Update charted to 0.4.8 and roll

packages/observe/benchmark/observation_benchmark_base.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 observe.test.benchmark.observation_benchmark_base;
-
-import 'dart:async';
-import 'dart:html';
-import 'package:observe/observe.dart';
-import 'package:benchmark_harness/benchmark_harness.dart';
-
-abstract class ObservationBenchmarkBase extends BenchmarkBase {
-  /// The number of objects to create and observe.
-  final int objectCount;
-
-  /// The number of mutations to perform.
-  final int mutationCount;
-
-  /// The current configuration.
-  final String config;
-
-  /// The number of pending mutations left to observe.
-  int mutations;
-
-  /// The objects we want to observe.
-  List<Observable> objects;
-
-  /// The change listeners on all of our objects.
-  List observers;
-
-  /// The current object being mutated.
-  int objectIndex;
-
-  ObservationBenchmarkBase(
-      String name, this.objectCount, this.mutationCount, this.config)
-      : super(name);
-
-  /// Subclasses should use this method to perform mutations on an object. The
-  /// return value indicates how many mutations were performed on the object.
-  int mutateObject(obj);
-
-  /// Subclasses should use this method to return an observable object to be
-  /// benchmarked.
-  Observable newObject();
-
-  /// Subclasses should override this to do anything other than a default change
-  /// listener. It must return either a StreamSubscription or a PathObserver.
-  /// If overridden this observer should decrement [mutations] each time a
-  /// change is observed.
-  newObserver(obj) {
-    decrement(_) => mutations--;
-    if (obj is ObservableList) return obj.listChanges.listen(decrement);
-    return obj.changes.listen(decrement);
-  }
-
-  /// Set up each benchmark by creating all the objects and listeners.
-  @override
-  void setup() {
-    mutations = 0;
-
-    objects = [];
-    observers = [];
-    objectIndex = 0;
-
-    while (objects.length < objectCount) {
-      var obj = newObject();
-      objects.add(obj);
-      observers.add(newObserver(obj));
-    }
-  }
-
-  /// Tear down each benchmark and make sure that [mutations] is 0.
-  @override
-  void teardown() {
-    if (mutations != 0) {
-      window.alert('$mutations mutation sets were not observed!');
-    }
-    mutations = 0;
-
-    while (observers.isNotEmpty) {
-      var observer = observers.removeLast();
-      if (observer is StreamSubscription) {
-        observer.cancel();
-      } else if (observer is PathObserver) {
-        observer.close();
-      } else {
-        throw 'Unknown observer type ${observer.runtimeType}. Only '
-            '[PathObserver] and [StreamSubscription] are supported.';
-      }
-    }
-    observers = null;
-
-    bool leakedObservers = false;
-    while (objects.isNotEmpty) {
-      leakedObservers = objects.removeLast().hasObservers || leakedObservers;
-    }
-    if (leakedObservers) window.alert('Observers leaked!');
-    objects = null;
-  }
-
-  /// Run the benchmark
-  @override
-  void run() {
-    var mutationsLeft = mutationCount;
-    while (mutationsLeft > 0) {
-      var obj = objects[objectIndex];
-      mutationsLeft -= mutateObject(obj);
-      this.mutations++;
-      this.objectIndex++;
-      if (this.objectIndex == this.objects.length) {
-        this.objectIndex = 0;
-      }
-      obj.deliverChanges();
-      if (obj is ObservableList) obj.deliverListChanges();
-    }
-    Observable.dirtyCheck();
-  }
-}