Adding standalone RPS requests per second stat collector

examples/simpletest.ex.js

@@ -23,6 +23,7 @@ nl.run({
         'result-codes', 
         { name: 'latency', percentiles: [0.9, 0.99] },
         'concurrency',
+        'rps',
         'uniques',
         { name: 'http-errors', successCodes: [200,404], log: 'http-errors.log' }
     ],

lib/monitoring/collectors.js

@@ -17,6 +17,7 @@ var stats = require('../stats');
 var Histogram = stats.Histogram;
 var Peak = stats.Peak;
 var ResultsCounter = stats.ResultsCounter;
+var Rate = stats.Rate;
 var Uniques = stats.Uniques;
 var Accumulator = stats.Accumulator;
 var LogFile = stats.LogFile;
@@ -41,6 +42,14 @@ StatsCollectors['result-codes'] = function ResultCodesCollector() {
     self.end = function(context, http) { self.stats.put(http.res.statusCode); };
 };
 
+/** Track requests per second, storing stats in a stats.js#Rate object. The client must call 
+.end({res: http.ClientResponse}). */
+StatsCollectors['rps'] = function RpsCollector() {
+    var self = this;
+    self.stats = new Rate();
+    self.end = function(context, http) { self.stats.put(); };
+};
+
 /** Track a status code that is returned in an HTTP header, storing stats in a stats.js#ResultsCounter
 object. The client must call .end({res: http.ClientResponse}). */
 StatsCollectors['header-code'] = function HeaderCodeCollector(params) {