Index: mojo/public/dart/third_party/barback/lib/src/graph/node_status.dart |
diff --git a/mojo/public/dart/third_party/barback/lib/src/graph/node_status.dart b/mojo/public/dart/third_party/barback/lib/src/graph/node_status.dart |
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+// 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_status; |
+ |
+/// The status of a node in barback's package graph. |
+/// |
+/// A node has three possible statuses: [IDLE], [MATERIALIZING], and [RUNNING]. |
+/// These are ordered from least dirty to most dirty; the [dirtier] and |
+/// [dirtiest] functions make use of this ordering. |
+class NodeStatus { |
+ /// The node has finished its work and won't do anything else until external |
+ /// input causes it to. |
+ /// |
+ /// For deferred nodes, this may indicate that they're finished declaring |
+ /// their outputs and waiting to be forced. |
+ static const IDLE = const NodeStatus("idle"); |
+ |
+ /// The node has declared its outputs but their concrete values are still |
+ /// being generated. |
+ /// |
+ /// This is only meaningful for nodes that are or contain declaring |
+ /// transformers. Note that a lazy transformer that's declared its outputs but |
+ /// isn't actively working to generate them is considered [IDLE], not |
+ /// [MATERIALIZING]. |
+ static const MATERIALIZING = const NodeStatus("materializing"); |
+ |
+ /// The node is actively working on declaring or generating its outputs. |
+ /// |
+ /// Declaring transformers are only considered dirty until they're finished |
+ /// declaring their outputs; past that point, they're always either |
+ /// [MATERIALIZING] or [IDLE]. Non-declaring transformers, by contrast, are |
+ /// always either [RUNNING] or [IDLE]. |
+ static const RUNNING = const NodeStatus("running"); |
+ |
+ final String _name; |
+ |
+ /// Returns the dirtiest status in [statuses]. |
+ static NodeStatus dirtiest(Iterable<NodeStatus> statuses) => |
+ statuses.fold(NodeStatus.IDLE, |
+ (status1, status2) => status1.dirtier(status2)); |
+ |
+ const NodeStatus(this._name); |
+ |
+ String toString() => _name; |
+ |
+ /// Returns [this] or [other], whichever is dirtier. |
+ NodeStatus dirtier(NodeStatus other) { |
+ if (this == RUNNING || other == RUNNING) return RUNNING; |
+ if (this == MATERIALIZING || other == MATERIALIZING) return MATERIALIZING; |
+ return IDLE; |
+ } |
+} |