No need for a list of secondary receivers

Author: andreasohlund

src/NServiceBus.RabbitMQ.Tests/RabbitMqContext.cs

@@ -86,17 +86,7 @@ public void SetUp()
 
             dequeueStrategy = new RabbitMqDequeueStrategy(connectionManager, null,
                 new Configure(new SettingsHolder(), new FakeContainer(), new List<Action<IConfigureComponents>>(), new PipelineSettings(new BusConfiguration())),
-                new SecondaryReceiveConfiguration(s =>
-                {
-                    var settings = new SecondaryReceiveSettings
-                    {
-                        MaximumConcurrencyLevel = 1
-                    };
-
-                    settings.SecondaryQueues.Add(CallbackQueue);
-
-                    return settings;
-                }));
+                new SecondaryReceiveConfiguration(s => new SecondaryReceiveSettings(CallbackQueue,1)));
 
 
             MakeSureQueueAndExchangeExists(ReceiverQueue);

src/NServiceBus.RabbitMQ/Config/RabbitMqTransport.cs

@@ -65,15 +65,7 @@ protected override void Configure(FeatureConfigurationContext context, string co
                     return new SecondaryReceiveSettings();
                 }
 
-                var settings = new SecondaryReceiveSettings
-                {
-                    MaximumConcurrencyLevel = maxConcurrencyForCallbackReceiver
-                };
-
-
-                settings.SecondaryQueues.Add(callbackQueue);
-
-                return settings;
+                return new SecondaryReceiveSettings(callbackQueue, maxConcurrencyForCallbackReceiver);
             }));
 
             context.Container.ConfigureComponent<RabbitMqDequeueStrategy>(DependencyLifecycle.InstancePerCall);

src/NServiceBus.RabbitMQ/RabbitMqDequeueStrategy.cs

@@ -69,11 +69,15 @@ public void Start(int maximumConcurrencyLevel)
         {
             var secondaryReceiveSettings = secondaryReceiveConfiguration.GetSettings(workQueue);
 
-            var actualConcurrencyLevel = maximumConcurrencyLevel +
-                secondaryReceiveSettings.MaximumConcurrencyLevel * secondaryReceiveSettings.SecondaryQueues.Count;
+            var actualConcurrencyLevel = maximumConcurrencyLevel;
+
+            if (secondaryReceiveSettings.Enabled)
+            {
+                actualConcurrencyLevel += secondaryReceiveSettings.MaximumConcurrencyLevel;
+            }
 
             tokenSource = new CancellationTokenSource();
-            
+
             // We need to add an extra one because if we fail and the count is at zero already, it doesn't allow us to add one more.
             countdownEvent = new CountdownEvent(actualConcurrencyLevel + 1);
 
@@ -82,14 +86,14 @@ public void Start(int maximumConcurrencyLevel)
                 StartConsumer(workQueue);
             }
 
-            foreach (var secondaryReceiveQueue in secondaryReceiveSettings.SecondaryQueues)
+            if (secondaryReceiveSettings.Enabled)
             {
                 for (var i = 0; i < secondaryReceiveSettings.MaximumConcurrencyLevel; i++)
                 {
-                    StartConsumer(secondaryReceiveQueue);
+                    StartConsumer(secondaryReceiveSettings.SecondaryReceiveQueue);
                 }
 
-                Logger.InfoFormat("Secondary receiver for queue '{0}' initiated with concurrency '{1}'",secondaryReceiveQueue,secondaryReceiveSettings.MaximumConcurrencyLevel);
+                Logger.InfoFormat("Secondary receiver for queue '{0}' initiated with concurrency '{1}'", secondaryReceiveSettings.SecondaryReceiveQueue, secondaryReceiveSettings.MaximumConcurrencyLevel);                
             }
         }
 
@@ -263,7 +267,7 @@ void Purge()
         static ILog Logger = LogManager.GetLogger(typeof(RabbitMqDequeueStrategy));
 
         RepeatedFailuresOverTimeCircuitBreaker circuitBreaker;
-    
+
         bool autoAck;
         CountdownEvent countdownEvent;
         Action<TransportMessage, Exception> endProcessMessage;

src/NServiceBus.RabbitMQ/SecondaryReceiveConfiguration.cs

@@ -8,8 +8,7 @@ public SecondaryReceiveConfiguration(Func<string, SecondaryReceiveSettings> getS
         {
             secondaryReceiveSettings = getSecondaryReceiveSettings;
         }
-        
-     
+
         public SecondaryReceiveSettings GetSettings(string queue)
         {
             return secondaryReceiveSettings(queue);

src/NServiceBus.RabbitMQ/SecondaryReceiveSettings.cs

@@ -1,10 +1,31 @@
 namespace NServiceBus.Transports.RabbitMQ
 {
-    using System.Collections.Generic;
+    using System;
 
     class SecondaryReceiveSettings
     {
-        public int MaximumConcurrencyLevel;
-        public List<string> SecondaryQueues = new List<string>();
+        public SecondaryReceiveSettings()
+        {
+            Enabled = false;
+        }
+
+        public SecondaryReceiveSettings(string secondaryReceiveQueue, int maximumConcurrencyLevel)
+        {
+            if (maximumConcurrencyLevel < 0)
+            {
+                throw new Exception("Concurrency level must be a positive value");
+            }
+
+            Enabled = true;
+
+            SecondaryReceiveQueue = secondaryReceiveQueue;
+
+            MaximumConcurrencyLevel = maximumConcurrencyLevel;
+        }
+
+        public bool Enabled { get; private set; }
+
+        public int MaximumConcurrencyLevel { get; private set; }
+        public string SecondaryReceiveQueue { get; private set; }
     }
 }