botpress/lib/janitor/index.js

The world's first CMS for bots. Easily create, manage and extend chatbots.

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _bluebird = require('bluebird');

var _bluebird2 = _interopRequireDefault(_bluebird);

var _nanoid = require('nanoid');

var _nanoid2 = _interopRequireDefault(_nanoid);

var _moment = require('moment');

var _moment2 = _interopRequireDefault(_moment);

var _ms = require('ms');

var _ms2 = _interopRequireDefault(_ms);

var _lodash = require('lodash');

var _helpers = require('../database/helpers');

var _helpers2 = _interopRequireDefault(_helpers);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _asyncToGenerator(fn) { return function () { var gen = fn.apply(this, arguments); return new _bluebird2.default(function (resolve, reject) { function step(key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { return _bluebird2.default.resolve(value).then(function (value) { step("next", value); }, function (err) { step("throw", err); }); } } return step("next"); }); }; }

const DEFAULTS = {
  timestampColumn: 'created_on'

  /** The DB Janitor is the component that
   automatically clears old records from the specific tables
   according to the configuration.
   @namespace DbJanitor
   @example
   bp.janitor.add({...})
   */
};const createJanitor = ({ db, logger, intervalMs = (0, _ms2.default)('1m') }) => {
  const tasks = [];
  let currentPromise = null;

  // TODO: impplement `debuounce` param which, when set,
  // prevents the specific task form running too often
  // The goal is to have the interval reasonably low (1/5/10s)
  // for some tasks like dialog sessions
  // but don't run other tasks like logs more often than every 1/5/10min
  const runTask = (() => {
    var _ref = _asyncToGenerator(function* ({ table, ttl, timestampColumn }) {
      logger.debug(`[DB Janitor] Running for table "${table}"`);
      const knex = yield db.get();
      const outdatedCondition = (0, _helpers2.default)(knex).date.isBefore(timestampColumn, (0, _moment2.default)().subtract(ttl, 'ms'));
      return knex(table).where(outdatedCondition).del().then();
    });

    return function runTask(_x) {
      return _ref.apply(this, arguments);
    };
  })();

  const runTasks = () => {
    logger.debug('[DB Janitor] Running tasks');
    if (currentPromise) {
      // don't run the tasks if the previous batch didn't finish yet
      logger.debug('[DB Janitor] Skipping the current run, previous operation still running');
      return;
    }
    currentPromise = _bluebird2.default.each(tasks, runTask).catch(err => {
      logger.error('[DB Janitor] Error:', err.message);
    }).finally(() => {
      currentPromise = null;
    });
  };

  let intervalId = null;

  /**
   * Start the daemon that will keep checking the DB and delete
   * the outdated records according to the config,
   * see {@link DbJanitor#add}.
   * @function DbJanitor#start
   * @returns {void}
   */
  const start = () => {
    if (intervalId) {
      return;
    }
    intervalId = setInterval(runTasks, intervalMs);
    logger.info('[DB Janitor] Started');
  };

  /**
   * Add the table for the janitor to keep watching and cleaning.
   * @function DbJanitor#add
   * @param {object} options
   * @param {string} options.table The name of the DB table to watch.
   * @param {number} options.ttl Records Time to Live in **milliseconds**.
   * @param {string} [options.timestampColumn="created_on"] The column
   *  to check if the record is outdated.
   * @returns {string} The id of the added task.
   */
  const add = options => {
    logger.debug(`[DB Janitor] Added table "${options.table}"`);
    const id = (0, _nanoid2.default)();
    tasks.push(Object.assign({ id }, DEFAULTS, options));
    return id;
  };

  /**
   * Remove the  table for the janitor to keep watching and cleaning.
   * @function DbJanitor#remove
   * @param {string} id The ID of the task returned by {@link DbJanitor#add}.
   * @returns {void}
   */
  const remove = id => {
    const i = (0, _lodash.findIndex)(tasks, { id });
    if (i < 0) {
      logger.error(`[DB Janitor] Unknown task ID "${id}"`);
      return;
    }
    const [{ table }] = tasks.splice(i, 1);
    logger.debug(`[DB Janitor] Removed table "${table}"`);
  };

  /**
   * Stop the daemon.
   * @function DbJanitor#stop
   * @returns {void}
   */
  const stop = () => {
    clearInterval(intervalId);
    intervalId = null;
    logger.info('[DB Janitor] Stopped');
  };

  return { start, add, remove, stop };
};

exports.default = createJanitor;
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