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[dotnet core]使用Peach简化Socket网络通讯协议开发

Peach是基于DotNetty的Socket网络通讯帮助类库,可以帮助开发者简化使用DotNetty,关于DotNetty可参考我之前的这篇文章
Peach内置实现了一个基于文本协议的CommandLineProtocol,下面的实例以这个协议展开,最后以DotBPE中Amp协议来介绍下如何扩展自定义协议。

Github地址: https://github.com/xuanye/Peach

QuickStart 使用

添加引用

dotnet nuget add Peach

要使用Peach编写网络程序,一般只需要三个步骤

  1. 实现协议传输消息IMessage
  2. 实现协议打包和解包逻辑IProtocol
  3. 实现ISocketService完成服务端逻辑编写

    在快速开始的实例中,我们使用内置的CommandLineProtocol,所以省去了步骤1,2让我们开始吧!

1 服务端

1.1 实现MyService

可分别重写

  1. OnConnected 有客户端连接上的事件
  2. OnDisConnected 客户端断开连接时的事件
  3. OnReceive 收到客户端消息的事件
  4. OnException 发生异常时的事件,如异常断开
public class MyService : Peach.AbsSocketService<Peach.Messaging.CommandLineMessage>
{
    private readonly ILogger<MyService> _logger;

    public MyService(ILogger<MyService> logger)
    {
        _logger = logger;
    }
    public override void OnConnected(ISocketContext<CommandLineMessage> context)
    {
        _logger.LogInformation("client connected from {0}", context.RemoteEndPoint);
        base.OnConnected(context);
    }

    public override void OnDisconnected(ISocketContext<CommandLineMessage> context)
    {
        _logger.LogInformation("client disconnected from {0}", context.RemoteEndPoint);
        base.OnDisconnected(context);
    }

    public override void OnException(ISocketContext<CommandLineMessage> context, Exception ex)
    {
        _logger.LogError(ex,"client from {0}, occ error {1}", context.RemoteEndPoint,ex.Message);
        base.OnException(context, ex);
    }

    public override void OnReceive(ISocketContext<CommandLineMessage> context, CommandLineMessage msg)
    {
        string replyMessage = string.Empty;
        string replyCmd = string.Empty;
        switch (msg.Command)
        {
            case "echo":
                replyMessage = msg.Parameters[0];
                replyCmd = "echo";
                break;
            case "init":
                replyMessage = "ok";
                replyCmd = "init_reply";

                break;
            default:
                replyMessage = "error unknow command";
                break;
        }


        Task.Run(async () =>
        {
            await context.SendAsync(new CommandLineMessage(replyCmd, replyMessage));
        });
    }

}

2. 挂载服务

服务默认挂载在5566端口

static void Main(string[] args)
{
    var builder = new HostBuilder()          
    .ConfigureServices((context,services) =>
    {
        //协议
        services.AddSingleton<IProtocol<CommandLineMessage>, CommandLineProtocol>();
        //挂载服务逻辑
        services.AddSingleton<ISocketService<CommandLineMessage>, MyService>();
        //添加挂载的宿主服务
        services.AddTcpServer<CommandLineMessage>();
    })
    .ConfigureLogging(
        logger =>
        {                   
            logger.AddConsole();
        }
    );
    builder.RunConsoleAsync().Wait();
}

2. 客户端

2.1 使用内置的TcpClient

监听接收消息和链接的消息,如下所示:

TcpClient<CommandLineMessage> client = new TcpClient<CommandLineMessage>(new CommandLineProtocol());
client.OnReceived += Client_OnReceived;
client.OnConnected += Client_OnConnected;

Task.Run(async () =>
{
    //连接服务器
    var socketContext = await client.ConnectAsync(new IPEndPoint(Hey.IPUtility.GetLocalIntranetIP(), 5566));
    //发送消息
    var initCmd = new Hey.Messaging.CommandLineMessage("init");
    await socketContext.SendAsync(initCmd);
}).Wait();

可用的事件:

  • OnReceived 当收到服务端消息时
  • OnError 当通讯发生异常时
  • OnConnected 当连接上服务器时
  • OnDisconnected 当与服务端断开链接时
  • OnIdleState 链接闲置时触发,一般在此事件中发送心跳包

3. 自定义协议

Peach支持使用自定义协议,扩展协议需要自行实现两个接口:

3.1. IMessage 接口

实现类具体实现通讯消息的内容载体,只需实现如何获取消息长度的属性

public interface IMessage
{
    int Length { get;  }
}

3.2. IProtocol 接口

实现类需要描述消息头信息和具体打包解包逻辑,头信息描述参见ProtocolMeta字段描述

/// <summary>
/// 协议接口
/// </summary>
/// <typeparam name="TMessage"></typeparam>
public interface IProtocol<TMessage>
    where TMessage :  Messaging.IMessage
{
    ProtocolMeta GetProtocolMeta();

    TMessage Parse(Buffer.IBufferReader reader);

    void Pack(Buffer.IBufferWriter writer, TMessage message);

}

3.3 Amp协议

为了更好让读者理解自定义协议的操作,这里以DotBPE中的Amp协议为例,来具体讲解一下,先来看下Amp协议的说明:

      0        1 2 3 4   5 6 7 8     9     10 11 12 13   1415      16171819    20    <length>-21
+------------+----------+---------+------+-------------+---------+---------+--------+------------+
| <ver/argc> | <length> |  <seq>  |<type>| <serviceId> | <msgId> |  <code> | <codec>|   <data>   |
+------------+----------+---------+------+-------------+---------+---------+--------+------------+

Amp协议固定包头上21个字节,说明如下:

  • ver/argc = 版本 固定填1
  • length = 为总包长
  • seq = 请求序列号
  • type = 消息类型
    • 1 = Request 请求消息
    • 2 = Response 响应消息
    • 3 = Notify 通知消息
    • 4 = OneWayRequest 调用不关心返回值
  • serId = serviceId 服务号
  • msgId = msgId 消息ID
  • code = 当 type = 0 (请求时)固定传0 ,其他即为响应码,如果响应码不为0 则认为请求失败,具体错误码再定义
  • codecType = 编码方式 0=默认 Protobuf 1=MessagePack 2=JSON
  • data = 实际的业务数据

3.3.1 AmpMessage实现

为了避免干扰因素,这里的代码去除了一些,辅助行的字段和方法,AmpMessage其实是主要用于描述头信息的,并且包含body的buffer数据 Data字段,并实现获取消息体Length的方法(用于发送消息时,计算缓冲区)

 public class AmpMessage :  Peach.Messaging.IMessage
    {
       /// <summary>
        /// 第一个版本为18个字节头固定长度
        /// </summary>
        public const int VERSION_0_HEAD_LENGTH = 18;
        /// <summary>
        /// 现有版本21个字节头固定长度
        /// </summary>
        public const int VERSION_1_HEAD_LENGTH = 21;
        /// <summary>
        /// 状态码
        /// </summary>
        public int Code { get; set; }

        //0 默认为Protobuf 1 MessagePack 2 = JSON
        public CodecType CodecType { get; set; }

        /// <summary>
        /// 实际的请求数据
        /// </summary>
        public byte[] Data { get; set; }

        public int Length {
            get
            {
                var hl = Version == 0 ? VERSION_0_HEAD_LENGTH : VERSION_1_HEAD_LENGTH;
                if(Data == null)
                {
                    return hl;
                }

                return hl + this.Data.Length;
            }
        }
        
        /// <summary>
        /// 消息标识
        /// </summary>
        public string Id => $"{ServiceId}|{MessageId}|{Sequence}";
        /// <summary>
        /// 调用服务的唯一消息号 确定哪个方法
        /// </summary>
        public ushort MessageId { get; set; }
        /// <summary>
        /// 请求的序列号
        /// </summary>
        public int Sequence { get; set; }
        /// <summary>
        /// 调用服务的唯一服务号 确定哪个服务
        /// </summary>
        public int ServiceId { get; set; }

        /// <summary>
        /// 协议版本0/1
        /// </summary>
        public byte Version { get; set; }

        public InvokeMessageType InvokeMessageType { get; set; }
    }
    
    public enum InvokeMessageType : byte
    {
        Request = 1,
        Response = 2,
        Notify = 3,
        OnewayRequest=4 //请求且不等待回复
    }

3.3.2 AmpProtocol的实现

AmpProtocol中的实现主要是对ProtocolMeta描述,代码中已有详细注释,至于打包和解包,就是根据协议Write或者Read对应的数据类型即可

/// <summary>
    /// Amp Protocol
    /// </summary>
    public class AmpProtocol : IProtocol<AmpMessage>
    {
        private readonly ISerializer _serializer;

        public AmpProtocol(ISerializer serializer)
        {
            this._serializer = serializer;
        }

        static readonly ProtocolMeta AMP_PROTOCOL_META = new ProtocolMeta
        {
            InitialBytesToStrip = 0, //读取时需要跳过的字节数
            LengthAdjustment = -5, //包实际长度的纠正,如果包长包括包头和包体,则要减去Length之前的部分
            LengthFieldLength = 4, //长度字段的字节数 整型为4个字节
            LengthFieldOffset = 1, //长度属性的起始(偏移)位
            MaxFrameLength = int.MaxValue, //最大的数据包字节数
            HeartbeatInterval = 30 * 1000 // 30秒没消息发一个心跳包
        };

        public ProtocolMeta GetProtocolMeta()
        {
            return AMP_PROTOCOL_META;
        }

        public void Pack(IBufferWriter writer, AmpMessage message)
        {
            writer.WriteByte(message.Version);
            writer.WriteInt(message.Length);
            writer.WriteInt(message.Sequence);
            writer.WriteByte((byte)message.InvokeMessageType);

            if (message.Version == 0)
            {
                writer.WriteUShort((ushort)message.ServiceId);
            }
            else
            {
                writer.WriteInt(message.ServiceId);
            }
            writer.WriteUShort(message.MessageId);
            writer.WriteInt(message.Code);
            if(message.Version == 1)
            {
                writer.WriteByte(_serializer.CodecType);
            }

            if (message.Data != null)
            {
                writer.WriteBytes(message.Data);
            }
        }

        public AmpMessage Parse(IBufferReader reader)
        {
            if (reader.ReadableBytes == 0)
            {
                return null;
            }

            var msg = new AmpMessage {Version = reader.ReadByte()};

            int headLength;
            if (msg.Version == 0 )
            {
                headLength = AmpMessage.VERSION_0_HEAD_LENGTH;
                if (reader.ReadableBytes < AmpMessage.VERSION_0_HEAD_LENGTH - 1)
                {
                    throw new RpcCodecException($"decode error ,ReadableBytes={reader.ReadableBytes+1},HEAD_LENGTH={AmpMessage.VERSION_0_HEAD_LENGTH}");
                }
            }
            else if (msg.Version == 1 )
            {
                headLength = AmpMessage.VERSION_1_HEAD_LENGTH;
                if (reader.ReadableBytes < AmpMessage.VERSION_1_HEAD_LENGTH - 1)
                {
                    throw new RpcCodecException($"decode error ,ReadableBytes={reader.ReadableBytes+1},HEAD_LENGTH={AmpMessage.VERSION_1_HEAD_LENGTH}");
                }
            }
            else
            {
                throw new RpcCodecException($"decode error ,{msg.Version} is not support");
            }

            var length = reader.ReadInt();
            msg.Sequence = reader.ReadInt();
            var type = reader.ReadByte();
            msg.InvokeMessageType = (InvokeMessageType)Enum.ToObject(typeof(InvokeMessageType), type);


            msg.ServiceId = msg.Version == 0 ? reader.ReadUShort() : reader.ReadInt();


            msg.MessageId = reader.ReadUShort();
            msg.Code = reader.ReadInt();

            if (msg.Version == 1)
            {
                byte codeType = reader.ReadByte();
                if (codeType != this._serializer.CodecType)
                {
                    throw  new RpcCodecException($"CodecType:{codeType} is not Match {this._serializer.CodecType}");
                }
                msg.CodecType = (CodecType)Enum.ToObject(typeof(CodecType), codeType);
            }
            else
            {
                msg.CodecType = CodecType.Protobuf;
            }

            int left = length - headLength;
            if (left > 0)
            {
                if (left > reader.ReadableBytes)
                {
                    throw new RpcCodecException("message not long enough!");
                }
                msg.Data = new byte[left];
                reader.ReadBytes(msg.Data);
            }
            return msg;
        }
    }
}

4. 后记

Peach的产生主要是源于对DotBPE的重构,因为在其他项目中有关于通讯的其他需求,所以这块虽然比较简单,也可比较独立,所以单独开了一个库来实现对DotNetty的封装。另外欢迎各位dotnet core的同学一起学习交流 QQ群号:699044833

posted @ 2019-02-27 14:13 假正经哥哥 阅读(...) 评论(...) 编辑 收藏