Index: mojo/public/dart/third_party/barback/lib/src/graph/node_streams.dart |
diff --git a/mojo/public/dart/third_party/barback/lib/src/graph/node_streams.dart b/mojo/public/dart/third_party/barback/lib/src/graph/node_streams.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..834479271abce7e6ac1f6cd3e95d65313ff84eff |
--- /dev/null |
+++ b/mojo/public/dart/third_party/barback/lib/src/graph/node_streams.dart |
@@ -0,0 +1,66 @@ |
+// 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. |
+ |
+library barback.graph.node_streams; |
+ |
+import 'dart:async'; |
+ |
+import '../asset/asset_node.dart'; |
+import '../log.dart'; |
+import '../utils/stream_pool.dart'; |
+import 'node_status.dart'; |
+ |
+/// A collection of streams that are common to nodes in barback's package graph. |
+class NodeStreams { |
+ /// A stream that emits an event every time the node's status changes. |
+ /// |
+ /// This will emit the new status. It's guaranteed to emit an event only when |
+ /// the status changes from the previous value. To ensure this, callers should |
+ /// emit status changes using [changeStatus]. The initial status is assumed to |
+ /// be [NodeStatus.RUNNING]. |
+ Stream<NodeStatus> get onStatusChange => _onStatusChangeController.stream; |
+ final _onStatusChangeController = |
+ new StreamController<NodeStatus>.broadcast(sync: true); |
+ |
+ /// A stream that emits any new assets produced by the node. |
+ /// |
+ /// Assets are emitted synchronously to ensure that any changes are thoroughly |
+ /// propagated as soon as they occur. |
+ Stream<AssetNode> get onAsset => onAssetPool.stream; |
+ final onAssetPool = new StreamPool<AssetNode>.broadcast(); |
+ final onAssetController = |
+ new StreamController<AssetNode>.broadcast(sync: true); |
+ |
+ /// A stream that emits an event whenever any the node logs an entry. |
+ Stream<LogEntry> get onLog => onLogPool.stream; |
+ final onLogPool = new StreamPool<LogEntry>.broadcast(); |
+ final onLogController = new StreamController<LogEntry>.broadcast(sync: true); |
+ |
+ var _previousStatus = NodeStatus.RUNNING; |
+ |
+ /// Whether [this] has been closed. |
+ bool get isClosed => onAssetController.isClosed; |
+ |
+ NodeStreams() { |
+ onAssetPool.add(onAssetController.stream); |
+ onLogPool.add(onLogController.stream); |
+ } |
+ |
+ /// Emits a status change notification via [onStatusChange]. |
+ /// |
+ /// This guarantees that a change notification won't be emitted if the status |
+ /// didn't actually change. |
+ void changeStatus(NodeStatus status) { |
+ if (_previousStatus != status) _onStatusChangeController.add(status); |
+ } |
+ |
+ /// Closes all the streams. |
+ void close() { |
+ _onStatusChangeController.close(); |
+ onAssetController.close(); |
+ onAssetPool.close(); |
+ onLogController.close(); |
+ onLogPool.close(); |
+ } |
+} |