Run pub tests against older versions of barback.

third_party/pkg/barback-0.13.0/lib/src/phase.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.graph.phase;
+library barback.phase;
 
 import 'dart:async';
 
-import '../asset/asset_id.dart';
-import '../asset/asset_node.dart';
-import '../asset/asset_node_set.dart';
-import '../errors.dart';
-import '../log.dart';
-import '../transformer/transformer.dart';
-import '../transformer/transformer_group.dart';
-import '../utils.dart';
-import '../utils/multiset.dart';
 import 'asset_cascade.dart';
+import 'asset_id.dart';
+import 'asset_node.dart';
+import 'errors.dart';
 import 'group_runner.dart';
-import 'node_status.dart';
-import 'node_streams.dart';
+import 'log.dart';
+import 'multiset.dart';
 import 'phase_forwarder.dart';
+import 'phase_input.dart';
 import 'phase_output.dart';
-import 'transformer_classifier.dart';
+import 'stream_pool.dart';
+import 'transformer.dart';
+import 'transformer_group.dart';
+import 'utils.dart';
 
 /// One phase in the ordered series of transformations in an [AssetCascade].
 ///
 /// Each phase can access outputs from previous phases and can in turn pass
 /// outputs to later phases. Phases are processed strictly serially. All
 /// transforms in a phase will be complete before moving on to the next phase.
 /// Within a single phase, all transforms will be run in parallel.
 ///
 /// Building can be interrupted between phases. For example, a source is added
 /// which starts the background process. Sometime during, say, phase 2 (which
 /// is running asynchronously) that source is modified. When the process queue
 /// goes to advance to phase 3, it will see that modification and start the
 /// waterfall from the beginning again.
 class Phase {
   /// The cascade that owns this phase.
   final AssetCascade cascade;
 
   /// A string describing the location of [this] in the transformer graph.
   final String _location;
 
   /// The index of [this] in its parent cascade or group.
   final int _index;
 
+  /// The transformers that can access [inputs].
+  ///
+  /// Their outputs will be available to the next phase.
+  final _transformers = new Set<Transformer>();
+
   /// The groups for this phase.
   final _groups = new Map<TransformerGroup, GroupRunner>();
 
   /// The inputs for this phase.
   ///
   /// For the first phase, these will be the source assets. For all other
   /// phases, they will be the outputs from the previous phase.
-  final _inputs = new AssetNodeSet();
-
-  /// The transformer classifiers for this phase.
-  final _classifiers = new Map<Transformer, TransformerClassifier>();
+  final _inputs = new Map<AssetId, PhaseInput>();
 
   /// The forwarders for this phase.
   final _forwarders = new Map<AssetId, PhaseForwarder>();
 
   /// The outputs for this phase.
   final _outputs = new Map<AssetId, PhaseOutput>();
 
   /// The set of all [AssetNode.origin] properties of the input assets for this
   /// phase.
   ///
   /// This is used to determine which assets have been passed unmodified through
-  /// [_classifiers] or [_groups]. It's possible that a given asset was consumed
-  /// by a group and not an individual transformer, and so shouldn't be
-  /// forwarded through the phase as a whole.
+  /// [_inputs] or [_groups]. Each input asset has a PhaseInput in [_inputs]. If
+  /// that input isn't consumed by any transformers, it will be forwarded
+  /// through the PhaseInput. However, it's possible that it was consumed by a
+  /// group, and so shouldn't be forwarded through the phase as a whole.
   ///
   /// In order to detect whether an output has been forwarded through a group or
-  /// a classifier, we must be able to distinguish it from other outputs with
+  /// a PhaseInput, we must be able to distinguish it from other outputs with
   /// the same id. To do so, we check if its origin is in [_inputOrigins]. If
   /// so, it's been forwarded unmodified.
   final _inputOrigins = new Multiset<AssetNode>();
 
-  /// The streams exposed by this phase.
-  final _streams = new NodeStreams();
-  Stream<NodeStatus> get onStatusChange => _streams.onStatusChange;
-  Stream<AssetNode> get onAsset => _streams.onAsset;
-  Stream<LogEntry> get onLog => _streams.onLog;
+  /// A stream that emits an event whenever [this] is no longer dirty.
+  ///
+  /// This is synchronous in order to guarantee that it will emit an event as
+  /// soon as [isDirty] flips from `true` to `false`.
+  Stream get onDone => _onDoneController.stream;
+  final _onDoneController = new StreamController.broadcast(sync: true);
 
-  /// How far along [this] is in processing its assets.
-  NodeStatus get status {
-    // Before any transformers are added, the phase should be dirty if and only
-    // if any input is dirty.
-    if (_classifiers.isEmpty && _groups.isEmpty && previous == null) {
-      return _inputs.any((input) => input.state.isDirty) ?
-          NodeStatus.RUNNING : NodeStatus.IDLE;
-    }
+  /// 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. Only a phase with no [next] phase will
+  /// emit assets.
+  Stream<AssetNode> get onAsset => _onAssetController.stream;
+  final _onAssetController =
+      new StreamController<AssetNode>.broadcast(sync: true);
 
-    var classifierStatus = NodeStatus.dirtiest(
-        _classifiers.values.map((classifier) => classifier.status));
-    var groupStatus = NodeStatus.dirtiest(
-        _groups.values.map((group) => group.status));
-    return (previous == null ? NodeStatus.IDLE : previous.status)
-        .dirtier(classifierStatus)
-        .dirtier(groupStatus);
-  }
+  /// Whether [this] is dirty and still has more processing to do.
+  ///
+  /// A phase is considered dirty if any of the previous phases in the same
+  /// cascade are dirty, since those phases could emit an asset that this phase
+  /// will then need to process.
+  bool get isDirty => (previous != null && previous.isDirty) ||
+      _inputs.values.any((input) => input.isDirty) ||
+      _groups.values.any((group) => group.isDirty);
+
+  /// A stream that emits an event whenever any transforms in this phase logs
+  /// an entry.
+  Stream<LogEntry> get onLog => _onLogPool.stream;
+  final _onLogPool = new StreamPool<LogEntry>.broadcast();
 
   /// The previous phase in the cascade, or null if this is the first phase.
   final Phase previous;
 
-  /// The subscription to [previous]'s [onStatusChange] stream.
-  StreamSubscription _previousStatusSubscription;
+  /// The subscription to [previous]'s [onDone] stream.
+  StreamSubscription _previousOnDoneSubscription;
 
   /// The subscription to [previous]'s [onAsset] stream.
   StreamSubscription<AssetNode> _previousOnAssetSubscription;
 
   /// A map of asset ids to completers for [getInput] requests.
   ///
   /// If an asset node is requested before it's available, we put a completer in
   /// this map to wait for the asset to be generated. If it's not generated, the
   /// completer should complete to `null`.
   final _pendingOutputRequests = new Map<AssetId, Completer<AssetNode>>();
 
   /// Returns all currently-available output assets for this phase.
   Set<AssetNode> get availableOutputs {
     return _outputs.values
         .map((output) => output.output)
         .where((node) => node.state.isAvailable)
         .toSet();
   }
 
   // TODO(nweiz): Rather than passing the cascade and the phase everywhere,
   // create an interface that just exposes [getInput]. Emit errors via
   // [AssetNode]s.
   Phase(AssetCascade cascade, String location)
       : this._(cascade, location, 0);
 
   Phase._(this.cascade, this._location, this._index, [this.previous]) {
     if (previous != null) {
       _previousOnAssetSubscription = previous.onAsset.listen(addInput);
-      _previousStatusSubscription = previous.onStatusChange
-          .listen((_) => _streams.changeStatus(status));
+      _previousOnDoneSubscription = previous.onDone.listen((_) {
+        if (!isDirty) _onDoneController.add(null);
+      });
     }
 
-    onStatusChange.listen((status) {
-      if (status == NodeStatus.RUNNING) return;
-
-      // All the previous phases have finished declaring or producing their
-      // outputs. If anyone's still waiting for outputs, cut off the wait; we
-      // won't be generating them, at least until a source asset changes.
+    onDone.listen((_) {
+      // All the previous phases have finished building. If anyone's still
+      // waiting for outputs, cut off the wait; we won't be generating them,
+      // at least until a source asset changes.
       for (var completer in _pendingOutputRequests.values) {
         completer.complete(null);
       }
       _pendingOutputRequests.clear();
     });
   }
 
   /// Adds a new asset as an input for this phase.
   ///
   /// [node] doesn't have to be [AssetState.AVAILABLE]. Once it is, the phase
   /// will automatically begin determining which transforms can consume it as a
   /// primary input. The transforms themselves won't be applied until [process]
   /// is called, however.
   ///
   /// This should only be used for brand-new assets or assets that have been
   /// removed and re-created. The phase will automatically handle updated assets
   /// using the [AssetNode.onStateChange] stream.
   void addInput(AssetNode node) {
+    if (_inputs.containsKey(node.id)) _inputs[node.id].remove();
+
+    node.force();
+
     // Each group is one channel along which an asset may be forwarded, as is
     // each transformer.
     var forwarder = new PhaseForwarder(
-        node, _classifiers.length, _groups.length);
+        node, _transformers.length, _groups.length);
     _forwarders[node.id] = forwarder;
     forwarder.onAsset.listen(_handleOutputWithoutForwarder);
     if (forwarder.output != null) {
       _handleOutputWithoutForwarder(forwarder.output);
     }
 
     _inputOrigins.add(node.origin);
-    _inputs.add(node);
-    node.onStateChange.listen((state) {
-      if (state.isRemoved) {
-        _inputOrigins.remove(node.origin);
-        _forwarders.remove(node.id).remove();
-      }
-      _streams.changeStatus(status);
+    var input = new PhaseInput(this, node, "$_location.$_index");
+    _inputs[node.id] = input;
+    input.input.whenRemoved(() {
+      _inputOrigins.remove(node.origin);
+      _inputs.remove(node.id);
+      _forwarders.remove(node.id).remove();
+      if (!isDirty) _onDoneController.add(null);
+    });
+    input.onAsset.listen(_handleOutput);
+    _onLogPool.add(input.onLog);
+    input.onDone.listen((_) {
+      if (!isDirty) _onDoneController.add(null);
     });
 
-    for (var classifier in _classifiers.values) {
-      classifier.addInput(node);
+    input.updateTransformers(_transformers);
+
+    for (var group in _groups.values) {
+      group.addInput(node);
     }
   }
 
   // TODO(nweiz): If the output is available when this is called, it's
   // theoretically possible for it to become unavailable between the call and
   // the return. If it does so, it won't trigger the rebuilding process. To
   // avoid this, we should have this and the methods it calls take explicit
   // callbacks, as in [AssetNode.whenAvailable].
   /// Gets the asset node for an output [id].
   ///
@@ skipping 15 matching lines @@
         // try again, since it could be generated again.
         output.force();
         return output.whenAvailable((_) {
           return output;
         }).catchError((error) {
           if (error is! AssetNotFoundException) throw error;
           return getOutput(id);
         });
       }
 
-      // If this phase and the previous phases are fully declared or done, the
-      // requested output won't be generated and we can safely return null.
-      if (status != NodeStatus.RUNNING) return null;
+      // If neither this phase nor the previous phases are dirty, the requested
+      // output won't be generated and we can safely return null.
+      if (!isDirty) return null;
 
       // Otherwise, store a completer for the asset node. If it's generated in
       // the future, we'll complete this completer.
       var completer = _pendingOutputRequests.putIfAbsent(id,
           () => new Completer.sync());
       return completer.future;
     });
   }
 
   /// Set this phase's transformers to [transformers].
   void updateTransformers(Iterable transformers) {
-    var newTransformers = transformers.where((op) => op is Transformer)
-        .toSet();
-    var oldTransformers = _classifiers.keys.toSet();
-    for (var removed in oldTransformers.difference(newTransformers)) {
-      _classifiers.remove(removed).remove();
-    }
-
-    for (var transformer in newTransformers.difference(oldTransformers)) {
-      var classifier = new TransformerClassifier(
-          this, transformer, "$_location.$_index");
-      _classifiers[transformer] = classifier;
-      classifier.onAsset.listen(_handleOutput);
-      _streams.onLogPool.add(classifier.onLog);
-      classifier.onStatusChange.listen((_) => _streams.changeStatus(status));
-      for (var input in _inputs) {
-        classifier.addInput(input);
-      }
+    var actualTransformers = transformers.where((op) => op is Transformer);
+    _transformers.clear();
+    _transformers.addAll(actualTransformers);
+    for (var input in _inputs.values) {
+      input.updateTransformers(actualTransformers);
     }
 
     var newGroups = transformers.where((op) => op is TransformerGroup)
         .toSet();
     var oldGroups = _groups.keys.toSet();
     for (var removed in oldGroups.difference(newGroups)) {
       _groups.remove(removed).remove();
     }
 
     for (var added in newGroups.difference(oldGroups)) {
-      var runner = new GroupRunner(previous, added, "$_location.$_index");
+      var runner = new GroupRunner(cascade, added, "$_location.$_index");
       _groups[added] = runner;
       runner.onAsset.listen(_handleOutput);
-      _streams.onLogPool.add(runner.onLog);
-      runner.onStatusChange.listen((_) => _streams.changeStatus(status));
+      _onLogPool.add(runner.onLog);
+      runner.onDone.listen((_) {
+        if (!isDirty) _onDoneController.add(null);
+      });
+      for (var input in _inputs.values) {
+        runner.addInput(input.input);
+      }
     }
 
     for (var forwarder in _forwarders.values) {
-      forwarder.updateTransformers(_classifiers.length, _groups.length);
+      forwarder.updateTransformers(_transformers.length, _groups.length);
     }
-
-    _streams.changeStatus(status);
   }
 
   /// Force all [LazyTransformer]s' transforms in this phase to begin producing
   /// concrete assets.
   void forceAllTransforms() {
-    for (var classifier in _classifiers.values) {
-      classifier.forceAllTransforms();
+    for (var group in _groups.values) {
+      group.forceAllTransforms();
     }
 
-    for (var group in _groups.values) {
-      group.forceAllTransforms();
+    for (var input in _inputs.values) {
+      input.forceAllTransforms();
     }
   }
 
   /// Add a new phase after this one.
   ///
-  /// The new phase will have a location annotation describing its place in the
-  /// package graph. By default, this annotation will describe it as being
-  /// directly after [this]. If [location] is passed, though, it's described as
-  /// being the first phase in that location.
-  Phase addPhase([String location]) {
-    var index = 0;
-    if (location == null) {
-      location = _location;
-      index = _index + 1;
-    }
-
-    var next = new Phase._(cascade, location, index, this);
+  /// This may only be called on a phase with no phase following it.
+  Phase addPhase() {
+    var next = new Phase._(cascade, _location, _index + 1, this);
     for (var output in _outputs.values.toList()) {
       // Remove [output]'s listeners because now they should get the asset from
       // [next], rather than this phase. Any transforms consuming [output] will
       // be re-run and will consume the output from the new final phase.
       output.removeListeners();
     }
     return next;
   }
 
   /// Mark this phase as removed.
   ///
   /// This will remove all the phase's outputs.
   void remove() {
-    for (var classifier in _classifiers.values.toList()) {
-      classifier.remove();
+    for (var input in _inputs.values.toList()) {
+      input.remove();
     }
     for (var group in _groups.values) {
       group.remove();
     }
-    _streams.close();
-    if (_previousStatusSubscription != null) {
-      _previousStatusSubscription.cancel();
+    _onAssetController.close();
+    _onLogPool.close();
+    if (_previousOnDoneSubscription != null) {
+      _previousOnDoneSubscription.cancel();
     }
     if (_previousOnAssetSubscription != null) {
       _previousOnAssetSubscription.cancel();
     }
   }
 
   /// Add [asset] as an output of this phase.
   void _handleOutput(AssetNode asset) {
     if (_inputOrigins.contains(asset.origin)) {
       _forwarders[asset.id].addIntermediateAsset(asset);
@@ skipping 16 matching lines @@
 
     var exception = _outputs[asset.id].collisionException;
     if (exception != null) cascade.reportError(exception);
   }
 
   /// Emit [asset] as an output of this phase.
   ///
   /// This should be called after [_handleOutput], so that collisions are
   /// resolved.
   void _emit(AssetNode asset) {
-    _streams.onAssetController.add(asset);
+    _onAssetController.add(asset);
     _providePendingAsset(asset);
   }
 
   /// Provide an asset to a pending [getOutput] call.
   void _providePendingAsset(AssetNode asset) {
     // If anyone's waiting for this asset, provide it to them.
     var request = _pendingOutputRequests.remove(asset.id);
     if (request == null) return;
 
     if (asset.state.isAvailable) {
       request.complete(asset);
       return;
     }
 
     // A lazy asset may be emitted while still dirty. If so, we wait until it's
     // either available or removed before trying again to access it.
     assert(asset.state.isDirty);
     asset.force();
     asset.whenStateChanges().then((state) {
       if (state.isRemoved) return getOutput(asset.id);
       return asset;
     }).then(request.complete).catchError(request.completeError);
   }
 
   String toString() => "phase $_location.$_index";
 }