《經過C#學Proto.Actor模型》之Supervision

時間 2019-12-09

標籤經過 c# proto.actor proto actor 模型 supervision 欄目 C# 简体版

原文原文鏈接

Supervision，字面意思是監督，是父Actor發現子Actor有異常發生後，對子Actor產用保種策略處理的機制，若是父Actor不處理，則往上傳遞。dom

子Actor發生異常後處理的策略有：ide

Resume：當即恢復spa

Restart：恢復以前中止Actor並從新建立它scala

Stop：中止code

Escalate：上報到父級 blog

Supervisor的經過Props.WithChildSupervisorStarategy()來實施的，這個方法第一個參數是接收異常和Actor的PID，以便按必定方式處理異常，第二個參數是重啓的次數，第三個參數是兩次重啓的間隔（按照官方文檔，兩個連續重啓時間大於間隔時間，次數會復位，但實則只按次數走，間隔不起做用）達到最大次數據，子Actor將從新生成。 ci

碼友看代碼：文檔

  1 using Proto;
  2 using System;
  3 using System.Collections.Generic;
  4 using System.Linq;
  5 using System.Threading.Tasks;
  6 
  7 namespace P006_Supervision
  8 {
  9     class Program
 10     {
 11         static void Main(string[] args)
 12         {
 13             //設置監督策略，指向SupervisiorMode方法，重啓次數爲3，兩次之間間隔1s
 14             var props = Actor.FromProducer(() => new ShopingCatActor()).WithChildSupervisorStrategy(new OneForOneStrategy(SupervisorMode.Decide, 3, TimeSpan.FromSeconds(1)));
 15             var pid = Actor.Spawn(props);
 16             var user = new User { UserName = "gsw" };
 17 
 18             var sn = 1;
 19             while (true)
 20             {
 21                 Console.WriteLine($"{sn++}--------------------begin-----------------");
 22                 foreach (var goods in user.ShopingCat.Goodses)
 23                 {
 24                     Console.WriteLine(goods);
 25                 }
 26                 Console.WriteLine("---------------------end------------------");
 27                 Console.ReadLine();
 28                 pid.Request(user, pid);
 29             }
 30         }
 31     }
 32     /// <summary>
 33     /// Supervisor 模式
 34     /// </summary>
 35     class SupervisorMode
 36     {
 37         /// <summary>
 38         /// 用來處理異常發生的後續操做
 39         /// </summary>
 40         /// <param name="pid">PID</param>
 41         /// <param name="reason">異常緣由，Exception類型</param>
 42         /// <returns></returns>
 43         public static SupervisorDirective Decide(PID pid, Exception reason)
 44         {
 45             Console.WriteLine("   異常發生：" + reason.Message + "   " + pid);
 46             switch (reason)
 47             {
 48                 //從新開始的異常
 49                 case RecoverableException _:
 50                     return SupervisorDirective.Restart;
 51                 //中止異常
 52                 case FatalException _:
 53                     return SupervisorDirective.Stop;
 54                 //其餘都上報
 55                 default:
 56                     return SupervisorDirective.Escalate;
 57             }
 58         }
 59     }
 60     /// <summary>
 61     /// 購物車actor
 62     /// </summary>
 63     class ShopingCatActor : IActor
 64     {
 65         ShopingCat _shopingCat;
 66         public ShopingCatActor()
 67         {
 68             _shopingCat = new ShopingCat();
 69             Console.WriteLine("*******************actor ShopingCatActor************************");
 70         }
 71         public Task ReceiveAsync(IContext context)
 72         {
 73             PID childPid;
 74             if (context.Children == null || context.Children.Count == 0)
 75             {
 76                 var props = Actor.FromProducer(() => new GoodsActor());
 77                 childPid = context.Spawn(props);
 78             }
 79             else
 80             {
 81                 childPid = context.Children.First();
 82             }
 83             switch (context.Message)
 84             {
 85                 case User user:
 86                     childPid.Request(_shopingCat, childPid);
 87                     user.ShopingCat = _shopingCat;
 88                     break;
 89             }
 90             return Actor.Done;
 91         }
 92     }
 93     /// <summary>
 94     /// 商品actor
 95     /// </summary>
 96     class GoodsActor : IActor
 97     { 
 98         public Task ReceiveAsync(IContext context)
 99         {
100             switch (context.Message)
101             {
102                 case ShopingCat shopingCat:
103 
104                     var goods = new Goods { Name = "紅茶", Price = 3.0m, Describe = "統一" };
105                     //用來隨機產生異常
106                     var random = new Random();
107                     goods.Quantity = random.Next(1, 3) - 1;
108                     if (goods.Quantity <= 0)
109                     {
110                         throw new RecoverableException("數量不能小於等於0");
111                     }
112                     else
113                     {
114                         shopingCat.Goodses.Add(goods);
115                         Console.WriteLine($"添加 {goods} 到購物車裏");
116                     }
117                     break;
118             }
119             return Actor.Done;
120         }
121     }
122     /// <summary>
123     /// 用戶
124     /// </summary>
125     class User
126     {
127         public ShopingCat ShopingCat { get; set; } = new ShopingCat();
128         public string UserName { get; set; }
129     }
130     /// <summary>
131     /// 購物車
132     /// </summary>
133     class ShopingCat
134     {
135         public List<Goods> Goodses
136         { get; set; } = new List<Goods>();
137     }
138     /// <summary>
139     /// 商品
140     /// </summary>
141     class Goods
142     {
143         public string Name { get; set; }
144 
145         public int Quantity { get; set; }
146 
147         public decimal Price { get; set; }
148 
149         public string Describe { get; set; }
150         public override string ToString()
151         {
152             return $"Name={Name}，Quantity={Quantity}，Price={Price}，Describe={Describe}";
153         }
154     }
155 
156 }