public function add($key, $value, $ttl = 2592000, $tags = NULL)
{
if (empty($key)) {
return false;
}
$auto_unlocker = NULL;
if (!$this->sem->get_access_write($auto_unlocker)) {
return false;
}
$key = (string) $key;
$this->readmemory();
if (isset($this->mem[self::map_keys][$key])) {
return false;
}
return $this->save($key, $value, $ttl, $tags);
}