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：http://files.cnblogs.com/files/kklldog/HeliosChat.7z