Add timer helper

lib/cartodb/stats/timer.js

@@ -0,0 +1,32 @@
+function Timer() {
+    this.times = {};
+}
+
+module.exports = Timer;
+
+Timer.prototype.start = function(label) {
+    this.timeIt(label, 'start');
+};
+
+Timer.prototype.end = function(label) {
+    this.timeIt(label, 'end');
+};
+
+Timer.prototype.timeIt = function(label, what) {
+    this.times[label] = this.times[label] || {};
+    this.times[label][what] = Date.now();
+};
+
+Timer.prototype.getTimes = function() {
+    var self = this;
+    var times = {};
+
+    Object.keys(this.times).forEach(function(label) {
+        var stat = self.times[label];
+        if (stat.start && stat.end) {
+            times[label] = Math.max(0, stat.end - stat.start);
+        }
+    });
+
+    return times;
+};