Added Stop method to ISubscriber

Tapeti/Connection/ITapetiClient.cs

@@ -77,8 +77,14 @@ namespace Tapeti.Connection
         /// <param name="cancellationToken">Cancelled when the connection is lost</param>
         /// <param name="queueName"></param>
         /// <param name="consumer">The consumer implementation which will receive the messages from the queue</param>
-        Task Consume(CancellationToken cancellationToken, string queueName, IConsumer consumer);
+        /// <returns>The consumer tag as returned by BasicConsume.</returns>
+        Task<string> Consume(CancellationToken cancellationToken, string queueName, IConsumer consumer);
 
+        /// <summary>
+        /// Stops the consumer with the specified tag.
+        /// </summary>
+        /// <param name="consumerTag">The consumer tag as returned by Consume.</param>
+        Task Cancel(string consumerTag);
 
         /// <summary>
         /// Creates a durable queue if it does not already exist, and updates the bindings.
@@ -118,7 +124,6 @@ namespace Tapeti.Connection
         /// <param name="binding">The binding to add to the dynamic queue</param>
         Task DynamicQueueBind(CancellationToken cancellationToken, string queueName, QueueBinding binding);
 
-
         /// <summary>
         /// Closes the connection to RabbitMQ gracefully.
         /// </summary>

Tapeti/Connection/TapetiClient.cs

@@ -72,7 +72,6 @@ namespace Tapeti.Connection
         }
 
 
-        /// <inheritdoc />
         public TapetiClient(ITapetiConfig config, TapetiConnectionParams connectionParams)
         {
             this.config = config;
@@ -184,29 +183,48 @@ namespace Tapeti.Connection
 
 
         /// <inheritdoc />
-        public async Task Consume(CancellationToken cancellationToken, string queueName, IConsumer consumer)
+        public async Task<string> Consume(CancellationToken cancellationToken, string queueName, IConsumer consumer)
         {
             if (deletedQueues.Contains(queueName))
-                return;
+                return null;
 
             if (string.IsNullOrEmpty(queueName))
                 throw new ArgumentNullException(nameof(queueName));
 
 
+            string consumerTag = null;
+
             await QueueWithRetryableChannel(channel =>
             {
                 if (cancellationToken.IsCancellationRequested)
                     return;
 
                 var basicConsumer = new TapetiBasicConsumer(consumer, Respond);
-                channel.BasicConsume(queueName, false, basicConsumer);
+                consumerTag = channel.BasicConsume(queueName, false, basicConsumer);
+            });
+
+            return consumerTag;
+        }
+
+
+        /// <inheritdoc />
+        public async Task Cancel(string consumerTag)
+        {
+            if (isClosing || string.IsNullOrEmpty(consumerTag))
+                return;
+
+            // No need for a retryable channel here, if the connection is lost
+            // so is the consumer.
+            await Queue(channel =>
+            {
+                channel.BasicCancel(consumerTag);
             });
         }
 
 
         private async Task Respond(ulong deliveryTag, ConsumeResult result)
         {
-            await taskQueue.Value.Add(() =>
+            await Queue(channel =>
             {
                 // No need for a retryable channel here, if the connection is lost we can't
                 // use the deliveryTag anymore.
@@ -214,15 +232,15 @@ namespace Tapeti.Connection
                 {
                     case ConsumeResult.Success:
                     case ConsumeResult.ExternalRequeue:
-                        GetChannel().BasicAck(deliveryTag, false);
+                        channel.BasicAck(deliveryTag, false);
                         break;
 
                     case ConsumeResult.Error:
-                        GetChannel().BasicNack(deliveryTag, false, false);
+                        channel.BasicNack(deliveryTag, false, false);
                         break;
 
                     case ConsumeResult.Requeue:
-                        GetChannel().BasicNack(deliveryTag, false, true);
+                        channel.BasicNack(deliveryTag, false, true);
                         break;
 
                     default:

Tapeti/Connection/TapetiSubscriber.cs

@@ -13,6 +13,7 @@ namespace Tapeti.Connection
         private readonly Func<ITapetiClient> clientFactory;
         private readonly ITapetiConfig config;
         private bool consuming;
+        private readonly List<string> consumerTags = new List<string>();
 
         private CancellationTokenSource initializeCancellationTokenSource;
 
@@ -50,6 +51,8 @@ namespace Tapeti.Connection
         {
             initializeCancellationTokenSource?.Cancel();
             initializeCancellationTokenSource = null;
+
+            consumerTags.Clear();
         }
 
 
@@ -65,6 +68,8 @@ namespace Tapeti.Connection
             initializeCancellationTokenSource?.Cancel();
             initializeCancellationTokenSource = new CancellationTokenSource();
 
+            consumerTags.Clear();
+
             cancellationToken = initializeCancellationTokenSource.Token;
 
             // ReSharper disable once MethodSupportsCancellation
@@ -91,6 +96,21 @@ namespace Tapeti.Connection
         }
 
 
+        /// <inheritdoc />
+        public async Task Stop()
+        {
+            if (!consuming)
+                return;
+
+            initializeCancellationTokenSource?.Cancel();
+            initializeCancellationTokenSource = null;
+
+            await Task.WhenAll(consumerTags.Select(async tag => await clientFactory().Cancel(tag)));
+
+            consumerTags.Clear();
+            consuming = false;
+        }
+
 
         private async Task ApplyBindings(CancellationToken cancellationToken)
         {
@@ -115,13 +135,13 @@ namespace Tapeti.Connection
         {
             var queues = config.Bindings.GroupBy(binding => binding.QueueName);
 
-            await Task.WhenAll(queues.Select(async group =>
+            consumerTags.AddRange(await Task.WhenAll(queues.Select(async group =>
             {
                 var queueName = group.Key;
                 var consumer = new TapetiConsumer(config, queueName, group);
 
-                await clientFactory().Consume(cancellationToken, queueName, consumer);
+                return await clientFactory().Consume(cancellationToken, queueName, consumer);
-            }));
+            })));
         }
 
 

Tapeti/ISubscriber.cs

@@ -13,5 +13,10 @@ namespace Tapeti
         /// Starts consuming from the subscribed queues if not already started.
         /// </summary>
         Task Resume();
+
+        /// <summary>
+        /// Stops consuming from the subscribed queues.
+        /// </summary>
+        Task Stop();
     }
 }