javascript benchmarker

how do you know if your javascript is being impacted by something on the client? CPU, memory, disk io. I don't know. Maybe set a timeout for a second and then when the timeout is triggered see how close to a second it was? The more variance from a second the more impact something is having on the browser/js. Then just keep looping that timeout.

benchmarker is probably the wrong term, but life is hard.

Seems mostly the thing that effects JS is CPU. To test:
https://blogs.msdn.microsoft.com/vijaysk/2012/10/26/tools-to-simulate-cpu-memory-disk-load/
http://download.sysinternals.com/files/CPUSTRES.zip


function Benchmarker() {

    var times = []; // records the time at each interval check
    var interval = 1000; // the amount of time (in msec) to wait between time checking
    var warningVarianceThreshold = 100; // the amount of time (in msec) as a variance from the expected time that counts as a warning
    var alertVarianceThreshold = 150; // the amount of time (in msec) as a variance from the expected time that counts as an alert
    var warningCount = 0;
    var alertCount = 0;
    var stopFlag = false;

    var intervalCallback = null;    // a callback function called each time the interval occurs

    // this method will run at a given interval and record the time
    // will compare the current time to the last run time and establish a variance to the expected difference
    function checkInterval() {
        if (stopFlag) {
            return;
        }
        var d = new Date();
        var currentSeconds = d.getTime();
        if (times.length > 0) {
            var lastSeconds = times[times.length - 1];
            var timeChanged = currentSeconds - lastSeconds;
            //console.log(currentSeconds + "; " + timeChanged);
            var variance = Math.abs(timeChanged - interval);
            if (variance >= alertVarianceThreshold) {
                alertCount++;
            } else if (variance >= warningVarianceThreshold) {
                warningCount++;
            }
            if (typeof intervalCallback === "function") {
                var data = getData();
                data = $.extend(data, { lastVariance: variance });
                intervalCallback(data);
            }
        } else {
            //console.log(currentSeconds);
        }
        times.push(currentSeconds);
        setTimeout(function () { checkInterval(); }, interval);
    }

    this.getData = function() {
        var data = { interval: interval, intervalCount:times.length, warningVarianceThreshold: warningVarianceThreshold, alertVarianceThreshold: alertVarianceThreshold, warningCount: warningCount, alertCount: alertCount };
        return data;
    }

    this.start = function () {
        checkInterval();
    }
    this.stop = function () {
        stopFlag = true;
    }

    this.getAlertCount = function () {
        return alertCount;
    }
    this.getWarningCount = function () {
        return warningCount;
    }
    this.setIntervalCallback = function(callback) {
        intervalCallback = callback;
    }
}