初步TimedTask完成

Falcon.SugarApi/TimedBackgroundTask/IServiceCollectionExtend.cs

@@ -0,0 +1,22 @@
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Falcon.SugarApi.TimedBackgroundTask
+{
+    /// <summary>
+    /// 服务集合扩展方法
+    /// </summary>
+    public static class IServiceCollectionExtend
+    {
+        /// <summary>
+        /// 向HostService中注册TimedBackgroundTask服务
+        /// </summary>
+        /// <typeparam name="T">TimedBackgroundTask的具体类型</typeparam>
+        /// <param name="services">服务集合</param>
+        /// <returns>服务集合</returns>
+        public static IServiceCollection AddTimedBackgroundTask<T>(this IServiceCollection services)
+            where T : TimedTask {
+            services.AddHostedService<T>();
+            return services;
+        }
+    }
+}

Falcon.SugarApi/TimedBackgroundTask/TimedTask.cs

@@ -0,0 +1,135 @@
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Falcon.SugarApi.TimedBackgroundTask
+{
+    /// <summary>
+    /// 由定时器驱动的后台任务
+    /// </summary>
+    public class TimedTask:BackgroundService, IDisposable
+    {
+        /// <summary>
+        /// 日志记录器
+        /// </summary>
+        protected readonly ILogger? Logger;
+        /// <summary>
+        /// 心跳计时器
+        /// </summary>
+        private readonly PeriodicTimer _timer;
+
+        /// <summary>
+        /// 运行一次任务
+        /// </summary>
+        /// <param name="cancellationToken">退出信号</param>
+        /// <returns>如果继续执行返回True，否则False</returns>
+        public virtual async Task<bool> Run(CancellationToken cancellationToken) => await Task.FromResult(true);
+
+        /// <summary>
+        /// Timer心跳
+        /// </summary>
+        public virtual int Heartbeat { get; set; } = 1;
+
+        /// <summary>
+        /// 执行计划的Cron串
+        /// </summary>
+        public virtual string CronSchedule { get; set; } = "30 * * * * *";
+
+        /// <summary>
+        /// 获取下次执行任务的计划
+        /// </summary>
+        public CronExpression Schedule { get; private set; }
+
+        /// <summary>
+        /// 任务正在运行
+        /// </summary>
+        private bool _isRunning = false;
+        /// <summary>
+        /// 下次执行时间
+        /// </summary>
+        public DateTime NextTickTime { get; set; } = DateTime.MinValue;
+
+        /// <summary>
+        /// 后台任务开始
+        /// </summary>
+        protected virtual void OnStart(TimedTask t,CancellationToken stoppingToken) { }
+        /// <summary>
+        /// 后台任务停止
+        /// </summary>
+        protected virtual void OnStop(TimedTask t,CancellationToken stoppingToken) { }
+        /// <summary>
+        /// 完成一次执行
+        /// </summary>
+        protected virtual void OnCompleted(TimedTask t,CancellationToken stoppingToken) { }
+        /// <summary>
+        /// 执行中发生未处理异常
+        /// </summary>
+        protected virtual bool OnException(TimedTask t,Exception ex,CancellationToken stoppingToken) {
+            return false;
+        }
+        /// <summary>
+        /// 系统服务
+        /// </summary>
+        public IServiceProvider Service { get; set; }
+        /// <summary>
+        /// 资源锁
+        /// </summary>
+        private static object _lock = new object();
+
+        /// <summary>
+        /// 构造Timed后台任务
+        /// </summary>
+        /// <param name="service">服务提供器</param>
+        public TimedTask(IServiceProvider service) {
+            this.Service = service;
+            this.Logger = service.GetService(typeof(ILogger<>).MakeGenericType(GetType())) as ILogger;
+            _timer = new PeriodicTimer(TimeSpan.FromSeconds(this.Heartbeat));
+            this.Schedule = new CronExpression(this.CronSchedule);
+        }
+
+        /// <summary>
+        /// 由系统调度执行任务
+        /// </summary>
+        /// <param name="stoppingToken">退出信号</param>
+        /// <returns>无返回</returns>
+        protected override async Task ExecuteAsync(CancellationToken stoppingToken) {
+            this.OnStart(this,stoppingToken);
+            while(await _timer.WaitForNextTickAsync(stoppingToken)) {
+                lock(_lock) {
+                    if(stoppingToken.IsCancellationRequested) {
+                        break;
+                    }
+                    if(this._isRunning || DateTime.Now < this.NextTickTime) {
+                        continue;
+                    }
+                    this._isRunning = true;
+                }
+                try {
+                    var goOn = await this.Run(stoppingToken);
+                    this.OnCompleted(this,stoppingToken);
+                    if(goOn) {
+                        continue;
+                    }
+                }
+                catch(Exception ex) {
+                    this.OnException(this,ex,stoppingToken);
+                }
+                SetNextTick();
+                this._isRunning = false;
+            }
+            this.OnStop(this,stoppingToken);
+        }
+
+        private void SetNextTick(string? cronSchedule = null) {
+            var s = cronSchedule == null ? this.Schedule : new CronExpression(cronSchedule);
+            this.NextTickTime = s.GetNextOccurrence(DateTime.Now);
+        }
+
+        public override void Dispose() {
+            this._timer?.Dispose();
+            base.Dispose();
+        }
+    }
+}