System.Net.CommandStream.ReceiveCommandResponse C# (CSharp) Method

        private ResponseDescription ReceiveCommandResponse()
        {
            // These are the things that will be needed to maintain state.
            ReceiveState state = new ReceiveState(this);

            try
            {
                // If a string of nonzero length was decoded from the buffered bytes after the last complete response, then we
                // will use this string as our first string to append to the response StatusBuffer, and we will
                // forego a Connection.Receive here.
                if (_buffer.Length > 0)
                {
                    ReceiveCommandResponseCallback(state, -1);
                }
                else
                {
                    int bytesRead;

                    try
                    {
                        if (_isAsync)
                        {
                            BeginRead(state.Buffer, 0, state.Buffer.Length, s_readCallbackDelegate, state);
                            return null;
                        }
                        else
                        {
                            bytesRead = Read(state.Buffer, 0, state.Buffer.Length);
                            if (bytesRead == 0)
                                CloseSocket();
                            ReceiveCommandResponseCallback(state, bytesRead);
                        }
                    }
                    catch (IOException)
                    {
                        MarkAsRecoverableFailure();
                        throw;
                    }
                    catch
                    {
                        throw;
                    }
                }
            }
            catch (Exception e)
            {
                if (e is WebException)
                    throw;
                throw GenerateException(SR.net_ftp_receivefailure, WebExceptionStatus.ReceiveFailure, e);
            }
            return state.Resp;
        }