internal override void OnTransfer()

in src/ReceiverLink.cs [372:444]
67 lines of code
11 McCabe index (conditional complexity)

        internal override void OnTransfer(Delivery delivery, Transfer transfer, ByteBuffer buffer)
        {
            if (delivery == null)
            {
                delivery = this.deliveryCurrent.Delivery;
                AmqpBitConverter.WriteBytes(delivery.Buffer, buffer.Buffer, buffer.Offset, buffer.Length);
            }
            else
            {
                this.deliveryCurrent = new MessageDelivery(delivery, transfer.MessageFormat);
                buffer.AddReference();
                delivery.Buffer = buffer;
                lock (this.ThisLock)
                {
                    this.OnDelivery(transfer.DeliveryId);
                }
            }

            if (!transfer.More)
            {
                delivery.Message = Message.Decode(delivery.Buffer);
                delivery.Message.Format = this.deliveryCurrent.MessageFormat;
                this.deliveryCurrent = MessageDelivery.None;

                IHandler handler = this.Session.Connection.Handler;
                if (handler != null && handler.CanHandle(EventId.ReceiveDelivery))
                {
                    handler.Handle(Event.Create(EventId.ReceiveDelivery, this.Session.Connection, this.Session, this, context: delivery));
                }

                Waiter waiter;
                MessageCallback callback = this.onMessage;
                lock (this.ThisLock)
                {
                    waiter = (Waiter)this.waiterList.First;
                    if (waiter != null)
                    {
                        this.waiterList.Remove(waiter);
                    }
                    else if (callback == null)
                    {
                        this.receivedMessages.Add(new MessageNode() { Message = delivery.Message });
                        return;
                    }
                }

                while (waiter != null)
                {
                    if (waiter.Signal(delivery.Message))
                    {
                        return;
                    }

                    lock (this.ThisLock)
                    {
                        waiter = (Waiter)this.waiterList.First;
                        if (waiter != null)
                        {
                            this.waiterList.Remove(waiter);
                        }
                        else if (callback == null)
                        {
                            this.receivedMessages.Add(new MessageNode() { Message = delivery.Message });
                            return;
                        }
                    }
                }

                Fx.Assert(waiter == null, "waiter must be null now");
                Fx.Assert(callback != null, "callback must not be null now");
                callback(this, delivery.Message);
            }
        }