Index: watcher/lib/src/directory_watcher/linux.dart |
diff --git a/watcher/lib/src/directory_watcher/linux.dart b/watcher/lib/src/directory_watcher/linux.dart |
deleted file mode 100644 |
index a747839d2ba1b2afc960ff3c2a56ee0ab609bdf9..0000000000000000000000000000000000000000 |
--- a/watcher/lib/src/directory_watcher/linux.dart |
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@@ -1,311 +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 watcher.directory_watcher.linux; |
- |
-import 'dart:async'; |
-import 'dart:io'; |
- |
-import '../directory_watcher.dart'; |
-import '../resubscribable.dart'; |
-import '../utils.dart'; |
-import '../watch_event.dart'; |
- |
-/// Uses the inotify subsystem to watch for filesystem events. |
-/// |
-/// Inotify doesn't suport recursively watching subdirectories, nor does |
-/// [Directory.watch] polyfill that functionality. This class polyfills it |
-/// instead. |
-/// |
-/// This class also compensates for the non-inotify-specific issues of |
-/// [Directory.watch] producing multiple events for a single logical action |
-/// (issue 14372) and providing insufficient information about move events |
-/// (issue 14424). |
-class LinuxDirectoryWatcher extends ResubscribableWatcher |
- implements DirectoryWatcher { |
- String get directory => path; |
- |
- LinuxDirectoryWatcher(String directory) |
- : super(directory, () => new _LinuxDirectoryWatcher(directory)); |
-} |
- |
-class _LinuxDirectoryWatcher |
- implements DirectoryWatcher, ManuallyClosedWatcher { |
- String get directory => path; |
- final String path; |
- |
- Stream<WatchEvent> get events => _eventsController.stream; |
- final _eventsController = new StreamController<WatchEvent>.broadcast(); |
- |
- bool get isReady => _readyCompleter.isCompleted; |
- |
- Future get ready => _readyCompleter.future; |
- final _readyCompleter = new Completer(); |
- |
- /// The last known state for each entry in this directory. |
- /// |
- /// The keys in this map are the paths to the directory entries; the values |
- /// are [_EntryState]s indicating whether the entries are files or |
- /// directories. |
- final _entries = new Map<String, _EntryState>(); |
- |
- /// The watchers for subdirectories of [directory]. |
- final _subWatchers = new Map<String, _LinuxDirectoryWatcher>(); |
- |
- /// A set of all subscriptions that this watcher subscribes to. |
- /// |
- /// These are gathered together so that they may all be canceled when the |
- /// watcher is closed. |
- final _subscriptions = new Set<StreamSubscription>(); |
- |
- _LinuxDirectoryWatcher(this.path) { |
- // Batch the inotify changes together so that we can dedup events. |
- var innerStream = new Directory(path).watch() |
- .transform(new BatchedStreamTransformer<FileSystemEvent>()); |
- _listen(innerStream, _onBatch, |
- onError: _eventsController.addError, |
- onDone: _onDone); |
- |
- _listen(new Directory(path).list(), (entity) { |
- _entries[entity.path] = new _EntryState(entity is Directory); |
- if (entity is! Directory) return; |
- _watchSubdir(entity.path); |
- }, onError: (error, stackTrace) { |
- _eventsController.addError(error, stackTrace); |
- close(); |
- }, onDone: () { |
- _waitUntilReady().then((_) => _readyCompleter.complete()); |
- }, cancelOnError: true); |
- } |
- |
- /// Returns a [Future] that completes once all the subdirectory watchers are |
- /// fully initialized. |
- Future _waitUntilReady() { |
- return Future.wait(_subWatchers.values.map((watcher) => watcher.ready)) |
- .then((_) { |
- if (_subWatchers.values.every((watcher) => watcher.isReady)) return null; |
- return _waitUntilReady(); |
- }); |
- } |
- |
- void close() { |
- for (var subscription in _subscriptions) { |
- subscription.cancel(); |
- } |
- for (var watcher in _subWatchers.values) { |
- watcher.close(); |
- } |
- |
- _subWatchers.clear(); |
- _subscriptions.clear(); |
- _eventsController.close(); |
- } |
- |
- /// Returns all files (not directories) that this watcher knows of are |
- /// recursively in the watched directory. |
- Set<String> get _allFiles { |
- var files = new Set<String>(); |
- _getAllFiles(files); |
- return files; |
- } |
- |
- /// Helper function for [_allFiles]. |
- /// |
- /// Adds all files that this watcher knows of to [files]. |
- void _getAllFiles(Set<String> files) { |
- files.addAll(_entries.keys |
- .where((path) => _entries[path] == _EntryState.FILE).toSet()); |
- for (var watcher in _subWatchers.values) { |
- watcher._getAllFiles(files); |
- } |
- } |
- |
- /// Watch a subdirectory of [directory] for changes. |
- /// |
- /// If the subdirectory was added after [this] began emitting events, its |
- /// contents will be emitted as ADD events. |
- void _watchSubdir(String path) { |
- if (_subWatchers.containsKey(path)) return; |
- var watcher = new _LinuxDirectoryWatcher(path); |
- _subWatchers[path] = watcher; |
- |
- // TODO(nweiz): Catch any errors here that indicate that the directory in |
- // question doesn't exist and silently stop watching it instead of |
- // propagating the errors. |
- _listen(watcher.events, (event) { |
- if (isReady) _eventsController.add(event); |
- }, onError: (error, stackTrace) { |
- _eventsController.addError(error, stackTrace); |
- close(); |
- }, onDone: () { |
- if (_subWatchers[path] == watcher) _subWatchers.remove(path); |
- |
- // It's possible that a directory was removed and recreated very quickly. |
- // If so, make sure we're still watching it. |
- if (new Directory(path).existsSync()) _watchSubdir(path); |
- }); |
- |
- // TODO(nweiz): Right now it's possible for the watcher to emit an event for |
- // a file before the directory list is complete. This could lead to the user |
- // seeing a MODIFY or REMOVE event for a file before they see an ADD event, |
- // which is bad. We should handle that. |
- // |
- // One possibility is to provide a general means (e.g. |
- // `DirectoryWatcher.eventsAndExistingFiles`) to tell a watcher to emit |
- // events for all the files that already exist. This would be useful for |
- // top-level clients such as barback as well, and could be implemented with |
- // a wrapper similar to how listening/canceling works now. |
- |
- // If a directory is added after we're finished with the initial scan, emit |
- // an event for each entry in it. This gives the user consistently gets an |
- // event for every new file. |
- watcher.ready.then((_) { |
- if (!isReady || _eventsController.isClosed) return; |
- _listen(new Directory(path).list(recursive: true), (entry) { |
- if (entry is Directory) return; |
- _eventsController.add(new WatchEvent(ChangeType.ADD, entry.path)); |
- }, onError: (error, stackTrace) { |
- // Ignore an exception caused by the dir not existing. It's fine if it |
- // was added and then quickly removed. |
- if (error is FileSystemException) return; |
- |
- _eventsController.addError(error, stackTrace); |
- close(); |
- }, cancelOnError: true); |
- }); |
- } |
- |
- /// The callback that's run when a batch of changes comes in. |
- void _onBatch(List<FileSystemEvent> batch) { |
- var changedEntries = new Set<String>(); |
- var oldEntries = new Map.from(_entries); |
- |
- // inotify event batches are ordered by occurrence, so we treat them as a |
- // log of what happened to a file. |
- for (var event in batch) { |
- // If the watched directory is deleted or moved, we'll get a deletion |
- // event for it. Ignore it; we handle closing [this] when the underlying |
- // stream is closed. |
- if (event.path == path) continue; |
- |
- changedEntries.add(event.path); |
- |
- if (event is FileSystemMoveEvent) { |
- changedEntries.add(event.destination); |
- _changeEntryState(event.path, ChangeType.REMOVE, event.isDirectory); |
- _changeEntryState(event.destination, ChangeType.ADD, event.isDirectory); |
- } else { |
- _changeEntryState(event.path, _changeTypeFor(event), event.isDirectory); |
- } |
- } |
- |
- for (var path in changedEntries) { |
- emitEvent(ChangeType type) { |
- if (isReady) _eventsController.add(new WatchEvent(type, path)); |
- } |
- |
- var oldState = oldEntries[path]; |
- var newState = _entries[path]; |
- |
- if (oldState != _EntryState.FILE && newState == _EntryState.FILE) { |
- emitEvent(ChangeType.ADD); |
- } else if (oldState == _EntryState.FILE && newState == _EntryState.FILE) { |
- emitEvent(ChangeType.MODIFY); |
- } else if (oldState == _EntryState.FILE && newState != _EntryState.FILE) { |
- emitEvent(ChangeType.REMOVE); |
- } |
- |
- if (oldState == _EntryState.DIRECTORY) { |
- var watcher = _subWatchers.remove(path); |
- if (watcher == null) continue; |
- for (var path in watcher._allFiles) { |
- _eventsController.add(new WatchEvent(ChangeType.REMOVE, path)); |
- } |
- watcher.close(); |
- } |
- |
- if (newState == _EntryState.DIRECTORY) _watchSubdir(path); |
- } |
- } |
- |
- /// Changes the known state of the entry at [path] based on [change] and |
- /// [isDir]. |
- void _changeEntryState(String path, ChangeType change, bool isDir) { |
- if (change == ChangeType.ADD || change == ChangeType.MODIFY) { |
- _entries[path] = new _EntryState(isDir); |
- } else { |
- assert(change == ChangeType.REMOVE); |
- _entries.remove(path); |
- } |
- } |
- |
- /// Determines the [ChangeType] associated with [event]. |
- ChangeType _changeTypeFor(FileSystemEvent event) { |
- if (event is FileSystemDeleteEvent) return ChangeType.REMOVE; |
- if (event is FileSystemCreateEvent) return ChangeType.ADD; |
- |
- assert(event is FileSystemModifyEvent); |
- return ChangeType.MODIFY; |
- } |
- |
- /// Handles the underlying event stream closing, indicating that the directory |
- /// being watched was removed. |
- void _onDone() { |
- // Most of the time when a directory is removed, its contents will get |
- // individual REMOVE events before the watch stream is closed -- in that |
- // case, [_entries] will be empty here. However, if the directory's removal |
- // is caused by a MOVE, we need to manually emit events. |
- if (isReady) { |
- _entries.forEach((path, state) { |
- if (state == _EntryState.DIRECTORY) return; |
- _eventsController.add(new WatchEvent(ChangeType.REMOVE, path)); |
- }); |
- } |
- |
- // The parent directory often gets a close event before the subdirectories |
- // are done emitting events. We wait for them to finish before we close |
- // [events] so that we can be sure to emit a remove event for every file |
- // that used to exist. |
- Future.wait(_subWatchers.values.map((watcher) { |
- try { |
- return watcher.events.toList(); |
- } on StateError catch (_) { |
- // It's possible that [watcher.events] is closed but the onDone event |
- // hasn't reached us yet. It's fine if so. |
- return new Future.value(); |
- } |
- })).then((_) => close()); |
- } |
- |
- /// Like [Stream.listen], but automatically adds the subscription to |
- /// [_subscriptions] so that it can be canceled when [close] is called. |
- void _listen(Stream stream, void onData(event), {Function onError, |
- void onDone(), bool cancelOnError}) { |
- var subscription; |
- subscription = stream.listen(onData, onError: onError, onDone: () { |
- _subscriptions.remove(subscription); |
- if (onDone != null) onDone(); |
- }, cancelOnError: cancelOnError); |
- _subscriptions.add(subscription); |
- } |
-} |
- |
-/// An enum for the possible states of entries in a watched directory. |
-class _EntryState { |
- final String _name; |
- |
- /// The entry is a file. |
- static const FILE = const _EntryState._("file"); |
- |
- /// The entry is a directory. |
- static const DIRECTORY = const _EntryState._("directory"); |
- |
- const _EntryState._(this._name); |
- |
- /// Returns [DIRECTORY] if [isDir] is true, and [FILE] otherwise. |
- factory _EntryState(bool isDir) => |
- isDir ? _EntryState.DIRECTORY : _EntryState.FILE; |
- |
- String toString() => _name; |
-} |