Imports System.IO
Imports System.IO.Compression

Public Class HbGzip

    Public Shared Function Compress(ByVal cheminSource As String, ByVal cheminCible As String) As String
        Try
            Dim hbread As New BinaryReader(File.OpenRead(cheminSource))
            Dim F_array(hbread.BaseStream.Length) As Byte
            hbread.BaseStream.Seek(0, SeekOrigin.Begin)
            hbread.BaseStream.Read(F_array, 0, F_array.Length)
            hbread.BaseStream.Flush()
            hbread.Close()
            Dim tmpstream As FileStream = New FileStream(cheminCible, FileMode.OpenOrCreate)
            Dim gzipper As GZipStream = New GZipStream(tmpstream, CompressionMode.Compress)
            gzipper.Write(F_array, 0, F_array.Length)
            gzipper.Flush()
            gzipper.Close()
            Return "compression effectuée avec succés"
        Catch ex As Exception
            Return ex.ToString
        End Try
    End Function

    Public Shared Function Decompress(ByVal cheminSource As String, ByVal cheminCible As String) As String
        Try
            Dim bufferLen As Integer = 1024
            Dim hbread As New BinaryReader(File.OpenRead(cheminSource))
            Dim gzipper As GZipStream = New GZipStream(hbread.BaseStream, CompressionMode.Decompress)
            Dim hbwrite As New BinaryWriter(File.OpenWrite(cheminCible))
            Dim F_array(bufferLen) As Byte
            Dim readlen As Integer
            Dim flag As Boolean = True
            Do
                readlen = gzipper.Read(F_array, 0, F_array.Length)
                If readlen > 0 Then
                    flag = True
                    If readlen = (bufferLen + 1) Then hbwrite.Write(F_array, 0, readlen) Else hbwrite.Write(F_array, 0, readlen - 1)
                Else
                    flag = False
                End If
            Loop While (flag)
            hbwrite.Close()
            gzipper.Close()
            Return "decompression effectuée avec succés"
        Catch ex As Exception
            Return ex.ToString
        End Try
    End Function
End Class