clean up

Modules.Filesystem/File.vb

@@ -75,6 +75,11 @@ Public Class File
         Return oCleanName
     End Function
 
+    ''' <summary>
+    ''' Reads the file at `FilePath` and computes a SHA256 Hash from its contents
+    ''' </summary>
+    ''' <param name="FilePath"></param>
+    ''' <returns></returns>
     Public Function GetChecksum(FilePath As String) As String
         Try
             Using oFileStream = IO.File.OpenRead(FilePath)
@@ -339,6 +344,24 @@ Public Class File
         End Try
     End Function
 
+    ''' <summary>
+    ''' Checks if a file is locked, ie. in use by another process.
+    ''' </summary>
+    ''' <remarks>
+    ''' https://docs.microsoft.com/en-us/dotnet/standard/io/handling-io-errors
+    ''' </remarks>
+    Public Function TestFileIsLocked(pFilePath As String) As Boolean
+        Try
+            Using stream As FileStream = IO.File.Open(FileMode.Open, FileAccess.Read, FileShare.None)
+                stream.Close()
+            End Using
+        Catch ex As Exception When ((ex.HResult And &HFFFF) = 32)
+            Return True
+        End Try
+
+        Return False
+    End Function
+
     Public Function TestPathIsDirectory(Path As String) As Boolean
         If Not Directory.Exists(Path) Then
             Return False