Implement redelivery policy.

src/NMS.AMQP/NmsMessageConsumer.cs

@@ -360,8 +360,7 @@ private async Task DeliverNextPendingAsync()
                                     Tracer.Debug($"{Info.Id} filtered message with excessive redelivery count: {envelope.RedeliveryCount.ToString()}");
                                 }
 
-                                // TODO: Apply redelivery policy
-                                await DoAckExpiredAsync(envelope).Await();
+                                await DoAckRejectedAsync(envelope).Await();
                             }
                             else
                             {
@@ -372,7 +371,9 @@ private async Task DeliverNextPendingAsync()
                                     await DoAckDeliveredAsync(envelope).Await();
                                 else
                                     await AckFromReceiveAsync(envelope).Await();
-
+
+                                await ApplyRedeliveryPolicy(envelope).Await();
+
                                 try
                                 {
                                     Listener.Invoke(envelope.Message.Copy());
@@ -428,6 +429,17 @@ private bool IsRedeliveryExceeded(InboundMessageDispatch envelope)
 
             return false;
         }
+
+        private int RedeliveryDelay(InboundMessageDispatch envelope)
+        {
+            Tracer.DebugFormat("Checking if envelope is redelivered");
+            IRedeliveryPolicy redeliveryPolicy = Session.Connection.RedeliveryPolicy;
+            if (redeliveryPolicy == null || envelope.RedeliveryCount <= 0) return 0;
+
+            var redeliveryDelay = redeliveryPolicy.RedeliveryDelay(envelope.RedeliveryCount);
+            Tracer.DebugFormat("Envelope has been redelivered, apply redelivery policy wait {0} milliseconds", redeliveryDelay);
+            return redeliveryDelay;
+        }
 
         private Task DoAckReleasedAsync(InboundMessageDispatch envelope)
         {
@@ -516,8 +528,7 @@ private async Task<T> ReceiveInternalBaseAsync<T>(int timeout, Func<InboundMessa
                             Tracer.Debug($"{Info.Id} filtered message with excessive redelivery count: {envelope.RedeliveryCount.ToString()}");
                         }
 
-                        // TODO: Apply redelivery policy
-                        await DoAckExpiredAsync(envelope).Await();
+                        await DoAckRejectedAsync(envelope).Await();
                     }
                     else
                     {
@@ -526,6 +537,8 @@ private async Task<T> ReceiveInternalBaseAsync<T>(int timeout, Func<InboundMessa
                             Tracer.Debug($"{Info.Id} received message {envelope.Message.NMSMessageId}.");
                         }
 
+                        await ApplyRedeliveryPolicy(envelope).Await();
+
                         return await func.Invoke(envelope);
                     }
                 }
@@ -539,7 +552,17 @@ private async Task<T> ReceiveInternalBaseAsync<T>(int timeout, Func<InboundMessa
                 throw ExceptionSupport.Wrap(ex, "Receive failed");
             }
         }
-
+
+        private async Task ApplyRedeliveryPolicy(InboundMessageDispatch envelope)
+        {
+            int redeliveryDelay = RedeliveryDelay(envelope);
+
+            if (redeliveryDelay > 0)
+            {
+                await Task.Delay(TimeSpan.FromMilliseconds(redeliveryDelay)).Await();
+            }
+        }
+
 
         private static long GetDeadline(int timeout)
         {
@@ -577,6 +600,11 @@ private Task DoAckExpiredAsync(InboundMessageDispatch envelope)
             return Session.AcknowledgeAsync(AckType.MODIFIED_FAILED_UNDELIVERABLE, envelope);
         }
 
+        private Task DoAckRejectedAsync(InboundMessageDispatch envelope)
+        {
+            return Session.AcknowledgeAsync(AckType.REJECTED, envelope);
+        }
+
         private void SetAcknowledgeCallback(InboundMessageDispatch envelope)
         {
             if (acknowledgementMode == AcknowledgementMode.ClientAcknowledge)

src/NMS.AMQP/Provider/Amqp/AmqpConsumer.cs

@@ -331,6 +331,10 @@ public void Acknowledge(InboundMessageDispatch envelope, AckType ackType)
                         receiverLink.Modify(message, true, true);
                         RemoveMessage(envelope);
                         break;
+                    case AckType.REJECTED:
+                        receiverLink.Reject(message);
+                        RemoveMessage(envelope);
+                        break;
                     default:
                         Tracer.ErrorFormat("Unsupported Ack Type for message: {0}", envelope);
                         throw new ArgumentException($"Unsupported Ack Type for message: {envelope}");

test/Apache-NMS-AMQP-Test/Integration/MessageRedeliveryPolicyIntegrationTest.cs

@@ -0,0 +1,115 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using System;
+using System.Threading;
+using Amqp.Framing;
+using Apache.NMS;
+using Apache.NMS.Policies;
+using NMS.AMQP.Test.TestAmqp;
+using NUnit.Framework;
+
+namespace NMS.AMQP.Test.Integration
+{
+    [TestFixture]
+    public class MessageRedeliveryPolicyIntegrationTest : IntegrationTestFixture
+    {
+        [Test, Timeout(20_000)]
+        public void TestIncomingDeliveryCountExceededMessageGetsRejected()
+        {
+            using (TestAmqpPeer testPeer = new TestAmqpPeer())
+            {
+                IConnection connection = EstablishConnection(testPeer);
+                int initialRedeliveryDelay = 1000;
+                int clockResolution = 15;
+                connection.RedeliveryPolicy = new RedeliveryPolicy() { MaximumRedeliveries = 1, InitialRedeliveryDelay = initialRedeliveryDelay};
+                connection.Start();
+
+                testPeer.ExpectBegin();
+
+                ISession session = connection.CreateSession(AcknowledgementMode.IndividualAcknowledge);
+                IQueue queue = session.GetQueue("myQueue");
+
+                testPeer.ExpectReceiverAttach();
+                testPeer.ExpectLinkFlowRespondWithTransfer(message: new Amqp.Message() { BodySection = new AmqpValue() { Value = "hello" } });
+                testPeer.ExpectDispositionThatIsRejectedAndSettled();
+
+                IMessageConsumer consumer = session.CreateConsumer(queue);
+
+                IMessage m = consumer.Receive(TimeSpan.FromMilliseconds(3000));
+                Assert.NotNull(m, "Message should have been received");
+                Assert.IsInstanceOf<ITextMessage>(m);
+                session.Recover();
+
+                DateTime startTimer = DateTime.UtcNow;
+                m = consumer.Receive(TimeSpan.FromMilliseconds(3000));
+                Assert.That(DateTime.UtcNow.Subtract(startTimer).TotalMilliseconds, Is.GreaterThanOrEqualTo(initialRedeliveryDelay - clockResolution));
+
+                Assert.NotNull(m, "Message should have been received");
+                Assert.IsInstanceOf<ITextMessage>(m);
+                session.Recover();
+
+                // Verify the message is no longer there. Will drain to be sure there are no messages.
+                Assert.IsNull(consumer.Receive(TimeSpan.FromMilliseconds(10)), "Message should not have been received");
+
+                testPeer.ExpectClose();
+                connection.Close();
+
+                testPeer.WaitForAllMatchersToComplete(3000);
+            }
+        }
+
+        [Test, Timeout(20_000)]
+        public void TestIncomingDeliveryCountExceededMessageGetsRejectedAsync()
+        {
+            using (TestAmqpPeer testPeer = new TestAmqpPeer())
+            {
+                IConnection connection = EstablishConnection(testPeer);
+                int initialRedeliveryDelay = 1000;
+                connection.RedeliveryPolicy = new RedeliveryPolicy() { MaximumRedeliveries = 1, InitialRedeliveryDelay = initialRedeliveryDelay};
+                connection.Start();
+
+                testPeer.ExpectBegin();
+
+                ISession session = connection.CreateSession(AcknowledgementMode.IndividualAcknowledge);
+                IQueue queue = session.GetQueue("myQueue");
+
+
+                testPeer.ExpectReceiverAttach();
+                testPeer.ExpectLinkFlowRespondWithTransfer(message: new Amqp.Message() { BodySection = new AmqpValue() { Value = "hello" } });
+                testPeer.ExpectDispositionThatIsRejectedAndSettled();
+
+                IMessageConsumer consumer = session.CreateConsumer(queue);
+
+                CountdownEvent success = new CountdownEvent(2);
+
+                consumer.Listener += m =>
+                {
+                        session.Recover();
+                        success.Signal();
+                };
+
+                Assert.IsTrue(success.Wait(TimeSpan.FromSeconds(5)), "Didn't get expected messages");
+
+                testPeer.ExpectClose();
+                connection.Close();
+
+                testPeer.WaitForAllMatchersToComplete(3000);
+            }
+        }
+    }
+}

test/Apache-NMS-AMQP-Test/TestAmqp/TestAmqpPeer.cs

@@ -726,6 +726,11 @@ public void ExpectDispositionThatIsReleasedAndSettled()
 
             ExpectDisposition(settled: true, stateMatcher: stateMatcher);
         }
+
+        public void ExpectDispositionThatIsRejectedAndSettled()
+        {
+            ExpectDisposition(settled: true, stateMatcher: Assert.IsInstanceOf<Rejected>);
+        }
 
         public void ExpectDisposition(bool settled, Action<DeliveryState> stateMatcher, uint? firstDeliveryId = null, uint? lastDeliveryId = null)
         {