function DrupalDatabaseCache::getMultiple

DrupalDatabaseCache::getMultiple(&$cids)

Implements DrupalCacheInterface::getMultiple().

Overrides DrupalCacheInterface::getMultiple

File

includes/cache.inc, line 337

Functions and interfaces for cache handling.

Class

DrupalDatabaseCache

Defines a default cache implementation.

Code

function getMultiple(&$cids) {
  try {
    // Garbage collection necessary when enforcing a minimum cache lifetime.
    $this->garbageCollection($this->bin);

    // When serving cached pages, the overhead of using db_select() was found
    // to add around 30% overhead to the request. Since $this->bin is a
    // variable, this means the call to db_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
    // db_select() is a much smaller proportion of the request.
    $result = db_query('SELECT cid, data, created, expire, serialized FROM {' . db_escape_table($this->bin) . '} WHERE cid IN (:cids)', array(':cids' => $cids));
    $cache = array();
    foreach ($result as $item) {
      $item = $this->prepareItem($item);
      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();
  }
}