private void ClearDeliveredList()

in src/MessageConsumer.cs [766:819]
48 lines of code
10 McCabe index (conditional complexity)

        private void ClearDeliveredList()
        {
            if (this.clearDeliveredList)
            {
                using(this.deliveredMessagesLock.Lock())
                {
                    if (!this.clearDeliveredList || deliveredMessages.Count == 0)
                    {
                        clearDeliveredList = false;
                        return;
                    }

                    if (session.IsTransacted)
                    {
                        Tracer.DebugFormat("Consumer[{0}]: tracking existing transacted delivered list {1} on transport interrupt",
                                           this.info.ConsumerId, deliveredMessages.Count);

                        if (previouslyDeliveredMessages == null)
                        {
                            previouslyDeliveredMessages = new PreviouslyDeliveredMap(session.TransactionContext.TransactionId);
                        }

                        foreach (MessageDispatch delivered in deliveredMessages)
                        {
                            this.previouslyDeliveredMessages[delivered.Message.MessageId] = false;
                        }
                    }
                    else
                    {
                        if (this.session.IsClientAcknowledge)
                        {
                            Tracer.DebugFormat("Consumer[{0}] rolling back delivered list " +
                                               "({1}) on transport interrupt",
                                               ConsumerId, deliveredMessages.Count);

                            // allow redelivery
                            if (!this.info.Browser)
                            {
                                foreach (MessageDispatch dispatch in deliveredMessages)
                                {
                                    this.session.Connection.RollbackDuplicate(this, dispatch.Message);
                                }
                            }
                        }
                        Tracer.DebugFormat("Consumer[{0}]: clearing delivered list {1} on transport interrupt",
                                           this.info.ConsumerId, deliveredMessages.Count);
                        this.deliveredMessages.Clear();
                        this.pendingAck = null;
                    }

                    this.clearDeliveredList = false;
                }
            }
        }