private void AddDirectory(FullPath directory)
{
DirectoryWatcherhEntry watcherEntry;
lock (_watchersLock) {
if (_pollingThread == null)
{
_pollingThread = new Thread(ThreadLoop)
{
IsBackground = true
};
_pollingThread.Start();
}
if (_watchers.TryGetValue(directory, out watcherEntry))
{
return;
}
watcherEntry = new DirectoryWatcherhEntry {
Path = directory,
DirectoryNameWatcher = _fileSystem.CreateDirectoryWatcher(directory),
FileNameWatcher = _fileSystem.CreateDirectoryWatcher(directory),
FileWriteWatcher = _fileSystem.CreateDirectoryWatcher(directory),
};
_watchers.Add(directory, watcherEntry);
}
Logger.LogInfo("Starting monitoring directory \"{0}\" for change notifications.", directory);
// Note: "DirectoryName" captures directory creation, deletion and rename
watcherEntry.DirectoryNameWatcher.NotifyFilter = NotifyFilters.DirectoryName;
watcherEntry.DirectoryNameWatcher.Changed += (s, e) => WatcherOnChanged(s, e, PathKind.Directory);
watcherEntry.DirectoryNameWatcher.Created += (s, e) => WatcherOnCreated(s, e, PathKind.Directory);
watcherEntry.DirectoryNameWatcher.Deleted += (s, e) => WatcherOnDeleted(s, e, PathKind.Directory);
watcherEntry.DirectoryNameWatcher.Renamed += (s, e) => WatcherOnRenamed(s, e, PathKind.Directory);
// Note: "FileName" captures file creation, deletion and rename
watcherEntry.FileNameWatcher.NotifyFilter = NotifyFilters.FileName;
watcherEntry.FileNameWatcher.Changed += (s, e) => WatcherOnChanged(s, e, PathKind.File);
watcherEntry.FileNameWatcher.Created += (s, e) => WatcherOnCreated(s, e, PathKind.File);
watcherEntry.FileNameWatcher.Deleted += (s, e) => WatcherOnDeleted(s, e, PathKind.File);
watcherEntry.FileNameWatcher.Renamed += (s, e) => WatcherOnRenamed(s, e, PathKind.File);
// Note: "LastWrite" will catch changes to *both* files and directories, i.e. it is
// not possible to known which one it is.
// For directories, a "LastWrite" change occurs when a child entry (file or directory) is added,
// renamed or deleted.
// For files, a "LastWrite" change occurs when the file is written to.
watcherEntry.FileWriteWatcher.NotifyFilter = NotifyFilters.LastWrite;
watcherEntry.FileWriteWatcher.Changed += (s, e) => WatcherOnChanged(s, e, PathKind.FileOrDirectory);
watcherEntry.FileWriteWatcher.Created += (s, e) => WatcherOnCreated(s, e, PathKind.FileOrDirectory);
watcherEntry.FileWriteWatcher.Deleted += (s, e) => WatcherOnDeleted(s, e, PathKind.FileOrDirectory);
watcherEntry.FileWriteWatcher.Renamed += (s, e) => WatcherOnRenamed(s, e, PathKind.FileOrDirectory);
foreach (var watcher in new[]
{ watcherEntry.DirectoryNameWatcher, watcherEntry.FileNameWatcher, watcherEntry.FileWriteWatcher })
{
watcher.IncludeSubdirectories = true;
// Note: The MSDN documentation says to use less than 64KB
// (see https://msdn.microsoft.com/en-us/library/system.io.filesystemwatcher.internalbuffersize(v=vs.110).aspx)
// "You can set the buffer to 4 KB or larger, but it must not exceed 64 KB."
// However, the implementation allows for arbitrary buffer sizes.
// Experience has shown that 64KB is small enough that we frequently run into "OverflowException"
// exceptions on heavily active file systems (e.g. during a build of a complex project
// such as Chromium).
// The issue with these exceptions is that the consumer must be extremely conservative
// when such errors occur, because we lost track of what happened at the individual
// directory/file level. In the case of VsChromium, the server will batch a full re-scan
// of the file system, instead of an incremental re-scan, and that can be quite time
// consuming (as well as I/O consuming).
// In the end, increasing the size of the buffer to 2 MB is the best option to avoid
// these issues (2 MB is not that much memory in the grand scheme of things).
watcher.InternalBufferSize = 2 * 1024 * 1024; // 2 MB
watcher.Error += WatcherOnError;
watcher.Start();
}
}
public abstract State OnWatcherRemoved(FullPath directory, DirectoryWatcherhEntry watcher);
public override State OnWatcherRemoved(FullPath directory, DirectoryWatcherhEntry watcher)
{
return(BackToState());
}
public override State OnWatcherAdded(FullPath directory, DirectoryWatcherhEntry watcher)
{
return(this);
}