| // 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.package_graph; |
| |
| import 'dart:async'; |
| import 'dart:collection'; |
| |
| import '../asset/asset_id.dart'; |
| import '../asset/asset_node.dart'; |
| import '../asset/asset_set.dart'; |
| import '../build_result.dart'; |
| import '../errors.dart'; |
| import '../log.dart'; |
| import '../package_provider.dart'; |
| import '../utils.dart'; |
| import 'asset_cascade.dart'; |
| import 'node_status.dart'; |
| import 'static_asset_cascade.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(); |
| }); |
| } |
| |
| if (provider is StaticPackageProvider) { |
| StaticPackageProvider staticProvider = provider; |
| for (var package in staticProvider.staticPackages) { |
| if (_cascades.containsKey(package)) { |
| throw new StateError('Package "$package" is in both ' |
| 'PackageProvider.packages and PackageProvider.staticPackages.'); |
| } |
| |
| var cascade = new StaticAssetCascade(this, package); |
| _cascades[package] = cascade; |
| } |
| } |
| |
| _errors = mergeStreams(_cascades.values.map((cascade) => cascade.errors), |
| broadcast: true); |
| _errors.listen(_accumulatedErrors.add); |
| |
| // Make sure a result gets scheduled even if there are no cascades or all |
| // of them are static. |
| if (provider.packages.isEmpty) _tryScheduleResult(); |
| }); |
| } |
| |
| /// 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<Future<AssetNode>>(() { |
| var cascade = _cascades[id.package]; |
| if (cascade != null) return cascade.getAssetNode(id); |
| return new Future.value(null); |
| }); |
| } |
| |
| /// Returns the stream of newly-emitted assets for the given package's |
| /// cascade. |
| /// |
| /// If there's no cascade for [package], returns `null`. |
| Stream<AssetNode> onAssetFor(String package) { |
| var cascade = _cascades[package]; |
| return cascade == null ? null : cascade.onAsset; |
| } |
| |
| /// 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<Future<AssetSet>>((_) => 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. |
| return Future |
| .wait(_cascades.values.map((cascade) => cascade.availableOutputs)) |
| .then((assetSets) { |
| var assets = unionAll(assetSets.map((assetSet) => assetSet.toSet())); |
| return 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 $package."); |
| _inErrorZone(() => cascade.removeSources(ids)); |
| }); |
| |
| // It's possible for removing sources not to cause any processing. The user |
| // still expects there to be a build, though, so we emit one immediately. |
| _tryScheduleResult(); |
| } |
| |
| void updateTransformers(String package, Iterable<Iterable> transformers) { |
| _inErrorZone(() => _cascades[package].updateTransformers(transformers)); |
| |
| // It's possible for updating transformers not to cause any processing. The |
| // user still expects there to be a build, though, so we emit one |
| // immediately. |
| _tryScheduleResult(); |
| } |
| |
| /// A handler for a log entry from an [AssetCascade]. |
| void _onLog(LogEntry entry) { |
| if (entry.level == LogLevel.ERROR) { |
| // TODO(nweiz): keep track of stack chain. |
| _accumulatedErrors |
| .add(new TransformerException(entry.transform, entry.message, null)); |
| } |
| |
| if (_logController.hasListener) { |
| _logController.add(entry); |
| } else if (entry.level != LogLevel.FINE) { |
| // No listeners, so just print entry. |
| var buffer = new StringBuffer(); |
| buffer.write("[${entry.level} ${entry.transform}] "); |
| |
| if (entry.span != null) { |
| buffer.write(entry.span.message(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<T> _inErrorZone<T>(T body()) { |
| var completer = new Completer<T>.sync(); |
| runZoned(() { |
| new Future.sync(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; |
| } |
| } |