《通過C#學Proto.Actor模型》之PID

PID對象是代表Actor對象的進程，是能過Actor.Spawn(props)獲取的；它有什麼成員呢？既然代理Actor，首先有一個ID，標識自己是誰，Actor在Spawn時可以命名這個ID，否則會自動生成。還有三種向郵箱發消息的方法，Tell()，Request()，RequestAsync()，還有一個發送系統消息(Started,Stoping,Stoped等)方法SendSystemMessage()，還有一個停止的方法Stop()。

 1 using Proto;
 2 using System;
 3 using System.Threading;
 4 using System.Threading.Tasks;
 5 
 6 namespace P004_PID
 7 {
 8     class Program
 9     {
10         static void Main(string[] args)
11         {
12             var props = Actor.FromProducer(() => new MyActor()); 
13             var pid = Actor.Spawn(props);           
14             while (true)
15             {
16                 Console.WriteLine("**************************************");
17                 Console.WriteLine("1、單向請求Tell  2、單向請求Request  3、雙向請求RequestAsync");
18                 switch (Console.ReadLine())
19                 {
20                     case "1":
21                         Console.WriteLine("單向請求開始");
22                         pid.Tell(new Request { Name = "單向請求 Tell", RequestType = "one-way", Time = DateTime.Now });
23                         break;
24                     case "2":
25                         Console.WriteLine("單向請求開始");
26                         //無法接回應簽，與官網說法不一
27                         pid.Request(new Request { Name = "單向請求 Request", RequestType = "two-way-1", Time = DateTime.Now }, pid);
28                         
29                         break;
30                     case "3":
31                         Console.WriteLine("雙向請求開始");
32                         var response = pid.RequestAsync<Response>(new Request { Name = "雙向請求 RequestAsync", RequestType = "two-way-2", Time = DateTime.Now }).Result;
33                         Console.WriteLine(response.Time + ":" + response.Name);
34                         break;
35                 }
36                 Thread.Sleep(2000);
37             }
38         }
39     }
40 
41     public class MyActor : IActor
42     {
43         public Task ReceiveAsync(IContext context)
44         {
45 
46             if (context.Message is Request request)
47             {
48                 switch (request.RequestType)
49                 {
50                     case "one-way"://context.Sender為null
51                         Console.WriteLine("接收到：" + request.RequestType + "," + request.Time + ":" + request.Name);
52                         break;
53                     case "two-way-1"://context.Sender= context.Self為自己
54                         Console.WriteLine("接收到：" + request.RequestType + "," + request.Time + ":" + request.Name);                      
55                         context.Respond(new Response() { Time = DateTime.Now, Name = "服務端應答 two-way-1" });                    
56                         break;
57                     case "two-way-2"://context.Sender!= context.Self為新實例
58                         Console.WriteLine("接收到：" + request.RequestType + "," + request.Time + ":" + request.Name);                       
59                         context.Respond(new Response() { Time = DateTime.Now, Name = "服務端應答 two-way-2" });
60                         break;
61                 }
62             }
63             return Actor.Done;
64         }
65     }
66 
67     public class Request
68     {
69         public string Name
70         { get; set; }
71         public string RequestType
72         { get; set; }
73         public DateTime Time
74         { get; set; }
75     }
76 
77     public class Response
78     {
79         public string Name
80         { get; set; }
81         public DateTime Time
82         { get; set; }
83     }
84 }

Actor中的Receive接到消息後，Context是中有兩個PID對象，一個Self，一個Sender，Tell方法到達後，Sender對象為空；Request到達後，Sender=Self；而RequestAsync則Sender,Self都有對象，但不相同，這是一個區別。再有就是Tell和Request都是單向調用（我實測與官方文檔說明有出入），RequestAsync是可以有返回值的，詳見代碼，如下是運行結果：