[jQuery] timer sample

Usage:

$.timer.start();
// some code
$.timer.mark('optional label');
// some code
$.timer.pause();
// some code to exclude from profiling
$.timer.resume();
// some code
$.timer.mark();
// some code
$.timer.show('optional label'); // displays a list of all marks to this point in an alert pop-up

The code:

// usage: $.debug({x:x, y:y, z:z})
$.debug = function(o) {
    var s = [];
    for (var name in o)
        s.push(name + ': ' + o[name])
    alert(s.join('\n'));
}

$.timer = {
    start: function() {
        this.info = {};
        this.count = 0;
        this.pauseTime = 0;
        this.time = new Date().getTime();
    },
    mark: function(s) {
        var t = ((this.pauseTime == 0) ? new Date().getTime() : this.pauseTime) - this.time;
        this.count++;
        if (s == undefined) s = 'mark ' + this.count;
        this.info[s] = '' + t + ' ms (' + (t/1000) + ' s)';
        this.time = new Date().getTime();
        if (this.pauseTime != 0) this.pauseTime = this.time;
    },
    pause: function() {
        if (this.pauseTime == 0)
            this.pauseTime = new Date().getTime();
    },
    resume: function() {
        if (this.pauseTime != 0)
            this.time += new Date().getTime() - this.pauseTime;
        this.pauseTime = 0;
    },
    show: function(s) {
        this.mark(s);
        $.debug( this.info);
    }
}