-    }
-    if (obj == null) {
-      obj = new ServiceMap._empty(owner);
-    }
-    obj.update(map);
-    return obj;
-  }
-
-  /// If [this] was created from a reference, load the full object
-  /// from the service by calling [reload]. Else, return [this].
-  Future<ServiceObject> load() {
-    if (loaded) {
-      return new Future.value(this);
-    }
-    // Call reload which will fill in the entire object.
-    return reload();
-  }
-
-  Future<ServiceObject> _inProgressReload;
-
-  /// Reload [this]. Returns a future which completes to [this] or
-  /// a [ServiceError].
-  Future<ServiceObject> reload() {
-    if (id == '') {
-      // Errors don't have ids.
-      assert(type == 'Error');
-      return new Future.value(this);
-    }
-    if (loaded && immutable) {
-      return new Future.value(this);
-    }
-    if (_inProgressReload == null) {
-      _inProgressReload = vm.getAsMap(link).then((ObservableMap map) {
-          var mapType = _stripRef(map['type']);
-          if (mapType != _type) {
-            // If the type changes, return a new object instead of
-            // updating the existing one.
-            //
-            // TODO(turnidge): Check for vmType changing as well?
-            assert(mapType == 'Error' || mapType == 'Sentinel');
-            return new ServiceObject._fromMap(owner, map);
-          }
-          update(map);
-          return this;
-      }).whenComplete(() {
-          // This reload is complete.
-          _inProgressReload = null;
-      });
-    }
-    return _inProgressReload;
-  }
-
-  /// Update [this] using [map] as a source. [map] can be a reference.
-  void update(ObservableMap map) {
-    assert(_isServiceMap(map));
-
-    // Don't allow the type to change on an object update.
-    // TODO(turnidge): Make this a ServiceError?
-    var mapIsRef = _hasRef(map['type']);
-    var mapType = _stripRef(map['type']);
-    assert(_type == null || _type == mapType);
-
-    if (_id != null && _id != map['id']) {
-      // It is only safe to change an id when the object isn't cacheable.
-      assert(!canCache);
-    }
-    _id = map['id'];
-
-    _type = mapType;
-
-    // When the response specifies a specific vmType, use it.
-    // Otherwise the vmType of the response is the same as the 'user'
-    // type.
-    if (map.containsKey('_vmType')) {
-      _vmType = _stripRef(map['_vmType']);
-    } else {
-      _vmType = _type;
-    }
-
-    _update(map, mapIsRef);
-  }
-
-  // Updates internal state from [map]. [map] can be a reference.
-  void _update(ObservableMap map, bool mapIsRef);
-
-  String relativeLink(String id) {
-    assert(id != null);
-    return "${link}/${id}";
-  }
-}
-
-abstract class Coverage {
-  // Following getters and functions will be provided by [ServiceObject].
-  ServiceObjectOwner get owner;
-  String get type;
-  VM get vm;
-  String relativeLink(String id);
-
-  /// Default handler for coverage data.
-  void processCoverageData(List coverageData) {
-    coverageData.forEach((scriptCoverage) {
-      assert(scriptCoverage['script'] != null);
-      scriptCoverage['script']._processHits(scriptCoverage['hits']);
-    });
-  }
-
-  Future refreshCoverage() {
-    return vm.getAsMap(relativeLink('coverage')).then((ObservableMap map) {
-      var coverageOwner = (type == 'Isolate') ? this : owner;
-      var coverage = new ServiceObject._fromMap(coverageOwner, map);
-      assert(coverage.type == 'CodeCoverage');
-      var coverageList = coverage['coverage'];
-      assert(coverageList != null);
-      processCoverageData(coverageList);
-    });
-  }
-}
-
-abstract class ServiceObjectOwner extends ServiceObject {
-  /// Creates an empty [ServiceObjectOwner].
-  ServiceObjectOwner._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  /// Builds a [ServiceObject] corresponding to the [id] from [map].
-  /// The result may come from the cache.  The result will not necessarily
-  /// be [loaded].
-  ServiceObject getFromMap(ObservableMap map);
-
-  /// Creates a link to [id] relative to [this].
-  String relativeLink(String id);
-}
-
-/// State for a VM being inspected.
-abstract class VM extends ServiceObjectOwner {
-  @reflectable VM get vm => this;
-  @reflectable Isolate get isolate => null;
-
-  @reflectable Iterable<Isolate> get isolates => _isolateCache.values;
-
-  @reflectable String get link => '$id';
-  @reflectable String relativeLink(String id) => '$id';
-
-  @observable String version = 'unknown';
-  @observable String targetCPU;
-  @observable int architectureBits;
-  @observable double uptime = 0.0;
-  @observable bool assertsEnabled = false;
-  @observable bool typeChecksEnabled = false;
-  @observable String pid = '';
-  @observable DateTime lastUpdate;
-
-  VM() : super._empty(null) {
-    name = 'vm';
-    vmName = 'vm';
-    _cache['vm'] = this;
-    update(toObservable({'id':'vm', 'type':'@VM'}));
-  }
-
-  final StreamController<ServiceException> exceptions =
-      new StreamController.broadcast();
-  final StreamController<ServiceError> errors =
-      new StreamController.broadcast();
-  final StreamController<ServiceEvent> events =
-      new StreamController.broadcast();
-
-  void postEventMessage(String eventMessage, [dynamic data]) {
-      var map;
-      try {
-        map = _parseJSON(eventMessage);
-        assert(!map.containsKey('_data'));
-        if (data != null) {
-          map['_data'] = data;
-        }
-      } catch (e, st) {
-        Logger.root.severe('Ignoring malformed event message: ${eventMessage}');
-        return;
-      }
-      if (map['type'] != 'ServiceEvent') {
-        Logger.root.severe(
-            "Expected 'ServiceEvent' but found '${map['type']}'");
-        return;
-      }
-
-      // Extract the owning isolate from the event itself.
-      String owningIsolateId = map['isolate']['id'];
-      _getIsolate(owningIsolateId).then((owningIsolate) {
-          if (owningIsolate == null) {
-            // TODO(koda): Do we care about GC events in VM isolate?
-            Logger.root.severe(
-                'Ignoring event with unknown isolate id: $owningIsolateId');
-          } else {
-            var event = new ServiceObject._fromMap(owningIsolate, map);
-            events.add(event);
-          }
-      });
-  }
-
-  static final RegExp _currentIsolateMatcher = new RegExp(r'isolates/\d+');
-  static final RegExp _currentObjectMatcher = new RegExp(r'isolates/\d+/');
-  static final String _isolatesPrefix = 'isolates/';
-
-  String _parseObjectId(String id) {
-    Match m = _currentObjectMatcher.matchAsPrefix(id);
-    if (m == null) {
-      return null;
-    }
-    return m.input.substring(m.end);
-  }
-
-  String _parseIsolateId(String id) {
-    Match m = _currentIsolateMatcher.matchAsPrefix(id);
-    if (m == null) {
-      return '';
-    }
-    return id.substring(0, m.end);
-  }
-
-  Map<String,ServiceObject> _cache = new Map<String,ServiceObject>();
-  Map<String,Isolate> _isolateCache = new Map<String,Isolate>();
-
-  ServiceObject getFromMap(ObservableMap map) {
-    throw new UnimplementedError();
-  }
-
-  Future<ServiceObject> _getIsolate(String isolateId) {
-    if (isolateId == '') {
-      return new Future.value(null);
-    }
-    Isolate isolate = _isolateCache[isolateId];
-    if (isolate != null) {
-      return new Future.value(isolate);
-    }
-    // The isolate is not in the cache.  Reload the vm and see if the
-    // requested isolate is found.
-    return reload().then((result) {
-        if (result is! VM) {
-          return null;
-        }
-        assert(result == this);
-        return _isolateCache[isolateId];
-      });
-  }
-
-  Future<ServiceObject> get(String id) {
-    assert(id.startsWith('/') == false);
-    // Isolates are handled specially, since they can cache sub-objects.
-    if (id.startsWith(_isolatesPrefix)) {
-      String isolateId = _parseIsolateId(id);
-      String objectId = _parseObjectId(id);
-      return _getIsolate(isolateId).then((isolate) {
-        if (isolate == null) {
-          // The isolate does not exist.  Return the VM object instead.
-          //
-          // TODO(turnidge): Generate a service error?
-          return this;
-        }
-        if (objectId == null) {
-          return isolate.reload();
-        } else {
-          return isolate.get(objectId);
-        }
-      });
-    }
-
-    var obj = _cache[id];
-    if (obj != null) {
-      return obj.reload();
-    }
-
-    // Cache miss.  Get the object from the vm directly.
-    return getAsMap(id).then((ObservableMap map) {
-      var obj = new ServiceObject._fromMap(this, map);
-      if (obj.canCache) {
-        _cache.putIfAbsent(id, () => obj);
-      }
-      return obj;
-    });
-  }
-
-  dynamic _reviver(dynamic key, dynamic value) {
-    return value;
-  }
-
-  ObservableMap _parseJSON(String response) {
-    var map;
-    try {
-      var decoder = new JsonDecoder(_reviver);
-      map = decoder.convert(response);
-    } catch (e, st) {
-      return null;
-    }
-    return toObservable(map);
-  }
-
-  Future<ObservableMap> _processMap(ObservableMap map) {
-    // Verify that the top level response is a service map.
-    if (!_isServiceMap(map)) {
-      return new Future.error(
-            new ServiceObject._fromMap(this, toObservable({
-        'type': 'ServiceException',
-        'id': '',
-        'kind': 'FormatException',
-        'response': map,
-        'message': 'Top level service responses must be service maps.',
-      })));
-    }
-    // Preemptively capture ServiceError and ServiceExceptions.
-    if (map['type'] == 'ServiceError') {
-      return new Future.error(new ServiceObject._fromMap(this, map));
-    } else if (map['type'] == 'ServiceException') {
-      return new Future.error(new ServiceObject._fromMap(this, map));
-    }
-    // map is now guaranteed to be a non-error/exception ServiceObject.
-    return new Future.value(map);
-  }
-
-  Future<ObservableMap> _decodeError(e) {
-    return new Future.error(new ServiceObject._fromMap(this, toObservable({
-      'type': 'ServiceException',
-      'id': '',
-      'kind': 'DecodeException',
-      'response':
-          'This is likely a result of a known V8 bug. Although the '
-          'the bug has been fixed the fix may not be in your Chrome'
-          ' version. For more information see dartbug.com/18385. '
-          'Observatory is still functioning and you should try your'
-          ' action again.',
-      'message': 'Could not decode JSON: $e',
-    })));
-  }
-
-  /// Gets [id] as an [ObservableMap] from the service directly. If
-  /// an error occurs, the future is completed as an error with a
-  /// ServiceError or ServiceException. Therefore any chained then() calls
-  /// will only receive a map encoding a valid ServiceObject.
-  Future<ObservableMap> getAsMap(String id) {
-    return getString(id).then((response) {
-      var map = _parseJSON(response);
-      if (Tracer.current != null) {
-        Tracer.current.trace("Received response for ${id}", map:map);
-      }
-      return _processMap(map);
-    }).catchError((error) {
-      // ServiceError, forward to VM's ServiceError stream.
-      errors.add(error);
-      return new Future.error(error);
-    }, test: (e) => e is ServiceError).catchError((exception) {
-      // ServiceException, forward to VM's ServiceException stream.
-      exceptions.add(exception);
-      return new Future.error(exception);
-    }, test: (e) => e is ServiceException);
-  }
-
-  /// Get [id] as a [String] from the service directly. See [getAsMap].
-  Future<String> getString(String id);
-  /// Force the VM to disconnect.
-  void disconnect();
-  /// Completes when the VM first connects.
-  Future get onConnect;
-  /// Completes when the VM disconnects or there was an error connecting.
-  Future get onDisconnect;
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    if (mapIsRef) {
-      return;
-    }
-    _loaded = true;
-    version = map['version'];
-    targetCPU = map['targetCPU'];
-    architectureBits = map['architectureBits'];
-    uptime = map['uptime'];
-    var dateInMillis = int.parse(map['date']);
-    lastUpdate = new DateTime.fromMillisecondsSinceEpoch(dateInMillis);
-    assertsEnabled = map['assertsEnabled'];
-    pid = map['pid'];
-    typeChecksEnabled = map['typeChecksEnabled'];
-    _updateIsolates(map['isolates']);
-  }
-
-  void _updateIsolates(List newIsolates) {
-    var oldIsolateCache = _isolateCache;
-    var newIsolateCache = new Map<String,Isolate>();
-    for (var isolateMap in newIsolates) {
-      var isolateId = isolateMap['id'];
-      var isolate = oldIsolateCache[isolateId];
-      if (isolate != null) {
-        newIsolateCache[isolateId] = isolate;
-      } else {
-        isolate = new ServiceObject._fromMap(this, isolateMap);
-        newIsolateCache[isolateId] = isolate;
-        Logger.root.info('New isolate \'${isolate.id}\'');
-      }
-    }
-    // Update the individual isolates asynchronously.
-    newIsolateCache.forEach((isolateId, isolate) {
-      isolate.reload();
-    });
-
-    _isolateCache = newIsolateCache;
-  }
-}
-
-/// Snapshot in time of tag counters.
-class TagProfileSnapshot {
-  final double seconds;
-  final List<int> counters;
-  int get sum => _sum;
-  int _sum = 0;
-  TagProfileSnapshot(this.seconds, int countersLength)
-      : counters = new List<int>(countersLength);
-
-  /// Set [counters] and update [sum].
-  void set(List<int> counters) {
-    this.counters.setAll(0, counters);
-    for (var i = 0; i < this.counters.length; i++) {
-      _sum += this.counters[i];
-    }
-  }
-
-  /// Set [counters] with the delta from [counters] to [old_counters]
-  /// and update [sum].
-  void delta(List<int> counters, List<int> old_counters) {
-    for (var i = 0; i < this.counters.length; i++) {
-      this.counters[i] = counters[i] - old_counters[i];
-      _sum += this.counters[i];
-    }
-  }
-
-  /// Update [counters] with new maximum values seen in [counters].
-  void max(List<int> counters) {
-    for (var i = 0; i < counters.length; i++) {
-      var c = counters[i];
-      this.counters[i] = this.counters[i] > c ? this.counters[i] : c;
-    }
-  }
-
-  /// Zero [counters].
-  void zero() {
-    for (var i = 0; i < counters.length; i++) {
-      counters[i] = 0;
-    }
-  }
-}
-
-class TagProfile {
-  final List<String> names = new List<String>();
-  final List<TagProfileSnapshot> snapshots = new List<TagProfileSnapshot>();
-  double get updatedAtSeconds => _seconds;
-  double _seconds;
-  TagProfileSnapshot _maxSnapshot;
-  int _historySize;
-  int _countersLength = 0;
-
-  TagProfile(this._historySize);
-
-  void _processTagProfile(double seconds, ObservableMap tagProfile) {
-    _seconds = seconds;
-    var counters = tagProfile['counters'];
-    if (names.length == 0) {
-      // Initialization.
-      names.addAll(tagProfile['names']);
-      _countersLength = tagProfile['counters'].length;
-      for (var i = 0; i < _historySize; i++) {
-        var snapshot = new TagProfileSnapshot(0.0, _countersLength);
-        snapshot.zero();
-        snapshots.add(snapshot);
-      }
-      // The counters monotonically grow, keep track of the maximum value.
-      _maxSnapshot = new TagProfileSnapshot(0.0, _countersLength);
-      _maxSnapshot.set(counters);
-      return;
-    }
-    var snapshot = new TagProfileSnapshot(seconds, _countersLength);
-    // We snapshot the delta from the current counters to the maximum counter
-    // values.
-    snapshot.delta(counters, _maxSnapshot.counters);
-    _maxSnapshot.max(counters);
-    snapshots.add(snapshot);
-    // Only keep _historySize snapshots.
-    if (snapshots.length > _historySize) {
-      snapshots.removeAt(0);
-    }
-  }
-}
-
-class HeapSpace extends Observable {
-  @observable int used = 0;
-  @observable int capacity = 0;
-  @observable int external = 0;
-  @observable int collections = 0;
-  @observable double totalCollectionTimeInSeconds = 0.0;
-  @observable double averageCollectionPeriodInMillis = 0.0;
-
-  void update(Map heapMap) {
-    used = heapMap['used'];
-    capacity = heapMap['capacity'];
-    external = heapMap['external'];
-    collections = heapMap['collections'];
-    totalCollectionTimeInSeconds = heapMap['time'];
-    averageCollectionPeriodInMillis = heapMap['avgCollectionPeriodMillis'];
-  }
-}
-
-/// State for a running isolate.
-class Isolate extends ServiceObjectOwner with Coverage {
-  @reflectable VM get vm => owner;
-  @reflectable Isolate get isolate => this;
-  @observable ObservableMap counters = new ObservableMap();
-
-  String get link => '/${_id}';
-
-  @observable ServiceEvent pauseEvent = null;
-  bool get _isPaused => pauseEvent != null;
-
-  @observable bool running = false;
-  @observable bool idle = false;
-  @observable bool loading = true;
-  @observable bool ioEnabled = false;
-
-  Map<String,ServiceObject> _cache = new Map<String,ServiceObject>();
-  final TagProfile tagProfile = new TagProfile(20);
-
-  Isolate._empty(ServiceObjectOwner owner) : super._empty(owner) {
-    assert(owner is VM);
-  }
-
-  /// Creates a link to [id] relative to [this].
-  @reflectable String relativeLink(String id) => '/${this.id}/$id';
-
-  static const TAG_ROOT_ID = 'code/tag-0';
-
-  /// Returns the Code object for the root tag.
-  Code tagRoot() {
-    // TODO(turnidge): Use get() here instead?
-    return _cache[TAG_ROOT_ID];
-  }
-
-  void processProfile(ServiceMap profile) {
-    assert(profile.type == 'Profile');
-    var codeTable = new List<Code>();
-    var codeRegions = profile['codes'];
-    for (var codeRegion in codeRegions) {
-      Code code = codeRegion['code'];
-      assert(code != null);
-      codeTable.add(code);
-    }
-    _resetProfileData();
-    _updateProfileData(profile, codeTable);
-    var exclusiveTrie = profile['exclusive_trie'];
-    if (exclusiveTrie != null) {
-      profileTrieRoot = _processProfileTrie(exclusiveTrie, codeTable);
-    }
-  }
-
-  void _resetProfileData() {
-    _cache.values.forEach((value) {
-        if (value is Code) {
-          Code code = value;
-          code.resetProfileData();
-        }
-      });
-  }
-
-  void _updateProfileData(ServiceMap profile, List<Code> codeTable) {
-    var codeRegions = profile['codes'];
-    var sampleCount = profile['samples'];
-    for (var codeRegion in codeRegions) {
-      Code code = codeRegion['code'];
-      code.updateProfileData(codeRegion, codeTable, sampleCount);
-    }
-  }
-
-  /// Fetches and builds the class hierarchy for this isolate. Returns the
-  /// Object class object.
-  Future<Class> getClassHierarchy() {
-    return get('classes').then(_loadClasses).then(_buildClassHierarchy);
-  }
-
-  /// Given the class list, loads each class.
-  Future<List<Class>> _loadClasses(ServiceMap classList) {
-    assert(classList.type == 'ClassList');
-    var futureClasses = [];
-    for (var cls in classList['members']) {
-      // Skip over non-class classes.
-      if (cls is Class) {
-        futureClasses.add(cls.load());
-      }
-    }
-    return Future.wait(futureClasses);
-  }
-
-  /// Builds the class hierarchy and returns the Object class.
-  Future<Class> _buildClassHierarchy(List<Class> classes) {
-    rootClasses.clear();
-    objectClass = null;
-    for (var cls in classes) {
-      if (cls.superclass == null) {
-        rootClasses.add(cls);
-      }
-      if ((cls.vmName == 'Object') && (cls.isPatch == false)) {
-        objectClass = cls;
-      }
-    }
-    assert(objectClass != null);
-    return new Future.value(objectClass);
-  }
-
-  ServiceObject getFromMap(ObservableMap map) {
-    if (map == null) {
-      return null;
-    }
-    String id = map['id'];
-    var obj = _cache[id];
-    if (obj != null) {
-      // Consider calling update when map is not a reference.
-      return obj;
-    }
-    // Build the object from the map directly.
-    obj = new ServiceObject._fromMap(this, map);
-    if (obj != null && obj.canCache) {
-      _cache[id] = obj;
-    }
-    return obj;
-  }
-
-  Future<ServiceObject> get(String id) {
-    // Do not allow null ids or empty ids.
-    assert(id != null && id != '');
-    var obj = _cache[id];
-    if (obj != null) {
-      return obj.reload();
-    }
-    // Cache miss.  Get the object from the vm directly.
-    return vm.getAsMap(relativeLink(id)).then((ObservableMap map) {
-      var obj = new ServiceObject._fromMap(this, map);
-      if (obj.canCache) {
-        _cache.putIfAbsent(id, () => obj);
-      }
-      return obj;
-    });
-  }
-
-  @observable Class objectClass;
-  @observable final rootClasses = new ObservableList<Class>();
-
-  @observable Library rootLib;
-  @observable ObservableList<Library> libraries =
-      new ObservableList<Library>();
-  @observable ObservableMap topFrame;
-
-  @observable String name;
-  @observable String vmName;
-  @observable String mainPort;
-  @observable ServiceFunction entry;
-
-  @observable final Map<String, double> timers =
-      toObservable(new Map<String, double>());
-
-  final HeapSpace newSpace = new HeapSpace();
-  final HeapSpace oldSpace = new HeapSpace();
-
-  @observable String fileAndLine;
-
-  @observable DartError error;
-
-  void updateHeapsFromMap(ObservableMap map) {
-    newSpace.update(map['new']);
-    oldSpace.update(map['old']);
-  }
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    mainPort = map['mainPort'];
-    name = map['name'];
-    vmName = map['name'];
-    if (mapIsRef) {
-      return;
-    }
-    _loaded = true;
-    loading = false;
-
-    reloadBreakpoints();
-    _upgradeCollection(map, isolate);
-    if (map['rootLib'] == null ||
-        map['timers'] == null ||
-        map['heaps'] == null) {
-      Logger.root.severe("Malformed 'Isolate' response: $map");
-      return;
-    }
-    rootLib = map['rootLib'];
-    if (map['entry'] != null) {
-      entry = map['entry'];
-    }
-    if (map['topFrame'] != null) {
-      topFrame = map['topFrame'];
-    } else {
-      topFrame = null ;
-    }
-
-    var countersMap = map['tagCounters'];
-    if (countersMap != null) {
-      var names = countersMap['names'];
-      var counts = countersMap['counters'];
-      assert(names.length == counts.length);
-      var sum = 0;
-      for (var i = 0; i < counts.length; i++) {
-        sum += counts[i];
-      }
-      // TODO: Why does this not work without this?
-      counters = toObservable({});
-      if (sum == 0) {
-        for (var i = 0; i < names.length; i++) {
-          counters[names[i]] = '0.0%';
-        }
-      } else {
-        for (var i = 0; i < names.length; i++) {
-          counters[names[i]] =
-              (counts[i] / sum * 100.0).toStringAsFixed(2) + '%';
-        }
-      }
-    }
-    var timerMap = {};
-    map['timers'].forEach((timer) {
-        timerMap[timer['name']] = timer['time'];
-      });
-    timers['total'] = timerMap['time_total_runtime'];
-    timers['compile'] = timerMap['time_compilation'];
-    timers['gc'] = 0.0;  // TODO(turnidge): Export this from VM.
-    timers['init'] = (timerMap['time_script_loading'] +
-                      timerMap['time_creating_snapshot'] +
-                      timerMap['time_isolate_initialization'] +
-                      timerMap['time_bootstrap']);
-    timers['dart'] = timerMap['time_dart_execution'];
-
-    updateHeapsFromMap(map['heaps']);
-
-    List features = map['features'];
-    if (features != null) {
-      for (var feature in features) {
-        if (feature == 'io') {
-          ioEnabled = true;
-        }
-      }
-    }
-    // Isolate status
-    pauseEvent = map['pauseEvent'];
-    running = (!_isPaused && map['topFrame'] != null);
-    idle = (!_isPaused && map['topFrame'] == null);
-    error = map['error'];
-
-    libraries.clear();
-    libraries.addAll(map['libraries']);
-    libraries.sort(ServiceObject.LexicalSortName);
-  }
-
-  Future<TagProfile> updateTagProfile() {
-    return vm.getAsMap(relativeLink('profile/tag')).then((ObservableMap m) {
-      var seconds = new DateTime.now().millisecondsSinceEpoch / 1000.0;
-      tagProfile._processTagProfile(seconds, m);
-      return tagProfile;
-    });
-  }
-
-  @reflectable CodeTrieNode profileTrieRoot;
-  // The profile trie is serialized as a list of integers. Each node
-  // is recreated by consuming some portion of the list. The format is as
-  // follows:
-  // [0] index into codeTable of code object.
-  // [1] tick count (number of times this stack frame occured).
-  // [2] child node count
-  // Reading the trie is done by recursively reading the tree depth-first
-  // pre-order.
-  CodeTrieNode _processProfileTrie(List<int> data, List<Code> codeTable) {
-    // Setup state shared across calls to _readTrieNode.
-    _trieDataCursor = 0;
-    _trieData = data;
-    if (_trieData == null) {
-      return null;
-    }
-    if (_trieData.length < 3) {
-      // Not enough integers for 1 node.
-      return null;
-    }
-    // Read the tree, returns the root node.
-    return _readTrieNode(codeTable);
-  }
-  int _trieDataCursor;
-  List<int> _trieData;
-  CodeTrieNode _readTrieNode(List<Code> codeTable) {
-    // Read index into code table.
-    var index = _trieData[_trieDataCursor++];
-    // Lookup code object.
-    var code = codeTable[index];
-    // Frame counter.
-    var count = _trieData[_trieDataCursor++];
-    // Create node.
-    var node = new CodeTrieNode(code, count);
-    // Number of children.
-    var children = _trieData[_trieDataCursor++];
-    // Recursively read child nodes.
-    for (var i = 0; i < children; i++) {
-      var child = _readTrieNode(codeTable);
-      node.children.add(child);
-      node.summedChildCount += child.count;
-    }
-    return node;
-  }
-
-  ServiceMap breakpoints;
-
-  void _removeBreakpoint(ServiceMap bpt) {
-    var script = bpt['location']['script'];
-    var tokenPos = bpt['location']['tokenPos'];
-    assert(tokenPos != null);
-    if (script.loaded) {
-      var line = script.tokenToLine(tokenPos);
-      assert(line != null);
-      assert(script.lines[line - 1].bpt == bpt);
-      script.lines[line - 1].bpt = null;
-    }
-  }
-
-  void _addBreakpoint(ServiceMap bpt) {
-    var script = bpt['location']['script'];
-    var tokenPos = bpt['location']['tokenPos'];
-    assert(tokenPos != null);
-    if (script.loaded) {
-      var line = script.tokenToLine(tokenPos);
-      assert(line != null);
-      assert(script.lines[line - 1].bpt == null);
-      script.lines[line - 1].bpt = bpt;
-    } else {
-      // Load the script and then plop in the breakpoint.
-      script.load().then((_) {
-          _addBreakpoint(bpt);
-      });
-    }
-  }
-
-  void _updateBreakpoints(ServiceMap newBreakpoints) {
-    // Remove all of the old breakpoints from the Script lines.
-    if (breakpoints != null) {
-      for (var bpt in breakpoints['breakpoints']) {
-        _removeBreakpoint(bpt);
-      }
-    }
-    // Add all of the new breakpoints to the Script lines.
-    for (var bpt in newBreakpoints['breakpoints']) {
-      _addBreakpoint(bpt);
-    }
-    breakpoints = newBreakpoints;
-  }
-
-  Future<ServiceObject> _inProgressReloadBpts;
-
-  Future reloadBreakpoints() {
-    // TODO(turnidge): Can reusing the Future here ever cause us to
-    // get stale breakpoints?
-    if (_inProgressReloadBpts == null) {
-      _inProgressReloadBpts =
-          get('debug/breakpoints').then((newBpts) {
-              _updateBreakpoints(newBpts);
-          }).whenComplete(() {
-              _inProgressReloadBpts = null;
-          });
-    }
-    return _inProgressReloadBpts;
-  }
-
-  Future<ServiceObject> setBreakpoint(Script script, int line) {
-    return get(script.id + "/setBreakpoint?line=${line}").then((result) {
-        if (result is DartError) {
-          // Unable to set a breakpoint at desired line.
-          script.lines[line - 1].possibleBpt = false;
-        }
-        return reloadBreakpoints();
-      });
-  }
-
-  Future clearBreakpoint(ServiceMap bpt) {
-    return get('${bpt.id}/clear').then((result) {
-        if (result is DartError) {
-          // TODO(turnidge): Handle this more gracefully.
-          Logger.root.severe(result.message);
-        }
-        if (pauseEvent != null &&
-            pauseEvent.breakpoint != null &&
-            (pauseEvent.breakpoint['id'] == bpt['id'])) {
-          return isolate.reload();
-        } else {
-          return reloadBreakpoints();
-        }
-      });
-  }
-
-  Future pause() {
-    return get("debug/pause").then((result) {
-        if (result is DartError) {
-          // TODO(turnidge): Handle this more gracefully.
-          Logger.root.severe(result.message);
-        }
-        return isolate.reload();
-      });
-  }
-
-  Future resume() {
-    return get("debug/resume").then((result) {
-        if (result is DartError) {
-          // TODO(turnidge): Handle this more gracefully.
-          Logger.root.severe(result.message);
-        }
-        return isolate.reload();
-      });
-  }
-
-  Future stepInto() {
-    return get("debug/resume?step=into").then((result) {
-        if (result is DartError) {
-          // TODO(turnidge): Handle this more gracefully.
-          Logger.root.severe(result.message);
-        }
-        return isolate.reload();
-      });
-  }
-
-  Future stepOver() {
-    return get("debug/resume?step=over").then((result) {
-        if (result is DartError) {
-          // TODO(turnidge): Handle this more gracefully.
-          Logger.root.severe(result.message);
-        }
-        return isolate.reload();
-      });
-  }
-
-  Future stepOut() {
-    return get("debug/resume?step=out").then((result) {
-        if (result is DartError) {
-          // TODO(turnidge): Handle this more gracefully.
-          Logger.root.severe(result.message);
-        }
-        return isolate.reload();
-      });
-  }
-
-  final ObservableMap<String, ServiceMetric> dartMetrics =
-      new ObservableMap<String, ServiceMetric>();
-
-  final ObservableMap<String, ServiceMetric> vmMetrics =
-      new ObservableMap<String, ServiceMetric>();
-
-  Future<ObservableMap<String, ServiceMetric>> _refreshMetrics(
-      String id,
-      ObservableMap<String, ServiceMetric> metricsMap) {
-    return get(id).then((result) {
-      if (result is DartError) {
-        // TODO(turnidge): Handle this more gracefully.
-        Logger.root.severe(result.message);
-        return null;
-      }
-      // Clear metrics map.
-      metricsMap.clear();
-      // Repopulate metrics map.
-      var members = result['members'];
-      for (var metric in members) {
-        metricsMap[metric.id] = metric;
-      }
-      return metricsMap;
-    });
-  }
-
-  Future<ObservableMap<String, ServiceMetric>> refreshDartMetrics() {
-    return _refreshMetrics('metrics', dartMetrics);
-  }
-
-  Future<ObservableMap<String, ServiceMetric>> refreshVMMetrics() {
-    return _refreshMetrics('metrics/vm', vmMetrics);
-  }
-
-  Future refreshMetrics() {
-    return refreshDartMetrics().then((_) => refreshVMMetrics());
-  }
-
-  String toString() => "Isolate($_id)";
-}
-
-/// A [ServiceObject] which implements [ObservableMap].
-class ServiceMap extends ServiceObject implements ObservableMap {
-  final ObservableMap _map = new ObservableMap();
-  static String objectIdRingPrefix = 'objects/';
-
-  bool get canCache {
-    return (_type == 'Class' ||
-            _type == 'Function' ||
-            _type == 'Field') &&
-           !_id.startsWith(objectIdRingPrefix);
-  }
-  bool get immutable => false;
-
-  ServiceMap._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _upgradeValues() {
-    assert(owner != null);
-    _upgradeCollection(_map, owner);
-  }
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    _loaded = !mapIsRef;
-
-    // TODO(turnidge): Currently _map.clear() prevents us from
-    // upgrading an already upgraded submap.  Is clearing really the
-    // right thing to do here?
-    _map.clear();
-    _map.addAll(map);
-
-    name = _map['name'];
-    vmName = (_map.containsKey('vmName') ? _map['vmName'] : name);
-    _upgradeValues();
-  }
-
-  // Forward Map interface calls.
-  void addAll(Map other) => _map.addAll(other);
-  void clear() => _map.clear();
-  bool containsValue(v) => _map.containsValue(v);
-  bool containsKey(k) => _map.containsKey(k);
-  void forEach(Function f) => _map.forEach(f);
-  putIfAbsent(key, Function ifAbsent) => _map.putIfAbsent(key, ifAbsent);
-  void remove(key) => _map.remove(key);
-  operator [](k) => _map[k];
-  operator []=(k, v) => _map[k] = v;
-  bool get isEmpty => _map.isEmpty;
-  bool get isNotEmpty => _map.isNotEmpty;
-  Iterable get keys => _map.keys;
-  Iterable get values => _map.values;
-  int get length => _map.length;
-
-  // Forward ChangeNotifier interface calls.
-  bool deliverChanges() => _map.deliverChanges();
-  void notifyChange(ChangeRecord record) => _map.notifyChange(record);
-  notifyPropertyChange(Symbol field, Object oldValue, Object newValue) =>
-      _map.notifyPropertyChange(field, oldValue, newValue);
-  void observed() => _map.observed();
-  void unobserved() => _map.unobserved();
-  Stream<List<ChangeRecord>> get changes => _map.changes;
-  bool get hasObservers => _map.hasObservers;
-
-  String toString() => "ServiceMap($_map)";
-}
-
-/// A [DartError] is peered to a Dart Error object.
-class DartError extends ServiceObject {
-  DartError._empty(ServiceObject owner) : super._empty(owner);
-
-  @observable String kind;
-  @observable String message;
-  @observable Instance exception;
-  @observable Instance stacktrace;
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    kind = map['kind'];
-    message = map['message'];
-    exception = new ServiceObject._fromMap(owner, map['exception']);
-    stacktrace = new ServiceObject._fromMap(owner, map['stacktrace']);
-    name = 'DartError $kind';
-    vmName = name;
-  }
-
-  String toString() => 'DartError($message)';
-}
-
-/// A [ServiceError] is an error that was triggered in the service
-/// server or client. Errors are prorammer mistakes that could have
-/// been prevented, for example, requesting a non-existant path over the
-/// service.
-class ServiceError extends ServiceObject {
-  ServiceError._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  @observable String kind;
-  @observable String message;
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    _loaded = true;
-    kind = map['kind'];
-    message = map['message'];
-    name = 'ServiceError $kind';
-    vmName = name;
-  }
-
-  String toString() => 'ServiceError($message)';
-}
-
-/// A [ServiceException] is an exception that was triggered in the service
-/// server or client. Exceptions are events that should be handled,
-/// for example, an isolate went away or the connection to the VM was lost.
-class ServiceException extends ServiceObject {
-  ServiceException._empty(ServiceObject owner) : super._empty(owner);
-
-  @observable String kind;
-  @observable String message;
-  @observable dynamic response;
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    kind = map['kind'];
-    message = map['message'];
-    response = map['response'];
-    name = 'ServiceException $kind';
-    vmName = name;
-  }
-
-  String toString() => 'ServiceException($message)';
-}
-
-/// A [ServiceEvent] is an asynchronous event notification from the vm.
-class ServiceEvent extends ServiceObject {
-  ServiceEvent._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  ServiceEvent.vmDisconencted() : super._empty(null) {
-    eventType = 'VMDisconnected';
-  }
-
-  @observable String eventType;
-  @observable ServiceMap breakpoint;
-  @observable ServiceMap exception;
-  @observable ByteData data;
-  @observable int count;
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    _loaded = true;
-    _upgradeCollection(map, owner);
-    eventType = map['eventType'];
-    name = 'ServiceEvent $eventType';
-    vmName = name;
-    if (map['breakpoint'] != null) {
-      breakpoint = map['breakpoint'];
-    }
-    if (map['exception'] != null) {
-      exception = map['exception'];
-    }
-    if (map['_data'] != null) {
-      data = map['_data'];
-    }
-    if (map['count'] != null) {
-      count = map['count'];
-    }
-  }
-
-  String toString() {
-    return 'ServiceEvent of type $eventType with '
-        '${data == null ? 0 : data.lengthInBytes} bytes of binary data';
-  }
-}
-
-class Library extends ServiceObject with Coverage {
-  @observable String url;
-  @reflectable final imports = new ObservableList<Library>();
-  @reflectable final scripts = new ObservableList<Script>();
-  @reflectable final classes = new ObservableList<Class>();
-  @reflectable final variables = new ObservableList<Field>();
-  @reflectable final functions = new ObservableList<ServiceFunction>();
-
-  bool get canCache => true;
-  bool get immutable => false;
-
-  Library._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    url = map['url'];
-    var shortUrl = url;
-    if (url.startsWith('file://') ||
-        url.startsWith('http://')) {
-      shortUrl = url.substring(url.lastIndexOf('/') + 1);
-    }
-    name = map['name'];
-    if (name.isEmpty) {
-      // When there is no name for a library, use the shortUrl.
-      name = shortUrl;
-    }
-    vmName = (map.containsKey('vmName') ? map['vmName'] : name);
-    if (mapIsRef) {
-      return;
-    }
-    _loaded = true;
-    _upgradeCollection(map, isolate);
-    imports.clear();
-    imports.addAll(removeDuplicatesAndSortLexical(map['imports']));
-    scripts.clear();
-    scripts.addAll(removeDuplicatesAndSortLexical(map['scripts']));
-    classes.clear();
-    classes.addAll(map['classes']);
-    classes.sort(ServiceObject.LexicalSortName);
-    variables.clear();
-    variables.addAll(map['variables']);
-    variables.sort(ServiceObject.LexicalSortName);
-    functions.clear();
-    functions.addAll(map['functions']);
-    functions.sort(ServiceObject.LexicalSortName);
-  }
-
-  String toString() => "Library($url)";
-}
-
-class AllocationCount extends Observable {
-  @observable int instances = 0;
-  @observable int bytes = 0;
-
-  void reset() {
-    instances = 0;
-    bytes = 0;
-  }
-
-  bool get empty => (instances == 0) && (bytes == 0);
-}
-
-class Allocations {
-  // Indexes into VM provided array. (see vm/class_table.h).
-  static const ALLOCATED_BEFORE_GC = 0;
-  static const ALLOCATED_BEFORE_GC_SIZE = 1;
-  static const LIVE_AFTER_GC = 2;
-  static const LIVE_AFTER_GC_SIZE = 3;
-  static const ALLOCATED_SINCE_GC = 4;
-  static const ALLOCATED_SINCE_GC_SIZE = 5;
-  static const ACCUMULATED = 6;
-  static const ACCUMULATED_SIZE = 7;
-
-  final AllocationCount accumulated = new AllocationCount();
-  final AllocationCount current = new AllocationCount();
-
-  void update(List stats) {
-    accumulated.instances = stats[ACCUMULATED];
-    accumulated.bytes = stats[ACCUMULATED_SIZE];
-    current.instances = stats[LIVE_AFTER_GC] + stats[ALLOCATED_SINCE_GC];
-    current.bytes = stats[LIVE_AFTER_GC_SIZE] + stats[ALLOCATED_SINCE_GC_SIZE];
-  }
-
-  bool get empty => accumulated.empty && current.empty;
-}
-
-class Class extends ServiceObject with Coverage {
-  @observable Library library;
-  @observable Script script;
-
-  @observable bool isAbstract;
-  @observable bool isConst;
-  @observable bool isFinalized;
-  @observable bool isPatch;
-  @observable bool isImplemented;
-
-  @observable int tokenPos;
-  @observable int endTokenPos;
-
-  @observable ServiceMap error;
-  @observable int vmCid;
-
-  final Allocations newSpace = new Allocations();
-  final Allocations oldSpace = new Allocations();
-  final AllocationCount promotedByLastNewGC = new AllocationCount();
-
-  bool get hasNoAllocations => newSpace.empty && oldSpace.empty;
-
-  @reflectable final fields = new ObservableList<Field>();
-  @reflectable final functions = new ObservableList<ServiceFunction>();
-
-  @observable Class superclass;
-  @reflectable final interfaces = new ObservableList<Class>();
-  @reflectable final subclasses = new ObservableList<Class>();
-
-  bool get canCache => true;
-  bool get immutable => false;
-
-  Class._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    name = map['name'];
-    vmName = (map.containsKey('vmName') ? map['vmName'] : name);
-    var idPrefix = "classes/";
-    assert(id.startsWith(idPrefix));
-    vmCid = int.parse(id.substring(idPrefix.length));
-
-    if (mapIsRef) {
-      return;
-    }
-
-    // We are fully loaded.
-    _loaded = true;
-
-    // Extract full properties.
-    _upgradeCollection(map, isolate);
-
-    // Some builtin classes aren't associated with a library.
-    if (map['library'] is Library) {
-      library = map['library'];
-    } else {
-      library = null;
-    }
-
-    script = map['script'];
-
-    isAbstract = map['abstract'];
-    isConst = map['const'];
-    isFinalized = map['finalized'];
-    isPatch = map['patch'];
-    isImplemented = map['implemented'];
-
-    tokenPos = map['tokenPos'];
-    endTokenPos = map['endTokenPos'];
-
-    subclasses.clear();
-    subclasses.addAll(map['subclasses']);
-    subclasses.sort(ServiceObject.LexicalSortName);
-
-    fields.clear();
-    fields.addAll(map['fields']);
-    fields.sort(ServiceObject.LexicalSortName);
-
-    functions.clear();
-    functions.addAll(map['functions']);
-    functions.sort(ServiceObject.LexicalSortName);
-
-    superclass = map['super'];
-    // Work-around Object not tracking its subclasses in the VM.
-    if (superclass != null && superclass.name == "Object") {
-      superclass._addSubclass(this);
-    }
-    error = map['error'];
-
-    var allocationStats = map['allocationStats'];
-    if (allocationStats != null) {
-      newSpace.update(allocationStats['new']);
-      oldSpace.update(allocationStats['old']);
-      promotedByLastNewGC.instances = allocationStats['promotedInstances'];
-      promotedByLastNewGC.bytes = allocationStats['promotedBytes'];
-    }
-  }
-
-  void _addSubclass(Class subclass) {
-    if (subclasses.contains(subclass)) {
-      return;
-    }
-    subclasses.add(subclass);
-    subclasses.sort(ServiceObject.LexicalSortName);
-  }
-
-  Future<ServiceObject> get(String command) {
-    return isolate.get(id + "/$command");
-  }
-
-  String toString() => 'Class($vmName)';
-}
-
-class Instance extends ServiceObject {
-  @observable Class clazz;
-  @observable int size;
-  @observable String valueAsString;  // If primitive.
-  @observable bool valueAsStringIsTruncated;
-  @observable ServiceFunction closureFunc;  // If a closure.
-  @observable Context closureCtxt;  // If a closure.
-  @observable String name;  // If a Type.
-  @observable int length; // If a List.
-
-  @observable var typeClass;
-  @observable var fields;
-  @observable var nativeFields;
-  @observable var elements;
-  @observable var userName;
-  @observable var referent;  // If a MirrorReference.
-  @observable Instance key;  // If a WeakProperty.
-  @observable Instance value;  // If a WeakProperty.
-
-  bool get isClosure => closureFunc != null;
-
-  Instance._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    // Extract full properties.
-    _upgradeCollection(map, isolate);
-
-    clazz = map['class'];
-    size = map['size'];
-    valueAsString = map['valueAsString'];
-    // Coerce absence to false.
-    valueAsStringIsTruncated = map['valueAsStringIsTruncated'] == true;
-    closureFunc = map['closureFunc'];
-    closureCtxt = map['closureCtxt'];
-    name = map['name'];
-    length = map['length'];
-
-    if (mapIsRef) {
-      return;
-    }
-
-    nativeFields = map['nativeFields'];
-    fields = map['fields'];
-    elements = map['elements'];
-    typeClass = map['type_class'];
-    userName = map['user_name'];
-    referent = map['referent'];
-    key = map['key'];
-    value = map['value'];
-
-    // We are fully loaded.
-    _loaded = true;
-  }
-
-  String get shortName => valueAsString != null ? valueAsString : 'a ${clazz.name}';
-
-  String toString() => 'Instance($shortName)';
-}
-
-
-class Context extends ServiceObject {
-  @observable Class clazz;
-  @observable int size;
-
-  @observable var parentContext;
-  @observable int length;
-  @observable var variables;
-
-  Context._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    // Extract full properties.
-    _upgradeCollection(map, isolate);
-
-    size = map['size'];
-    length = map['length'];
-    parentContext = map['parent'];
-
-    if (mapIsRef) {
-      return;
-    }
-
-    clazz = map['class'];
-    variables = map['variables'];
-
-    // We are fully loaded.
-    _loaded = true;
-  }
-
-  String toString() => 'Context($length)';
-}
-
-
-// TODO(koda): Sync this with VM.
-class FunctionKind {
-  final String _strValue;
-  FunctionKind._internal(this._strValue);
-  toString() => _strValue;
-  bool isFake() => [kCollected, kNative, kTag, kReused].contains(this);
-
-  static FunctionKind fromJSON(String value) {
-    switch(value) {
-      case 'kRegularFunction': return kRegularFunction;
-      case 'kClosureFunction': return kClosureFunction;
-      case 'kGetterFunction': return kGetterFunction;
-      case 'kSetterFunction': return kSetterFunction;
-      case 'kConstructor': return kConstructor;
-      case 'kImplicitGetter': return kImplicitGetterFunction;
-      case 'kImplicitSetter': return kImplicitSetterFunction;
-      case 'kStaticInitializer': return kStaticInitializer;
-      case 'kMethodExtractor': return kMethodExtractor;
-      case 'kNoSuchMethodDispatcher': return kNoSuchMethodDispatcher;
-      case 'kInvokeFieldDispatcher': return kInvokeFieldDispatcher;
-      case 'Collected': return kCollected;
-      case 'Native': return kNative;
-      case 'Tag': return kTag;
-      case 'Reused': return kReused;
-    }
-    return kUNKNOWN;
-  }
-
-  static FunctionKind kRegularFunction = new FunctionKind._internal('function');
-  static FunctionKind kClosureFunction = new FunctionKind._internal('closure function');
-  static FunctionKind kGetterFunction = new FunctionKind._internal('getter function');
-  static FunctionKind kSetterFunction = new FunctionKind._internal('setter function');
-  static FunctionKind kConstructor = new FunctionKind._internal('constructor');
-  static FunctionKind kImplicitGetterFunction = new FunctionKind._internal('implicit getter function');
-  static FunctionKind kImplicitSetterFunction = new FunctionKind._internal('implicit setter function');
-  static FunctionKind kStaticInitializer = new FunctionKind._internal('static initializer');
-  static FunctionKind kMethodExtractor = new FunctionKind._internal('method extractor');
-  static FunctionKind kNoSuchMethodDispatcher = new FunctionKind._internal('noSuchMethod dispatcher');
-  static FunctionKind kInvokeFieldDispatcher = new FunctionKind._internal('invoke field dispatcher');
-  static FunctionKind kCollected = new FunctionKind._internal('Collected');
-  static FunctionKind kNative = new FunctionKind._internal('Native');
-  static FunctionKind kTag = new FunctionKind._internal('Tag');
-  static FunctionKind kReused = new FunctionKind._internal('Reused');
-  static FunctionKind kUNKNOWN = new FunctionKind._internal('UNKNOWN');
-}
-
-class ServiceFunction extends ServiceObject with Coverage {
-  @observable Class owningClass;
-  @observable Library owningLibrary;
-  @observable bool isStatic;
-  @observable bool isConst;
-  @observable ServiceFunction parent;
-  @observable Script script;
-  @observable int tokenPos;
-  @observable int endTokenPos;
-  @observable Code code;
-  @observable Code unoptimizedCode;
-  @observable bool isOptimizable;
-  @observable bool isInlinable;
-  @observable FunctionKind kind;
-  @observable int deoptimizations;
-  @observable String qualifiedName;
-  @observable int usageCounter;
-  @observable bool isDart;
-
-  ServiceFunction._empty(ServiceObject owner) : super._empty(owner);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    name = map['name'];
-    vmName = (map.containsKey('vmName') ? map['vmName'] : name);
-
-    _upgradeCollection(map, isolate);
-
-    owningClass = map.containsKey('owningClass') ? map['owningClass'] : null;
-    owningLibrary = map.containsKey('owningLibrary') ? map['owningLibrary'] : null;
-    kind = FunctionKind.fromJSON(map['kind']);
-    isDart = !kind.isFake();
-
-    if (mapIsRef) { return; }
-
-    isStatic = map['static'];
-    isConst = map['const'];
-    parent = map['parent'];
-    script = map['script'];
-    tokenPos = map['tokenPos'];
-    endTokenPos = map['endTokenPos'];
-    code = _convertNull(map['code']);
-    unoptimizedCode = _convertNull(map['unoptimizedCode']);
-    isOptimizable = map['optimizable'];
-    isInlinable = map['inlinable'];
-    deoptimizations = map['deoptimizations'];
-    usageCounter = map['usageCounter'];
-
-    if (parent == null) {
-      qualifiedName = (owningClass != null) ?
-          "${owningClass.name}.${name}" :
-          name;
-    } else {
-      qualifiedName = "${parent.qualifiedName}.${name}";
-    }
-
-  }
-}
-
-
-class Field extends ServiceObject {
-  @observable var /* Library or Class */ owner;
-  @observable Instance declaredType;
-  @observable bool isStatic;
-  @observable bool isFinal;
-  @observable bool isConst;
-  @observable Instance value;
-  @observable String name;
-  @observable String vmName;
-
-  @observable bool guardNullable;
-  @observable String guardClass;
-  @observable String guardLength;
-  @observable Script script;
-  @observable int tokenPos;
-
-  Field._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    // Extract full properties.
-    _upgradeCollection(map, isolate);
-
-    name = map['name'];
-    vmName = (map.containsKey('vmName') ? map['vmName'] : name);
-    owner = map['owner'];
-    declaredType = map['declaredType'];
-    isStatic = map['static'];
-    isFinal = map['final'];
-    isConst = map['const'];
-    value = map['value'];
-
-    if (mapIsRef) {
-      return;
-    }
-
-    guardNullable = map['guardNullable'];
-    guardClass = map['guardClass'];
-    guardLength = map['guardLength'];
-    script = map['script'];
-    tokenPos = map['tokenPos'];
-
-    _loaded = true;
-  }
-
-  String toString() => 'Field(${owner.name}.$name)';
-}
-
-
-class ScriptLine extends Observable {
-  final Script script;
-  final int line;
-  final String text;
-  @observable int hits;
-  @observable ServiceMap bpt;
-  @observable bool possibleBpt = true;
-
-  static bool _isTrivialToken(String token) {
-    if (token == 'else') {
-      return true;
-    }
-    for (var c in token.split('')) {
-      switch (c) {
-        case '{':
-        case '}':
-        case '(':
-        case ')':
-        case ';':
-          break;
-        default:
-          return false;
-      }
-    }
-    return true;
-  }
-
-  static bool _isTrivialLine(String text) {
-    var wsTokens = text.split(new RegExp(r"(\s)+"));
-    for (var wsToken in wsTokens) {
-      var tokens = wsToken.split(new RegExp(r"(\b)"));
-      for (var token in tokens) {
-        if (!_isTrivialToken(token)) {
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  ScriptLine(this.script, this.line, this.text) {
-    possibleBpt = !_isTrivialLine(text);
-
-    // TODO(turnidge): This is not so efficient.  Consider improving.
-    for (var bpt in this.script.isolate.breakpoints['breakpoints']) {
-      var bptScript = bpt['location']['script'];
-      var bptTokenPos = bpt['location']['tokenPos'];
-      if (bptScript == this.script &&
-          bptScript.tokenToLine(bptTokenPos) == line) {
-        this.bpt = bpt;
-      }
-    }
-  }
-}
-
-class Script extends ServiceObject with Coverage {
-  final lines = new ObservableList<ScriptLine>();
-  final _hits = new Map<int, int>();
-  @observable String kind;
-  @observable int firstTokenPos;
-  @observable int lastTokenPos;
-  @observable Library owningLibrary;
-  bool get canCache => true;
-  bool get immutable => true;
-
-  String _shortUrl;
-  String _url;
-
-  Script._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  ScriptLine getLine(int line) {
-    assert(line >= 1);
-    return lines[line - 1];
-  }
-
-  /// This function maps a token position to a line number.
-  int tokenToLine(int token) => _tokenToLine[token];
-  Map _tokenToLine = {};
-
-  /// This function maps a token position to a column number.
-  int tokenToCol(int token) => _tokenToCol[token];
-  Map _tokenToCol = {};
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    _upgradeCollection(map, isolate);
-    kind = map['kind'];
-    _url = map['name'];
-    _shortUrl = _url.substring(_url.lastIndexOf('/') + 1);
-    name = _shortUrl;
-    vmName = _url;
-    if (mapIsRef) {
-      return;
-    }
-    _processSource(map['source']);
-    _parseTokenPosTable(map['tokenPosTable']);
-    owningLibrary = map['owningLibrary'];
-  }
-
-  void _parseTokenPosTable(List<List<int>> table) {
-    if (table == null) {
-      return;
-    }
-    _tokenToLine.clear();
-    _tokenToCol.clear();
-    firstTokenPos = null;
-    lastTokenPos = null;
-    var lineSet = new Set();
-
-    for (var line in table) {
-      // Each entry begins with a line number...
-      var lineNumber = line[0];
-      lineSet.add(lineNumber);
-      for (var pos = 1; pos < line.length; pos += 2) {
-        // ...and is followed by (token offset, col number) pairs.
-        var tokenOffset = line[pos];
-        var colNumber = line[pos+1];
-        if (firstTokenPos == null) {
-          // Mark first token position.
-          firstTokenPos = tokenOffset;
-          lastTokenPos = tokenOffset;
-        } else {
-          // Keep track of max and min token positions.
-          firstTokenPos = (firstTokenPos <= tokenOffset) ?
-              firstTokenPos : tokenOffset;
-          lastTokenPos = (lastTokenPos >= tokenOffset) ?
-              lastTokenPos : tokenOffset;
-        }
-        _tokenToLine[tokenOffset] = lineNumber;
-        _tokenToCol[tokenOffset] = colNumber;
-      }
-    }
-
-    for (var line in lines) {
-      // Remove possible breakpoints on lines with no tokens.
-      if (!lineSet.contains(line.line)) {
-        line.possibleBpt = false;
-      }
-    }
-  }
-
-  void _processHits(List scriptHits) {
-    // Update hits table.
-    for (var i = 0; i < scriptHits.length; i += 2) {
-      var line = scriptHits[i];
-      var hit = scriptHits[i + 1]; // hit status.
-      assert(line >= 1); // Lines start at 1.
-      var oldHits = _hits[line];
-      if (oldHits != null) {
-        hit += oldHits;
-      }
-      _hits[line] = hit;
-    }
-    _applyHitsToLines();
-  }
-
-  void _processSource(String source) {
-    // Preemptyively mark that this is not loaded.
-    _loaded = false;
-    if (source == null) {
-      return;
-    }
-    var sourceLines = source.split('\n');
-    if (sourceLines.length == 0) {
-      return;
-    }
-    // We have the source to the script. This is now loaded.
-    _loaded = true;
-    lines.clear();
-    Logger.root.info('Adding ${sourceLines.length} source lines for ${_url}');
-    for (var i = 0; i < sourceLines.length; i++) {
-      lines.add(new ScriptLine(this, i + 1, sourceLines[i]));
-    }
-    _applyHitsToLines();
-  }
-
-  void _applyHitsToLines() {
-    for (var line in lines) {
-      var hits = _hits[line.line];
-      line.hits = hits;
-    }
-  }
-}
-
-class CodeTick {
-  final int address;
-  final int exclusiveTicks;
-  final int inclusiveTicks;
-  CodeTick(this.address, this.exclusiveTicks, this.inclusiveTicks);
-}
-
-class PcDescriptor extends Observable {
-  final int address;
-  @reflectable final int deoptId;
-  @reflectable final int tokenPos;
-  @reflectable final int tryIndex;
-  @reflectable final String kind;
-  @observable Script script;
-  @observable String formattedLine;
-  PcDescriptor(this.address, this.deoptId, this.tokenPos, this.tryIndex,
-               this.kind);
-
-  @reflectable String formattedDeoptId() {
-    if (deoptId == -1) {
-      return 'N/A';
-    }
-    return deoptId.toString();
-  }
-
-  @reflectable String formattedTokenPos() {
-    if (tokenPos == -1) {
-      return '';
-    }
-    return tokenPos.toString();
-  }
-
-  void processScript(Script script) {
-    this.script = null;
-    if (tokenPos == -1) {
-      return;
-    }
-    var line = script.tokenToLine(tokenPos);
-    if (line == null) {
-      return;
-    }
-    this.script = script;
-    var scriptLine = script.getLine(line);
-    formattedLine = scriptLine.text;
-  }
-}
-
-class PcDescriptors extends ServiceObject {
-  @observable Class clazz;
-  @observable int size;
-  bool get canCache => false;
-  bool get immutable => true;
-  @reflectable final List<PcDescriptor> descriptors =
-      new ObservableList<PcDescriptor>();
-
-  PcDescriptors._empty(ServiceObjectOwner owner) : super._empty(owner) {
-    print('created PcDescriptors.');
-  }
-
-  void _update(ObservableMap m, bool mapIsRef) {
-    if (mapIsRef) {
-      return;
-    }
-    _upgradeCollection(m, isolate);
-    clazz = m['class'];
-    size = m['size'];
-    descriptors.clear();
-    for (var descriptor in m['members']) {
-      var address = int.parse(descriptor['pc'], radix:16);
-      var deoptId = descriptor['deoptId'];
-      var tokenPos = descriptor['tokenPos'];
-      var tryIndex = descriptor['tryIndex'];
-      var kind = descriptor['kind'].trim();
-      descriptors.add(
-          new PcDescriptor(address, deoptId, tokenPos, tryIndex, kind));
-    }
-  }
-}
-
-class LocalVarDescriptor extends Observable {
-  @reflectable final String name;
-  @reflectable final int index;
-  @reflectable final int beginPos;
-  @reflectable final int endPos;
-  @reflectable final int scopeId;
-  @reflectable final String kind;
-
-  LocalVarDescriptor(this.name, this.index, this.beginPos, this.endPos,
-                     this.scopeId, this.kind);
-}
-
-class LocalVarDescriptors extends ServiceObject {
-  @observable Class clazz;
-  @observable int size;
-  bool get canCache => false;
-  bool get immutable => true;
-  @reflectable final List<LocalVarDescriptor> descriptors =
-        new ObservableList<LocalVarDescriptor>();
-  LocalVarDescriptors._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap m, bool mapIsRef) {
-    if (mapIsRef) {
-      return;
-    }
-    _upgradeCollection(m, isolate);
-    clazz = m['class'];
-    size = m['size'];
-    descriptors.clear();
-    for (var descriptor in m['members']) {
-      var name = descriptor['name'];
-      var index = descriptor['index'];
-      var beginPos = descriptor['beginPos'];
-      var endPos = descriptor['endPos'];
-      var scopeId = descriptor['scopeId'];
-      var kind = descriptor['kind'].trim();
-      descriptors.add(
-          new LocalVarDescriptor(name, index, beginPos, endPos, scopeId, kind));
-    }
-  }
-}
-
-class TokenStream extends ServiceObject {
-  @observable Class clazz;
-  @observable int size;
-  bool get canCache => false;
-  bool get immutable => true;
-
-  @observable String privateKey;
-
-  TokenStream._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  void _update(ObservableMap m, bool mapIsRef) {
-    if (mapIsRef) {
-      return;
-    }
-    _upgradeCollection(m, isolate);
-    clazz = m['class'];
-    size = m['size'];
-    privateKey = m['privateKey'];
-  }
-}
-
-class CodeInstruction extends Observable {
-  @observable final int address;
-  @observable final String machine;
-  @observable final String human;
-  @observable CodeInstruction jumpTarget;
-  @reflectable List<PcDescriptor> descriptors =
-      new ObservableList<PcDescriptor>();
-
-  static String formatPercent(num a, num total) {
-    var percent = 100.0 * (a / total);
-    return '${percent.toStringAsFixed(2)}%';
-  }
-
-  CodeInstruction(this.address, this.machine, this.human);
-
-  @reflectable bool get isComment => address == 0;
-  @reflectable bool get hasDescriptors => descriptors.length > 0;
-
-  @reflectable String formattedAddress() {
-    if (address == 0) {
-      return '';
-    }
-    return '0x${address.toRadixString(16)}';
-  }
-
-  @reflectable String formattedInclusive(Code code) {
-    if (code == null) {
-      return '';
-    }
-    var tick = code.addressTicks[address];
-    if (tick == null) {
-      return '';
-    }
-    // Don't show inclusive ticks if they are the same as exclusive ticks.
-    if (tick.inclusiveTicks == tick.exclusiveTicks) {
-      return '';
-    }
-    var pcent = formatPercent(tick.inclusiveTicks, code.totalSamplesInProfile);
-    return '$pcent (${tick.inclusiveTicks})';
-  }
-
-  @reflectable String formattedExclusive(Code code) {
-    if (code == null) {
-      return '';
-    }
-    var tick = code.addressTicks[address];
-    if (tick == null) {
-      return '';
-    }
-    var pcent = formatPercent(tick.exclusiveTicks, code.totalSamplesInProfile);
-    return '$pcent (${tick.exclusiveTicks})';
-  }
-
-  bool _isJumpInstruction() {
-    return human.startsWith('j');
-  }
-
-  int _getJumpAddress() {
-    assert(_isJumpInstruction());
-    var chunks = human.split(' ');
-    if (chunks.length != 2) {
-      // We expect jump instructions to be of the form 'j.. address'.
-      return 0;
-    }
-    var address = chunks[1];
-    if (address.startsWith('0x')) {
-      // Chop off the 0x.
-      address = address.substring(2);
-    }
-    try {
-      return int.parse(address, radix:16);
-    } catch (_) {
-      return 0;
-    }
-  }
-
-  void _resolveJumpTarget(List<CodeInstruction> instructions) {
-    if (!_isJumpInstruction()) {
-      return;
-    }
-    int address = _getJumpAddress();
-    if (address == 0) {
-      // Could not determine jump address.
-      Logger.root.severe('Could not determine jump address for $human');
-      return;
-    }
-    for (var i = 0; i < instructions.length; i++) {
-      var instruction = instructions[i];
-      if (instruction.address == address) {
-        jumpTarget = instruction;
-        return;
-      }
-    }
-    Logger.root.severe(
-        'Could not find instruction at ${address.toRadixString(16)}');
-  }
-}
-
-class CodeKind {
-  final _value;
-  const CodeKind._internal(this._value);
-  String toString() => '$_value';
-
-  static CodeKind fromString(String s) {
-    if (s == 'Native') {
-      return Native;
-    } else if (s == 'Dart') {
-      return Dart;
-    } else if (s == 'Collected') {
-      return Collected;
-    } else if (s == 'Reused') {
-      return Reused;
-    } else if (s == 'Tag') {
-      return Tag;
-    }
-    Logger.root.warning('Unknown code kind $s');
-    throw new FallThroughError();
-  }
-  static const Native = const CodeKind._internal('Native');
-  static const Dart = const CodeKind._internal('Dart');
-  static const Collected = const CodeKind._internal('Collected');
-  static const Reused = const CodeKind._internal('Reused');
-  static const Tag = const CodeKind._internal('Tag');
-}
-
-class CodeCallCount {
-  final Code code;
-  final int count;
-  CodeCallCount(this.code, this.count);
-}
-
-class CodeTrieNode {
-  final Code code;
-  final int count;
-  final children = new List<CodeTrieNode>();
-  int summedChildCount = 0;
-  CodeTrieNode(this.code, this.count);
-}
-
-class Code extends ServiceObject {
-  @observable CodeKind kind;
-  @observable int totalSamplesInProfile = 0;
-  @reflectable int exclusiveTicks = 0;
-  @reflectable int inclusiveTicks = 0;
-  @reflectable int startAddress = 0;
-  @reflectable int endAddress = 0;
-  @reflectable final callers = new List<CodeCallCount>();
-  @reflectable final callees = new List<CodeCallCount>();
-  @reflectable final instructions = new ObservableList<CodeInstruction>();
-  @reflectable final addressTicks = new ObservableMap<int, CodeTick>();
-  @observable String formattedInclusiveTicks = '';
-  @observable String formattedExclusiveTicks = '';
-  @observable Instance objectPool;
-  @observable ServiceFunction function;
-  @observable Script script;
-  @observable bool isOptimized = false;
-
-  bool get canCache => true;
-  bool get immutable => true;
-
-  Code._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  // Reset all data associated with a profile.
-  void resetProfileData() {
-    totalSamplesInProfile = 0;
-    exclusiveTicks = 0;
-    inclusiveTicks = 0;
-    formattedInclusiveTicks = '';
-    formattedExclusiveTicks = '';
-    callers.clear();
-    callees.clear();
-    addressTicks.clear();
-  }
-
-  void _updateDescriptors(Script script) {
-    this.script = script;
-    for (var instruction in instructions) {
-      for (var descriptor in instruction.descriptors) {
-        descriptor.processScript(script);
-      }
-    }
-  }
-
-  void loadScript() {
-    if (script != null) {
-      // Already done.
-      return;
-    }
-    if (kind != CodeKind.Dart){
-      return;
-    }
-    if (function == null) {
-      return;
-    }
-    if (function.script == null) {
-      // Attempt to load the function.
-      function.load().then((func) {
-        var script = function.script;
-        if (script == null) {
-          // Function doesn't have an associated script.
-          return;
-        }
-        // Load the script and then update descriptors.
-        script.load().then(_updateDescriptors);
-      });
-      return;
-    }
-    // Load the script and then update descriptors.
-    function.script.load().then(_updateDescriptors);
-  }
-
-  /// Reload [this]. Returns a future which completes to [this] or
-  /// a [ServiceError].
-  Future<ServiceObject> reload() {
-    assert(kind != null);
-    if (kind == CodeKind.Dart) {
-      // We only reload Dart code.
-      return super.reload();
-    }
-    return new Future.value(this);
-  }
-
-  void _resolveCalls(List<CodeCallCount> calls, List data, List<Code> codes) {
-    // Assert that this has been cleared.
-    assert(calls.length == 0);
-    // Resolve.
-    for (var i = 0; i < data.length; i += 2) {
-      var index = int.parse(data[i]);
-      var count = int.parse(data[i + 1]);
-      assert(index >= 0);
-      assert(index < codes.length);
-      calls.add(new CodeCallCount(codes[index], count));
-    }
-    // Sort to descending count order.
-    calls.sort((a, b) => b.count - a.count);
-  }
-
-
-  static String formatPercent(num a, num total) {
-    var percent = 100.0 * (a / total);
-    return '${percent.toStringAsFixed(2)}%';
-  }
-
-  void updateProfileData(Map profileData,
-                         List<Code> codeTable,
-                         int sampleCount) {
-    // Assert we have a CodeRegion entry.
-    assert(profileData['type'] == 'CodeRegion');
-    // Assert we are handed profile data for this code object.
-    assert(profileData['code'] == this);
-    totalSamplesInProfile = sampleCount;
-    inclusiveTicks = int.parse(profileData['inclusive_ticks']);
-    exclusiveTicks = int.parse(profileData['exclusive_ticks']);
-    _resolveCalls(callers, profileData['callers'], codeTable);
-    _resolveCalls(callees, profileData['callees'], codeTable);
-    var ticks = profileData['ticks'];
-    if (ticks != null) {
-      _processTicks(ticks);
-    }
-    formattedInclusiveTicks =
-        '${formatPercent(inclusiveTicks, totalSamplesInProfile)} '
-        '($inclusiveTicks)';
-    formattedExclusiveTicks =
-        '${formatPercent(exclusiveTicks, totalSamplesInProfile)} '
-        '($exclusiveTicks)';
-  }
-
-  void _update(ObservableMap m, bool mapIsRef) {
-    name = m['name'];
-    vmName = (m.containsKey('vmName') ? m['vmName'] : name);
-    isOptimized = m['optimized'] != null ? m['optimized'] : false;
-    kind = CodeKind.fromString(m['kind']);
-    startAddress = int.parse(m['start'], radix:16);
-    endAddress = int.parse(m['end'], radix:16);
-    function = isolate.getFromMap(m['function']);
-    objectPool = isolate.getFromMap(m['objectPool']);
-    var disassembly = m['disassembly'];
-    if (disassembly != null) {
-      _processDisassembly(disassembly);
-    }
-    var descriptors = m['descriptors'];
-    if (descriptors != null) {
-      descriptors = descriptors['members'];
-      _processDescriptors(descriptors);
-    }
-    // We are loaded if we have instructions or are not Dart code.
-    _loaded = (instructions.length != 0) || (kind != CodeKind.Dart);
-    hasDisassembly = (instructions.length != 0) && (kind == CodeKind.Dart);
-  }
-
-  @observable bool hasDisassembly = false;
-
-  void _processDisassembly(List<String> disassembly){
-    assert(disassembly != null);
-    instructions.clear();
-    assert((disassembly.length % 3) == 0);
-    for (var i = 0; i < disassembly.length; i += 3) {
-      var address = 0;  // Assume code comment.
-      var machine = disassembly[i + 1];
-      var human = disassembly[i + 2];
-      if (disassembly[i] != '') {
-        // Not a code comment, extract address.
-        address = int.parse(disassembly[i]);
-      }
-      var instruction = new CodeInstruction(address, machine, human);
-      instructions.add(instruction);
-    }
-    for (var instruction in instructions) {
-      instruction._resolveJumpTarget(instructions);
-    }
-  }
-
-  void _processDescriptor(Map d) {
-    var address = int.parse(d['pc'], radix:16);
-    var deoptId = d['deoptId'];
-    var tokenPos = d['tokenPos'];
-    var tryIndex = d['tryIndex'];
-    var kind = d['kind'].trim();
-    for (var instruction in instructions) {
-      if (instruction.address == address) {
-        instruction.descriptors.add(new PcDescriptor(address,
-                                                     deoptId,
-                                                     tokenPos,
-                                                     tryIndex,
-                                                     kind));
-        return;
-      }
-    }
-    Logger.root.warning(
-        'Could not find instruction with pc descriptor address: $address');
-  }
-
-  void _processDescriptors(List<Map> descriptors) {
-    for (Map descriptor in descriptors) {
-      _processDescriptor(descriptor);
-    }
-  }
-
-  void _processTicks(List<String> profileTicks) {
-    assert(profileTicks != null);
-    assert((profileTicks.length % 3) == 0);
-    for (var i = 0; i < profileTicks.length; i += 3) {
-      var address = int.parse(profileTicks[i], radix:16);
-      var exclusive = int.parse(profileTicks[i + 1]);
-      var inclusive = int.parse(profileTicks[i + 2]);
-      var tick = new CodeTick(address, exclusive, inclusive);
-      addressTicks[address] = tick;
-    }
-  }
-
-  /// Returns true if [address] is contained inside [this].
-  bool contains(int address) {
-    return (address >= startAddress) && (address < endAddress);
-  }
-
-  /// Sum all caller counts.
-  int sumCallersCount() => _sumCallCount(callers);
-  /// Specific caller count.
-  int callersCount(Code code) => _callCount(callers, code);
-  /// Sum of callees count.
-  int sumCalleesCount() => _sumCallCount(callees);
-  /// Specific callee count.
-  int calleesCount(Code code) => _callCount(callees, code);
-
-  int _sumCallCount(List<CodeCallCount> calls) {
-    var sum = 0;
-    for (CodeCallCount caller in calls) {
-      sum += caller.count;
-    }
-    return sum;
-  }
-
-  int _callCount(List<CodeCallCount> calls, Code code) {
-    for (CodeCallCount caller in calls) {
-      if (caller.code == code) {
-        return caller.count;
-      }
-    }
-    return 0;
-  }
-
-  @reflectable bool get isDartCode => kind == CodeKind.Dart;
-}
-
-
-class SocketKind {
-  final _value;
-  const SocketKind._internal(this._value);
-  String toString() => '$_value';
-
-  static SocketKind fromString(String s) {
-    if (s == 'Listening') {
-      return Listening;
-    } else if (s == 'Normal') {
-      return Normal;
-    } else if (s == 'Pipe') {
-      return Pipe;
-    } else if (s == 'Internal') {
-      return Internal;
-    }
-    Logger.root.warning('Unknown socket kind $s');
-    throw new FallThroughError();
-  }
-  static const Listening = const SocketKind._internal('Listening');
-  static const Normal = const SocketKind._internal('Normal');
-  static const Pipe = const SocketKind._internal('Pipe');
-  static const Internal = const SocketKind._internal('Internal');
-}
-
-/// A snapshot of statistics associated with a [Socket].
-class SocketStats {
-  @reflectable final int bytesRead;
-  @reflectable final int bytesWritten;
-  @reflectable final int readCalls;
-  @reflectable final int writeCalls;
-  @reflectable final int available;
-
-  SocketStats(this.bytesRead, this.bytesWritten,
-              this.readCalls, this.writeCalls,
-              this.available);
-}
-
-/// A peer to a Socket in dart:io. Sockets can represent network sockets or
-/// OS pipes. Each socket is owned by another ServceObject, for example,
-/// a process or an HTTP server.
-class Socket extends ServiceObject {
-  Socket._empty(ServiceObjectOwner owner) : super._empty(owner);
-
-  bool get canCache => true;
-
-  ServiceObject socketOwner;
-
-  @reflectable bool get isPipe => (kind == SocketKind.Pipe);
-
-  @observable SocketStats latest;
-  @observable SocketStats previous;
-
-  @observable SocketKind kind;
-
-  @observable String protocol = '';
-
-  @observable bool readClosed = false;
-  @observable bool writeClosed = false;
-  @observable bool closing = false;
-
-  /// Listening for connections.
-  @observable bool listening = false;
-
-  @observable int fd;
-
-  @observable String localAddress;
-  @observable int localPort;
-  @observable String remoteAddress;
-  @observable int remotePort;
-
-  // Updates internal state from [map]. [map] can be a reference.
-  void _update(ObservableMap map, bool mapIsRef) {
-    name = map['name'];
-    vmName = map['name'];
-
-    kind = SocketKind.fromString(map['kind']);
-
-    if (mapIsRef) {
-      return;
-    }
-
-    _loaded = true;
-
-    _upgradeCollection(map, isolate);
-
-    readClosed = map['readClosed'];
-    writeClosed = map['writeClosed'];
-    closing = map['closing'];
-    listening = map['listening'];
-
-    protocol = map['protocol'];
-
-    localAddress = map['localAddress'];
-    localPort = map['localPort'];
-    remoteAddress = map['remoteAddress'];
-    remotePort = map['remotePort'];
-
-    fd = map['fd'];
-    socketOwner = map['owner'];
-  }
-}
-
-class MetricSample {
-  final double value;
-  final DateTime time;
-  MetricSample(this.value) : time = new DateTime.now();
-}
-
-class ServiceMetric extends ServiceObject {
-  ServiceMetric._empty(ServiceObjectOwner owner) : super._empty(owner) {
-  }
-
-  bool get canCache => true;
-  bool get immutable => false;
-
-  @observable bool recording = false;
-  MetricPoller poller;
-
-  final ObservableList<MetricSample> samples =
-      new ObservableList<MetricSample>();
-  int _sampleBufferSize = 100;
-  int get sampleBufferSize => _sampleBufferSize;
-  set sampleBufferSize(int size) {
-    _sampleBufferSize = size;
-    _removeOld();
-  }
-
-  void addSample(MetricSample sample) {
-    samples.add(sample);
-    _removeOld();
-  }
-
-  void _removeOld() {
-    // TODO(johnmccutchan): If this becomes hot, consider using a circular
-    // buffer.
-    if (samples.length > _sampleBufferSize) {
-      int count = samples.length - _sampleBufferSize;
-      samples.removeRange(0, count);
-    }
-  }
-
-  @observable String description;
-  @observable double value = 0.0;
-  // Only a guage has a non-null min and max.
-  @observable double min;
-  @observable double max;
-
-  bool get isGauge => (min != null) && (max != null);
-
-  void _update(ObservableMap map, bool mapIsRef) {
-    name = map['name'];
-    description = map['description'];
-    vmName = map['name'];
-    value = map['value'];
-    min = map['min'];
-    max = map['max'];
-  }
-
-  String toString() => "ServiceMetric($_id)";
-}
-
-class MetricPoller {
-  // Metrics to be polled.
-  final List<ServiceMetric> metrics = new List<ServiceMetric>();
-  final Duration pollPeriod;
-  Timer _pollTimer;
-
-  MetricPoller(int milliseconds) :
-      pollPeriod = new Duration(milliseconds: milliseconds) {
-    start();
-  }
-
-  void start() {
-    _pollTimer = new Timer.periodic(pollPeriod, _onPoll);
-  }
-
-  void cancel() {
-    if (_pollTimer != null) {
-      _pollTimer.cancel();
-    }
-    _pollTimer = null;
-  }
-
-  void _onPoll(_) {
-    // Reload metrics and add a sample to each.
-    for (var metric in metrics) {
-      metric.reload().then((m) {
-        m.addSample(new MetricSample(m.value));
-      });
-    }
-  }
-}
-
-// Convert any ServiceMaps representing a null instance into an actual null.
-_convertNull(obj) {
-  if (obj.isNull) {
-    return null;
-  }
-  return obj;
-}
-
-// Returns true if [map] is a service map. i.e. it has the following keys:
-// 'id' and a 'type'.
-bool _isServiceMap(ObservableMap m) {
-  return (m != null) && (m['id'] != null) && (m['type'] != null);
-}
-
-bool _hasRef(String type) => type.startsWith('@');
-String _stripRef(String type) => (_hasRef(type) ? type.substring(1) : type);
-
-/// Recursively upgrades all [ServiceObject]s inside [collection] which must
-/// be an [ObservableMap] or an [ObservableList]. Upgraded elements will be
-/// associated with [vm] and [isolate].
-void _upgradeCollection(collection, ServiceObjectOwner owner) {
-  if (collection is ServiceMap) {
-    return;
-  }
-  if (collection is ObservableMap) {
-    _upgradeObservableMap(collection, owner);
-  } else if (collection is ObservableList) {
-    _upgradeObservableList(collection, owner);
-  }
-}
-
-void _upgradeObservableMap(ObservableMap map, ServiceObjectOwner owner) {
-  map.forEach((k, v) {
-    if ((v is ObservableMap) && _isServiceMap(v)) {
-      map[k] = owner.getFromMap(v);
-    } else if (v is ObservableList) {
-      _upgradeObservableList(v, owner);
-    } else if (v is ObservableMap) {
-      _upgradeObservableMap(v, owner);
-    }
-  });
-}
-
-void _upgradeObservableList(ObservableList list, ServiceObjectOwner owner) {
-  for (var i = 0; i < list.length; i++) {
-    var v = list[i];
-    if ((v is ObservableMap) && _isServiceMap(v)) {
-      list[i] = owner.getFromMap(v);
-    } else if (v is ObservableList) {
-      _upgradeObservableList(v, owner);
-    } else if (v is ObservableMap) {
-      _upgradeObservableMap(v, owner);
-    }
-  }
-}