Use 'Directory.watch' on Windows in pkg/watcher, instead of pooling.
This is a close copy of MacOS, except for the special handling on mac, and the extra watcher on Windows for detecting if the watched folder is deleted.
BUG=https://code.google.com/p/dart/issues/detail?id=14428,https://code.google.com/p/dart/issues/detail?id=18108,http://code.google.com/p/dart/issues/detail?id=19189
R=kasperl@google.com, sgjesse@google.com
Review URL: https://codereview.chromium.org//312743002
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@36988 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/lib/src/directory_watcher.dart b/lib/src/directory_watcher.dart
index 78b1174..27dbb3f 100644
--- a/lib/src/directory_watcher.dart
+++ b/lib/src/directory_watcher.dart
@@ -10,6 +10,7 @@
import 'watch_event.dart';
import 'directory_watcher/linux.dart';
import 'directory_watcher/mac_os.dart';
+import 'directory_watcher/windows.dart';
import 'directory_watcher/polling.dart';
/// Watches the contents of a directory and emits [WatchEvent]s when something
@@ -56,6 +57,7 @@
factory DirectoryWatcher(String directory, {Duration pollingDelay}) {
if (Platform.isLinux) return new LinuxDirectoryWatcher(directory);
if (Platform.isMacOS) return new MacOSDirectoryWatcher(directory);
+ if (Platform.isWindows) return new WindowsDirectoryWatcher(directory);
return new PollingDirectoryWatcher(directory, pollingDelay: pollingDelay);
}
}
diff --git a/lib/src/directory_watcher/windows.dart b/lib/src/directory_watcher/windows.dart
new file mode 100644
index 0000000..ddcf897
--- /dev/null
+++ b/lib/src/directory_watcher/windows.dart
@@ -0,0 +1,419 @@
+// Copyright (c) 2014, 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.
+// TODO(rnystrom): Merge with mac_os version.
+
+library watcher.directory_watcher.windows;
+
+import 'dart:async';
+import 'dart:collection';
+import 'dart:io';
+
+import 'package:path/path.dart' as p;
+import 'package:stack_trace/stack_trace.dart';
+
+import '../constructable_file_system_event.dart';
+import '../path_set.dart';
+import '../utils.dart';
+import '../watch_event.dart';
+import 'resubscribable.dart';
+
+class WindowsDirectoryWatcher extends ResubscribableDirectoryWatcher {
+ WindowsDirectoryWatcher(String directory)
+ : super(directory, () => new _WindowsDirectoryWatcher(directory));
+}
+
+class _EventBatcher {
+ static const Duration _BATCH_DELAY = const Duration(milliseconds: 100);
+ final List<FileSystemEvent> events = [];
+ Timer timer;
+
+ void addEvent(FileSystemEvent event) {
+ events.add(event);
+ }
+
+ void startTimer(void callback()) {
+ if (timer != null) {
+ timer.cancel();
+ }
+ timer = new Timer(_BATCH_DELAY, callback);
+ }
+
+ void cancelTimer() {
+ timer.cancel();
+ }
+}
+
+class _WindowsDirectoryWatcher implements ManuallyClosedDirectoryWatcher {
+ final String directory;
+
+ 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();
+
+ final Map<String, _EventBatcher> _eventBatchers =
+ new HashMap<String, _EventBatcher>();
+
+ /// The set of files that are known to exist recursively within the watched
+ /// directory.
+ ///
+ /// The state of files on the filesystem is compared against this to determine
+ /// the real change that occurred. This is also used to emit REMOVE events
+ /// when subdirectories are moved out of the watched directory.
+ final PathSet _files;
+
+ /// The subscription to the stream returned by [Directory.watch].
+ StreamSubscription<FileSystemEvent> _watchSubscription;
+
+ /// The subscription to the stream returned by [Directory.watch] of the
+ /// parent directory to [directory]. This is needed to detect changes to
+ /// [directory], as they are not included on Windows.
+ StreamSubscription<FileSystemEvent> _parentWatchSubscription;
+
+ /// The subscription to the [Directory.list] call for the initial listing of
+ /// the directory to determine its initial state.
+ StreamSubscription<FileSystemEntity> _initialListSubscription;
+
+ /// The subscriptions to the [Directory.list] call for listing the contents of
+ /// subdirectories that was moved into the watched directory.
+ final Set<StreamSubscription<FileSystemEntity>> _listSubscriptions
+ = new HashSet<StreamSubscription<FileSystemEntity>>();
+
+ _WindowsDirectoryWatcher(String directory)
+ : directory = directory, _files = new PathSet(directory) {
+ _startWatch();
+ _startParentWatcher();
+
+ // Before we're ready to emit events, wait for [_listDir] to complete.
+ _listDir().then(_readyCompleter.complete);
+ }
+
+ void close() {
+ if (_watchSubscription != null) _watchSubscription.cancel();
+ if (_parentWatchSubscription != null) _parentWatchSubscription.cancel();
+ if (_initialListSubscription != null) _initialListSubscription.cancel();
+ for (var sub in _listSubscriptions) {
+ sub.cancel();
+ }
+ _listSubscriptions.clear();
+ for (var batcher in _eventBatchers.values) {
+ batcher.cancelTimer();
+ }
+ _eventBatchers.clear();
+ _watchSubscription = null;
+ _parentWatchSubscription = null;
+ _initialListSubscription = null;
+ _eventsController.close();
+ }
+
+ /// On Windows, if [directory] is deleted, we will not receive any event.
+ /// Instead, we add a watcher on the parent folder (if any), that can notify
+ /// us about [directory].
+ /// This also includes events such as moves.
+ void _startParentWatcher() {
+ var absoluteDir = p.absolute(directory);
+ var parent = p.dirname(absoluteDir);
+ // Check if we [directory] is already the root directory.
+ if (FileSystemEntity.identicalSync(parent, directory)) return;
+ var parentStream = Chain.track(
+ new Directory(parent).watch(recursive: false));
+ _parentWatchSubscription = parentStream.listen((event) {
+ // Only look at events for 'directory'.
+ if (p.basename(event.path) != p.basename(absoluteDir)) return;
+ // Test if the directory is removed. FileSystemEntity.typeSync will
+ // return NOT_FOUND if it's unable to decide upon the type, including
+ // access denied issues, which may happen when the directory is deleted.
+ // FileSystemMoveEvent and FileSystemDeleteEvent events will always mean
+ // the directory is now gone.
+ if (event is FileSystemMoveEvent ||
+ event is FileSystemDeleteEvent ||
+ (FileSystemEntity.typeSync(directory) ==
+ FileSystemEntityType.NOT_FOUND)) {
+ for (var path in _files.toSet()) {
+ _emitEvent(ChangeType.REMOVE, path);
+ }
+ _files.clear();
+ close();
+ }
+ }, onError: (error) {
+ // Ignore errors, simply close the stream.
+ _parentWatchSubscription.cancel();
+ _parentWatchSubscription = null;
+ });
+ }
+
+ void _onEvent(FileSystemEvent event) {
+ // If we get a event before we're ready to begin emitting events,
+ // ignore those events and re-list the directory.
+ if (!isReady) {
+ _listDir().then((_) {
+ _readyCompleter.complete();
+ });
+ return;
+ }
+
+ _EventBatcher batcher = _eventBatchers.putIfAbsent(
+ event.path, () => new _EventBatcher());
+ batcher.addEvent(event);
+ batcher.startTimer(() {
+ _eventBatchers.remove(event.path);
+ _onBatch(batcher.events);
+ });
+ }
+
+ /// The callback that's run when [Directory.watch] emits a batch of events.
+ void _onBatch(List<FileSystemEvent> batch) {
+ _sortEvents(batch).forEach((path, events) {
+ var relativePath = p.relative(path, from: directory);
+
+ var canonicalEvent = _canonicalEvent(events);
+ events = canonicalEvent == null ?
+ _eventsBasedOnFileSystem(path) : [canonicalEvent];
+
+ for (var event in events) {
+ if (event is FileSystemCreateEvent) {
+ if (!event.isDirectory) {
+ if (_files.contains(path)) continue;
+
+ _emitEvent(ChangeType.ADD, path);
+ _files.add(path);
+ continue;
+ }
+
+ if (_files.containsDir(path)) continue;
+
+ var stream = Chain.track(new Directory(path).list(recursive: true));
+ var sub;
+ sub = stream.listen((entity) {
+ if (entity is Directory) return;
+ if (_files.contains(path)) return;
+
+ _emitEvent(ChangeType.ADD, entity.path);
+ _files.add(entity.path);
+ }, onDone: () {
+ _listSubscriptions.remove(sub);
+ }, onError: (e, stackTrace) {
+ _listSubscriptions.remove(sub);
+ _emitError(e, stackTrace);
+ }, cancelOnError: true);
+ _listSubscriptions.add(sub);
+ } else if (event is FileSystemModifyEvent) {
+ if (!event.isDirectory) {
+ _emitEvent(ChangeType.MODIFY, path);
+ }
+ } else {
+ assert(event is FileSystemDeleteEvent);
+ for (var removedPath in _files.remove(path)) {
+ _emitEvent(ChangeType.REMOVE, removedPath);
+ }
+ }
+ }
+ });
+ }
+
+ /// Sort all the events in a batch into sets based on their path.
+ ///
+ /// A single input event may result in multiple events in the returned map;
+ /// for example, a MOVE event becomes a DELETE event for the source and a
+ /// CREATE event for the destination.
+ ///
+ /// The returned events won't contain any [FileSystemMoveEvent]s, nor will it
+ /// contain any events relating to [directory].
+ Map<String, Set<FileSystemEvent>> _sortEvents(List<FileSystemEvent> batch) {
+ var eventsForPaths = {};
+
+ // Events within directories that already have events are superfluous; the
+ // directory's full contents will be examined anyway, so we ignore such
+ // events. Emitting them could cause useless or out-of-order events.
+ var directories = unionAll(batch.map((event) {
+ if (!event.isDirectory) return new Set();
+ if (event is! FileSystemMoveEvent) return new Set.from([event.path]);
+ return new Set.from([event.path, event.destination]);
+ }));
+
+ isInModifiedDirectory(path) =>
+ directories.any((dir) => path != dir && path.startsWith(dir));
+
+ addEvent(path, event) {
+ if (isInModifiedDirectory(path)) return;
+ var set = eventsForPaths.putIfAbsent(path, () => new Set());
+ set.add(event);
+ }
+
+ for (var event in batch) {
+ if (event is FileSystemMoveEvent) {
+ FileSystemMoveEvent moveEvent = event;
+ addEvent(moveEvent.destination, event);
+ }
+ addEvent(event.path, event);
+ }
+
+ return eventsForPaths;
+ }
+
+ /// Returns the canonical event from a batch of events on the same path, if
+ /// one exists.
+ ///
+ /// If [batch] doesn't contain any contradictory events (e.g. DELETE and
+ /// CREATE, or events with different values for [isDirectory]), this returns a
+ /// single event that describes what happened to the path in question.
+ ///
+ /// If [batch] does contain contradictory events, this returns `null` to
+ /// indicate that the state of the path on the filesystem should be checked to
+ /// determine what occurred.
+ FileSystemEvent _canonicalEvent(Set<FileSystemEvent> batch) {
+ // An empty batch indicates that we've learned earlier that the batch is
+ // contradictory (e.g. because of a move).
+ if (batch.isEmpty) return null;
+
+ var type = batch.first.type;
+ var isDir = batch.first.isDirectory;
+ var hadModifyEvent = false;
+
+ for (var event in batch.skip(1)) {
+ // If one event reports that the file is a directory and another event
+ // doesn't, that's a contradiction.
+ if (isDir != event.isDirectory) return null;
+
+ // Modify events don't contradict either CREATE or REMOVE events. We can
+ // safely assume the file was modified after a CREATE or before the
+ // REMOVE; otherwise there will also be a REMOVE or CREATE event
+ // (respectively) that will be contradictory.
+ if (event is FileSystemModifyEvent) {
+ hadModifyEvent = true;
+ continue;
+ }
+ assert(event is FileSystemCreateEvent ||
+ event is FileSystemDeleteEvent ||
+ event is FileSystemMoveEvent);
+
+ // If we previously thought this was a MODIFY, we now consider it to be a
+ // CREATE or REMOVE event. This is safe for the same reason as above.
+ if (type == FileSystemEvent.MODIFY) {
+ type = event.type;
+ continue;
+ }
+
+ // A CREATE event contradicts a REMOVE event and vice versa.
+ assert(type == FileSystemEvent.CREATE ||
+ type == FileSystemEvent.DELETE ||
+ type == FileSystemEvent.MOVE);
+ if (type != event.type) return null;
+ }
+
+ switch (type) {
+ case FileSystemEvent.CREATE:
+ return new ConstructableFileSystemCreateEvent(batch.first.path, isDir);
+ case FileSystemEvent.DELETE:
+ return new ConstructableFileSystemDeleteEvent(batch.first.path, isDir);
+ case FileSystemEvent.MODIFY:
+ return new ConstructableFileSystemModifyEvent(
+ batch.first.path, isDir, false);
+ case FileSystemEvent.MOVE:
+ return null;
+ default: assert(false);
+ }
+ }
+
+ /// Returns one or more events that describe the change between the last known
+ /// state of [path] and its current state on the filesystem.
+ ///
+ /// This returns a list whose order should be reflected in the events emitted
+ /// to the user, unlike the batched events from [Directory.watch]. The
+ /// returned list may be empty, indicating that no changes occurred to [path]
+ /// (probably indicating that it was created and then immediately deleted).
+ List<FileSystemEvent> _eventsBasedOnFileSystem(String path) {
+ var fileExisted = _files.contains(path);
+ var dirExisted = _files.containsDir(path);
+ var fileExists = new File(path).existsSync();
+ var dirExists = new Directory(path).existsSync();
+
+ var events = [];
+ if (fileExisted) {
+ if (fileExists) {
+ events.add(new ConstructableFileSystemModifyEvent(path, false, false));
+ } else {
+ events.add(new ConstructableFileSystemDeleteEvent(path, false));
+ }
+ } else if (dirExisted) {
+ if (dirExists) {
+ // If we got contradictory events for a directory that used to exist and
+ // still exists, we need to rescan the whole thing in case it was
+ // replaced with a different directory.
+ events.add(new ConstructableFileSystemDeleteEvent(path, true));
+ events.add(new ConstructableFileSystemCreateEvent(path, true));
+ } else {
+ events.add(new ConstructableFileSystemDeleteEvent(path, true));
+ }
+ }
+
+ if (!fileExisted && fileExists) {
+ events.add(new ConstructableFileSystemCreateEvent(path, false));
+ } else if (!dirExisted && dirExists) {
+ events.add(new ConstructableFileSystemCreateEvent(path, true));
+ }
+
+ return events;
+ }
+
+ /// The callback that's run when the [Directory.watch] stream is closed.
+ /// Note that this is unlikely to happen on Windows, unless the system itself
+ /// closes the handle.
+ void _onDone() {
+ _watchSubscription = null;
+
+ // Emit remove-events for any remaining files.
+ for (var file in _files.toSet()) {
+ _emitEvent(ChangeType.REMOVE, file);
+ }
+ _files.clear();
+ close();
+ }
+
+ /// Start or restart the underlying [Directory.watch] stream.
+ void _startWatch() {
+ // Batch the events changes together so that we can dedup events.
+ var innerStream =
+ Chain.track(new Directory(directory).watch(recursive: true));
+ _watchSubscription = innerStream.listen(_onEvent,
+ onError: _eventsController.addError,
+ onDone: _onDone);
+ }
+
+ /// Starts or restarts listing the watched directory to get an initial picture
+ /// of its state.
+ Future _listDir() {
+ assert(!isReady);
+ if (_initialListSubscription != null) _initialListSubscription.cancel();
+
+ _files.clear();
+ var completer = new Completer();
+ var stream = Chain.track(new Directory(directory).list(recursive: true));
+ void handleEntity(entity) {
+ if (entity is! Directory) _files.add(entity.path);
+ }
+ _initialListSubscription = stream.listen(
+ handleEntity,
+ onError: _emitError,
+ onDone: completer.complete,
+ cancelOnError: true);
+ return completer.future;
+ }
+
+ /// Emit an event with the given [type] and [path].
+ void _emitEvent(ChangeType type, String path) {
+ if (!isReady) return;
+
+ _eventsController.add(new WatchEvent(type, path));
+ }
+
+ /// Emit an error, then close the watcher.
+ void _emitError(error, StackTrace stackTrace) {
+ _eventsController.addError(error, stackTrace);
+ close();
+ }
+}
diff --git a/test/directory_watcher/windows_test.dart b/test/directory_watcher/windows_test.dart
new file mode 100644
index 0000000..3e9a854
--- /dev/null
+++ b/test/directory_watcher/windows_test.dart
@@ -0,0 +1,41 @@
+// Copyright (c) 2014, 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.
+
+import 'package:path/path.dart' as p;
+import 'package:scheduled_test/scheduled_test.dart';
+import 'package:watcher/src/directory_watcher/windows.dart';
+import 'package:watcher/watcher.dart';
+
+import 'shared.dart';
+import '../utils.dart';
+
+main() {
+ initConfig();
+
+ watcherFactory = (dir) => new WindowsDirectoryWatcher(dir);
+
+ setUp(createSandbox);
+
+ sharedTests();
+
+ test('DirectoryWatcher creates a WindowsDirectoryWatcher on Windows', () {
+ expect(new DirectoryWatcher('.'),
+ new isInstanceOf<WindowsDirectoryWatcher>());
+ });
+
+ test('when the watched directory is moved, removes all files', () {
+ writeFile("dir/a.txt");
+ writeFile("dir/b.txt");
+
+ startWatcher(dir: "dir");
+
+ renameDir("dir", "moved_dir");
+ createDir("dir");
+ inAnyOrder([
+ isRemoveEvent("dir/a.txt"),
+ isRemoveEvent("dir/b.txt")
+ ]);
+ });
+}
+
diff --git a/test/utils.dart b/test/utils.dart
index b520bbd..8b660e8 100644
--- a/test/utils.dart
+++ b/test/utils.dart
@@ -71,6 +71,11 @@
// Delete the sandbox when done.
currentSchedule.onComplete.schedule(() {
if (_sandboxDir != null) {
+ // TODO(rnystrom): Issue 19155. The watcher should already be closed when
+ // we clean up the sandbox.
+ if (_watcherEvents != null) {
+ _watcherEvents.close();
+ }
new Directory(_sandboxDir).deleteSync(recursive: true);
_sandboxDir = null;
}
