public function DatabaseBackend::getMultiple

Implements Drupal\Core\Cache\CacheBackendInterface::getMultiple().

Overrides CacheBackendInterface::getMultiple

File

drupal/core/lib/Drupal/Core/Cache/DatabaseBackend.php, line 54

Definition of Drupal\Core\Cache\DatabaseBackend.

Class

DatabaseBackend

Defines a default cache implementation.

Namespace

Code

public function getMultiple(&$cids, $allow_invalid = FALSE) {
  try {

    // When serving cached pages, the overhead of using ::select() was found
    // to add around 30% overhead to the request. Since $this->bin is a
    // variable, this means the call to ::query() here uses a concatenated
    // string. This is highly discouraged under any other circumstances, and
    // is used here only due to the performance overhead we would incur
    // otherwise. When serving an uncached page, the overhead of using
    // ::select() is a much smaller proportion of the request.
    $result = Database::getConnection()
      ->query('SELECT cid, data, created, expire, serialized, tags, checksum_invalidations, checksum_deletions FROM {' . Database::getConnection()
      ->escapeTable($this->bin) . '} WHERE cid IN (:cids)', array(
      ':cids' => $cids,
    ));
    $cache = array();
    foreach ($result as $item) {
      $item = $this
        ->prepareItem($item, $allow_invalid);
      if ($item) {
        $cache[$item->cid] = $item;
      }
    }
    $cids = array_diff($cids, array_keys($cache));
    return $cache;
  } catch (Exception $e) {

    // If the database is never going to be available, cache requests should
    // return FALSE in order to allow exception handling to occur.
    return array();
  }
}