1
 2/*!
 3 * Connect - favicon
 4 * Copyright(c) 2010 Sencha Inc.
 5 * Copyright(c) 2011 TJ Holowaychuk
 6 * MIT Licensed
 7 */
 8
 9/**
10 * Module dependencies.
11 */
12
13var crypto = require('crypto')
14  , fs = require('fs');
15
16/**
17 * Favicon cache.
18 */
19
20var icon;
21
22/**
23 * Return md5 hash of the given string and optional encoding,
24 * defaulting to hex.
25 *
26 *     utils.md5('wahoo');
27 *     // => "e493298061761236c96b02ea6aa8a2ad"
28 *
29 * @param {String} str
30 * @param {String} encoding
31 * @return {String}
32 * @api public
33 */
34
35exports.md5 = function (str, encoding) {
36  return crypto
37    .createHash('md5')
38    .update(str)
39    .digest(encoding || 'hex');
40};
41
42/**
43 * By default serves the connect favicon, or the favicon
44 * located by the given `path`.
45 *
46 * Options:
47 *
48 *   - `maxAge`  cache-control max-age directive, defaulting to 1 day
49 *
50 * Examples:
51 *
52 *     connect.createServer(
53 *       connect.favicon()
54 *     );
55 *
56 *     connect.createServer(
57 *       connect.favicon(__dirname + '/public/favicon.ico')
58 *     );
59 *
60 * @param {String} path
61 * @param {Object} options
62 * @return {Function}
63 * @api public
64 */
65
66module.exports = function favicon(path, options) {
67  var options = options || {}
68    , path = path || __dirname + '/../public/favicon.ico'
69    , maxAge = options.maxAge || 86400000;
70
71  return function favicon(req, res, next) {
72    if ('/favicon.ico' == req.url) {
73      if (icon) {
74        res.writeHead(200, icon.headers);
75        res.end(icon.body);
76      } else {
77        fs.readFile(path, function (err, buf) {
78          if (err) return next(err);
79          icon = {
80            headers: {
81                'Content-Type': 'image/x-icon'
82              , 'Content-Length': buf.length
83              , 'ETag': '"' + exports.md5(buf) + '"'
84              , 'Cache-Control': 'public, max-age=' + (maxAge / 1000)
85            },
86            body: buf
87          };
88          res.writeHead(200, icon.headers);
89          res.end(icon.body);
90        });
91      }
92    } else {
93      next();
94    }
95  };
96};