jj: Add filecontainer

Filesystem/Compression.vb

@@ -0,0 +1,70 @@
+Imports System.IO
+Imports System.IO.Compression
+Imports DigitalData.Modules.Logging
+
+Friend Class Compression
+    Private ReadOnly _logger As Logger
+
+    Public Sub New(LogConfig As LogConfig)
+        _logger = LogConfig.GetLogger()
+    End Sub
+
+    Public Async Function CompressAsync(data As Byte()) As Task(Of Byte())
+        Return Await Task.Run(Function() As Byte()
+                                  Return Compress(data)
+                              End Function)
+    End Function
+
+    Public Function Compress(data As Byte()) As Byte()
+        Try
+            ' ByteArray in Stream umwandeln
+            Using originalStream As New MemoryStream(data)
+                ' Ziel Stream erstellen
+                Using compressedStream As New MemoryStream()
+                    ' Gzip-Stream erstellen, der alle Daten komprimiert und zu compressedStream durchleitet
+                    '
+                    '  > MemoryStream      > GzipStream          > MemoryStream  
+                    '  originalStream  --> compressionStream --> compressedFileStream
+                    '
+                    Using compressionStream As New GZipStream(compressedStream, CompressionMode.Compress)
+                        originalStream.CopyTo(compressionStream)
+                        compressionStream.Close()
+                        Return compressedStream.ToArray()
+                    End Using
+                End Using
+            End Using
+        Catch ex As Exception
+            _logger.Error(ex)
+            Throw ex
+        End Try
+    End Function
+
+    Public Async Function DecompressAsync(data As Byte()) As Task(Of Byte())
+        Return Await Task.Run(Function() As Byte()
+                                  Return Decompress(data)
+                              End Function)
+    End Function
+
+    Public Function Decompress(data As Byte()) As Byte()
+        Try
+            ' ByteArray in Stream umwandeln
+            Using compressedStream As New MemoryStream(data)
+                ' Ziel Stream erstellen
+                Using decompressedStream As New MemoryStream()
+                    ' Gzip-Stream erstellen, der alle Daten komprimiert und zu compressedStream durchleitet
+                    '
+                    '  > MemoryStream        > GzipStream            > MemoryStream  
+                    '  compressedStream  --> decompressionStream --> decompressedStream
+                    '
+                    Using decompressionStream As New GZipStream(compressedStream, CompressionMode.Decompress)
+                        decompressionStream.CopyTo(decompressedStream)
+                        Return decompressedStream.ToArray()
+                    End Using
+                End Using
+            End Using
+        Catch ex As Exception
+            _logger.Error(ex)
+            Throw ex
+        End Try
+    End Function
+End Class