go实现多聊天并发 服务端

package main

import (
   "fmt"
   "net"
   "time"
)
type Client struct {
   ch chan string //用户发送数据的管道
   name string //用户名
    addr string//网络地址
}
 var message = make(chan string) //用来保存用户的消息
//定义一个map 值为在线的用户
var onlineClientMap map[string]Client//
func main() {
    listener,err := net.Listen("tcp","127.0.0.1:8000")
    if err !=nil{
      fmt.Println(err)
    }
    defer listener.Close()
    go Manager()
    //主协程,循环阻塞用户连接
   for{
      conn, err := listener.Accept()
      if err!=nil{
         fmt.Println(err)
         continue
      }
      go handleConn(conn)

    }

}
func makeMsg(client Client,msg string)(buff string){

      buff ="["+client.addr+"]"+client.name+":"+msg+"
"
      return
}

func handleConn(conn net.Conn){
   cliAddr:= conn.RemoteAddr().String()
   defer conn.Close()
   client :=Client{
      make(chan string),
           cliAddr,
            cliAddr,
   }
   onlineClientMap[cliAddr] = client
   //给当前客户端发送信息
   go writeMsgToClient(client,conn)
   //广播某个在线
   message<-"I am here
"
   message<- makeMsg(client,"login")
   //是否主动退出
   isQuit:=make(chan bool)
   hasData:= make(chan bool)
   //新开一个协程接收用户发过来的数据
   go func() {
      buff:= make([]byte,2048)
      for{
         n,err :=conn.Read(buff)
         fmt.Println(n)
         if err!=nil{
            fmt.Println(nil)
         }
         if n==0{
            fmt.Println("断开连接")
            isQuit<-true
            return
         }
         msg := string(buff[:n-1])
         if len(msg)==3&& msg =="who"{
            for _,tmp := range onlineClientMap{
               msg = tmp.addr+":"+tmp.name+"
"
               conn.Write([]byte(msg))

            }
         }else{
            message<-makeMsg(client,msg)
         }
         hasData<-true
        }
   }()
   for{
      select {

      case <-isQuit:
         delete(onlineClientMap,cliAddr)//当前用户从map移除
         message<-makeMsg(client,"login out")//广播退出
         return
      case <-hasData:

      case <-time.After(60*time.Second):
         delete(onlineClientMap,cliAddr)//当前用户从map移除
         message<-makeMsg(client,"time out")//广播退出
         return
      }
      


   }

}
func Manager()  {
   onlineClientMap = make(map[string]Client)//给map分配空间
   for{
         msg := <-message
      for _ ,client :=range onlineClientMap{
         client.ch<-msg

      }
   }
}

func writeMsgToClient(client Client,conn net.Conn)  {
   for  msg:= range client.ch{
         conn.Write([]byte(msg))
      }

}