Simple speed tester

gistfile1.js

(function (sources, delay, success, fail) {
	function onload() {
		this.stop = new Date().getTime();
		window.setTimeout(next, success.apply(this, arguments) || delay);
	}

	function onerror() {
		this.stop = new Date().getTime();
		window.setTimeout(next, fail.apply(this, arguments) || delay);
	}

	function next() {
		var source = sources.pop();
		var img;

		if (source !== void(0)) {
			img = new Image();
			img.onload = onload;
			img.onerror = onerror;
			img.start = new Date().getTime();
			img.src = source + "?" + img.start;
		}
	}

	next();
})([
	"http://example.com/img-1.jpg",
	"http://example.com/img-2.jpg",
	"http://example.com/img-3.jpg",
	"http://example.com/img-4.jpg",
	"http://example.com/img-5.jpg",
], 100, function () {
	console.info("send", "timing", "SpeedTest", "sampleLoadTime", this.stop - this.start , this.src);
}, function () {
	console.error("send", "timing", "SpeedTest", "sampleErrorTime", this.stop - this.start , this.src);
});