freeloader-bundle/lib/reporters/console-summary.js

Collecion of streams for freeloader

var _         = require('lodash');
var q         = require('q');
var util      = require('util');
var Stats     = require('fast-stats').Stats;
var ReporterStream = require('../ReporterStream');

function ConsoleSummary() {
  ReporterStream.call(this);
  this.on('request', this.request);
  this.on('responses', this.printStats);
  this.responseTimes = [];
  this.startTime = new Date();
}

util.inherits(ConsoleSummary, ReporterStream);
ConsoleSummary.prototype.name = 'ConsoleSummary';

// for each incoming request
// calculate the response time
ConsoleSummary.prototype.request = function(item) {
  var startTime = new Date();
  item.response.then(function(res) {
    this.responseTimes.push(new Date() - startTime);
  }.bind(this)).done();
  this.push(item);
};

// we the upstream ends
// we end too
ConsoleSummary.prototype.end = function() {
  this.push(null);
};

// prints stats
ConsoleSummary.prototype.printStats = function(responses) {
  var timeDelta = new Date() - this.startTime;
  var stats = new Stats().push(this.responseTimes);
  console.log('\n');
  console.log('Duration        = ', time(timeDelta));
  console.log('Response count  = ', this.responseTimes.length);
  console.log('Requests / sec  = ', Math.floor(this.responseTimes.length / timeDelta * 1000));
  console.log('\n');
  console.log('Response times');
  console.log('  min    = ', time(_.min(this.responseTimes)));
  console.log('  max    = ', time(_.max(this.responseTimes)));
  console.log('  mean   = ', time(stats.amean()));
  console.log('  median = ', time(stats.median()));
  console.log('  75th percentile = ', time(stats.percentile(75)));
  console.log('  90th percentile = ', time(stats.percentile(90)));
  console.log('');
};

function time(millis) {
  if (millis < 1000) {
    return Math.floor(millis) + 'ms';
  } else {
    var seconds = millis / 1000;
    return seconds.toFixed(2) + 's';
  }
}

module.exports = function() {
  return new ConsoleSummary();
};