Remove barback from the repo.

pkg/barback/lib/src/utils/stream_pool.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 barback.utils.stream_pool;
-
-import 'dart:async';
-
-/// A pool of streams whose events are unified and emitted through a central
-/// stream.
-class StreamPool<T> {
-  /// The stream through which all events from streams in the pool are emitted.
-  Stream<T> get stream => _controller.stream;
-  final StreamController<T> _controller;
-
-  /// Subscriptions to the streams that make up the pool.
-  final _subscriptions = new Map<Stream<T>, StreamSubscription<T>>();
-
-  /// Creates a new stream pool that only supports a single subscriber.
-  ///
-  /// Any events from broadcast streams in the pool will be buffered until a
-  /// listener is subscribed.
-  StreamPool()
-      // Create the controller as sync so that any sync input streams will be
-      // forwarded synchronously. Async input streams will have their asynchrony
-      // preserved, since _controller.add will be called asynchronously.
-      : _controller = new StreamController<T>(sync: true);
-
-  /// Creates a new stream pool where [stream] can be listened to more than
-  /// once.
-  ///
-  /// Any events from buffered streams in the pool will be emitted immediately,
-  /// regardless of whether [stream] has any subscribers.
-  StreamPool.broadcast()
-      // Create the controller as sync so that any sync input streams will be
-      // forwarded synchronously. Async input streams will have their asynchrony
-      // preserved, since _controller.add will be called asynchronously.
-      : _controller = new StreamController<T>.broadcast(sync: true);
-
-  /// Adds [stream] as a member of this pool.
-  ///
-  /// Any events from [stream] will be emitted through [this.stream]. If
-  /// [stream] is sync, they'll be emitted synchronously; if [stream] is async,
-  /// they'll be emitted asynchronously.
-  void add(Stream<T> stream) {
-    if (_subscriptions.containsKey(stream)) return;
-    _subscriptions[stream] = stream.listen(_controller.add,
-        onError: _controller.addError,
-        onDone: () => remove(stream));
-  }
-
-  /// Removes [stream] as a member of this pool.
-  void remove(Stream<T> stream) {
-    var subscription = _subscriptions.remove(stream);
-    if (subscription != null) subscription.cancel();
-  }
-
-  /// Removes all streams from this pool and closes [stream].
-  void close() {
-    for (var subscription in _subscriptions.values) {
-      subscription.cancel();
-    }
-    _subscriptions.clear();
-    _controller.close();
-  }
-}