Remove Autofac from the EventBusRabbitMQ project

Refactor the EventBusRabbitMQ class

src/BuildingBlocks/EventBus/EventBusRabbitMQ/EventBusRabbitMQ.cs

@@ -1,45 +1,47 @@
-using Autofac;
+using System;
+using System.Net.Sockets;
+using System.Text;
+using System.Text.Json;
+using System.Threading.Tasks;
 using Microsoft.eShopOnContainers.BuildingBlocks.EventBus;
 using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
 using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Events;
 using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Extensions;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Polly;
-using Polly.Retry;
 using RabbitMQ.Client;
 using RabbitMQ.Client.Events;
 using RabbitMQ.Client.Exceptions;
-using System;
-using System.Net.Sockets;
-using System.Text;
-using System.Threading.Tasks;
-using System.Text.Json;
 
 namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
 {
     public class EventBusRabbitMQ : IEventBus, IDisposable
     {
-        const string BROKER_NAME = "eshop_event_bus";
-        const string AUTOFAC_SCOPE_NAME = "eshop_event_bus";
+        private const string BrokerName = "eshop_event_bus";
 
         private readonly IRabbitMQPersistentConnection _persistentConnection;
         private readonly ILogger<EventBusRabbitMQ> _logger;
         private readonly IEventBusSubscriptionsManager _subsManager;
-        private readonly ILifetimeScope _autofac;
+        private readonly IServiceScopeFactory _serviceScopeFactory;
         private readonly int _retryCount;
 
         private IModel _consumerChannel;
         private string _queueName;
 
-        public EventBusRabbitMQ(IRabbitMQPersistentConnection persistentConnection, ILogger<EventBusRabbitMQ> logger,
-            ILifetimeScope autofac, IEventBusSubscriptionsManager subsManager, string queueName = null, int retryCount = 5)
+        public EventBusRabbitMQ(IRabbitMQPersistentConnection persistentConnection,
+            ILogger<EventBusRabbitMQ> logger,
+            IServiceScopeFactory serviceScopeFactory,
+            IEventBusSubscriptionsManager subsManager,
+            string queueName = null,
+            int retryCount = 5)
         {
             _persistentConnection = persistentConnection ?? throw new ArgumentNullException(nameof(persistentConnection));
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
             _subsManager = subsManager ?? new InMemoryEventBusSubscriptionsManager();
             _queueName = queueName;
             _consumerChannel = CreateConsumerChannel();
-            _autofac = autofac;
+            _serviceScopeFactory = serviceScopeFactory;
             _retryCount = retryCount;
             _subsManager.OnEventRemoved += SubsManager_OnEventRemoved;
         }
@@ -53,15 +55,15 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
 
             using (var channel = _persistentConnection.CreateModel())
             {
-                channel.QueueUnbind(queue: _queueName,
-                    exchange: BROKER_NAME,
-                    routingKey: eventName);
+                channel.QueueUnbind(_queueName, BrokerName, eventName);
 
-                if (_subsManager.IsEmpty)
+                if (!_subsManager.IsEmpty)
                 {
-                    _queueName = string.Empty;
-                    _consumerChannel.Close();
+                    return;
                 }
+
+                _queueName = string.Empty;
+                _consumerChannel.Close();
             }
         }
 
@@ -72,23 +74,27 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
                 _persistentConnection.TryConnect();
             }
 
-            var policy = RetryPolicy.Handle<BrokerUnreachableException>()
+            var policy = Policy.Handle<BrokerUnreachableException>()
                 .Or<SocketException>()
-                .WaitAndRetry(_retryCount, retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)), (ex, time) =>
-                {
-                    _logger.LogWarning(ex, "Could not publish event: {EventId} after {Timeout}s ({ExceptionMessage})", @event.Id, $"{time.TotalSeconds:n1}", ex.Message);
-                });
+                .WaitAndRetry(_retryCount, retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)),
+                    (ex, time) =>
+                    {
+                        _logger.LogWarning(ex,
+                            "Could not publish event: {EventId} after {Timeout}s ({ExceptionMessage})", @event.Id,
+                            $"{time.TotalSeconds:n1}", ex.Message);
+                    });
 
             var eventName = @event.GetType().Name;
 
-            _logger.LogTrace("Creating RabbitMQ channel to publish event: {EventId} ({EventName})", @event.Id, eventName);
+            _logger.LogTrace("Creating RabbitMQ channel to publish event: {EventId} ({EventName})", @event.Id,
+                eventName);
 
             using (var channel = _persistentConnection.CreateModel())
             {
                 _logger.LogTrace("Declaring RabbitMQ exchange to publish event: {EventId}", @event.Id);
 
-                channel.ExchangeDeclare(exchange: BROKER_NAME, type: "direct");
-                                
+                channel.ExchangeDeclare(BrokerName, "direct");
+
                 var body = JsonSerializer.SerializeToUtf8Bytes(@event, @event.GetType(), new JsonSerializerOptions
                 {
                     WriteIndented = true
@@ -97,86 +103,81 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
                 policy.Execute(() =>
                 {
                     var properties = channel.CreateBasicProperties();
-                    properties.DeliveryMode = 2; // persistent
+                    properties.DeliveryMode = 2;
 
                     _logger.LogTrace("Publishing event to RabbitMQ: {EventId}", @event.Id);
 
                     channel.BasicPublish(
-                        exchange: BROKER_NAME,
-                        routingKey: eventName,
-                        mandatory: true,
-                        basicProperties: properties,
-                        body: body);
+                        BrokerName,
+                        eventName,
+                        true,
+                        properties,
+                        body);
                 });
             }
         }
 
-        public void SubscribeDynamic<TH>(string eventName)
-            where TH : IDynamicIntegrationEventHandler
+        public void SubscribeDynamic<TH>(string eventName) where TH : IDynamicIntegrationEventHandler
         {
-            _logger.LogInformation("Subscribing to dynamic event {EventName} with {EventHandler}", eventName, typeof(TH).GetGenericTypeName());
+            _logger.LogInformation("Subscribing to dynamic event {EventName} with {EventHandler}", eventName,
+                typeof(TH).GetGenericTypeName());
 
             DoInternalSubscription(eventName);
+
             _subsManager.AddDynamicSubscription<TH>(eventName);
+
             StartBasicConsume();
         }
 
-        public void Subscribe<T, TH>()
-            where T : IntegrationEvent
-            where TH : IIntegrationEventHandler<T>
+        public void Subscribe<T, TH>() where T : IntegrationEvent where TH : IIntegrationEventHandler<T>
         {
             var eventName = _subsManager.GetEventKey<T>();
-            DoInternalSubscription(eventName);
 
-            _logger.LogInformation("Subscribing to event {EventName} with {EventHandler}", eventName, typeof(TH).GetGenericTypeName());
+            DoInternalSubscription(eventName);
 
+            _logger.LogInformation("Subscribing to event {EventName} with {EventHandler}", eventName,
+                typeof(TH).GetGenericTypeName());
             _subsManager.AddSubscription<T, TH>();
+
             StartBasicConsume();
         }
 
         private void DoInternalSubscription(string eventName)
         {
             var containsKey = _subsManager.HasSubscriptionsForEvent(eventName);
-            if (!containsKey)
+
+            if (containsKey)
             {
-                if (!_persistentConnection.IsConnected)
-                {
-                    _persistentConnection.TryConnect();
-                }
+                return;
+            }
 
-                using (var channel = _persistentConnection.CreateModel())
-                {
-                    channel.QueueBind(queue: _queueName,
-                                      exchange: BROKER_NAME,
-                                      routingKey: eventName);
-                }
+            if (!_persistentConnection.IsConnected)
+            {
+                _persistentConnection.TryConnect();
+            }
+
+            using (var channel = _persistentConnection.CreateModel())
+            {
+                channel.QueueBind(_queueName, BrokerName, eventName);
             }
         }
 
-        public void Unsubscribe<T, TH>()
-            where T : IntegrationEvent
-            where TH : IIntegrationEventHandler<T>
+        public void Unsubscribe<T, TH>() where T : IntegrationEvent where TH : IIntegrationEventHandler<T>
         {
             var eventName = _subsManager.GetEventKey<T>();
 
             _logger.LogInformation("Unsubscribing from event {EventName}", eventName);
-
             _subsManager.RemoveSubscription<T, TH>();
         }
 
-        public void UnsubscribeDynamic<TH>(string eventName)
-            where TH : IDynamicIntegrationEventHandler
+        public void UnsubscribeDynamic<TH>(string eventName) where TH : IDynamicIntegrationEventHandler
         {
             _subsManager.RemoveDynamicSubscription<TH>(eventName);
         }
 
         public void Dispose()
         {
-            if (_consumerChannel != null)
-            {
-                _consumerChannel.Dispose();
-            }
-
+            _consumerChannel?.Dispose();
             _subsManager.Clear();
         }
 
@@ -191,9 +192,9 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
                 consumer.Received += Consumer_Received;
 
                 _consumerChannel.BasicConsume(
-                    queue: _queueName,
-                    autoAck: false,
-                    consumer: consumer);
+                    _queueName,
+                    false,
+                    consumer);
             }
             else
             {
@@ -223,7 +224,7 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
             // Even on exception we take the message off the queue.
             // in a REAL WORLD app this should be handled with a Dead Letter Exchange (DLX). 
             // For more information see: https://www.rabbitmq.com/dlx.html
-            _consumerChannel.BasicAck(eventArgs.DeliveryTag, multiple: false);
+            _consumerChannel.BasicAck(eventArgs.DeliveryTag, false);
         }
 
         private IModel CreateConsumerChannel()
@@ -237,21 +238,19 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
 
             var channel = _persistentConnection.CreateModel();
 
-            channel.ExchangeDeclare(exchange: BROKER_NAME,
-                                    type: "direct");
-
-            channel.QueueDeclare(queue: _queueName,
-                                 durable: true,
-                                 exclusive: false,
-                                 autoDelete: false,
-                                 arguments: null);
+            channel.ExchangeDeclare(BrokerName, "direct");
+            channel.QueueDeclare(_queueName,
+                true,
+                false,
+                false,
+                null);
 
             channel.CallbackException += (sender, ea) =>
             {
                 _logger.LogWarning(ea.Exception, "Recreating RabbitMQ consumer channel");
-
                 _consumerChannel.Dispose();
                 _consumerChannel = CreateConsumerChannel();
+
                 StartBasicConsume();
             };
 
@@ -264,29 +263,46 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
 
             if (_subsManager.HasSubscriptionsForEvent(eventName))
             {
-                using (var scope = _autofac.BeginLifetimeScope(AUTOFAC_SCOPE_NAME))
+                using (var scope = _serviceScopeFactory.CreateScope())
                 {
                     var subscriptions = _subsManager.GetHandlersForEvent(eventName);
+
                     foreach (var subscription in subscriptions)
                     {
                         if (subscription.IsDynamic)
                         {
-                            var handler = scope.ResolveOptional(subscription.HandlerType) as IDynamicIntegrationEventHandler;
-                            if (handler == null) continue;
-                            using dynamic eventData = JsonDocument.Parse(message);                            
+                            if (!(scope.ServiceProvider.GetService(subscription.HandlerType) is
+                                IDynamicIntegrationEventHandler handler))
+                            {
+                                continue;
+                            }
+
+                            using dynamic eventData = JsonDocument.Parse(message);
+
                             await Task.Yield();
                             await handler.Handle(eventData);
                         }
                         else
                         {
-                            var handler = scope.ResolveOptional(subscription.HandlerType);
-                            if (handler == null) continue;
+                            var handler = scope.ServiceProvider.GetService(subscription.HandlerType);
+                            if (handler == null)
+                            {
+                                continue;
+                            }
+
                             var eventType = _subsManager.GetEventTypeByName(eventName);
-                            var integrationEvent = JsonSerializer.Deserialize(message, eventType, new JsonSerializerOptions() { PropertyNameCaseInsensitive= true});                            
+                            var integrationEvent = JsonSerializer.Deserialize(message, eventType,
+                                new JsonSerializerOptions
+                                {
+                                    PropertyNameCaseInsensitive = true
+                                });
                             var concreteType = typeof(IIntegrationEventHandler<>).MakeGenericType(eventType);
 
                             await Task.Yield();
-                            await (Task)concreteType.GetMethod("Handle").Invoke(handler, new object[] { integrationEvent });
+                            await (Task) concreteType.GetMethod("Handle").Invoke(handler, new[]
+                            {
+                                integrationEvent
+                            });
                         }
                     }
                 }
@@ -297,4 +313,4 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
             }
         }
     }
-}
+}

src/BuildingBlocks/EventBus/EventBusRabbitMQ/EventBusRabbitMQ.csproj

@@ -6,7 +6,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Autofac" Version="6.1.0" />
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageReference Include="Microsoft.Extensions.Logging" Version="5.0.0" />    
     <PackageReference Include="Polly" Version="7.2.1" />