[网络协议]获取基于Websocket的网络延时

npm install nodejs-websocket

构建服务器，接收ping请求，并返回pong请求

var ws = require("nodejs-websocket");
console.log("开始建立连接...")
var server = ws.createServer(function(conn){
    conn.on("text", function (str) {
        if (str.indexOf('ping') !== -1) {
            console.log("收到客户端"+str);
            setTimeout(() => {
                conn.sendText(str.replace(/i/, "o"))
            }, Math.random()*470+10);
            
        }
        setTimeout(() => {
            conn.sendText("我是服务器")
        },1000); 
    })
    conn.on("close", function (code, reason) {
        console.log("关闭连接")
    });
    conn.on("error", function (code, reason) {
        console.log("异常关闭")
    });
}).listen(8001)
console.log("WebSocket建立完毕")

连接成功后发送请求，并记录时间并存入数组

ws.onopen = function (e) {
			//发送ping包
			pingInterval = setInterval(() => {
				let now = new Date().getTime();
				let timeStampKey = now.toString().substr(3);
				// 随机清栈
				if(Object.keys(timemap).length > 10){
					timemap = {};
					
				}
				console.log(Object.keys(timemap).length);
				timemap[timeStampKey] = [now];
				ws.send('ping'+ timeStampKey)
			}, 1000);

接收服务端返回信息，记录时间，寻找对应位置并存入

console.log(timemap);
			if (message.data.indexOf('pong') !== -1) {
				var timeStampKey = message.data.slice(4);
				let backtime = new Date().getTime();
				if (timemap[timeStampKey]) {
					timemap[timeStampKey].push(backtime);
				}
				let netspeed = getAverage(timemap);
				document.getElementById('netspeed').innerHTML = netspeed ;
			}

求平均值

function getAverage(map) {
			let sum = 0;
			for (let i in map) {
				if (map[i].length === 2)
					sum += (map[i][1] - map[i][0])
			}
			return Math.round(sum / Object.keys(map).length);
		}

最终效果