responseSizes.js

var fs = require('fs');

var http = require('http');
var request = require('request');

var zlib = require('zlib');


// res.headers = {
// "Date": "Thu, 03 Apr 2014 00:05:39 GMT",
// "Content-Encoding": "gzip",
// "Last-Modified": "Wed, 02 Apr 2014 23:29:18 GMT",
// "Server": "nginx",
// "Vary": "Accept-Encoding",
// "Content-Type": "application/x-javascript; charset=utf-8",
// "Cache-Control": "max-age=315357817",
// "Connection": "keep-alive",
// "Accept-Ranges": "bytes",
// "X-Backend-Server": "web11",
// "Content-Length": "1390",
// "Expires": "Sat, 30 Mar 2024 23:29:16 GMT"
// };

var headers = {
"Accept-Encoding": "gzip,deflate,sdch",
"Host": "marketplace.cdn.mozilla.net",
"Accept-Language": "en-US,en;q=0.8",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.152 Safari/537.36",
"Accept": "*/*",
"Referer": "https://marketplace.firefox.com/",
"Cookie": "__utma=47135163.2010848095.1372800783.1378849530.1390451775.3; __utmz=47135163.1372800783.1.1.utmcsr=bugzilla.mozilla.org|utmccn=(referral)|utmcmd=referral|utmcct=/show_bug.cgi",
"Connection": "keep-alive",
//"If-Modified-Since": "Wed, 02 Apr 2014 23:29:18 GMT",
"Cache-Control": "max-age=0"
};


var opts = {
  method: 'GET',
  // url: 'https://marketplace.cdn.mozilla.net/media/fireplace/css/include.css?b=1395770989729',
  url: 'https://marketplace.cdn.mozilla.net/media/fireplace/js/l10n.js?b=1396481346261',
  headers: headers
}

var req = request(opts, function(err, res, body) {

}).on('response', function(res) {
    var gzip;

    var rawHeaders = ('HTTP/' + res.httpVersion + ' ' + res.statusCode +
                      ' ' + http.STATUS_CODES[res.statusCode] + '\r\n');

    Object.keys(res.headers).forEach(function(headerKey) {
        rawHeaders += headerKey + ': ' + res.headers[headerKey] + '\r\n';
    });

    rawHeaders += '\r\n';
    console.log(rawHeaders)

    if (res.headers['content-encoding'] == 'gzip') {
      gzip = zlib.createGunzip();

      var uncompressedSize = 0;
      var bodySize = 0;
      var body = '';

      res.on('data', function (data) {
        console.log(data.length)
        bodySize += data.length;
      })

      gzip.on('data', function (data) {
        body += data;
        uncompressedSize += data.length;
      });

      gzip.on('end', function() {


console.log(body);

        console.log('headersSize:', Buffer.byteLength(rawHeaders, 'utf8'));  // 386
        console.log('content.size uncompressed:', uncompressedSize);  // 3957


        console.log('bodySize compressed:', bodySize); // 1390


      });

      res.pipe(gzip);

    } else {
      output = res;
    }

});