I’ve been working on a small tool to aid in removing duplicate files and as I’m going back over my roughed in code, I’m trying to optimize it for some performance gains.

This snippet of code works really well for recursively counting files given a specific path.  I originally found it at StackOverflow and slightly modified to suit my needs.

Sub ProcessFile(ByVal path As String)
        fileCounter += 1
    End Sub

    Sub ApplyAllFiles(ByVal folder As String, ByVal extension As String, ByVal fileAction As ProcessFileDelegate)
        For Each file In Directory.GetFiles(folder, extension)
        For Each subDir In Directory.GetDirectories(folder)
                ApplyAllFiles(subDir, extension, fileAction)
            Catch ex As Exception
            End Try

    End Sub

It processes about 27k files in 1.5 seconds on my SSD disk.  I have it running against a NAS with considerably larger amount of files, so I’ll see how well it performs.

In my sub, I use the following to kick it off.

        Dim fileCounter as Long = 0L
        Dim path = "z:"
        Dim ext = "*.*"

        ToolStripStatusLabel1.Text = "Calculating files..."


        Dim runProcess As ProcessFileDelegate = AddressOf ProcessFile
        ApplyAllFiles(path, ext, runProcess)


        Dim rslts3 As String = String.Format("Total files = {0:n0}. Took {1:n0} ms.", fileCounter, stpw.ElapsedMilliseconds)
        ToolStripStatusLabel1.Text = rslts3.ToString

Graphically speaking, this isn’t much to look at – but the important part is in the ToolStripStatus. I have a timer on my form that updates the latest file count every 15 seconds so that a user would know it’s still working. Interestingly enough, if I update the ToolStripStatus with every single file that is found, it exponentially increases the time it takes to go through the files, so I decided to just update every 15 seconds.