private async Task CreateAndOpen()

in src/Apache.IoTDB/SessionPool.cs [426:490]
54 lines of code
8 McCabe index (conditional complexity)

        private async Task<Client> CreateAndOpen(string host, int port, bool enableRpcCompression, int timeout, string sqlDialect, string database, CancellationToken cancellationToken = default)
        {
            var tcpClient = new TcpClient(host, port);
            tcpClient.SendTimeout = timeout;
            tcpClient.ReceiveTimeout = timeout;
            var transport = new TFramedTransport(new TSocketTransport(tcpClient, null));

            if (!transport.IsOpen)
            {
                await transport.OpenAsync(cancellationToken);
            }

            var client = enableRpcCompression ?
                new IClientRPCService.Client(new TCompactProtocol(transport)) :
                new IClientRPCService.Client(new TBinaryProtocol(transport));

            var openReq = new TSOpenSessionReq(ProtocolVersion, _zoneId, _username)
            {
                Password = _password,
            };
            if (openReq.Configuration == null)
            {
                openReq.Configuration = new Dictionary<string, string>();
            }
            openReq.Configuration.Add("sql_dialect", sqlDialect);
            if (!String.IsNullOrEmpty(database))
            {
                openReq.Configuration.Add("db", database);
            }

            try
            {
                var openResp = await client.openSessionAsync(openReq, cancellationToken);

                if (openResp.ServerProtocolVersion != ProtocolVersion)
                {
                    throw new TException($"Protocol Differ, Client version is {ProtocolVersion} but Server version is {openResp.ServerProtocolVersion}", null);
                }

                if (openResp.ServerProtocolVersion == 0)
                {
                    throw new TException("Protocol not supported", null);
                }

                var sessionId = openResp.SessionId;
                var statementId = await client.requestStatementIdAsync(sessionId, cancellationToken);

                var endpoint = new TEndPoint(host, port);

                var returnClient = new Client(
                    client,
                    sessionId,
                    statementId,
                    transport,
                    endpoint);

                return returnClient;
            }
            catch (Exception)
            {
                transport.Close();

                throw;
            }
        }