HttpServer.HttpClientContext.OnReceive C# (CSharp) Method

        private void OnReceive(IAsyncResult ar)
        {
            try
            {
                if (ar == null)
                {
                    LogWriter.Write (this, LogPrio.Debug, "Failed to end receive : NullRef");
                    Disconnect (SocketError.NoRecovery);
                    return;
                }
                int retry = 0;
                tryAgain:
                if (Stream == null)
                {
                    System.Threading.Thread.Sleep (1);
                    if (retry < 5)
                    {
                        retry++;
                        goto tryAgain;
                    }
                    LogWriter.Write (this, LogPrio.Warning, "Failed to end receive : NullRef");
                    Disconnect (SocketError.NoRecovery);
                    return; // "Connection: Close" in effect.
                }
                int bytesRead = Stream.EndRead(ar);
                if (bytesRead == 0)
                {
                    Disconnect(SocketError.ConnectionReset);
                    return;
                }
                _bytesLeft += bytesRead;
                if (_bytesLeft > _buffer.Length)
                {
#if DEBUG
                    throw new BadRequestException("Too large HTTP header: " + Encoding.UTF8.GetString(_buffer, 0, bytesRead));
#else
                    throw new BadRequestException("Too large HTTP header: " + _bytesLeft);
#endif
                }

#if DEBUG
#pragma warning disable 219
                string temp = Encoding.ASCII.GetString(_buffer, 0, _bytesLeft);
                LogWriter.Write(this, LogPrio.Trace, "Received: " + temp);
#pragma warning restore 219
#endif
                int offset = _parser.Parse(_buffer, 0, _bytesLeft);
				if (Stream == null)
					return; // "Connection: Close" in effect.

                // try again to see if we can parse another message (check parser to see if it is looking for a new message)
                int oldOffset = offset;
                while (_parser.CurrentState == RequestParserState.FirstLine && offset != 0 && _bytesLeft - offset > 0)
                {
#if DEBUG
                    temp = Encoding.ASCII.GetString(_buffer, offset, _bytesLeft - offset);
                    LogWriter.Write(this, LogPrio.Trace, "Processing: " + temp);
#endif
                    offset = _parser.Parse(_buffer, offset, _bytesLeft - offset);
					if (Stream == null)
						return; // "Connection: Close" in effect.
				}

                // need to be able to move prev bytes, so restore offset.
                if (offset == 0)
                    offset = oldOffset;

                // copy unused bytes to the beginning of the array
                if (offset > 0 && _bytesLeft != offset && _bytesLeft - offset > 0)
					Buffer.BlockCopy(_buffer, offset, _buffer, 0, _bytesLeft - offset);

                _bytesLeft -= offset;
                if (_bytesLeft >= 0 && Stream != null && Stream.CanRead)
					Stream.BeginRead(_buffer, _bytesLeft, _buffer.Length - _bytesLeft, OnReceive, null);
				else
				{
					_log.Write(this, LogPrio.Warning, "Could not read any more from the socket.");
					Disconnect(SocketError.Success);
				}
            }
            catch (BadRequestException err)
            {
                LogWriter.Write(this, LogPrio.Warning, "Bad request, responding with it. Error: " + err);
                try
                {
                    Respond("HTTP/1.0", HttpStatusCode.BadRequest, err.Message);
                }
                catch(Exception err2)
                {
                    LogWriter.Write(this, LogPrio.Fatal, "Failed to reply to a bad request. " + err2);
                }
                Disconnect(SocketError.NoRecovery);
            }
            catch (IOException err)
            {
                LogWriter.Write(this, LogPrio.Debug, "Failed to end receive: " + err.Message);
                if (err.InnerException is SocketException)
                    Disconnect((SocketError) ((SocketException) err.InnerException).ErrorCode);
                else
                    Disconnect(SocketError.ConnectionReset);
            }
            catch (ObjectDisposedException err)
            {
                LogWriter.Write(this, LogPrio.Warning, "Failed to end receive : " + err.Message);
                Disconnect(SocketError.NotSocket);
            }
            catch (NullReferenceException err)
            {
                LogWriter.Write(this, LogPrio.Debug, "Failed to end receive : NullRef: " + err.Message);
                Disconnect(SocketError.NoRecovery);
            }
            catch (Exception err)
            {
                LogWriter.Write(this, LogPrio.Warning, "Failed to end receive : Exception: " + err.ToString());
                Disconnect(SocketError.NoRecovery);
            }
        }