事务性发件箱模式

libraries/HelloShop.EventBus.Logging/DistributedEventWorker.cs

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+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+
+using HelloShop.EventBus.Abstractions;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace HelloShop.EventBus.Logging
+{
+    public class DistributedEventWorker(IServiceScopeFactory serviceScopeFactory) : BackgroundService
+    {
+        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+        {
+            while (!stoppingToken.IsCancellationRequested)
+            {
+                using var scope = serviceScopeFactory.CreateScope();
+
+                var eventBus = scope.ServiceProvider.GetRequiredService<IEventBus>();
+                var eventLogService = scope.ServiceProvider.GetRequiredService<IDistributedEventLogService>();
+                var logger = scope.ServiceProvider.GetRequiredService<ILogger<DistributedEventWorker>>();
+
+                try
+                {
+                    var failedEventLogs = await eventLogService.RetrieveEventLogsFailedToPublishAsync(stoppingToken);
+
+                    foreach (var eventLog in failedEventLogs)
+                    {
+                        DistributedEvent @event = eventLog.DistributedEvent;
+
+                        try
+                        {
+                            await eventLogService.MarkEventAsInProgressAsync(@event.Id, stoppingToken);
+                            await eventBus.PublishAsync(@event, stoppingToken);
+                            await eventLogService.MarkEventAsPublishedAsync(@event.Id, stoppingToken);
+                        }
+                        catch (Exception ex)
+                        {
+                            logger.LogError(ex, "Publish through event bus failed for {EventId}.", @event.Id);
+                            await eventLogService.MarkEventAsFailedAsync(@event.Id, stoppingToken);
+                        }
+                    }
+                }
+                catch (Exception ex)
+                {
+                    logger.LogError(ex, "An error occurred while retrieving failed event logs.");
+                }
+
+                await Task.Delay(TimeSpan.FromSeconds(30), stoppingToken);
+            }
+        }
+    }
+}