MyOddWeb.DirectoryWatcher 0.0.1

Myoddweb.Directorywatcher

A fast and reliable File/Directory watcher for c#/c++ to replace the current .NET FileSystemWatcher class.

What it does

• Reliable monitoring of
  • Renamed files/directories
  • Deleted files/directories
  • Created files/directories
• All exceptions are passed back to the caller.
• Non-blocking delegates, if one function takes a long time ... we don't all have to suffer.
• The interface does allow for porting to other platforms.
• No buffer limitations, (well there is, but we play nicely).
• Try and remove duplicates, (where possible).

Use case

My needs were to, reliably, monitor entire volumes for created/deleted/renamed files. I do really care for pattern matching.

What it doesn't do

• Bring me coffee.

The issue(s) with FileSystemWatcher

The current version of File Watcher is great, but it does have a couple of issues.

• There is a buffer limitation, (in the API itself), and a badly written application can 'block' or 'miss' certain notification.
• Duplicates are often sent, (when a file is updated 3 times between calls, we only need to know about the once).
• Certain Exceptions cause the entire app to close.
• UNC/Unix files are not supported, (in fact it causes FileSystemWatcher to take your system down).
• Does not handle large volumes nicely.

Example

Simple Watch

Add all the directories we want to 'observe'

    var watch = new Watcher();
    watch.Add(new Request("c:\\", true));
    watch.Add(new Request("d:\\foo\\bar\\", true));
    watch.Add(new Request("y:\\", true));

Then start

    // start watching
    watch.Start();

Get notifications in case a file is created.

    watch.OnAddedAsync += async (f, t) =>
    {
      Console.ForegroundColor = ConsoleColor.Green;
      Console.WriteLine(
        $"[{f.DateTimeUtc.Hour}:{f.DateTimeUtc.Minute}:{f.DateTimeUtc.Second}]:{f.FileSystemInfo}");
      Console.ForegroundColor = foreground;
    };

we get given the file that was added as well as a cancellation token

And when we are done stop it ...

    watch.Stop();