question/engine/statisticslib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Functions common to the question usage statistics code.
  19  *
  20  * @package    moodlecore
  21  * @subpackage questionbank
  22  * @copyright  2013 The Open University
  23  * @author     Jamie Pratt <me@jamiep.org>
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 /**
  30  * Question statistics cron code. Deletes cached stats more than a certain age.
  31  */
  32 function question_usage_statistics_cron() {
  33     global $DB;
  34
  35     $expiretime = time() - 5 * HOURSECS;
  36
  37     mtrace("\n  Cleaning up old question statistics cache records...", '');
  38
  39     $DB->delete_records_select('question_statistics', 'timemodified < ?', array($expiretime));
  40     $responseanlysisids = $DB->get_records_select_menu('question_response_analysis',
  41                                                            'timemodified < ?',
  42                                                            array($expiretime),
  43                                                            'id',
  44                                                            'id, id AS id2');
  45
  46     $DB->delete_records_list('question_response_analysis', 'id', $responseanlysisids);
  47     $DB->delete_records_list('question_response_count', 'analysisid', $responseanlysisids);
  48
  49     mtrace('done.');
  50     return true;
  51 }