messing around

mongo-stats.js

/**
 * Module dependencies.
 */

var strftime = require('strftime');

/**
 * Creates the `record` function for `collection`.
 *
 * Usage:
 *
 *  ```
 *  var visits = db.collection('visit_stats');
 *  var record = mongostats(visits);
 *
 *  record('www.example.com', {
 *    account: 'xxxx-xxxx-xxxx',
 *  }, callback);
 *  ```
 *
 * TODO:
 *
 *  - make pre-allocations smarter so we dont
 *  waste send so many useless bytes over the wire.
 *
 * @param {Collection} collection
 * @return {Function}
 * @public
 */

module.exports = function (collection) {
  return function record (name, meta, callback) {
    if ('function' == typeof meta) {
      callback = meta;
      meta = null;
    }

    var inc = {};
    var date = new Date();
    var setOnInsert = prealloc(date, meta);

    inc['total'] = 1;
    inc[strftime('hour.%k', date)] = 1;
    inc[strftime('minute.%k.%M', date)] = 1;

    collection.update({
      query: {
        _id: strftime('%Y-%M-%d_' + name)
      },
      update: {
        $setOnInsert: setOnInsert,
        $inc: inc
      },
      upsert: true
    }, callback || noop);
  };
}

/**
 * Document pre-allocation.
 *
 * @param {Date} date
 * @param {Object|Null} meta
 * @return {Object}
 * @private
 */

function prealloc (date, meta) {
  var stats = {
    meta: meta || {}
    minute: {},
    hour: {},
    total: 0,
  };

  range(0, 24, set(stats.hour, 0));
  range(0, 60, set(stats.minute, 0));

  return stats;
}

/**
 * Naive sequence.
 *
 * @param {Number} start
 * @param {Number} stop
 * @param {Function} fn
 * @private
 */

function range (start, stop, fn) {
  for (var i = start; i < stop; ++i) fn(i);
}

/**
 * Assignment utility.
 *
 * @param {Object} object
 * @param {Mixed} value
 * @return {Function}
 * @private
 */

function set (object, value) {
  return function (key) {
    object[key] = value;
  };
}

/**
 * Noop.
 *
 * @private
 */

function noop () {}