Measure Function Execution Times

By JoeSimmons — Last update May 13, 2009 — Installed 2,883 times.
There are 14 previous versions of this script.
scr_meta=<><![CDATA[
// ==UserScript==
// @name           Measure Function Execution Times
// @namespace      http://userscripts.org/users/23652
// @description    Measures and compares 2 functions' run-times that you define in the script
// @include        http://*.*/*
// @include        https://*.*/*
// @include        file://*
// @copyright      JoeSimmons
// @version        1.0.2
// @license        Creative Commons Attribution-Noncommercial 3.0 United States License
// ==/UserScript==
]]></>.toString();

var loops = 10000; // Don't go too high.
                  // I suggest trying out 10,000 if it's a first function run

// DEFINE FUNCTION 1 HERE
function function1() {
var i=500, arr = new Array(500);
do {
a = 0;
} while(a=arr[--i]);
}

// DEFINE FUNCTION 2 HERE
function function2() {
var arr = new Array(500);
for(var i=0; i<500; i++) {
arr[i] = 0;
}
}






///////// NO EDITING BELOW HERE /////////////////////////////////////
function addCommas(nStr) {
	nStr += '';
	var x = nStr.split('.'),
	x1 = x[0],
	x2 = x.length > 1 ? '.' + x[1] : '',
	rgx = /(\d+)(\d{3})/;
	while (rgx.test(x1)) {
		x1 = x1.replace(rgx, '$1' + ',' + '$2');
	}
	return x1 + x2;
}

function measure1() {
var time=new Date().getTime(), Loops=loops, i=0;
while(++i<Loops) function1();
return (new Date().getTime()) - time;
}

function measure2() {
var time=new Date().getTime(), Loops=loops, i=0;
while(++i<Loops) function2();
return (new Date().getTime()) - time;
}

function esc(e) {
e.target.value = e.target.value.replace(/^.+\n.*\n/,'').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;').replace(/code\:\n/g,'code:\n<pre>').replace(/\}(?=\n\nFunction 2)/g,'}</pre>').replace(/}$/,'}</pre>');
e.target.removeEventListener('click', esc, false);
}

var before_time = new Date().getTime(),
time_measure_1 = measure1(),
time_measure_2 = measure2(),
diff = (new Date().getTime()) - before_time;

if(time_measure_1 < time_measure_2) {
var result = "Function 1 is " + addCommas((time_measure_2 - time_measure_1))  + " ms ("+(time_measure_2 / time_measure_1).toFixed(2)+" times) faster than Function 2\nUsed " + addCommas(loops) + " loops twice over " + (diff/1000) + " seconds total\nFunction 1 time: "+addCommas(time_measure_1)+" ms\nFunction 2 time: "+addCommas(time_measure_2)+" ms\n\nFunction 1 code:\n"+function1+"\n\nFunction 2 code:\n"+function2;
}
else {
var result = "Function 2 is " + addCommas((time_measure_1 - time_measure_2)) + " ms ("+(time_measure_1 / time_measure_2).toFixed(2)+" times) faster than Function 1\nUsed " + addCommas(loops) +  " loops twice over " + (diff/1000) + " seconds total\nFunction 1 time: "+addCommas(time_measure_1)+" ms\nFunction 2 time: "+addCommas(time_measure_2)+" ms\n\nFunction 1 code:\n"+function1+"\n\nFunction 2 code:\n"+function2;
}

var ta = document.createElement('textarea');
ta.addEventListener('dblclick', function(){this.style.display='none';}, false);
ta.addEventListener('click', esc, false);
ta.textContent = '(Single-Click to ready text for posting on Userscripts.org)\n(Double-Click to close these results)\n' + result;
ta.setAttribute('style', 'width:98%; height:50%; padding:4px; font:13px arial; position:fixed;'
+                        'bottom:2px; left:4px;');
document.body.appendChild(ta);

// Auto-Update by sizzlemctwizzle
aaus_38017={
i:'37031', // Script id on Userscripts.org
d:1, // Days to wait between update checks
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