zlib-demo.js

var zlib = require('zlib');

var compress = function(req, res, result) {
    var acceptEncoding = req.headers['accept-encoding'];
    if (!acceptEncoding) { acceptEncoding = ''; }    
    if (acceptEncoding.match(/\bdeflate\b/)) {
        zlib.deflate(result, function(err, result) {
           if (!err) {
                res.writeHead(200, { 'content-encoding': 'deflate' });
                res.send(result);
           }
        });
    } else if (acceptEncoding.match(/\bgzip\b/)) {
        zlib.gzip(result, function(err, result){
           if (!err) {
                res.writeHead(200, { 'content-encoding': 'gzip' });
                res.send(result);
           }
        });
    } else {
        res.writeHead(200, {});
        res.send(result);
    }
}