• Node.js实现的BigPipe


    以前用PHP实现过,详情点击这里查看《Nginx中的PHP的缓冲问题》

    无论用java、.net还是python都是可以实现bigpipe的…

    拿那篇文章中的php显示页做示例:

    先输出页面的主体结构:

    然后按顺序更新页面的内容:

    2s后输出header

    4s后输出content

    6s后输出footer

    从加载到显示共消耗约13s (2 + 4 + 6 + 1 ~= 13s),符合预期结果

    这个示例的源码(可复制至本地直接运行):

    /**
    * Created with JetBrains WebStorm.
    * User: Meteoric_cry
    * Date: 13-4-13
    * Time: 上午11:10
    * To change this template use File | Settings | File Templates.
    */

    var http = require('http');

    var server = http.createServer(function(req, res) {

    res.writeHead(200, {
    'Content-Type' : 'text/html',
    'Transfer-Encoding' : 'chunked'
    });

    res.write([
    '<!DOCTYPE html>',
    '<html>',
    '<head>',
    '<meta charset="utf-8">',
    '<title>Node.js Bigpipe Demo</title>',
    '<style type="text/css">',
    ' * {margin: 0; padding:0;}',
    ' body {background-color:#fff;}',
    ' div{border:2px solid #4F81BD; margin:30px; padding: 10px;}',
    ' p {word-wrap:break-wrod; word-break:break-all; color: #666;}',
    ' .red {color: #f00;}',
    ' .blue {color:blue;}',
    ' .green {color:green;}',
    '</style>',
    '<script>',
    'var g_startTime = new Date();',
    'var g_renderArr = []',
    'function render(nodeID,html){',
    ' g_renderArr.push(new Date())',
    ' document.getElementById(nodeID).innerHTML=html;',
    '}',
    '</script>',
    '</head>',
    '<body>',
    '<div id="header"><p>Loading...</p></div>',
    '<div id="content"><p>Loading...</p></div>',
    '<div id="footer"><p>Loading...</p></div>'
    ].join('\r\n'));

    function out_header() {
    res.write("<script type='text/javascript'>render('header', '<p><span class=\"blue\">111111</span></p>');</script>\r\n");

    setTimeout(out_content, 4 * 1000);
    }

    function out_content() {
    res.write("<script type='text/javascript'>render('content', '<p><span class=\"red\">222222</span></p>');</script>\r\n");

    setTimeout(out_footer, 6 * 1000);
    }

    function out_footer() {
    res.write("<script type='text/javascript'>render('footer', '<p><span class=\"green\">333333</span></p>');</script>\r\n");

    setTimeout(out_end, 1 * 1000);
    }

    function out_end() {

    res.write([
    '<script>',
    'var str = [',
    ' "start:" + g_startTime.toGMTString(),',
    ' "header:" + g_renderArr[0].toGMTString() + "-" + (g_renderArr[0] - g_startTime) / 1000,',
    ' "content:" + g_renderArr[1].toGMTString() + "-" + (g_renderArr[1] - g_renderArr[0]) / 1000,',
    ' "footer:" + g_renderArr[2].toGMTString() + "-" + (g_renderArr[2] - g_renderArr[1]) / 1000,',
    ' "end:" + new Date().toGMTString() + "-" + (new Date() - g_renderArr[2]) / 1000 + "-" + (new Date() - g_startTime) / 1000',
    '].join("\\n");',
    'alert(str);',
    '</script>'
    ].join(''));

    res.end("\r\n</body></html>");
    }

    setTimeout(out_header, 2 * 1000);


    }).listen(3002);

    上面是将界面的显示顺序固定写死了,下面将展示一个灵活的动态界面:

    先输出6个内容容器,然后构建6个客户端请求,当收到请求数据时直接返回给客户端。如果你需要让界面的内容按顺序显示,只需要修改,返回的delay值,比如按索引值的大小进行修改

       1: var params = url.parse(request.url, true);
       2: var delay = params.query.id * 3000; console.log(delay);

    这个示例的完整源码:

    /**
    * Created with JetBrains WebStorm.
    * User: zhangyi
    * Date: 13-4-23
    * Time: 上午10:57
    * To change this template use File | Settings | File Templates.
    */
    var http = require('http');
    var sys = require('sys');
    var url = require("url");

    http.createServer(function(request, response) {

    response.writeHead(200, {"Content-Type" : "text/html"});
    response.write("<!Doctype html><html><head>");
    response.write("<style type='text/css'>div{border:2px solid #4F81BD; margin:30px; padding: 10px;}</style>");
    response.write("<script type=\"text/javascript\">function arrived(id,text) { var b=document.getElementById(id); b.innerHTML = text; }</script>");
    response.write("</head><body><div>Progressive Loading");
    for(var i = 0; i < 6; i++) {
    response.write("<div id='" + i + "'>Loading...</div>");
    }
    response.write("</div>");


    var down = 6;
    for (i = 0; i < 6; i++) {
    var proxy = http.createClient(2000, "localhost");
    var proxyRequest = proxy.request("GET", "/?id=" + i, {"host" : "localhost"});

    proxyRequest.addListener('response', function (proxyResponse) {
    --down;
    proxyResponse.addListener('data', function(chunk) {
    response.write(chunk, 'binary');
    });
    proxyResponse.addListener('end', function() {
    if(down == 0) {
    response.end();
    }
    });
    });
    proxyRequest.end();
    }
    response.write("</body></html>");

    }).listen(8080);

    http.createServer(function(request, response) {

    var delay = Math.round(Math.random() * 8000);
    /*
    var params = url.parse(request.url, true);
    var delay = params.query.id * 3000; console.log(delay);
    */
    setTimeout(function() {
    var params = url.parse(request.url, true);
    var id = params.query.id;
    response.writeHead(200, {"Content-Type" : "text/html"});
    var content = "<span>Content of Module " + id + "</span>";
    response.write("<script>" +
    "arrived('" + id + "', '" + content + "');" +
    "</script>");
    response.end();
    }, delay);
    }).listen(2000);
     
    上面的示例中并没有像第一个例子一样,显示输出header信息('Transfer-Encoding' : 'chunked'),而浏览器,在response里却看到了,猜测是node.js在输出的时候内部加上去的。
     
     
    相比php,node.js内部实现并没有“缓冲池”的功能,都是直接输出,很简单吧…
     
     
    本文参考:
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  • 原文地址:https://www.cnblogs.com/meteoric_cry/p/3037384.html
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