Reorganize barback's source files.

pkg/barback/lib/src/package_graph.dart

Index: pkg/barback/lib/src/package_graph.dart
diff --git a/pkg/barback/lib/src/package_graph.dart b/pkg/barback/lib/src/package_graph.dart
deleted file mode 100644
index bbb480db51e0b975c26c8ef89958fd0d568d94ec..0000000000000000000000000000000000000000
--- a/pkg/barback/lib/src/package_graph.dart
+++ /dev/null
@@ -1,264 +0,0 @@
-// 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.package_graph;
-
-import 'dart:async';
-import 'dart:collection';
-
-import 'asset_cascade.dart';
-import 'asset_id.dart';
-import 'asset_node.dart';
-import 'asset_set.dart';
-import 'build_result.dart';
-import 'errors.dart';
-import 'log.dart';
-import 'node_status.dart';
-import 'package_provider.dart';
-import 'transformer.dart';
-import 'utils.dart';
-
-/// The collection of [AssetCascade]s for an entire application.
-///
-/// This tracks each package's [AssetCascade] and routes asset requests between
-/// them.
-class PackageGraph {
-  /// The provider that exposes asset and package information.
-  final PackageProvider provider;
-
-  /// The [AssetCascade] for each package.
-  final _cascades = <String, AssetCascade>{};
-
-  /// A stream that emits a [BuildResult] each time the build is completed,
-  /// whether or not it succeeded.
-  ///
-  /// This will emit a result only once every package's [AssetCascade] has
-  /// finished building.
-  ///
-  /// If an unexpected error in barback itself occurs, it will be emitted
-  /// through this stream's error channel.
-  Stream<BuildResult> get results => _resultsController.stream;
-  final _resultsController =
-      new StreamController<BuildResult>.broadcast(sync: true);
-
-  /// A stream that emits any errors from the graph or the transformers.
-  ///
-  /// This emits errors as they're detected. If an error occurs in one part of
-  /// the graph, unrelated parts will continue building.
-  ///
-  /// This will not emit programming errors from barback itself. Those will be
-  /// emitted through the [results] stream's error channel.
-  Stream<BarbackException> get errors => _errors;
-  Stream<BarbackException> _errors;
-
-  /// The stream of [LogEntry] objects used to report transformer log entries.
-  Stream<LogEntry> get log => _logController.stream;
-  final _logController = new StreamController<LogEntry>.broadcast(sync: true);
-
-  /// How far along [this] is in processing its assets.
-  NodeStatus get _status => NodeStatus.dirtiest(
-      _cascades.values.map((cascade) => cascade.status));
-
-  /// Whether a [BuildResult] is scheduled to be emitted on [results] (see
-  /// [_tryScheduleResult]).
-  bool _resultScheduled = false;
-
-  /// The most recent [BuildResult] emitted on [results].
-  BuildResult _lastResult;
-
-  // TODO(nweiz): This can have bogus errors if an error is created and resolved
-  // in the space of one build.
-  /// The errors that have occurred since the current build started.
-  ///
-  /// This will be empty if no build is occurring.
-  final _accumulatedErrors = new Queue<BarbackException>();
-
-  /// The most recent error emitted from a cascade's result stream.
-  ///
-  /// This is used to pipe an unexpected error from a build to the resulting
-  /// [Future] returned by [getAllAssets].
-  var _lastUnexpectedError;
-
-  /// The stack trace for [_lastUnexpectedError].
-  StackTrace _lastUnexpectedErrorTrace;
-
-  /// Creates a new [PackageGraph] that will transform assets in all packages
-  /// made available by [provider].
-  PackageGraph(this.provider) {
-    _inErrorZone(() {
-      for (var package in provider.packages) {
-        var cascade = new AssetCascade(this, package);
-        _cascades[package] = cascade;
-        cascade.onLog.listen(_onLog);
-        cascade.onStatusChange.listen((status) {
-          if (status == NodeStatus.IDLE) _tryScheduleResult();
-        });
-      }
-
-      _errors = mergeStreams(_cascades.values.map((cascade) => cascade.errors),
-          broadcast: true);
-      _errors.listen(_accumulatedErrors.add);
-    });
-  }
-
-  /// Gets the asset node identified by [id].
-  ///
-  /// If [id] is for a generated or transformed asset, this will wait until it
-  /// has been created and return it. This means that the returned asset will
-  /// always be [AssetState.AVAILABLE].
-  ///
-  /// If the asset cannot be found, returns null.
-  Future<AssetNode> getAssetNode(AssetId id) {
-    return _inErrorZone(() {
-      var cascade = _cascades[id.package];
-      if (cascade != null) return cascade.getAssetNode(id);
-      return new Future.value(null);
-    });
-  }
-
-  /// Gets all output assets.
-  ///
-  /// If a build is currently in progress, waits until it completes. The
-  /// returned future will complete with an error if the build is not
-  /// successful.
-  ///
-  /// Any transforms using [LazyTransformer]s will be forced to generate
-  /// concrete outputs, and those outputs will be returned.
-  Future<AssetSet> getAllAssets() {
-    for (var cascade in _cascades.values) {
-      _inErrorZone(() => cascade.forceAllTransforms());
-    }
-
-    if (_status != NodeStatus.IDLE) {
-      // A build is still ongoing, so wait for it to complete and try again.
-      return results.first.then((_) => getAllAssets());
-    }
-
-    // If an unexpected error occurred, complete with that.
-    if (_lastUnexpectedError != null) {
-      var error = _lastUnexpectedError;
-      _lastUnexpectedError = null;
-      return new Future.error(error, _lastUnexpectedErrorTrace);
-    }
-
-    // If the last build completed with an error, complete the future with it.
-    if (!_lastResult.succeeded) {
-      return new Future.error(BarbackException.aggregate(_lastResult.errors));
-    }
-
-    // Otherwise, return all of the final output assets.
-    var assets = unionAll(_cascades.values.map(
-        (cascade) => cascade.availableOutputs.toSet()));
-
-    return new Future.value(new AssetSet.from(assets));
-  }
-
-  /// Adds [sources] to the graph's known set of source assets.
-  ///
-  /// Begins applying any transforms that can consume any of the sources. If a
-  /// given source is already known, it is considered modified and all
-  /// transforms that use it will be re-applied.
-  void updateSources(Iterable<AssetId> sources) {
-    groupBy(sources, (id) => id.package).forEach((package, ids) {
-      var cascade = _cascades[package];
-      if (cascade == null) throw new ArgumentError("Unknown package $package.");
-      _inErrorZone(() => cascade.updateSources(ids));
-    });
-
-    // It's possible for adding sources not to cause any processing. The user
-    // still expects there to be a build, though, so we emit one immediately.
-    _tryScheduleResult();
-  }
-
-  /// Removes [removed] from the graph's known set of source assets.
-  void removeSources(Iterable<AssetId> sources) {
-    groupBy(sources, (id) => id.package).forEach((package, ids) {
-      var cascade = _cascades[package];
-      if (cascade == null) throw new ArgumentError("Unknown package $package.");
-      _inErrorZone(() => cascade.removeSources(ids));
-    });
-
-    // It's possible for removing sources not to cause any processing. The user
-    // still expects there to be a build, though, so we emit one immediately.
-    _tryScheduleResult();
-  }
-
-  void updateTransformers(String package,
-      Iterable<Iterable<Transformer>> transformers) {
-    _inErrorZone(() => _cascades[package].updateTransformers(transformers));
-
-    // It's possible for updating transformers not to cause any processing. The
-    // user still expects there to be a build, though, so we emit one
-    // immediately.
-    _tryScheduleResult();
-  }
-
-  /// A handler for a log entry from an [AssetCascade].
-  void _onLog(LogEntry entry) {
-    if (entry.level == LogLevel.ERROR) {
-      // TODO(nweiz): keep track of stack chain.
-      _accumulatedErrors.add(
-          new TransformerException(entry.transform, entry.message, null));
-    }
-
-    if (_logController.hasListener) {
-      _logController.add(entry);
-    } else if (entry.level != LogLevel.FINE) {
-      // No listeners, so just print entry.
-      var buffer = new StringBuffer();
-      buffer.write("[${entry.level} ${entry.transform}] ");
-
-      if (entry.span != null) {
-        buffer.write(entry.span.getLocationMessage(entry.message));
-      } else {
-        buffer.write(entry.message);
-      }
-
-      print(buffer);
-    }
-  }
-
-  /// If [this] is done processing, schedule a [BuildResult] to be emitted on
-  /// [results].
-  ///
-  /// This schedules the result (as opposed to just emitting one directly on
-  /// [BuildResult]) to ensure that calling multiple functions synchronously
-  /// produces only a single [BuildResult].
-  void _tryScheduleResult() {
-    if (_status != NodeStatus.IDLE) return;
-    if (_resultScheduled) return;
-
-    _resultScheduled = true;
-    newFuture(() {
-      _resultScheduled = false;
-      if (_status != NodeStatus.IDLE) return;
-
-      _lastResult = new BuildResult(_accumulatedErrors);
-      _accumulatedErrors.clear();
-      _resultsController.add(_lastResult);
-    });
-  }
-
-  /// Run [body] in an error-handling [Zone] and pipe any unexpected errors to
-  /// the error channel of [results].
-  ///
-  /// [body] can return a value or a [Future] that will be piped to the returned
-  /// [Future]. If it throws a [BarbackException], that exception will be piped
-  /// to the returned [Future] as well. Any other exceptions will be piped to
-  /// [results].
-  Future _inErrorZone(body()) {
-    var completer = new Completer.sync();
-    runZoned(() {
-      syncFuture(body).then(completer.complete).catchError((error, stackTrace) {
-        if (error is! BarbackException) throw error;
-        completer.completeError(error, stackTrace);
-      });
-    }, onError: (error, stackTrace) {
-      _lastUnexpectedError = error;
-      _lastUnexpectedErrorTrace = stackTrace;
-      _resultsController.addError(error, stackTrace);
-    });
-    return completer.future;
-  }
-}