public override bool StartOperations()
{
if (base.StartOperations())
{
_folderWatcher.NotifyFilter = NotificationFilter;
if (MonitorChangeTypes.HasFlag(WatcherChangeTypes.Created))
{
_folderWatcher.Created += ChangeReceived;
}
if (MonitorChangeTypes.HasFlag(WatcherChangeTypes.Renamed))
{
_folderWatcher.Renamed += ChangeReceived;
}
if (MonitorChangeTypes.HasFlag(WatcherChangeTypes.Deleted))
{
_folderWatcher.Deleted += ChangeReceived;
}
if (MonitorChangeTypes.HasFlag(WatcherChangeTypes.Changed))
{
_folderWatcher.Changed += ChangeReceived;
}
_folderWatcher.EnableRaisingEvents = true;
return(true);
}
return(false);
}
public FileWatcherRx(string path, string filter,
NotifyFilters notifyFilters = NotifyFilters.LastWrite,
WatcherChangeTypes changeTypes = WatcherChangeTypes.Changed)
{
Watcher = new FileSystemWatcher
{
Path = path,
IncludeSubdirectories = false,
NotifyFilter = notifyFilters,
Filter = filter,
EnableRaisingEvents = true
};
if (changeTypes.HasFlag(WatcherChangeTypes.Changed))
{
Changed = Observable.FromEventPattern <FileSystemEventArgs>(Watcher, "Changed");
}
if (changeTypes.HasFlag(WatcherChangeTypes.Created))
{
Created = Observable.FromEventPattern <FileSystemEventArgs>(Watcher, "Created");
}
if (changeTypes.HasFlag(WatcherChangeTypes.Deleted))
{
Deleted = Observable.FromEventPattern <FileSystemEventArgs>(Watcher, "Deleted");
}
if (changeTypes.HasFlag(WatcherChangeTypes.Renamed))
{
Renamed = Observable.FromEventPattern <RenamedEventArgs>(Watcher, "Renamed");
}
Error = Observable.FromEventPattern <ErrorEventArgs>(Watcher, nameof(Watcher.Error));
}
public FileMonitor(string path, string filter = null, WatcherChangeTypes watchedChangeTypes = WatcherChangeTypes.All)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path");
}
_fileChangedSubject = Subject.Synchronize(new SubjectSlim <FileSystemEventArgs>());
_fsw = new FileSystemWatcher(path, filter);
// by default, try to reduce to a minimum the information returned by the FileSystemWatcher
// to reduce the occurence of an InternalBufferOverflowException when dealing with many files
_fsw.NotifyFilter = NotifyFilters.FileName;
// Changed event requires NotifyFilters.LastWrite
if (watchedChangeTypes.HasFlag(WatcherChangeTypes.Changed))
{
_fsw.NotifyFilter |= NotifyFilters.LastWrite;
}
// increase internal buffer size of the FSW to avoid an InternalBufferOverflowException
// (the size must be a multiple of 4096 for a better performance on Intel platform)
// see http://stackoverflow.com/questions/13916595/is-it-really-that-expensive-to-increase-filesystemwatcher-internalbuffersize
_fsw.InternalBufferSize = 16 * 4096; // 64KB
if (watchedChangeTypes.HasFlag(WatcherChangeTypes.Changed))
{
_fsw.Changed += (s, e) => _fileChangedSubject.OnNext(e);
}
if (watchedChangeTypes.HasFlag(WatcherChangeTypes.Created))
{
_fsw.Created += (s, e) => _fileChangedSubject.OnNext(e);
}
if (watchedChangeTypes.HasFlag(WatcherChangeTypes.Deleted))
{
_fsw.Deleted += (s, e) => _fileChangedSubject.OnNext(e);
}
if (watchedChangeTypes.HasFlag(WatcherChangeTypes.Renamed))
{
_fsw.Renamed += (s, e) => _fileChangedSubject.OnNext(e);
}
_fsw.Error += (s, e) => _fileChangedSubject.OnError(e.GetException());
}
private void AddEventSubscriptions(FileSystemWatcher fileWatcher, WatcherChangeTypes changeTypes)
{
if (changeTypes.HasFlag(WatcherChangeTypes.Changed))
{
fileWatcher.Changed += OnFileChanged;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Created))
{
fileWatcher.Created += OnFileChanged;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Deleted))
{
fileWatcher.Deleted += OnFileChanged;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Renamed))
{
fileWatcher.Renamed += OnFileChanged;
}
}
private void AddEventSubscriptions(FileSystemWatcher fileWatcher, WatcherChangeTypes changeTypes)
{
if (changeTypes.HasFlag(WatcherChangeTypes.Changed))
{
fileWatcher.Changed += OnFileChanged;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Created))
{
fileWatcher.Created += OnFileChanged;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Deleted))
{
fileWatcher.Deleted += OnFileChanged;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Renamed))
{
fileWatcher.Renamed += OnFileChanged;
}
}
private void DetachHandlersForChangeTypes(WatcherChangeTypes changeType)
{
if (changeType.HasFlag(WatcherChangeTypes.Created))
{
Created -= WaitForChangeHandler;
}
if (changeType.HasFlag(WatcherChangeTypes.Deleted))
{
Deleted -= WaitForChangeHandler;
}
if (changeType.HasFlag(WatcherChangeTypes.Changed))
{
Changed -= WaitForChangeHandler;
}
if (changeType.HasFlag(WatcherChangeTypes.Renamed))
{
Renamed -= WaitForChangeRenameHandler;
}
}
private static IObservable <EventPattern <FileSystemEventArgs> > CreateObservableEventsWithoutRenamed(
FileSystemWatcher watcher,
WatcherChangeTypes changes)
{
Contract.Requires(watcher != null);
IObservable <EventPattern <FileSystemEventArgs> > events = null;
if (changes.HasFlag(WatcherChangeTypes.Changed))
{
events = Observable.FromEventPattern <FileSystemEventHandler, FileSystemEventArgs>(
eh => eh.Invoke,
eh => watcher.Changed += eh,
eh => watcher.Changed -= eh);
}
if (changes.HasFlag(WatcherChangeTypes.Created))
{
var created = Observable.FromEventPattern <FileSystemEventHandler, FileSystemEventArgs>(
eh => eh.Invoke,
eh => watcher.Created += eh,
eh => watcher.Created -= eh);
events = events == null ? created : events.Merge(created);
}
if (changes.HasFlag(WatcherChangeTypes.Deleted))
{
var deleted = Observable.FromEventPattern <FileSystemEventHandler, FileSystemEventArgs>(
eh => eh.Invoke,
eh => watcher.Deleted += eh,
eh => watcher.Deleted -= eh);
events = events == null ? deleted : events.Merge(deleted);
}
return(events);
}
/// <summary>
/// Starts watching the file system.
/// </summary>
/// <param name="cancellationToken">
/// A cancellation token that should be used to cancel the watching task.
/// </param>
/// <returns>A <see cref="Task"/> that represent the watching process.</returns>
public async Task Watch(CancellationToken cancellationToken)
{
try {
var watcher = new FileSystemWatcher(_dir)
{
IncludeSubdirectories = true
};
cancellationToken.Register(() => watcher?.Dispose());
if (_events.HasFlag(WatcherChangeTypes.Created))
{
watcher.Created += OnWatcherFileSystemEvent;
}
if (_events.HasFlag(WatcherChangeTypes.Changed))
{
watcher.Changed += OnWatcherFileSystemEvent;
}
if (_events.HasFlag(WatcherChangeTypes.Deleted))
{
watcher.Deleted += OnWatcherFileSystemEvent;
}
if (_events.HasFlag(WatcherChangeTypes.Renamed))
{
watcher.Renamed += OnWatcherRenameEvent;
}
watcher.EnableRaisingEvents = true;
await Task.Delay(Timeout.Infinite, cancellationToken);
} catch (TaskCanceledException) {
Console.WriteLine("Stopping by request...");
}
}
private static IObservable <FileSystemNotification> CreateObservableEvents(
FileSystemWatcher watcher,
WatcherChangeTypes changes)
{
Contract.Requires(watcher != null);
Contract.Ensures(Contract.Result <IObservable <FileSystemNotification> >() != null);
IObservable <FileSystemNotification> allEvents = null;
var events = CreateObservableEventsWithoutRenamed(watcher, changes);
if (events != null)
{
allEvents = from e in events
select new FileSystemNotification(
e.EventArgs.ChangeType,
e.EventArgs.Name,
e.EventArgs.FullPath);
}
if (changes.HasFlag(WatcherChangeTypes.Renamed))
{
var renamed = Observable
.FromEventPattern <RenamedEventHandler, RenamedEventArgs>(
eh => eh.Invoke,
eh => watcher.Renamed += eh,
eh => watcher.Renamed -= eh)
.Select(e => new FileSystemNotification(
e.EventArgs.OldName,
e.EventArgs.OldFullPath,
e.EventArgs.Name,
e.EventArgs.FullPath));
allEvents = allEvents == null ? renamed : allEvents.Merge(renamed);
}
if (allEvents == null)
{
throw new InvalidEnumArgumentException("changes", (int)changes, typeof(WatcherChangeTypes));
}
return(allEvents);
}
public WaitForChangedResult WaitForChanged(WatcherChangeTypes type, int timeout)
{
if (type == WatcherChangeTypes.Renamed ||
type == WatcherChangeTypes.Changed ||
type == (WatcherChangeTypes.Changed | WatcherChangeTypes.Renamed)) // Polling cannot monitor these changes
{
throw new NotImplementedException("File System Poller can not monitor \"Rename\" or \"Changed\" item changes.");
}
// Using this stopwatch to check I'm staying in the method longer then the timeout set
Stopwatch timeInMethodStopwatch = Stopwatch.StartNew();
Interlocked.Increment(ref _waiters);
while (true)
{
int remainingTimeToWait = timeout - (int)timeInMethodStopwatch.ElapsedMilliseconds;
var timedOut = !_changesWatchingEvent.WaitOne(remainingTimeToWait);
if (timedOut) // wait timed out, exit method.
{
Interlocked.Decrement(ref _waiters);
return(new WaitForChangedResult()
{
ChangeType = type, TimedOut = true
});
}
// wait didn't time out - check results
WaitForChangedResult results;
lock (_latestChangeLocker)
{
results = _latestChange;
}
// Check if the reported results match the requestsed result type.
// Otherwise - continue waiting for more changes
if (type.HasFlag(results.ChangeType))
{
Interlocked.Decrement(ref _waiters);
return(results);
}
}
}
private async void OnLibraryChanged(WatcherChangeTypes changeType, string oldPath, string newPath)
{
if (newPath != null && (!newPath.ToLowerInvariant().EndsWith(ShellLibraryItem.EXTENSION, StringComparison.Ordinal) || !File.Exists(newPath)))
{
System.Diagnostics.Debug.WriteLine($"Ignored library event: {changeType}, {oldPath} -> {newPath}");
return;
}
System.Diagnostics.Debug.WriteLine($"Library event: {changeType}, {oldPath} -> {newPath}");
if (connection?.IsConnected ?? false)
{
var response = new ValueSet {
{ "Library", newPath ?? oldPath }
};
switch (changeType)
{
case WatcherChangeTypes.Deleted:
case WatcherChangeTypes.Renamed:
response["OldPath"] = oldPath;
break;
default:
break;
}
if (!changeType.HasFlag(WatcherChangeTypes.Deleted))
{
var library = SafetyExtensions.IgnoreExceptions(() => new ShellLibrary2(Shell32.ShellUtil.GetShellItemForPath(newPath), true));
if (library == null)
{
Program.Logger.Warn($"Failed to open library after {changeType}: {newPath}");
return;
}
response["Item"] = JsonConvert.SerializeObject(ShellFolderExtensions.GetShellLibraryItem(library, newPath));
library.Dispose();
}
// Send message to UWP app to refresh items
await Win32API.SendMessageAsync(connection, response);
}
}
public WaitForChangedResult WaitForChanged(WatcherChangeTypes type)
{
if (type == WatcherChangeTypes.Renamed ||
type == WatcherChangeTypes.Changed ||
type == (WatcherChangeTypes.Changed | WatcherChangeTypes.Renamed)) // Polling cannot monitor these changes
{
throw new NotImplementedException("File System Poller can not monitor \"Rename\" or \"Changed\" file changes.");
}
while (true)
{
Interlocked.Increment(ref _waiters);
_changesWatchingEvent.WaitOne();
Interlocked.Decrement(ref _waiters);
WaitForChangedResult results;
lock (_latestChangeLocker)
{
results = _latestChange;
}
// Check if the report fits the one the current thread is looking for
if (type.HasFlag(results.ChangeType))
{
// It does, returning the report.
return(results);
}
else
{
// It doesn't.
// allowing a signle other thread to examine it this report:
_changesWatchingEvent.Set();
// making sure the event is reset when the current thread returns to it. (If a thread is waiting it will exit after the .Set and before the .Reset)
_changesWatchingEvent.Reset();
}
}
}
public static IDisposable OnAnyEvent(this FileSystemWatcher source,
WatcherChangeTypes changeTypes, FileSystemEventHandler handler, int delay)
{
var cancellations = new Dictionary <string, CancellationTokenSource>(
StringComparer.OrdinalIgnoreCase);
var locker = new object();
if (changeTypes.HasFlag(WatcherChangeTypes.Created))
{
source.Created += FileSystemWatcher_Event;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Deleted))
{
source.Deleted += FileSystemWatcher_Event;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Changed))
{
source.Changed += FileSystemWatcher_Event;
}
if (changeTypes.HasFlag(WatcherChangeTypes.Renamed))
{
source.Renamed += FileSystemWatcher_Event;
}
return(new Disposable(() =>
{
source.Created -= FileSystemWatcher_Event;
source.Deleted -= FileSystemWatcher_Event;
source.Changed -= FileSystemWatcher_Event;
source.Renamed -= FileSystemWatcher_Event;
}));
async void FileSystemWatcher_Event(object sender, FileSystemEventArgs e)
{
var key = e.FullPath;
var cts = new CancellationTokenSource();
lock (locker)
{
if (cancellations.TryGetValue(key, out var existing))
{
existing.Cancel();
}
cancellations[key] = cts;
}
try
{
await Task.Delay(delay, cts.Token);
// Omitting ConfigureAwait(false) is intentional here.
// Continuing in the captured context is desirable.
}
catch (TaskCanceledException)
{
return;
}
lock (locker)
{
if (cancellations.TryGetValue(key, out var existing) &&
existing == cts)
{
cancellations.Remove(key);
}
}
cts.Dispose();
handler(sender, e);
}
}
public WaitForChangedResult WaitForChanged(WatcherChangeTypes type, int timeout)
{
if (type == WatcherChangeTypes.Renamed ||
type == WatcherChangeTypes.Changed ||
type == (WatcherChangeTypes.Changed | WatcherChangeTypes.Renamed)) // Polling cannot monitor these changes
{
throw new NotImplementedException("File System Poller can not monitor \"Rename\" or \"Changed\" item changes.");
}
// Using this stopwatch to check I'm staying in the method longer then the timeout set
Stopwatch timeInMethodStopwatch = Stopwatch.StartNew();
Interlocked.Increment(ref _waiters);
while (true)
{
int remainingTimeToWait = timeout - (int)timeInMethodStopwatch.ElapsedMilliseconds;
var timedOut = !_changesWatchingEvent.WaitOne(remainingTimeToWait);
if (timedOut) // wait timed out, exit method.
{
Interlocked.Decrement(ref _waiters);
return new WaitForChangedResult() { ChangeType = type, TimedOut = true };
}
// wait didn't time out - check results
WaitForChangedResult results;
lock (_latestChangeLocker)
{
results = _latestChange;
}
// Check if the reported results match the requestsed result type.
// Otherwise - continue waiting for more changes
if (type.HasFlag(results.ChangeType))
{
Interlocked.Decrement(ref _waiters);
return results;
}
}
}
public WaitForChangedResult WaitForChanged(WatcherChangeTypes type)
{
if (type == WatcherChangeTypes.Renamed ||
type == WatcherChangeTypes.Changed ||
type == (WatcherChangeTypes.Changed | WatcherChangeTypes.Renamed)) // Polling cannot monitor these changes
{
throw new NotImplementedException("File System Poller can not monitor \"Rename\" or \"Changed\" file changes.");
}
while (true)
{
Interlocked.Increment(ref _waiters);
_changesWatchingEvent.WaitOne();
Interlocked.Decrement(ref _waiters);
WaitForChangedResult results;
lock (_latestChangeLocker)
{
results = _latestChange;
}
// Check if the report fits the one the current thread is looking for
if (type.HasFlag(results.ChangeType))
{
// It does, returning the report.
return results;
}
else
{
// It doesn't.
// allowing a signle other thread to examine it this report:
_changesWatchingEvent.Set();
// making sure the event is reset when the current thread returns to it. (If a thread is waiting it will exit after the .Set and before the .Reset)
_changesWatchingEvent.Reset();
}
}
}
