public function getLock($tag)
{
if ($this->_locks === null) {
$locksFile = $this->logPath . '/locks.data';
if (is_file($locksFile)) {
$this->_locks = array_flip(unserialize(file_get_contents($locksFile)));
} else {
$this->_locks = array();
}
}
return isset($this->_locks[$tag]);
}