Reorganize barback's source files.

pkg/barback/lib/src/group_runner.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.group_runner;
-
-import 'dart:async';
-
-import 'asset_cascade.dart';
-import 'asset_node.dart';
-import 'log.dart';
-import 'node_status.dart';
-import 'phase.dart';
-import 'stream_pool.dart';
-import 'transformer_group.dart';
-
-/// A class that processes all of the phases in a single transformer group.
-///
-/// A group takes many inputs, processes them, and emits many outputs.
-class GroupRunner {
-  /// The group this runner runs.
-  final TransformerGroup _group;
-
-  /// A string describing the location of [this] in the transformer graph.
-  final String _location;
-
-  /// The phases defined by this group.
-  final _phases = new List<Phase>();
-
-  /// How far along [this] is in processing its assets.
-  NodeStatus get status {
-    // Just check the last phase, since it will check all the previous phases
-    // itself.
-    return _phases.last.status;
-  }
-
-  /// A stream that emits an event every time the group's status changes.
-  Stream<NodeStatus> get onStatusChange => _onStatusChange;
-  Stream _onStatusChange;
-
-  /// A stream that emits any new assets emitted by [this].
-  ///
-  /// Assets are emitted synchronously to ensure that any changes are thoroughly
-  /// propagated as soon as they occur.
-  Stream<AssetNode> get onAsset => _onAsset;
-  Stream<AssetNode> _onAsset;
-
-  /// A stream that emits an event whenever any transforms in this group logs
-  /// an entry.
-  Stream<LogEntry> get onLog => _onLogPool.stream;
-  final _onLogPool = new StreamPool<LogEntry>.broadcast();
-
-  GroupRunner(AssetCascade cascade, this._group, this._location) {
-    _addPhase(new Phase(cascade, _location), []);
-    for (var phase in _group.phases) {
-      _addPhase(_phases.last.addPhase(), phase);
-    }
-
-    _onAsset = _phases.last.onAsset;
-    _onStatusChange = _phases.last.onStatusChange;
-  }
-
-  /// Add a phase with [contents] to [this]'s list of phases.
-  ///
-  /// [contents] should be an inner [Iterable] from a [TransformGroup.phases]
-  /// value.
-  void _addPhase(Phase phase, Iterable contents) {
-    _phases.add(phase);
-    _onLogPool.add(phase.onLog);
-    phase.updateTransformers(contents);
-  }
-
-  /// Force all [LazyTransformer]s' transforms in this group to begin producing
-  /// concrete assets.
-  void forceAllTransforms() {
-    for (var phase in _phases) {
-      phase.forceAllTransforms();
-    }
-  }
-
-  /// Adds a new asset as an input for this group.
-  void addInput(AssetNode node) {
-    _phases.first.addInput(node);
-  }
-
-  /// Removes this group and all sub-phases within it.
-  void remove() {
-    _onLogPool.close();
-    for (var phase in _phases) {
-      phase.remove();
-    }
-  }
-
-  String toString() => "group in phase $_location for $_group";
-}