VERY simple benchmarker for code. Produce a light report on console.

bencher.js

/**
 * VERY simple benchmarker for code.
 * Produce a light report on console.
 *
 * USAGE:
 *
 * Bencher.get('a bench description').start();
 *
 * // code here
 *
 * Bencher.get('a bench description').log('first code done');
 *
 * // code here
 *
 * Bencher.get('a bench description').log('second code done');
 *
 * Bencher.get('a bench description').stop();
 */
var Bencher = {
    benchs: {},

    get: function(name) {
        if (this.benchs[name] === undefined) {
            this.benchs[name] = {
                bencher : this,
                name    : name,
                markers : [],

                log: function(description) {
                    this.markers.push(
                        {
                            time        : new Date().getTime(),
                            description : description
                        }
                    );
                },

                start: function() {
                    this.log('Start');
                },

                stop: function() {
                    this.log('Stop');

                    var startTime    = 0;
                    var previousTime = 0;

                    console.group('Bench: ' + this.name);

                    for (var i = 0; i < this.markers.length; i++) {
                        var marker = this.markers[i];

                        if (startTime === 0) {
                            previousTime = startTime = marker.time;
                        }

                        console.log(
                            '%s : %dms (+%dms)',
                            marker.description,
                            marker.time - startTime,
                            marker.time - previousTime
                        );

                        previousTime = marker.time;
                    }

                    console.groupEnd();

                    delete this.bencher.benchs[name];
                }
            };
        }

        return this.benchs[name];
    }
};

reportExemple

Bench: get team schedules bencher.js:30
  Start : 0ms (+0ms) bencher.js:39
  begin ScheduleRepository.findTeamSchedules : 1ms (+1ms) bencher.js:39
  raw schedules loaded : 968ms (+967ms) bencher.js:39
  schedules sorted by week and TeamMember : 975ms (+7ms) bencher.js:39
  end ScheduleRepository.findTeamSchedules : 996ms (+21ms) bencher.js:39
  data loaded : 996ms (+0ms) bencher.js:39
  Stop : 996ms (+0ms)