Go语言实现广播式并发聊天服务器

type Client struct {
	C    chan string //用于发送数据的管道
	Name string      //用户名
	Addr string      //网络地址
}

var onlineMap map[string]Client

var message = make(chan string)

func main() {
	//监听
	listener, err := net.Listen("tcp", "127.0.0.1:8000")
	if err != nil {
		fmt.Println("net.Listen.err=", err)
		return
	}

	defer listener.Close()

	//新开一个协程，转发消息，只要有消息，就遍历map，给每个成员发送消息
	go Manager()
	//主协程，循环阻塞等待用户连接
	for {
		conn, err1 := listener.Accept()
		if err1 != nil {
			fmt.Println("listener.Accept.err1=", err1)
			continue
		}

		//处理用户连接
		go HandleConn(conn)
	}

}

func HandleConn(conn net.Conn) {
	cliAddr := conn.RemoteAddr().String()
	cli := Client{make(chan string), cliAddr, cliAddr}

	//把结构体添加到map
	onlineMap[cliAddr] = cli

	//新开一个协程，给客户端发送信息
	go WriteMsgToClient(cli, conn)

	//广播某个人在线
	message <- MakeMsg(cli, "login")
	//提示当前用户
	cli.C <- MakeMsg(cli, "I am here")

	isQuit := make(chan bool) //对方是否主动退出

	hasData := make(chan bool) //对方是否有数据

	//新开一个协程，接收用户的请求
	go func() {
		buf := make([]byte, 2048)
		for {
			n, err := conn.Read(buf)
			if n == 0 {
				//对方断开或者出问题
				isQuit <- true
				fmt.Println("conn.Read.err=", err)
				return
			}
			msg := string(buf[:n-1])
			if len(msg) == 3 && msg == "who" {
				//遍历map，给当前用户发送所有成员
				conn.Write([]byte("user list:\n"))
				for _, tmp := range onlineMap {
					msg := tmp.Addr + ":" + tmp.Name + "\n"
					conn.Write([]byte(msg))
				}
			} else if len(msg) >= 8 && msg[:6] == "rename" {
				name := strings.Split(msg, "|")[1]
				cli.Name = name
				onlineMap[cliAddr] = cli
				conn.Write([]byte("rename ok\n"))

			} else {
				message <- MakeMsg(cli, msg)
			}

			hasData <- true //代表有数据

		}

	}()
	for {
		//通过select检测channel的流动
		select {
		case <-isQuit:
			delete(onlineMap, cliAddr)           //当前用户从map移除
			message <- MakeMsg(cli, "login out") //广播谁下线了
			return
		case <-hasData:
		case <-time.After(60 * time.Second):
			delete(onlineMap, cliAddr)
			message <- MakeMsg(cli, "time out leave out")
			return
		}
	}

}

func WriteMsgToClient(cli Client, conn net.Conn) {
	for msg := range cli.C {
		conn.Write([]byte(msg + "\n"))

	}

}

func MakeMsg(cli Client, msg string) (buf string) {
	buf = "[" + cli.Addr + "]" + cli.Name + ":" + msg
	return
}

func Manager() {
	//给map分配空间
	onlineMap = make(map[string]Client)

	for {
		msg := <-message //没有消息前，会阻塞
		for _, cli := range onlineMap {
			cli.C <- msg
		}
	}
}