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watcher/lib/src/directory_watcher/polling.dart

Index: watcher/lib/src/directory_watcher/polling.dart
diff --git a/watcher/lib/src/directory_watcher/polling.dart b/watcher/lib/src/directory_watcher/polling.dart
deleted file mode 100644
index 7f417d630702bed0bec7a57d904f0b535de4be57..0000000000000000000000000000000000000000
--- a/watcher/lib/src/directory_watcher/polling.dart
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@@ -1,182 +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.polling;
-
-import 'dart:async';
-import 'dart:io';
-
-import '../async_queue.dart';
-import '../directory_watcher.dart';
-import '../resubscribable.dart';
-import '../stat.dart';
-import '../utils.dart';
-import '../watch_event.dart';
-
-/// Periodically polls a directory for changes.
-class PollingDirectoryWatcher extends ResubscribableWatcher
-    implements DirectoryWatcher {
-  String get directory => path;
-
-  /// Creates a new polling watcher monitoring [directory].
-  ///
-  /// If [_pollingDelay] is passed, it specifies the amount of time the watcher
-  /// will pause between successive polls of the directory contents. Making this
-  /// shorter will give more immediate feedback at the expense of doing more IO
-  /// and higher CPU usage. Defaults to one second.
-  PollingDirectoryWatcher(String directory, {Duration pollingDelay})
-      : super(directory, () {
-        return new _PollingDirectoryWatcher(directory,
-            pollingDelay != null ? pollingDelay : new Duration(seconds: 1));
-      });
-}
-
-class _PollingDirectoryWatcher
-    implements DirectoryWatcher, ManuallyClosedWatcher {
-  String get directory => path;
-  final String path;
-
-  Stream<WatchEvent> get events => _events.stream;
-  final _events = new StreamController<WatchEvent>.broadcast();
-
-  bool get isReady => _ready.isCompleted;
-
-  Future get ready => _ready.future;
-  final _ready = new Completer();
-
-  /// The amount of time the watcher pauses between successive polls of the
-  /// directory contents.
-  final Duration _pollingDelay;
-
-  /// The previous modification times of the files in the directory.
-  ///
-  /// Used to tell which files have been modified.
-  final _lastModifieds = new Map<String, DateTime>();
-
-  /// The subscription used while [directory] is being listed.
-  ///
-  /// Will be `null` if a list is not currently happening.
-  StreamSubscription<FileSystemEntity> _listSubscription;
-
-  /// The queue of files waiting to be processed to see if they have been
-  /// modified.
-  ///
-  /// Processing a file is asynchronous, as is listing the directory, so the
-  /// queue exists to let each of those proceed at their own rate. The lister
-  /// will enqueue files as quickly as it can. Meanwhile, files are dequeued
-  /// and processed sequentially.
-  AsyncQueue<String> _filesToProcess;
-
-  /// The set of files that have been seen in the current directory listing.
-  ///
-  /// Used to tell which files have been removed: files that are in [_statuses]
-  /// but not in here when a poll completes have been removed.
-  final _polledFiles = new Set<String>();
-
-  _PollingDirectoryWatcher(this.path, this._pollingDelay) {
-    _filesToProcess = new AsyncQueue<String>(_processFile,
-        onError: (e, stackTrace) {
-      if (!_events.isClosed) _events.addError(e, stackTrace);
-    });
-
-    _poll();
-  }
-
-  void close() {
-    _events.close();
-
-    // If we're in the middle of listing the directory, stop.
-    if (_listSubscription != null) _listSubscription.cancel();
-
-    // Don't process any remaining files.
-    _filesToProcess.clear();
-    _polledFiles.clear();
-    _lastModifieds.clear();
-  }
-
-  /// Scans the contents of the directory once to see which files have been
-  /// added, removed, and modified.
-  void _poll() {
-    _filesToProcess.clear();
-    _polledFiles.clear();
-
-    endListing() {
-      assert(!_events.isClosed);
-      _listSubscription = null;
-
-      // Null tells the queue consumer that we're done listing.
-      _filesToProcess.add(null);
-    }
-
-    var stream = new Directory(path).list(recursive: true);
-    _listSubscription = stream.listen((entity) {
-      assert(!_events.isClosed);
-
-      if (entity is! File) return;
-      _filesToProcess.add(entity.path);
-    }, onError: (error, stackTrace) {
-      if (!isDirectoryNotFoundException(error)) {
-        // It's some unknown error. Pipe it over to the event stream so the
-        // user can see it.
-        _events.addError(error, stackTrace);
-      }
-
-      // When an error occurs, we end the listing normally, which has the
-      // desired effect of marking all files that were in the directory as
-      // being removed.
-      endListing();
-    }, onDone: endListing, cancelOnError: true);
-  }
-
-  /// Processes [file] to determine if it has been modified since the last
-  /// time it was scanned.
-  Future _processFile(String file) {
-    // `null` is the sentinel which means the directory listing is complete.
-    if (file == null) return _completePoll();
-
-    return getModificationTime(file).then((modified) {
-      if (_events.isClosed) return null;
-
-      var lastModified = _lastModifieds[file];
-
-      // If its modification time hasn't changed, assume the file is unchanged.
-      if (lastModified != null && lastModified == modified) {
-        // The file is still here.
-        _polledFiles.add(file);
-        return null;
-      }
-
-      if (_events.isClosed) return null;
-
-      _lastModifieds[file] = modified;
-      _polledFiles.add(file);
-
-      // Only notify if we're ready to emit events.
-      if (!isReady) return null;
-
-      var type = lastModified == null ? ChangeType.ADD : ChangeType.MODIFY;
-      _events.add(new WatchEvent(type, file));
-    });
-  }
-
-  /// After the directory listing is complete, this determines which files were
-  /// removed and then restarts the next poll.
-  Future _completePoll() {
-    // Any files that were not seen in the last poll but that we have a
-    // status for must have been removed.
-    var removedFiles = _lastModifieds.keys.toSet().difference(_polledFiles);
-    for (var removed in removedFiles) {
-      if (isReady) _events.add(new WatchEvent(ChangeType.REMOVE, removed));
-      _lastModifieds.remove(removed);
-    }
-
-    if (!isReady) _ready.complete();
-
-    // Wait and then poll again.
-    return new Future.delayed(_pollingDelay).then((_) {
-      if (_events.isClosed) return;
-      _poll();
-    });
-  }
-}