.NET开源高性能Socket通信中间件Helios介绍及演示

一:Helios是什么

　　Helios是一套高性能的Socket通信中间件，使用C#编写。Helios的开发受到Netty的启发，使用非阻塞的事件驱动模型架构来实现高并发高吞吐量。Helios为我们大大的简化了Socket编程，它已经为我们处理好了高并发情况下的解包，粘包，buffer管理等等。

　　GitHub：https://github.com/helios-io/helios/

　　为避免误会特别提示：helios不是本人作品，小弟还在努力的路上。

二:Helios的特点

　　1.Powerful APIs

　　　　Takes the complexity out of socket programming with intelligent I/O, concurrency, buffer management, and pipelining APIs.

　　　　使用socket编程不再复杂。提供智能的I/O，并发，buffer管理，管道形式的API。

　　2.Event-Driven

　　　　Helios is Reactive - it uses a event-driven architecture to simplify development and build responsive systems that scale.

　　　　Helios是反应式的，它使用事件驱动的架构来简化开发和构建易伸缩的系统。

　　3.Performant

　　　　Performance is a cross-cutting concern we factor in at every level in the design of the framework in order to eliminate overhead for your apps and clients.

　　　　这个系统在开发和设计的时候都充分考虑到了性能，构建你的app和client的时候请消除这方面的顾虑。

　　4.Battle-Tested

　　　　Helios powers the clustering and remoting capbilities built into Akka.NET and more.

　　　　Akka.net的集群，远程功能构建在Helios之上。

三:一个基于Helios的聊天室示例

　　要用来演示Socket通信那么最好的示例无非就是聊天程序了。

　　整个解决方案包含3个项目：

　　

　　1.HeliosChat.Common

　　这个项目里是一些公共的类型，新建完之后使用nuget添加helios的库

　　

　　Message 类：所有发送的消息都是通过Message包装的，每一个消息都有一个Command跟Content来构成。

 public class Message
    {
        public Command Command { get; set; }

        public string Content { get; set; }
    }

　　Command枚举：用来描述消息的命令

public enum Command
    {
        Join,
        Send,
    }

　　MessageConverter静态类：这个类用来转换Message对象为Byte[]，或者把Byte[]转换成Message对象。Message对象在通过Helios传输的时候需要先转成Byte[]，所以我们需要自己定义包的格式。我们用Byte[]的前四位来存放Command，Content转成Byte后从第5位开始存放。

public class MessageConverter
    {
        public static Message ToMessage(NetworkData data)
        {
            try
            {
                var commandData = data.Buffer.Take(4).ToArray();
                var contentData = data.Buffer.Skip(4).Take(data.Buffer.Length - 4).ToArray();

                var command = BitConverter.ToInt32(commandData,0);
                var content = Encoding.UTF8.GetString(contentData);

                return new Message()
                {
                    Command = (Command)command,
                    Content = content
                };
            }
            catch (Exception exc)
            {
                Console.WriteLine("Cant convert NetworkData to Message : {0}", exc.Message);
            }

            return null;

        }

        public static byte[] ToBytes(Message message)
        {
            try
            {
                var commandBytes = BitConverter.GetBytes((int)message.Command);
                var messageBytes = Encoding.UTF8.GetBytes(message.Content);
                var bytes = new byte[commandBytes.Length + messageBytes.Length];
                commandBytes.CopyTo(bytes, 0);
                messageBytes.CopyTo(bytes, commandBytes.Length);

                return bytes;
            }
            catch (Exception exc)
            {
                Console.WriteLine("Cant convert message to bytes : {0}", exc.Message);
            }

            return null;
        }

    }

　　2.HeliosChat.Server

　　不用说也知道，这是聊天室的服务端，负责连接用户及转发消息。

internal class Program
    {
        private static readonly ConcurrentDictionary<string, IConnection> Clients =
            new ConcurrentDictionary<string, IConnection>();

        private static void Main(string[] args)
        {
            var host = IPAddress.Any;
            var port = 9991;
            Console.Title = "Server";
            Console.WriteLine("Starting server on {0}:{1}", host, port);

            var serverFactory =
                new ServerBootstrap()
                    .SetTransport(TransportType.Tcp)
                    .Build();
            var server = serverFactory.NewReactor(NodeBuilder.BuildNode().Host(host).WithPort(port));
            server.OnConnection += (address, connection) =>
            {
                Console.WriteLine("Connected: {0}", address);
                connection.BeginReceive(Receive);
            };
            server.OnDisconnection += (reason, address) =>
                Console.WriteLine("Disconnected: {0}; Reason: {1}", address.RemoteHost, reason.Type);
            server.Start();
            Console.WriteLine("Running, press any key to exit");
            Console.ReadKey();
        }

        /// <summary>
        /// 处理接受到的消息
        /// </summary>
        /// <param name="data"></param>
        /// <param name="channel"></param>
        public static void Receive(NetworkData data, IConnection channel)
        {
            var message = MessageConverter.ToMessage(data);
            switch (message.Command)
            {
                case Command.Join:
                    JoinGroup(message.Content, channel);
                    break;
                case Command.Send:
                    Broadcast(message.Content);
                    break;
            }
        }

        public static void JoinGroup(string clientName, IConnection channel)
        {
            if (Clients.TryAdd(clientName, channel))
            {
                Broadcast(string.Format("{0} join group successful .", clientName));
            }
            else
            {
                var errMsg = new Message()
                {
                    Command = Command.Send,
                    Content = "client name is used."
                };
                SendMessage(channel, errMsg);
            }
        }

        /// <summary>
        /// 广播消息
        /// </summary>
        /// <param name="clientMessage"></param>
        public static void Broadcast(string clientMessage)
        {
            Console.WriteLine(clientMessage);
            var clientName = clientMessage.Split(':')[0];
            var message = new Message
            {
                Command = Command.Send,
                Content = clientMessage
            };
            foreach (var client in Clients)
            {
                if (client.Key != clientName)
                {
                    SendMessage(client.Value, message);
                }
            }
        }

        public static void SendMessage(IConnection connection, Message message)
        {
            var messageBytes = MessageConverter.ToBytes(message);
            connection.Send(new NetworkData { Buffer = messageBytes, Length = messageBytes.Length });
        }
    }

　　3.HeliosChat.Client

　　聊天服务的客户端

internal class Program
    {
        public static IConnection Client;
        public static string ClientName;

        private static void Main(string[] args)
        {
            var host = IPAddress.Loopback;
            var port = 9991;
            var connectionFactory =
                new ClientBootstrap()
                    .SetTransport(TransportType.Tcp).Build();
            //New一个Client
            Client = connectionFactory.NewConnection(Node.Empty(), NodeBuilder.BuildNode().Host(host).WithPort(port));
            Client.OnConnection += (address, connection) =>
            {
                Console.WriteLine("Connect server successful.");
                connection.BeginReceive(Received);
            };
            Client.OnDisconnection += (address, reason) => Console.WriteLine("Disconnected.");
            Console.WriteLine("Input ClientName ");
            ClientName = Console.ReadLine();
            Console.Title = string.Format("Client {0}", ClientName);
            //建立连接
            Client.Open();
            //加入聊天组
            Join();
            //等待输入
            WaitInput();
        }

        public static void WaitInput()
        {
            while (true)
            {
                var input = Console.ReadLine();
                if (!string.IsNullOrEmpty(input))
                {
                    var message = MakeSendMessage(input);
                    SendMessage(Client, message);
                }
            }
        }

        /// <summary>
        /// Jion chat group
        /// </summary>
        public static void Join()
        {
            var message = MakeJoinMessage();
            SendMessage(Client,message);
        }

        /// <summary>
        /// 处理接受到的消息
        /// </summary>
        /// <param name="data"></param>
        /// <param name="responseChannel"></param>
        public static void Received(NetworkData data, IConnection responseChannel)
        {
            var message = MessageConverter.ToMessage(data);
            if (message.Command == Command.Send)
            {
                Console.WriteLine(message.Content);
            }
        }

        /// <summary>
        /// 构造聊天消息
        /// </summary>
        /// <param name="input"></param>
        /// <returns></returns>
        public static Message MakeSendMessage(string input)
        {
            return new Message
            {
                Command = Command.Send,
                Content = string.Format("{0}:{1}", ClientName, input)
            };
        }
        /// <summary>
        /// 构造加入组的消息
        /// </summary>
        /// <returns></returns>
        public static Message MakeJoinMessage()
        {
            var message = new Message();
            message.Command = Command.Join;
            message.Content = ClientName;

            return message;
        }

        public static void SendMessage(IConnection connection, Message message)
        {
            var messageBytes = MessageConverter.ToBytes(message);
            connection.Send(new NetworkData { Buffer = messageBytes, Length = messageBytes.Length });
        }
    }

　　4.运行结果

　　这样一个简单的聊天室程序就完成了。

四：Helios 2.0

　　helios 1.0的异步编程模型是基于APM的，从helios 2.0开始会改成SocketAsyncEventArgs方式来实现异步。SocketAsyncEventArgs底层封装了IOCP，IOCP是Windows server上Socket通讯性能最高的技术，使用了IOCP的helios 2.0势必具有更高的性能，所以对于helios 2.0还是非常期待的。

　　示例下载：https://files.cnblogs.com/files/kklldog/HeliosChat.7z