鉴于聊天已然成为大部分app的基础功能,而大部分app用户基数有没有辣么大,常用的聊天server架构如xmpp或者消息队列实现之类的用起来还挺麻烦的,有比较难跟网页端做交互,加之H5标准落地,所以websocket已然成为一个轻巧可用性高的聊天server实现方法;
websocket的server常见的是用nodejs或者java的netty框架实现,netty相对重一点,direct buffer的内存泄露调起来比较麻烦,试了一下go,轻巧,稳定性不错,性能不错,所以用go实现了一下;
websocket的协议标准和基本概念网上一搜一片,这里不赘述;
http server用gin来做,websocket的handler则用gorilla,由于不重复造轮子,所以整个搭建的过程很快;
import (
"util"
"os"
"fmt"
"github.com/DeanThompson/ginpprof"
"github.com/gin-gonic/gin"
"runtime"
)
var (
logger * util.LogHelper
)
func main() {
runtime.GOMAXPROCS(runtime.NumCPU())
logFile,err := os.OpenFile("/var/log/gows.log",os.O_CREATE|os.O_RDWR,0777)
if err!=nil {
fmt.Println(err.Error())
os.Exit(0)
}
defer logFile.Close()
logger = util.NewLogger(logFile)
logger.Info("Starting system...")
wsHandler := new(WebSocketHandler)
gin.SetMode(gin.ReleaseMode)
r := gin.Default()
r.GET("/", func(c *gin.Context) {
wsHandler.HandleConn(c.Writer, c.Request)
})
ginpprof.Wrapper(r)//调试用 可以看到堆栈状态和所有goroutine状态
//err = r.Run(listenPath, certPath, keyPath) 这样可以支持wss
err = r.Run("127.0.0.1:8888")
if err != nil {
fmt.Println(err)
}
}
这样我们的入口就有了~
websocket的模式大概是 onopen onmessage onerror onclose四个callback来覆盖整个通信流程
所以我们来看下简易版本的websockethandler的实现
package main
import (
"bytes"
"compress/gzip"
"encoding/json"
"errors"
"net/http"
"strconv"
"time"
"util"
"github.com/gorilla/websocket"
)
var (
ctxHashMap = util.NewConcurrentMap()
)
//用来升级http协议到ws协议
type WebSocketHandler struct {
wsupgrader websocket.Upgrader
}
func (wsh *WebSocketHandler) NewWebSocketHandler() {
wsh.wsupgrader = websocket.Upgrader{
ReadBufferSize: 4096,
WriteBufferSize: 4096,
}
}
func (wsh *WebSocketHandler) onMessage(conn *websocket.Conn, ctx *ConnContext, msg []byte, msgType int) {
//处理文本消息 或者 2进制消息 2进制通常是些 gzip的文本 语音或者图片视频之类的一般会用其他云服务不然带宽会爆掉
if msgType == websocket.TextMessage {
wsh.processIncomingTextMsg(conn, ctx, msg)
}
if msgType == websocket.BinaryMessage {
}
}
func (wsh *WebSocketHandler) onOpen(conn *websocket.Conn, r *http.Request) (ctx *ConnContext, err error) {
if err := r.ParseForm(); err != nil {
return nil, errors.New("参数校验错误")
}
specialKey := r.FormValue("specialKey")
supportGzip := r.FormValue("support_gzip")
ctx = &ConnContext{specialKey, supportGzip}
//用来标识一个tcp链接
keyString := ctx.AsHashKey()
if oldConn, ok := ctxHashMap.Get(keyString); ok {
wsh.onClose(oldConn.(*websocket.Conn), ctx)
oldConn.(*websocket.Conn).Close()
}
ctxHashMap.Set(keyString, conn)
return ctx, nil
}
func (wsh *WebSocketHandler) onClose(conn *websocket.Conn, ctx *ConnContext) {
logger.Info("client close itself as " + ctx.String())
wsh.closeConnWithCtx(ctx)
return
}
func (wsh *WebSocketHandler) onError(errMsg string) {
logger.Error(errMsg)
}
func (wsh *WebSocketHandler) HandleConn(w http.ResponseWriter, r *http.Request) {
wsh.wsupgrader.CheckOrigin = func(r *http.Request) b