blob: 6240b30832fb0e2e27ae6162428e5de70d1f8328 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
/**
* Module dependencies
*/
var crypto = require('crypto');
/**
* 62 characters in the ascii range that can be used in URLs without special
* encoding.
*/
var UIDCHARS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
/**
* Make a Buffer into a string ready for use in URLs
*
* @param {String}
* @returns {String}
* @api private
*/
function tostr(bytes) {
var chars, r, i;
r = [];
for (i = 0; i < bytes.length; i++) {
r.push(UIDCHARS[bytes[i] % UIDCHARS.length]);
}
return r.join('');
}
/**
* Generate an Unique Id
*
* @param {Number} length The number of chars of the uid
* @param {Number} cb (optional) Callback for async uid generation
* @api public
*/
function uid(length, cb) {
if (typeof cb === 'undefined') {
return tostr(crypto.pseudoRandomBytes(length));
} else {
crypto.pseudoRandomBytes(length, function(err, bytes) {
if (err) return cb(err);
cb(null, tostr(bytes));
})
}
}
/**
* Exports
*/
module.exports = uid;
|
