connect/lib/connect/middleware/favicon.js

High performance middleware framework

/*!
 * Ext JS Connect
 * Copyright(c) 2010 Sencha Inc.
 * MIT Licensed
 */

/**
 * Module dependencies.
 */

var fs = require('fs'),
    utils = require('../utils');

/**
 * Favicon cache.
 * 
 * @type Object
 */

var icon;

/**
 * By default serves the connect favicon, or the favicon
 * located by the given path.
 *
 * Examples:
 *
 *     connect.createServer(
 *         connect.favicon()    
 *     );
 *
 *     connect.createServer(
 *         connect.favicon(__dirname + '/public/favicon.ico')    
 *     );
 *
 * @param {String} path
 * @return {Function}
 * @api public
 */

module.exports = function favicon(path){
  path = path || __dirname + '/../public/favicon.ico';
  return function favicon(req, res, next){
    if ('/favicon.ico' == req.url) {
      if (icon) {
        res.writeHead(200, icon.headers);
        res.end(icon.body);
      } else {
        fs.readFile(path, function(err, buf){
          if (err) return next(err);
          icon = {
            headers: {
                'Content-Type': 'image/x-icon'
              , 'Content-Length': buf.length
              , 'ETag': utils.md5(buf)
              , 'Cache-Control': 'public max-age=3600'
            },
            body: buf
          };
          res.writeHead(200, icon.headers);
          res.end(icon.body);
        });
      }
    } else {
      next();
    }
  };
};