分布式事件的设计与抽象

src/HelloShop.OrderingService/Behaviors/TransactionBehavior.cs

@@ -1,4 +1,7 @@
-using HelloShop.OrderingService.Extensions;
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using HelloShop.OrderingService.Extensions;
 using HelloShop.OrderingService.Infrastructure;
 using MediatR;
 using Microsoft.EntityFrameworkCore;

src/HelloShop.OrderingService/Controllers/OrdersController.cs

@@ -7,10 +7,8 @@ using HelloShop.OrderingService.Commands.Orders;
 using HelloShop.OrderingService.Models.Orders;
 using MediatR;
 using Microsoft.AspNetCore.Authorization;
-using Microsoft.AspNetCore.Components.Forms;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
-using System.ComponentModel.DataAnnotations;
 using System.Security.Claims;
 
 namespace HelloShop.OrderingService.Controllers;

src/HelloShop.OrderingService/Services/MessageService.cs

@@ -1,8 +1,6 @@
 // Copyright (c) HelloShop Corporation. All rights reserved.
 // See the license file in the project root for more information.
 
-using Microsoft.Extensions.Logging;
-
 namespace HelloShop.OrderingService.Services
 {
     public class MessageService(ILogger<MessageService> logger) : IEmailSender, ISmsSender

src/HelloShop.ServiceDefaults/DistributedEvents/Abstractions/DistributedEvent.cs

@@ -0,0 +1,24 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace HelloShop.ServiceDefaults.DistributedEvents.Abstractions
+{
+    public record DistributedEvent
+    {
+        public DistributedEvent()
+        {
+            Id = Guid.NewGuid();
+            CreationTime = DateTimeOffset.UtcNow;
+        }
+
+        public Guid Id { get; set; }
+
+        public DateTimeOffset CreationTime { get; set; }
+
+        [JsonExtensionData]
+        public Dictionary<string, JsonElement>? ExtensionData { get; set; }
+    }
+}

src/HelloShop.ServiceDefaults/DistributedEvents/Abstractions/DistributedEventBusBuilderExtensions.cs

@@ -0,0 +1,61 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using Microsoft.Extensions.DependencyInjection;
+using System.Reflection;
+using System.Text.Json;
+
+namespace HelloShop.ServiceDefaults.DistributedEvents.Abstractions
+{
+    public static class DistributedEventBusBuilderExtensions
+    {
+        public static IDistributedEventBusBuilder ConfigureJsonOptions(this IDistributedEventBusBuilder eventBusBuilder, Action<JsonSerializerOptions> configure)
+        {
+            eventBusBuilder.Services.Configure<DistributedEventBusOptions>(o =>
+            {
+                configure(o.JsonSerializerOptions);
+            });
+
+            return eventBusBuilder;
+        }
+
+        public static IDistributedEventBusBuilder AddSubscription<TEvent, TEventHandler>(this IDistributedEventBusBuilder eventBusBuilder) where TEvent : DistributedEvent where TEventHandler : class, IDistributedEventHandler<TEvent>
+        {
+            eventBusBuilder.Services.AddKeyedTransient<IDistributedEventHandler, TEventHandler>(typeof(TEvent));
+
+            eventBusBuilder.Services.Configure<DistributedEventBusOptions>(o =>
+            {
+                o.EventTypes[typeof(TEvent).Name] = typeof(TEvent);
+            });
+
+            return eventBusBuilder;
+        }
+
+        public static IDistributedEventBusBuilder AddSubscription(this IDistributedEventBusBuilder eventBusBuilder, Type eventType, Type eventHandlerType)
+        {
+            eventBusBuilder.Services.AddKeyedTransient(typeof(IDistributedEventHandler), eventType, eventHandlerType);
+
+            eventBusBuilder.Services.Configure<DistributedEventBusOptions>(o =>
+            {
+                o.EventTypes[eventType.Name] = eventType;
+            });
+
+            return eventBusBuilder;
+        }
+
+        public static IDistributedEventBusBuilder AddSubscriptionFromAssembly(this IDistributedEventBusBuilder eventBusBuilder, Assembly? assembly = null)
+        {
+            assembly ??= Assembly.GetCallingAssembly();
+
+            var handlers = assembly.GetTypes().Where(t => t.IsAssignableTo(typeof(IDistributedEventHandler))).ToList();
+
+            handlers.ForEach(handler =>
+            {
+                var eventType = handler.GetInterfaces().Single(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IDistributedEventHandler<>)).GetGenericArguments().Single();
+                eventBusBuilder.AddSubscription(eventType, handler);
+            });
+
+            return eventBusBuilder;
+        }
+    }
+}

src/HelloShop.ServiceDefaults/DistributedEvents/Abstractions/DistributedEventBusOptions.cs

@@ -0,0 +1,20 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using System.Text.Json;
+using System.Text.Json.Serialization.Metadata;
+
+namespace HelloShop.ServiceDefaults.DistributedEvents.Abstractions
+{
+    public class DistributedEventBusOptions
+    {
+        public Dictionary<string, Type> EventTypes { get; } = [];
+
+        public JsonSerializerOptions JsonSerializerOptions { get; } = new(DefaultSerializerOptions);
+
+        internal static readonly JsonSerializerOptions DefaultSerializerOptions = new()
+        {
+            TypeInfoResolver = JsonSerializer.IsReflectionEnabledByDefault ? new DefaultJsonTypeInfoResolver() : JsonTypeInfoResolver.Combine()
+        };
+    }
+}

src/HelloShop.ServiceDefaults/DistributedEvents/Abstractions/IDistributedEventBus.cs

@@ -0,0 +1,10 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+namespace HelloShop.ServiceDefaults.DistributedEvents.Abstractions
+{
+    public interface IDistributedEventBus
+    {
+        Task PublishAsync(DistributedEvent @event, CancellationToken cancellationToken = default);
+    }
+}

src/HelloShop.ServiceDefaults/DistributedEvents/Abstractions/IDistributedEventBusBuilder.cs

@@ -0,0 +1,12 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using Microsoft.Extensions.DependencyInjection;
+
+namespace HelloShop.ServiceDefaults.DistributedEvents.Abstractions
+{
+    public interface IDistributedEventBusBuilder
+    {
+        public IServiceCollection Services { get; }
+    }
+}

src/HelloShop.ServiceDefaults/DistributedEvents/Abstractions/IDistributedEventHandler.cs

@@ -0,0 +1,17 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+namespace HelloShop.ServiceDefaults.DistributedEvents.Abstractions
+{
+    public interface IDistributedEventHandler
+    {
+        Task HandleAsync(DistributedEvent @event);
+    }
+
+    public interface IDistributedEventHandler<in TDistributedEvent> : IDistributedEventHandler where TDistributedEvent : DistributedEvent
+    {
+        Task HandleAsync(TDistributedEvent @event);
+
+        Task IDistributedEventHandler.HandleAsync(DistributedEvent @event) => HandleAsync((TDistributedEvent)@event);
+    }
+}