simple-stats-server/metrics/cpu.js

dead-simple resource stats for Node.js servers

(function() {
  var add, maxInterval, os, sample, samples, timer, utilization;

  os = require('os');

  utilization = require('./helper/cpu-calc');

  timer = false;

  samples = [];

  maxInterval = 61;

  module.exports = sample = function() {
    var cb, doCalc, interval;
    if (typeof arguments[0] === 'number') {
      interval = arguments[0], cb = arguments[1];
    } else {
      cb = arguments[0];
    }
    if (interval == null) {
      interval = 1;
    }
    if (typeof cb !== 'function') {
      cb = (function() {});
    }
    doCalc = function() {
      var diffs, final, initial, _i, _ref, _results;
      initial = samples.slice(-1 - interval)[0];
      final = samples.slice(-1)[0];
      diffs = (function() {
        _results = [];
        for (var _i = 0, _ref = initial.length; 0 <= _ref ? _i < _ref : _i > _ref; 0 <= _ref ? _i++ : _i--){ _results.push(_i); }
        return _results;
      }).apply(this).map(function(i) {
        return utilization(initial[i], final[i]);
      });
      cb(null, diffs);
      return diffs;
    };
    if (samples.length <= interval) {
      if (maxInterval <= interval) {
        maxInterval = interval + 1;
      }
      return setTimeout(doCalc, 1000 * interval - samples.length + 1);
    } else {
      return doCalc();
    }
  };

  add = function(label, timeout) {
    return sample[label] = sample.bind(null, timeout);
  };

  add('1s', 1);

  add('5s', 5);

  add('15s', 15);

  add('1m', 60);

  Object.defineProperty(sample, 'cancel', {
    value: function() {
      if (!timer) {
        return;
      }
      clearInterval(timer);
      return timer = false;
    }
  });

  Object.defineProperty(sample, 'collect', {
    value: function() {
      if (timer) {
        return;
      }
      return timer = setInterval((function() {
        if (samples.length >= maxInterval) {
          samples.unshift();
        }
        return samples.push(os.cpus());
      }), 1000);
    }
  });

}).call(this);