Excess buffer space removal

[kevin21388]

I am getting say a persons name over a tcp connection. The problem is that when I do this :

            Dim buffSize As Integer
            Dim inStream(10024) As Byte
            buffSize = playerSockets(connectionCount).ReceiveBufferSize
            playerStreams(connectionCount).Read(inStream, 0, buffSize)
            Dim curName As String=System.Text.Encoding.ASCII.GetString   (inStream)

The curName string has a length of 10025. How do I get rid of excess blank space in either the byte array I recieve the data in or the string after I convert it?

[Curtis Rutland]

can you .Trim() the resulting string?

[kevin21388]

How would I know when the string's data end and excess space starts? the length function returns 10025.

[Plater]

Why are you trying to read in the buffersize? Why not try reading in the amount of data on the stream?
This is like the 3rd question I have seen about tcp connection where people are trying to read buffersize amount of bytes and getting excess data (since they asked for buffersize amount of data) instead of reading the correct amount.
Where did you learn this way of doing things? I feel as though I need to track down the source and have them correct their error.

[Curtis Rutland]

Looks like I misread your question. Please disregard.

[kevin21388]

How do I get the recieveDataSize ?
If you really want to know I was using this site as a reference on how to do the TCP connections:

http://vb.net-informations.com/communications/vb.net_Server_Socket.htm

[balabaster]

How do I get the recieveDataSize ?
If you really want to know I was using this site as a reference on how to do the TCP connections:
http://vb.net-informations.com/commu...ver_Socket.htm

If you're using the asynchronous BeginReceive, EndReceive methods to receive data and hold your asynchronous data, then the BytesRead method returns the actual number of bytes read from the tcp connection as opposed to the size of the buffer.

I've cut and pasted some code from an application I wrote a year or two ago now that demonstrates the BeginReceive and EndReceive. The BeginReceive is initiated in the OnConnected sub, you didn't need all of the code, and most of it probably won't make sense, but I thought the complete subs would give you a little more context as to how it is used. The EndReceive is found in the OnReceiveData sub which is actually a callback which is fired as a delegate of the BeginReceive method.

A simplified example is this:

Dim SessionObject As New MyCustomSessionObject

Sub StartListening()
  Dim Socket As TcpSocket
  Dim UserObject As New MyCustomUserObject
  'Usage:
  '  BeginReceive(
  '    BufferToReceiveTo, 'The buffer to receive the data do
  '    PositionToStartReadAt, 'The offset at which to begin reading from the buffer
  '    BufferSize, 'An integer describing the length of the receive buffer
  '    SocketFlags, 'Don't remember what this is, but I set it to none, it works.
  '    CallbackDelegate, 'This is fired when data is received
  '    SessionObject 'An object to hold asynchronous session specific data
  '  )
  '
  ' Stuff needed to set up TCP connection or this won't work...
  '
  Socket.BeginReceive(SessionObject.ReadBuffer, 0, UserObject.BufferSize,   SocketFlags.None, AddressOf OnReceiveData, SessionObject)
End Sub

Sub OnReceiveData()
  bytesRead = oSocket.EndReceive(IAResult)
  Dim thisRead() As Byte
  thisRead = TruncateByteArray(SessionObject.ReadBuffer, 0, bytesRead)
  SessionObject.Binary = JoinByteArrays(SessionObject.Binary, thisRead)
End Sub

Private Function TruncateByteArray(ByVal Input() As Byte, ByVal StartIndex As UInt64, ByVal Count As UInt64) As Byte()

  'Do stuff to truncate your byte array to just the part starting at StartIndex to the correct length.

End Function

Private Function JoinByteArrays(ByVal array1() As Byte, ByVal array2() As Byte) As Byte()

  'Do stuff to join together two byte arrays...

End Function

The code below is the actual code cut and pasted from my application:

    Private Sub OnConnected(ByVal IAResult As IAsyncResult)

        Dim oListener As TcpListener = CType(IAResult.AsyncState, TcpListener)
        Dim sEvent As String = ""

        Try
            Dim oSocket As Socket = oListener.EndAcceptSocket(IAResult)

            Dim oRemoteEP As IPEndPoint = oSocket.RemoteEndPoint
            sEvent = String.Format("[{0}:{1}] Connected.", oRemoteEP.Address.ToString, oRemoteEP.Port)
            ReportEvent(sEvent, EventLogEntryType.Information, LogPriority.Low)

            'oSocket.ReceiveTimeout = 60000
            'oSocket.SendTimeout = 60000

            clientConnected.Set()

            Dim oSession As New UserSession(_OutputDirectory)
            AddHandler oSession.CaptureStarted, AddressOf OnCaptureEvent
            AddHandler oSession.CaptureStopped, AddressOf OnCaptureEvent
            AddHandler oSession.CaptureFailed, AddressOf OnCaptureEvent

            Dim DisplayMsg As MsgBoxResult
            If _ListenerMode Then DisplayMsg = MsgBox("An incoming connection request has been received from " & oRemoteEP.Address.ToString & " do you wish to accept this request?", MsgBoxStyle.Information Or MsgBoxStyle.YesNo, "Confirm.")

            If (Not _ListenerMode) Or (DisplayMsg = MsgBoxResult.Yes) Then

                oSession.ActiveSocket = oSocket
                oSession.RemoteAddress = oSocket.RemoteEndPoint

                'Add this session to the array so we shut it down
                'correctly when we close down.
                _Sessions.Add(oSession)

                oSocket.BeginReceive(oSession.ReadBuffer, 0, UserSession.BufferSize, SocketFlags.None, AddressOf OnReceiveData, oSession)

            Else

                SendASCII(oSession, "Info", "Connection request denied by user of remote host.")
                oSocket.Disconnect(True)

            End If

        Catch e As Exception
            sEvent = e.Message
            ReportEvent(sEvent, EventLogEntryType.Error, LogPriority.Low)

        End Try

    End Sub

    Private Sub OnReceiveData(ByVal IAResult As System.IAsyncResult)

        Dim oSession As UserSession = CType(IAResult.AsyncState, UserSession)
        oSession.Refresh()

        Dim oSocket As Socket = oSession.ActiveSocket
        Dim bytesRead As Int32 = 0

        Try
            bytesRead = oSocket.EndReceive(IAResult)

            If bytesRead > 0 Then

                Dim thisRead() As Byte
                thisRead = TruncateByteArray(oSession.ReadBuffer, 0, bytesRead)
                oSession.Binary = JoinByteArrays(oSession.Binary, thisRead)

                If ProtocolBuilder.HasProtocolSignature(oSession.Binary) Then

                    If ProtocolBuilder.IsEOF(oSession.Binary) Then

                        Call CommandProcessor(oSession)
                        oSession.Binary = Nothing

                    End If

                    'Tell the socket that we want to continue listening and skip out of the sub
                    oSocket.BeginReceive(oSession.ReadBuffer, 0, UserSession.BufferSize, SocketFlags.None, AddressOf OnReceiveData, oSession)

                Else
                    'Boot the session
                    oSocket.BeginDisconnect(True, AddressOf OnDisconnected, oSession)

                End If

            End If

        Catch e As Exception
            If oSocket.Connected Then
                oSocket.BeginDisconnect(True, AddressOf OnDisconnected, oSession)
            Else
                oSession.ActiveSocket = Nothing
                oSession = Nothing
            End If
        End Try

    End Sub

Hopefully that will point you in the right direction. It's not complete by any means, if you don't have your head around delegates and asynchronous callbacks, then you're going to have to get your head around those concepts first before much of this will make sense.

[Plater]

Well, it would depend on your object, but it's really pretty simple/straightforward .
Try the .Available property on a TcpClient or a Socket object

[kevin21388]

Thanks balabaster, I will keep this code in mind while I finish the app. There is some very useful stuff in there.

Also thanks to plater, the available attribute is exactly what I was looking for.