async Task ReceiveRequestOverRendezvousAsync()

in src/Microsoft.Azure.Relay/HybridHttpConnection.cs [136:174]
33 lines of code
6 McCabe index (conditional complexity)

        async Task<RequestCommandAndStream> ReceiveRequestOverRendezvousAsync()
        {
            using (var cancelSource = new CancellationTokenSource(this.OperationTimeout))
            {
                // A Rendezvous is required to get full request
                await this.EnsureRendezvousAsync(cancelSource.Token).ConfigureAwait(false);
            }

            RelayEventSource.Log.HybridHttpReadRendezvousValue(this, "request command");
            ListenerCommand.RequestCommand requestCommand;
            using (var rendezvousCommandStream = new WebSocketMessageStream(this.rendezvousWebSocket, this.OperationTimeout))
            {
                // Deserializing the object from stream makes a sync-over-async call which can deadlock
                // if performed on the websocket transport's callback thread.
                requestCommand = await Task.Run(() => ListenerCommand.ReadObject(rendezvousCommandStream).Request).ConfigureAwait(false);
                if (rendezvousCommandStream.MessageType == WebSocketMessageType.Close)
                {
                    throw RelayEventSource.Log.ThrowingException(new InvalidOperationException(SR.EntityClosedOrAborted), this);
                }
                else if (rendezvousCommandStream.MessageType != WebSocketMessageType.Text)
                {
                    throw RelayEventSource.Log.ThrowingException(
                        new ProtocolViolationException(SR.GetString(SR.InvalidType, WebSocketMessageType.Text, rendezvousCommandStream.MessageType)), this);
                }
                else if (requestCommand == null)
                {
                    throw RelayEventSource.Log.ThrowingException(new ProtocolViolationException(SR.GetString(SR.InvalidType, "request", "{unknown}")), this);
                }
            }

            Stream requestStream = null;
            if (requestCommand.Body.HasValue && requestCommand.Body.Value)
            {
                RelayEventSource.Log.HybridHttpReadRendezvousValue(this, "request body");
                requestStream = new WebSocketMessageStream(this.rendezvousWebSocket, this.OperationTimeout);
            }

            return new RequestCommandAndStream(requestCommand, requestStream);
        }