RFID.RFIDInterface.LakeChabotReader.FileHandlerClass.GetPendingPacket C# (CSharp) Method

            public PacketData.PacketWrapper GetPendingPacket( )
            {
                PacketData.PacketWrapper result = null;
                if ( NoTempFile )
                    return result;

                System.Diagnostics.Debug.Assert( _fileStream != null );

                long oldPosition;
                long newPosistion;

                if ( _fileStream != null &&
                     ( oldPosition = _fileStream.Position ) >
                     ( newPosistion = _lastPosition > FIXED_HEADER_SIZE ? _lastPosition : FIXED_HEADER_SIZE ) )
                {
                    _fileStream.Position = newPosistion;
                    result = _formatter.Deserialize( _fileStream ) as PacketData.PacketWrapper;
                    _lastPosition = _fileStream.Position;
                    _fileStream.Position = oldPosition;
                }
                return result;
            }