go_并发聊天室

用法:
使用nc工具
win+r打开多个终端,分别在终端输入:nc 127.0.0.1 8080
不同终端之间可以进行简单的通信
介绍:
声明handler函数,进行处理客户端发来的信息
声明broadcaster函数,进行全局广播,传递数据
程序使用了channel进行数据的阻塞和传递

package main

import (
"bufio"
"fmt"
"net"
"time"
)

type Client struct {
Name string
Addr string
ch chan string
}

var(
entering = make(chan Client)
message = make(chan string)
leaving = make(chan Client)
list = make(chan Client)
rename = make(chan Client)
)

func broadcaster(){
clients := make(map[string] Client)

for {
select {
case cli := <- entering:
clients[cli.Addr] = cli

case msg := <- message:
for _,cli := range clients {
cli.ch <- msg
}

case cli := <- leaving:
delete(clients, cli.Addr)
close(cli.ch)

case cli := <- list:
cli.ch <- "list of users:"
for _, v := range clients {
cli.ch <- "[" + v.Addr + "]" + v.Name
}

case cli := <- rename:
clients[cli.Addr] = cli
}
}
}

//处理客户端发来的信息
func handler(conn net.Conn) {
ch := make(chan string)
go clientWriter(conn, ch)

//客户端连接地址
addr := conn.RemoteAddr().String()
name := addr
cli := Client{name,addr,ch}

//通知客户端自己的名字
ch <- "You are:" + cli.Name
//广播给所有在线用户,新的用户链入
message <- cli.Name + "has arrived"
entering <- cli

//超时强踢功能
hasData := make(chan struct{})
go func() {
for {
select {
case <- hasData:

case <- time.After(time.Second * 10):
conn.Close()
return
}
}
}()

//循环读取conn中的消息
input := bufio.NewScanner(conn)
for input.Scan(){
msg := input.Text()
if msg == "#list" {
list <- cli
} else if len(msg)>8 && len(msg)<126 && msg[:8]=="#rename|" {
cli.Name = msg[8:]
rename <- cli
} else {
message <- cli.Name + "say:" + input.Text()
}
//重置超时强踢计时
hasData <- struct{}{}
}

//客户端断开链接是,把客户端信息写入leaving通道,通知broadcaster断开连接
leaving <- cli
message <- cli.Name + "has left"

conn.Close()
}

//监听广播者的信息,并把消息写入客户端
func clientWriter(conn net.Conn, ch chan string) {
for msg := range ch {
fmt.Fprintln(conn,msg)
}
}

func main() {
listener, err := net.Listen("tcp","127.0.0.1:8080")
if err != nil {
fmt.Println("net.Listen err ",err)
return
}

go broadcaster()

for {
conn, err := listener.Accept()
if err != nil {
fmt.Println("listener.Accept err ",err)
continue
}

go handler(conn)
}
}