Beispiel #1
0
        private void SendLastValue(Message msg)
        {
            var key = LabelWithoutPrefix(msg);

            if (string.IsNullOrWhiteSpace(msg.ResponseQueue))
            {
                Console.Error.WriteLine($"INFO: Received a request for '{key}' without the response queue being set");
                return;
            }

            var last = _cache[key];

            if (last == null)
            {
                Console.Error.WriteLine($"DEBUG: there is no cached value for '{key}', sending an empty message");
                last = new Message {
                    Label = key
                };
            }

            var replyQueue = _queueCache.Open(msg.ResponseQueue, QueueAccessMode.Send);

            last.CorrelationId = msg.Id;
            replyQueue.Write(last);
            Console.Error.WriteLine($"DEBUG: sent reply for '{key}' to {msg.ResponseQueue}");
            // note: we do not wait for confirmation of delivery, we just report errors on via the AdminAsync (_adminTask)
        }
        /// <summary>Read messages from the input queue and forward to subscribers</summary>
        async Task MulticastInputDispatcher()
        {
            await Task.Yield();

            try
            {
                for (;;)
                {
                    var msg = _inputReader.Read(Properties.All, TimeSpan.Zero) ?? await _inputReader.ReadAsync(Properties.All);

                    // we could avoid the lock by using an immutable collection
                    var subscribers = _subscriptions.GetSubscribers(msg.Label);
                    if (subscribers.Count == 0)
                    {
                        continue;
                    }

                    var fn = string.Join(",", subscribers.Select(s => s.FormatName).Distinct()); // create a multi-element format name
                    var q  = _responseQueueCache.Open(fn, QueueAccessMode.Send);
                    msg.AdministrationQueue = _adminQueueFormatName;
                    q.Write(msg);
                }
            }
            catch (QueueException ex) when(ex.ErrorCode == ErrorCode.OperationCanceled)
            {
                // stopped
            }
            catch (ObjectDisposedException)
            {
                // stopped
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine("ERROR MulticastInputDispatcher: " + ex);
            }
        }