Unity3d在线游戏Socket通讯

网络游戏是一个人的互动娱乐软件应用。因为它是交互式，当然，需要了解对方的通信。这需要通信Socket：我们今天要实现的主角即套接字。Socket的英文原义是“孔”或“插座”。正如其英文原意那样。象一个多孔插座。

一台电脑机器宛如布满各种插座的房间，每一个插座有一个编号，有的插座提供220伏交流电， 有的提供110伏交流电。有的则提供有线电视节目。
客户软件将插头插到不同编号的插座，就能够得到不同的服务。以下我们来看看下图，游戏中玩家移动是怎样通讯：

以下是Unity3d游戏通讯Socket实现： BaseGameSocket.cs

//@原创：dongfu.luo
using System;
using System.Collections.Generic;
using System.Net.Sockets;
public abstract class BaseGameSocket
{
    //用来接收服务端发过来的缓冲Buff
    private byte[] _data_buffer;

  //缓冲二进制数组从哪里開始读
    private int _data_offset;

//缓冲二进制数组读多少个byte
    private int _data_size;

//游戏serverIP地址
    private string _ip;
    private bool _is_read_head;

//游戏server端口
    private int _port;

//要服务端发送的数据命令列表
    private List<PacketOut> _send_list = new List<PacketOut>();
    private Socket _sock;
    private const int MAX_SEND_QUEUE = 0x3e8;

//清空数据，通常是在断开重联时候调用
    private void Clear()
    {
        this._ip = null;
        this._port = 0;
        this._sock = null;
        List<PacketOut> list = this._send_list;
        lock (list)
        {
            this._send_list.Clear();
        }
        this._is_read_head = false;
        this._data_buffer = null;
        this._data_offset = 0;
        this._data_size = 0;
    }

//关闭client的Socket
    public void Close()
    {
 try
        {
            Socket socket = this._sock;
            this.Clear();
            if ((socket != null) && socket.Connected)
            {
                socket.Shutdown(SocketShutdown.Both);
                socket.Close();
            }
        }
        catch (Exception exception)
        {
            UEDebug.LogError("Connect: " + exception.ToString());
            this.Error(Lang.GetString("k3432"));
        }
    }

 //连接游戏服务端
public void Connect(string ip, int port)
    {
        try
        {
            this.Close();
            this._ip = ip;
            this._port = port;
            this._sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            this._sock.NoDelay = true;
            this._sock.BeginConnect(this._ip, this._port, new AsyncCallback(this.OnConnect), this._sock);
        }
        catch (Exception exception)
        {
            UEDebug.LogError("Connect: " + exception.ToString());
            this.Error(Lang.GetString("k3432"));
        }
    }

//假设Socket没有关闭继续等server信息，假设有信息则開始读
    private void ContinueRead()
    {
        try
        {
            if (this.IsConnected)
            {
this._sock.BeginReceive(this._data_buffer, this._data_offset, this._data_size - this._data_offset, SocketFlags.None, new AsyncCallback(this.OnRead), null);
            }
        }
        catch (Exception exception)
        {
            UEDebug.LogError(exception.ToString());
            this.Error(Lang.GetString("k3432"));
        }
    }

//从发送队列从不断向游戏server发送命令
    private void ContinueSend()
    {
        PacketOut state = null;
        List<PacketOut> list = this._send_list;
 lock (list)
        {
            if (this._send_list.Count == 0)
            {
                return;
            }
            state = this._send_list[0];
            if (state.start)
            {
                return;
            }
            state.start = true;
        }
        Socket sock = state.sock;
        if (sock.Connected)
        {
            sock.BeginSend(state.buff, 0, state.buff.Length, SocketFlags.None, new AsyncCallback(this.OnSend), state);
        }
    }
//发送失败或错误，则关闭Socket通常是网络断了server关闭了
    protected void Error(string msg)
    {
        this.Close();
        this.OnError(msg);
    }

//程序员都知道这是析构函数
    ~PackedSocket()
    {
        this.Close();
    }
    public int GetSendQueueSize()
    {
        List<PacketOut> list = this._send_list;
        lock (list)
        {
            return this._send_list.Count;
        }
    }

//此函数由子类去处理
    protected abstract void OnConnect();

//假设是第一次连接上了，解析消息头
    private void OnConnect(IAsyncResult ret)
    {
        if (ret.AsyncState == this._sock)
        {
            try
            {
                this._sock.EndConnect(ret);
                this.ReadHead();
                this.OnConnect();
            }
            catch (Exception exception)
            {
                  Debug.log(exception);
             }
        }
    }
    protected abstract void OnError(string msg);
    protected abstract void OnPack(byte[] data);

//有服务端信息来，開始解析，现解析信息头再解析消息体
    private void OnRead(IAsyncResult ar)
    {
        try
        {
            if (this.IsConnected)
            {
                int num = this._sock.EndReceive(ar);
                this._data_offset += num;
                if (num <= 0)
                {

                }
                else if (this._data_offset != this._data_size)
                {
                    this.ContinueRead();
                }
                else if (this._is_read_head)
                {
 int num2 = BitConverter.ToInt32(this._data_buffer, 0);
                    this.ReadData(num2);
                }
                else
                {
                    this.OnPack(this._data_buffer);
                    this.ReadHead();
                }
            }
        }
        catch (Exception exception)
        {
      Debug.log(exception);
       }
    }

//假设命令发送成功。检查发送队列是否还有须要发送的命令。

假设有则继续发送
    private void OnSend(IAsyncResult ar)
    {
        PacketOut asyncState = ar.AsyncState as PacketOut;
        Socket sock = asyncState.sock;
        if (sock.Connected)
        {
            sock.EndSend(ar);
            List<PacketOut> list = this._send_list;
            lock (list)
            {
                if (this._send_list.Contains(asyncState))
                {
                    this._send_list.Remove(asyncState);
                }
            }
            this.ContinueSend();
        }
    }
//读取消息体
    private void ReadData(int pack_len)
    {
        this._is_read_head = false;
        this._data_size = pack_len;
        this._data_offset = 4;
        this._data_buffer = new byte[this._data_size];
        this.ContinueRead();
    }

//读取消息头
    private void ReadHead()
    {
        this._is_read_head = true;
        this._data_size = 4;
        this._data_offset = 0;
        this._data_buffer = new byte[this._data_size];
        this.ContinueRead();
    }

//详细的发送信息，先把数据发到发送队列
    public void Send(byte[] buff)
{
        if (this.IsConnected)
        {
            PacketOut item = new PacketOut {
                start = false,
                buff = buff,
                sock = this._sock
            };
            int count = 0;
            List<PacketOut> list = this._send_list;
            lock (list)
            {
                this._send_list.Add(item);
                count = this._send_list.Count;
            }
            if (count > 0x3e8)
            {

            }
 else
            {
                this.ContinueSend();
            }
        }
    }
    public bool IsClosed
    {
        get
        {
            return (this._sock == null);
        }
    }
    public bool IsConnected
    {
        get
        {
            return ((this._sock != null) && this._sock.Connected);
        }
    }
private class PacketOut
    {
        public byte[] buff;
        public Socket sock;
        public bool start;
    }
}