Remove PhaseInput and add TransformerSorter to barback.

pkg/barback/lib/src/phase_input.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.phase_input;
-
-import 'dart:async';
-
-import 'asset_forwarder.dart';
-import 'asset_node.dart';
-import 'log.dart';
-import 'node_status.dart';
-import 'node_streams.dart';
-import 'phase.dart';
-import 'transform_node.dart';
-import 'transformer.dart';
-
-/// A class for watching a single [AssetNode] and running any transforms that
-/// take that node as a primary input.
-class PhaseInput {
-  /// The phase for which this is an input.
-  final Phase _phase;
-
-  /// A string describing the location of [this] in the transformer graph.
-  final String _location;
-
-  /// The transforms currently applicable to [input].
-  ///
-  /// These are the transforms that have been "wired up": they represent a
-  /// repeatable transformation of a single concrete set of inputs. "dart2js" is
-  /// a transformer. "dart2js on web/main.dart" is a transform.
-  final _transforms = new Set<TransformNode>();
-
-  /// A forwarder for the input [AssetNode] for this phase.
-  ///
-  /// This is used to mark the node as removed should the input ever be removed.
-  final AssetForwarder _inputForwarder;
-
-  /// The asset node for this input.
-  AssetNode get input => _inputForwarder.node;
-
-  /// The subscription to [input]'s [AssetNode.onStateChange] stream.
-  StreamSubscription _inputSubscription;
-
-  /// The streams exposed by this input.
-  final _streams = new NodeStreams();
-  Stream get onStatusChange => _streams.onStatusChange;
-  Stream<AssetNode> get onAsset => _streams.onAsset;
-  Stream<LogEntry> get onLog => _streams.onLog;
-
-  /// How far along [this] is in processing its assets.
-  NodeStatus get status {
-    var status = input.state.isDirty && !input.isLazy ?
-        NodeStatus.MATERIALIZING : NodeStatus.IDLE;
-    return status.dirtier(NodeStatus.dirtiest(
-        _transforms.map((transform) => transform.status)));
-  }
-
-  PhaseInput(this._phase, AssetNode input, this._location)
-      : _inputForwarder = new AssetForwarder(input) {
-    _inputSubscription = input.onStateChange.listen((state) {
-      if (state.isRemoved) {
-        remove();
-      } else {
-        _streams.changeStatus(status);
-      }
-    });
-  }
-
-  /// Removes this input.
-  ///
-  /// This marks all outputs of the input as removed.
-  void remove() {
-    _streams.close();
-    _inputSubscription.cancel();
-    _inputForwarder.close();
-  }
-
-  /// Set this input's transformers to [transformers].
-  void updateTransformers(Iterable<Transformer> newTransformersIterable) {
-    var newTransformers = newTransformersIterable.toSet();
-    for (var transform in _transforms.toList()) {
-      if (newTransformers.remove(transform.transformer)) continue;
-      transform.remove();
-    }
-
-    // The remaining [newTransformers] are those for which there are no
-    // transforms in [_transforms].
-    for (var transformer in newTransformers) {
-      var transform = new TransformNode(
-          _phase, transformer, input, _location);
-      _transforms.add(transform);
-
-      transform.onStatusChange.listen(
-          (_) => _streams.changeStatus(status),
-          onDone: () => _transforms.remove(transform));
-
-      _streams.onAssetPool.add(transform.onAsset);
-      _streams.onLogPool.add(transform.onLog);
-    }
-  }
-
-  /// Force all [LazyTransformer]s' transforms in this input to begin producing
-  /// concrete assets.
-  void forceAllTransforms() {
-    for (var transform in _transforms) {
-      transform.force();
-    }
-  }
-
-  String toString() => "phase input in $_location for $input";
-}