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Differences Between: [Versions 310 and 401] [Versions 311 and 401] [Versions 39 and 401] [Versions 400 and 401] [Versions 401 and 403]

   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   * Simple moodle database engine.
  19   *
  20   * @package    search_simpledb
  21   * @copyright  2016 David Monllao {@link http://www.davidmonllao.com}
  22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  namespace search_simpledb;
  26  
  27  defined('MOODLE_INTERNAL') || die();
  28  
  29  /**
  30   * Simple moodle database engine.
  31   *
  32   * @package    search_simpledb
  33   * @copyright  2016 David Monllao {@link http://www.davidmonllao.com}
  34   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  35   */
  36  class engine extends \core_search\engine {
  37  
  38      /**
  39       * Total number of available results.
  40       *
  41       * @var null|int
  42       */
  43      protected $totalresults = null;
  44  
  45      /**
  46       * Prepares a SQL query, applies filters and executes it returning its results.
  47       *
  48       * @throws \core_search\engine_exception
  49       * @param  stdClass     $filters Containing query and filters.
  50       * @param  array        $usercontexts Contexts where the user has access. True if the user can access all contexts.
  51       * @param  int          $limit The maximum number of results to return.
  52       * @return \core_search\document[] Results or false if no results
  53       */
  54      public function execute_query($filters, $usercontexts, $limit = 0) {
  55          global $DB, $USER;
  56  
  57          $serverstatus = $this->is_server_ready();
  58          if ($serverstatus !== true) {
  59              throw new \core_search\engine_exception('engineserverstatus', 'search');
  60          }
  61  
  62          if (empty($limit)) {
  63              $limit = \core_search\manager::MAX_RESULTS;
  64          }
  65  
  66          $params = array();
  67  
  68          // To store all conditions we will add to where.
  69          $ands = array();
  70  
  71          // Get results only available for the current user.
  72          $ands[] = '(owneruserid = ? OR owneruserid = ?)';
  73          $params = array_merge($params, array(\core_search\manager::NO_OWNER_ID, $USER->id));
  74  
  75          // Restrict it to the context where the user can access, we want this one cached.
  76          // If the user can access all contexts $usercontexts value is just true, we don't need to filter
  77          // in that case.
  78          if ($usercontexts && is_array($usercontexts)) {
  79              // Join all area contexts into a single array and implode.
  80              $allcontexts = array();
  81              foreach ($usercontexts as $areaid => $areacontexts) {
  82                  if (!empty($filters->areaids) && !in_array($areaid, $filters->areaids)) {
  83                      // Skip unused areas.
  84                      continue;
  85                  }
  86                  foreach ($areacontexts as $contextid) {
  87                      // Ensure they are unique.
  88                      $allcontexts[$contextid] = $contextid;
  89                  }
  90              }
  91              if (empty($allcontexts)) {
  92                  // This means there are no valid contexts for them, so they get no results.
  93                  return array();
  94              }
  95  
  96              list($contextsql, $contextparams) = $DB->get_in_or_equal($allcontexts);
  97              $ands[] = 'contextid ' . $contextsql;
  98              $params = array_merge($params, $contextparams);
  99          }
 100  
 101          // Course id filter.
 102          if (!empty($filters->courseids)) {
 103              list($conditionsql, $conditionparams) = $DB->get_in_or_equal($filters->courseids);
 104              $ands[] = 'courseid ' . $conditionsql;
 105              $params = array_merge($params, $conditionparams);
 106          }
 107  
 108          // Area id filter.
 109          if (!empty($filters->areaids)) {
 110              list($conditionsql, $conditionparams) = $DB->get_in_or_equal($filters->areaids);
 111              $ands[] = 'areaid ' . $conditionsql;
 112              $params = array_merge($params, $conditionparams);
 113          }
 114  
 115          if (!empty($filters->title)) {
 116              $ands[] = $DB->sql_like('title', '?', false, false);
 117              $params[] = $filters->title;
 118          }
 119  
 120          if (!empty($filters->timestart)) {
 121              $ands[] = 'modified >= ?';
 122              $params[] = $filters->timestart;
 123          }
 124          if (!empty($filters->timeend)) {
 125              $ands[] = 'modified <= ?';
 126              $params[] = $filters->timeend;
 127          }
 128  
 129          // And finally the main query after applying all AND filters.
 130          if (!empty($filters->q)) {
 131              switch ($DB->get_dbfamily()) {
 132                  case 'postgres':
 133                      $ands[] = "(" .
 134                          "to_tsvector('simple', title) @@ plainto_tsquery('simple', ?) OR ".
 135                          "to_tsvector('simple', content) @@ plainto_tsquery('simple', ?) OR ".
 136                          "to_tsvector('simple', description1) @@ plainto_tsquery('simple', ?) OR ".
 137                          "to_tsvector('simple', description2) @@ plainto_tsquery('simple', ?)".
 138                          ")";
 139                      $params[] = $filters->q;
 140                      $params[] = $filters->q;
 141                      $params[] = $filters->q;
 142                      $params[] = $filters->q;
 143                      break;
 144                  case 'mysql':
 145                      if ($DB->is_fulltext_search_supported()) {
 146                          $ands[] = "MATCH (title, content, description1, description2) AGAINST (?)";
 147                          $params[] = $filters->q;
 148  
 149                          // Sorry for the hack, but it does not seem that we will have a solution for
 150                          // this soon (https://bugs.mysql.com/bug.php?id=78485).
 151                          if ($filters->q === '*') {
 152                              return array();
 153                          }
 154                      } else {
 155                          // Clumsy version for mysql versions with no fulltext support.
 156                          list($queryand, $queryparams) = $this->get_simple_query($filters->q);
 157                          $ands[] = $queryand;
 158                          $params = array_merge($params, $queryparams);
 159                      }
 160                      break;
 161                  case 'mssql':
 162                      if ($DB->is_fulltext_search_supported()) {
 163                          $ands[] = "CONTAINS ((title, content, description1, description2), ?)";
 164                          // Special treatment for double quotes:
 165                          // - Puntuation is ignored so we can get rid of them.
 166                          // - Phrases should be enclosed in double quotation marks.
 167                          $params[] = '"' . str_replace('"', '', $filters->q) . '"';
 168                      } else {
 169                          // Clumsy version for mysql versions with no fulltext support.
 170                          list($queryand, $queryparams) = $this->get_simple_query($filters->q);
 171                          $ands[] = $queryand;
 172                          $params = array_merge($params, $queryparams);
 173                      }
 174                      break;
 175                  default:
 176                      list($queryand, $queryparams) = $this->get_simple_query($filters->q);
 177                      $ands[] = $queryand;
 178                      $params = array_merge($params, $queryparams);
 179                      break;
 180              }
 181          }
 182  
 183          // It is limited to $limit, no need to use recordsets.
 184          $documents = $DB->get_records_select('search_simpledb_index', implode(' AND ', $ands), $params, 'docid', '*', 0, $limit);
 185  
 186          // Hopefully database cached results as this applies the same filters than above.
 187          $this->totalresults = $DB->count_records_select('search_simpledb_index', implode(' AND ', $ands), $params);
 188  
 189          $numgranted = 0;
 190  
 191          // Iterate through the results checking its availability and whether they are available for the user or not.
 192          $docs = array();
 193          foreach ($documents as $docdata) {
 194              if ($docdata->owneruserid != \core_search\manager::NO_OWNER_ID && $docdata->owneruserid != $USER->id) {
 195                  // If owneruserid is set, no other user should be able to access this record.
 196                  continue;
 197              }
 198  
 199              if (!$searcharea = $this->get_search_area($docdata->areaid)) {
 200                  $this->totalresults--;
 201                  continue;
 202              }
 203  
 204              // Switch id back to the document id.
 205              $docdata->id = $docdata->docid;
 206              unset($docdata->docid);
 207  
 208              $access = $searcharea->check_access($docdata->itemid);
 209              switch ($access) {
 210                  case \core_search\manager::ACCESS_DELETED:
 211                      $this->delete_by_id($docdata->id);
 212                      $this->totalresults--;
 213                      break;
 214                  case \core_search\manager::ACCESS_DENIED:
 215                      $this->totalresults--;
 216                      break;
 217                  case \core_search\manager::ACCESS_GRANTED:
 218                      $numgranted++;
 219                      $docs[] = $this->to_document($searcharea, (array)$docdata);
 220                      break;
 221              }
 222  
 223              // This should never happen.
 224              if ($numgranted >= $limit) {
 225                  $docs = array_slice($docs, 0, $limit, true);
 226                  break;
 227              }
 228          }
 229  
 230          return $docs;
 231      }
 232  
 233      /**
 234       * Adds a document to the search engine.
 235       *
 236       * This does not commit to the search engine.
 237       *
 238       * @param \core_search\document $document
 239       * @param bool $fileindexing True if file indexing is to be used
 240       * @return bool False if the file was skipped or failed, true on success
 241       */
 242      public function add_document($document, $fileindexing = false) {
 243          global $DB;
 244  
 245          $doc = (object)$document->export_for_engine();
 246  
 247          // Moodle's ids using DML are always autoincremented.
 248          $doc->docid = $doc->id;
 249          unset($doc->id);
 250  
 251          $id = $DB->get_field('search_simpledb_index', 'id', array('docid' => $doc->docid));
 252          try {
 253              if ($id) {
 254                  $doc->id = $id;
 255                  $DB->update_record('search_simpledb_index', $doc);
 256              } else {
 257                  $DB->insert_record('search_simpledb_index', $doc);
 258              }
 259  
 260          } catch (\dml_exception $ex) {
 261              debugging('dml error while trying to insert document with id ' . $doc->docid . ': ' . $ex->getMessage(),
 262                  DEBUG_DEVELOPER);
 263              return false;
 264          }
 265  
 266          return true;
 267      }
 268  
 269      /**
 270       * Deletes the specified document.
 271       *
 272       * @param string $id The document id to delete
 273       * @return void
 274       */
 275      public function delete_by_id($id) {
 276          global $DB;
 277          $DB->delete_records('search_simpledb_index', array('docid' => $id));
 278      }
 279  
 280      /**
 281       * Delete all area's documents.
 282       *
 283       * @param string $areaid
 284       * @return void
 285       */
 286      public function delete($areaid = null) {
 287          global $DB;
 288          if ($areaid) {
 289              $DB->delete_records('search_simpledb_index', array('areaid' => $areaid));
 290          } else {
 291              $DB->delete_records('search_simpledb_index');
 292          }
 293      }
 294  
 295      /**
 296       * Checks that the required table was installed.
 297       *
 298       * @return true|string Returns true if all good or an error string.
 299       */
 300      public function is_server_ready() {
 301          global $DB;
 302          if (!$DB->get_manager()->table_exists('search_simpledb_index')) {
 303              return 'search_simpledb_index table does not exist';
 304          }
 305  
 306          return true;
 307      }
 308  
 309      /**
 310       * It is always installed.
 311       *
 312       * @return true
 313       */
 314      public function is_installed() {
 315          return true;
 316      }
 317  
 318      /**
 319       * Returns the total results.
 320       *
 321       * Including skipped results.
 322       *
 323       * @return int
 324       */
 325      public function get_query_total_count() {
 326          if (!is_null($this->totalresults)) {
 327              // This is a just in case as we count total results in execute_query.
 328              return \core_search\manager::MAX_RESULTS;
 329          }
 330  
 331          return $this->totalresults;
 332      }
 333  
 334      /**
 335       * Returns the default query for db engines.
 336       *
 337       * @param string $q The query string
 338       * @return array SQL string and params list
 339       */
 340      protected function get_simple_query($q) {
 341          global $DB;
 342  
 343          $sql = '(' .
 344              $DB->sql_like('title', '?', false, false) . ' OR ' .
 345              $DB->sql_like('content', '?', false, false) . ' OR ' .
 346              $DB->sql_like('description1', '?', false, false) . ' OR ' .
 347              $DB->sql_like('description2', '?', false, false) .
 348              ')';
 349  
 350          // Remove quotes from the query.
 351          $q = str_replace('"', '', $q);
 352          $params = [
 353              '%' . $q . '%',
 354              '%' . $q . '%',
 355              '%' . $q . '%',
 356              '%' . $q . '%'
 357          ];
 358  
 359          return array($sql, $params);
 360      }
 361  
 362      /**
 363       * Simpledb supports deleting the index for a context.
 364       *
 365       * @param int $oldcontextid Context that has been deleted
 366       * @return bool True to indicate that any data was actually deleted
 367       * @throws \core_search\engine_exception
 368       */
 369      public function delete_index_for_context(int $oldcontextid) {
 370          global $DB;
 371          try {
 372              $DB->delete_records('search_simpledb_index', ['contextid' => $oldcontextid]);
 373          } catch (\dml_exception $e) {
 374              throw new \core_search\engine_exception('dbupdatefailed');
 375          }
 376          return true;
 377      }
 378  
 379      /**
 380       * Simpledb supports deleting the index for a course.
 381       *
 382       * @param int $oldcourseid
 383       * @return bool True to indicate that any data was actually deleted
 384       * @throws \core_search\engine_exception
 385       */
 386      public function delete_index_for_course(int $oldcourseid) {
 387          global $DB;
 388          try {
 389              $DB->delete_records('search_simpledb_index', ['courseid' => $oldcourseid]);
 390          } catch (\dml_exception $e) {
 391              throw new \core_search\engine_exception('dbupdatefailed');
 392          }
 393          return true;
 394      }
 395  }