關於 hangfire 初始化工作機制

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hangfire初始化的配置方法 ：UseHangfire 。

   public static class OwinBootstrapper
    {
        /// <summary>
        /// Bootstraps Hangfire components using the given configuration
        /// action and maps Hangfire Dashboard to the app builder pipeline
        /// at the configured path ('/hangfire' by default).
        /// </summary>
        /// <param name="app">The app builder</param>
        /// <param name="configurationAction">Configuration action</param>
        public static void UseHangfire([NotNull] this IAppBuilder app,[NotNull] Action<IBootstrapperConfiguration> configurationAction)
        {
            if (app == null) throw new ArgumentNullException("app");
            if (configurationAction == null) throw new ArgumentNullException("configurationAction");
            // 初始化配置，給了默認值
            var configuration = new BootstrapperConfiguration(); 
            // 委托  賦值
            configurationAction(configuration);

            if (configuration.Activator != null)
            {
                JobActivator.Current = configuration.Activator;
            }

            if (configuration.Storage == null)
            {
                throw new InvalidOperationException("Job storage was not configured. Please call either `UseStorage` method or its overloads.");
            }
            // 獲取當前的存儲方式
            JobStorage.Current = configuration.Storage;
            // 通過UseFilter()將配置的過濾器放入容器中
            foreach (var filter in configuration.Filters)
            {
                GlobalJobFilters.Filters.Add(filter);
            }
            // 通過UseServers()將配置的過濾器放入容器中 ，如果需要分布式配置的話，在客戶端就不要配置server
            foreach (var server in configuration.Servers)
            {
                app.RunHangfireServer(server());
            }
            // 將Route和權限filter注入到owin管道中
            app.MapHangfireDashboard(configuration.DashboardPath, configuration.AuthorizationFilters);
        }
    }

 

用委托的方式來處理而不是讓開發人員自己去實現IBootstrapperConfiguration接口

這種方式確實開發人員使用上更方便了。 

 

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      public static void MapHangfireDashboard(
            [NotNull] this IAppBuilder app,
            string dashboardPath,
            IEnumerable<IAuthorizationFilter> authorizationFilters,
            JobStorage storage)
        {
            if (app == null) throw new ArgumentNullException("app");

            SignatureConversions.AddConversions(app);

            app.Map(dashboardPath,subApp => subApp.Use<DashboardMiddleware>(
                storage,
                DashboardRoutes.Routes,
                authorizationFilters));
        }

MapHangfireDashboard方法是將DashboardMiddleware注冊到own管道中

dashboardPath默認值是“/hangfire”  ,也就是說當你通過 Http://www.xxx.com/hangfire 訪問的每個請求都會進入DashboardMiddleware

DashboardMiddleware繼承了OwinMiddleware

 // 方法在DashboardMiddleware內

        public override Task Invoke(IOwinContext context)
        {
            // RouteCollection 是路由規則集合，
            var dispatcher = _routes.FindDispatcher(context.Request.Path.Value);
            
            if (dispatcher == null)
            {
                // 下一個OwinMiddleware中去處理
                // 一個請求會有多個OwinMiddleware
                return Next.Invoke(context);
            }
             
            foreach (var filter in _authorizationFilters)
            {
                if (!filter.Authorize(context.Environment))
                {
                    context.Response.StatusCode = (int) HttpStatusCode.Unauthorized;
                    return Task.FromResult(false);
                }
            }
            
            // 輸出內容
            var dispatcherContext = new RequestDispatcherContext(
                _storage,
                context.Environment,
                dispatcher.Item2);
            
            return dispatcher.Item1.Dispatch(dispatcherContext);
        }

 

RequestDispatcherContext 內部調度實現相對有些復雜，暫時沒時間去研究，我機會再分享了。