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   1  <?php
   2  
   3  // This file is part of Moodle - http://moodle.org/
   4  //
   5  // Moodle is free software: you can redistribute it and/or modify
   6  // it under the terms of the GNU General Public License as published by
   7  // the Free Software Foundation, either version 3 of the License, or
   8  // (at your option) any later version.
   9  //
  10  // Moodle is distributed in the hope that it will be useful,
  11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  // GNU General Public License for more details.
  14  //
  15  // You should have received a copy of the GNU General Public License
  16  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17  
  18  /**
  19   * @package    moodlecore
  20   * @subpackage backup-dbops
  21   * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  /**
  26   * Non instantiable helper class providing DB support to the backup_structure stuff
  27   *
  28   * This class contains various static methods available for all the DB operations
  29   * performed by the backup_structure stuff (mainly @backup_nested_element class)
  30   *
  31   * TODO: Finish phpdocs
  32   */
  33  abstract class backup_structure_dbops extends backup_dbops {
  34  
  35      public static function get_iterator($element, $params, $processor) {
  36          global $DB;
  37          // Check we are going to get_iterator for one backup_nested_element
  38          if (! $element instanceof backup_nested_element) {
  39              throw new base_element_struct_exception('backup_nested_element_expected');
  40          }
  41          // If var_array, table and sql are null, and element has no final elements it is one nested element without source
  42          // Just return one 1 element iterator without information
  43          if ($element->get_source_array() === null && $element->get_source_table() === null &&
  44              $element->get_source_sql() === null && count($element->get_final_elements()) == 0) {
  45              return new backup_array_iterator(array(0 => null));
  46  
  47          } else if ($element->get_source_array() !== null) { // It's one array, return array_iterator
  48              return new backup_array_iterator($element->get_source_array());
  49  
  50          } else if ($element->get_source_table() !== null) { // It's one table, return recordset iterator
  51              return $DB->get_recordset($element->get_source_table(), self::convert_params_to_values($params, $processor), $element->get_source_table_sortby());
  52  
  53          } else if ($element->get_source_sql() !== null) { // It's one sql, return recordset iterator
  54              return $DB->get_recordset_sql($element->get_source_sql(), self::convert_params_to_values($params, $processor));
  55  
  56          } else { // No sources, supress completely, using null iterator
  57              return new backup_null_iterator();
  58          }
  59      }
  60  
  61      protected static function convert_params_to_values($params, $processor) {
  62          $newparams = array();
  63          foreach ($params as $key => $param) {
  64              $newvalue = null;
  65              // If we have a base element, get its current value, exception if not set
  66              if ($param instanceof base_atom) {
  67                  if ($param->is_set()) {
  68                      $newvalue = $param->get_value();
  69                  } else {
  70                      throw new base_element_struct_exception('valueofparamelementnotset', $param->get_name());
  71                  }
  72  
  73              } else if ($param < 0) { // Possibly one processor variable, let's process it
  74                  // See @backup class for all the VAR_XXX variables available.
  75                  // Note1: backup::VAR_PARENTID is handled by nested elements themselves
  76                  // Note2: trying to use one non-existing var will throw exception
  77                  $newvalue = $processor->get_var($param);
  78  
  79              // Else we have one raw param value, use it
  80              } else {
  81                  $newvalue = $param;
  82              }
  83  
  84              $newparams[$key] = $newvalue;
  85          }
  86          return $newparams;
  87      }
  88  
  89      public static function insert_backup_ids_record($backupid, $itemname, $itemid) {
  90          global $DB;
  91          // We need to do some magic with scales (that are stored in negative way)
  92          if ($itemname == 'scale') {
  93              $itemid = -($itemid);
  94          }
  95          // Now, we skip any annotation with negatives/zero/nulls, ids table only stores true id (always > 0)
  96          if ($itemid <= 0 || is_null($itemid)) {
  97              return;
  98          }
  99          // TODO: Analyze if some static (and limited) cache by the 3 params could save us a bunch of record_exists() calls
 100          // Note: Sure it will!
 101          if (!$DB->record_exists('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname, 'itemid' => $itemid))) {
 102              $DB->insert_record('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname, 'itemid' => $itemid));
 103          }
 104      }
 105  
 106      /**
 107       * Adds backup id database record for all files in the given file area.
 108       *
 109       * @param string $backupid Backup ID
 110       * @param int $contextid Context id
 111       * @param string $component Component
 112       * @param string $filearea File area
 113       * @param int $itemid Item id
 114       * @param \core\progress\base $progress
 115       */
 116      public static function annotate_files($backupid, $contextid, $component, $filearea, $itemid,
 117              \core\progress\base $progress = null) {
 118          global $DB;
 119          $sql = 'SELECT id
 120                    FROM {files}
 121                   WHERE contextid = ?
 122                     AND component = ?';
 123          $params = array($contextid, $component);
 124  
 125          if (!is_null($filearea)) { // Add filearea to query and params if necessary
 126              $sql .= ' AND filearea = ?';
 127              $params[] = $filearea;
 128          }
 129  
 130          if (!is_null($itemid)) { // Add itemid to query and params if necessary
 131              $sql .= ' AND itemid = ?';
 132              $params[] = $itemid;
 133          }
 134          if ($progress) {
 135              $progress->start_progress('');
 136          }
 137          $rs = $DB->get_recordset_sql($sql, $params);
 138          foreach ($rs as $record) {
 139              if ($progress) {
 140                  $progress->progress();
 141              }
 142              self::insert_backup_ids_record($backupid, 'file', $record->id);
 143          }
 144          if ($progress) {
 145              $progress->end_progress();
 146          }
 147          $rs->close();
 148      }
 149  
 150      /**
 151       * Moves all the existing 'item' annotations to their final 'itemfinal' ones
 152       * for a given backup.
 153       *
 154       * @param string $backupid Backup ID
 155       * @param string $itemname Item name
 156       * @param \core\progress\base $progress Progress tracker
 157       */
 158      public static function move_annotations_to_final($backupid, $itemname, \core\progress\base $progress) {
 159          global $DB;
 160          $progress->start_progress('move_annotations_to_final');
 161          $rs = $DB->get_recordset('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname));
 162          $progress->progress();
 163          foreach($rs as $annotation) {
 164              // If corresponding 'itemfinal' annotation does not exist, update 'item' to 'itemfinal'
 165              if (! $DB->record_exists('backup_ids_temp', array('backupid' => $backupid,
 166                                                                'itemname' => $itemname . 'final',
 167                                                                'itemid' => $annotation->itemid))) {
 168                  $DB->set_field('backup_ids_temp', 'itemname', $itemname . 'final', array('id' => $annotation->id));
 169              }
 170              $progress->progress();
 171          }
 172          $rs->close();
 173          // All the remaining $itemname annotations can be safely deleted
 174          $DB->delete_records('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname));
 175          $progress->end_progress();
 176      }
 177  
 178      /**
 179       * Returns true/false if there are annotations for a given item
 180       */
 181      public static function annotations_exist($backupid, $itemname) {
 182          global $DB;
 183          return (bool)$DB->count_records('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname));
 184      }
 185  }