Hi everyone. Here's my attempt:
"use strict";
/*!
* JavaScript UUID Generator, v0.0.1
*
* Copyright (c) 2009 Massimo Lombardo.
* Dual licensed under the MIT and the GNU GPL licenses.
*/
function UUID() {
var uuid = (function () {
var i,
c = "89ab",
u = [];
for (i = 0; i < 36; i += 1) {
u[i] = (Math.random() * 16 | 0).toString(16);
}
u[8] = u[13] = u[18] = u[23] = "-";
u[14] = "4";
u[19] = c.charAt(Math.random() * 4 | 0);
return u.join("");
})();
return {
toString: function () {
return uuid;
},
valueOf: function () {
return uuid;
}
};
}
Generates valid version 4 UUIDs as specified in RFC 4122.
Special thanks are due to Robert Kieffer [1], whose example showed me the way.
By the way, my code is so damn faster than Robert's... ;-)
Particularly, using a standalone V8 build [2], this benchmarking
routine (available in the V8 benchmark suite [3])
var benchmark = function (f) {
var r = 0,
e = 0,
s = new Date();
for (r = 0; e < 60000; r += 1) { // runs non-stop for 60 human seconds
f();
e = (new Date()) - s;
}
return ((e * 1000) / r);
}
and then running
print(benchmark(function () {
Math.uuid()
}));
print(benchmark(function () {
(new UUID()).toString()
}));
print(benchmark(function () {
(new afdUUID()).toString() //AF-Design implementation [4]
}));
I get (values are expressed in microseconds)
72.36090726105525
34.95077765480282
43.292667088048624
which means that Robert's code is slower than mine by 107%, while
AF-Designs' is by 23.8%.
All in all, not bad considering I'm a JavaScript newbie :)
Also, minified using the YUI compressor [5] then gzip'd the whole
thing weights just 328 bytes! :)
As usual, every comment counts and is really welcomed and appreciated.
Links:
[1] http://www.broofa.com/Tools/Math.uuid.js
[2] http://code.google.com/p/v8/
[3] http://code.google.com/apis/v8/benchmarks.html
[4] http://af-design.com/services/javascript/uuid/uuid.js
[5] http://developer.yahoo.com/yui/compressor/
--
unwiredbrain
Linux user #437712
