分布式EventBus的Socket实现

在这篇文章中，EventBus实现 - 发布订阅 - XML加载 所适用的范围只是本机的事件传播，要是牵涉到多台服务器之间的事件传播就不行了，解决办法有用msmq解决的，Node.js解决的，也有用redis的发布订阅解决的，这次用C# socket来实现，能实现立刻推送事件到所有订阅了相关event的server上。

这次的子系统适用的场景如下：

主要分2个部分：各个server使用的Event Bus Broker以及Event Bus Server。

Broker与Server之间的通信协议就3个：ME、Subscribe、Publish。分别代表：我的名字是、我要订阅的事件是、我触发事件。

Event Bus Server是基于SuperSocket开源组件写的，非常方便。实现了3个对应的命令类（建议大家先看看SuperSocket的文档），如下： 

public class ME : CommandBase<EventDispatcherBusSession, StringRequestInfo>
    {
        public override void ExecuteCommand(EventDispatcherBusSession session, StringRequestInfo requestInfo)
        {
            session.AssociatedServerIdentity = EventBase.Helper.RestoreSpecialCharacters(requestInfo.Parameters[0]);
            Console.WriteLine(string.Format("[{0}]: connected.", session.AssociatedServerIdentity));
        }
    }

public class Publish : CommandBase<EventDispatcherBusSession, StringRequestInfo>
    {
        public override void ExecuteCommand(EventDispatcherBusSession session, StringRequestInfo requestInfo)
        {
            string evtClassPath = EventBase.Helper.RestoreSpecialCharacters(requestInfo.Parameters[0]);
            string evtXml = EventBase.Helper.RestoreSpecialCharacters(requestInfo.Parameters[1]);

            foreach(EventDispatcherBusSession s in session.AppServer.GetAllSessions())
            {
                if (s.AssociatedServerIdentity == session.AssociatedServerIdentity)
                    continue;

                if (s.SubscribedEventClasses.Contains(evtClassPath))
                {
                    s.Send("Publish " + requestInfo.Body);//forward only
                    Console.WriteLine(string.Format("Forwarding publish command from {1} to server: [{0}]", s.AssociatedServerIdentity, session.AssociatedServerIdentity));
                }
            }
        }
    }

public class Subscribe : CommandBase<EventDispatcherBusSession, StringRequestInfo>
    {
        public override void ExecuteCommand(EventDispatcherBusSession session, StringRequestInfo requestInfo)
        {
            string classPath = EventBase.Helper.RestoreSpecialCharacters(requestInfo.Parameters[0]);
            if (session.SubscribedEventClasses.Contains(classPath))
                return;

            session.SubscribedEventClasses.Add(classPath);

            string msg = "";
            msg+=string.Format("[{0}], now subscribed these events:
", session.AssociatedServerIdentity);
            foreach(string evtClass in session.SubscribedEventClasses)
                msg += string.Format("              {0}
", evtClass);
            Console.WriteLine(msg);
        }
    }

 启动server代码：

static void Main(string[] args)
        {
            var appServer = new EventDispatcherBusServer();

            if (!appServer.Setup(2012))
            {
                Console.WriteLine("Failed to setup!");
                Console.ReadKey();
                return;
            }

            Console.WriteLine();

            if (!appServer.Start())
            {
                Console.WriteLine("Failed to start!");
                Console.ReadKey();
                return;
            }

            Console.WriteLine("The server started successfully, press key 'q' to stop it!");

            Console.ReadKey();

            appServer.Stop();
        }

 server端没多少好说的，都是很简单的，下面来看看客户端：

static void Main(string[] args)
        {
            EventBusClientBroker busBroker = new EventBusClientBroker("127.0.0.1", 2012, "App server 2", "AppEvents.dll");
            busBroker.NewEventReceived += new EventReceived(busBroker_NewEventReceived);//新event被推送过来的事件
            busBroker.Connect();

            busBroker.Subscribe<NewUserRegisteredEvent>();//订阅Event

            //busBroker.Close();
        }

        static void busBroker_NewEventReceived(string evtClass, object evt)
        {
            //这里会将event对象发过来
            //evtClass是evt的class全路径
            if (evt is NewUserRegisteredEvent)
                Console.WriteLine(((NewUserRegisteredEvent)evt).UserName);
            else if (evt is UserProfileUpdatedEvent)
                Console.WriteLine(((UserProfileUpdatedEvent)evt).UserID);
        }

如果要触发一个事件，则：

                   NewUserRegisteredEvent evt = new NewUserRegisteredEvent();
                    evt.RegisterDate = DateTime.Now;
                    evt.UserName = "aaron";
                    busBroker.Publish<NewUserRegisteredEvent>(evt);

我们来看看效果图：

搞定，代码下载。