Added option to silence timer

Added a third attribute to set timer to silent, so that it doesn’t
write to the stdout. Also, added a demo.js.

Author: jkrenge

README.md

@@ -35,15 +35,18 @@ First, you need to spin up a timer. When doing so, you can assign the timer a `n
 
 **name**: Okay, so the `name` will also be the name of the metric on CloudWatch. This means, this should be unique for every loop you want to measure. Whereas the `namespace` when requiring the module could be the same throughout the project.
 
-**pulse**: The `pulse` is the number of seconds how often your timer pushed data to CloudWatch. E.g. if you set it to `5`, loop times will be averaged over five seconds and this average will be uploaded only. If you don't set a pulse, i.e. set it to `0`, each loop time will be uploaded immediately.
+**pulse** (optional): The `pulse` is the number of seconds how often your timer pushed data to CloudWatch. E.g. if you set it to `5`, loop times will be averaged over five seconds and this average will be uploaded only. If you don't set a pulse, i.e. set it to `0`, each loop time will be uploaded immediately.
 
 **You probably should set a pulse, because CloudWatch only allows 150 uploads per second!** For more info on that topic, read below.
 
+**silent** (optional): As per default, the timer writes its results also to the default output. If you want to override this behavior, you can set it to `silent` using any truthy value, e.g. `true` or `'silent'`, latter being a bit more explicit.
+
 ```
 var name = 'name-of-the-timer'; // this will be your metric's name
 var pulse = 5; // this means data will be pushed to CloudWatch every five seconds
 
-var timer = Timer.getTimer(name, pulse);
+var timer = Timer.getTimer(name, pulse); // this will write results to the console
+var silentTimer = Timer.getTimer('i-am-silent', 0, 'silent'); // this one will not
 ```
 
 ## Measure

demo.js

@@ -0,0 +1,14 @@
+var Timer = require('./index.js')('eu-central-1', 'AWS-KEY', 'AWS-SECRET', 'namespace');
+
+var timer = Timer.getTimer('my-timer', 10);
+var silentTimer = Timer.getTimer('i-am-silent', 0, 'silent');
+
+timer.start();
+silentTimer.start();
+
+setTimeout(function () {
+
+  timer.end();
+  silentTimer.end();
+
+}, 1000);

index.js

@@ -11,10 +11,10 @@ var namespace = 'empty';
 // Prototype //
 ///////////////
 
-function Timer(name, pulse) {
+function Timer(name, pulse, isSilent) {
 
   // validate
-  if (!(this instanceof Timer)) return new Timer('unnamed', 0);
+  if (!(this instanceof Timer)) return new Timer('unnamed');
   if (!_.isString(name)) return console.error('Name must be a string');
   if (_.isUndefined(pulse)) pulse = 0;
   if (!_.isNumber(pulse) || _.isNaN(pulse) || pulse < 0)
@@ -23,6 +23,7 @@ function Timer(name, pulse) {
   // set
   this.name = name;
   this.pulse = pulse;
+  this.isSilent = isSilent;
 
   // init
   this.startDate = null;
@@ -104,7 +105,7 @@ Timer.prototype.pushPulseToCloudWatch = function () {
 
     // inform
     if (!_.isNaN(averageCycletime)) {
-      print(_this.name, averageCycletime, true);
+      if (!this.isSilent) print(_this.name, averageCycletime, true);
       uploadMetricToCloudWatch(_this.name, averageCycletime);
     }
 
@@ -125,13 +126,16 @@ Timer.prototype.pushPulseToCloudWatch = function () {
  * returns a timer object
  * @param  {String} name  the name of the timer
  * @param  {Number} pulse the pulse in seconds, is optional
- * @return {[type]}       [description]
+ * @param  {Boolean} silent whether the timer should write to the log
+ *                          (default false, any truthy value works)
+ * @return {Object}         a timer
  */
-function getTimer(name, pulse) {
+function getTimer(name, pulse, silent) {
 
   if (_.isUndefined(pulse)) pulse = 0;
+  var writeResultsToLog = _.isUndefined(silent) || silent === false;
 
-  var timer = new Timer(name, pulse);
+  var timer = new Timer(name, pulse, !writeResultsToLog);
   if (timer.pulse > 0) timer.pushPulseToCloudWatch();
   return timer;
 
@@ -164,7 +168,7 @@ Timer.prototype.end = function () {
   }
 
   // inform
-  print(this.name, cycletime, false);
+  if (!this.isSilent) print(this.name, cycletime, false);
   return cycletime;
 };