Support for flock().
$operation: One of the following:
Always returns TRUE at the present time.
Overrides StreamWrapperInterface::stream_lock
http://php.net/manual/streamwrapper.stream-lock.php
public function stream_lock($operation) {
if (in_array($operation, array(
LOCK_SH,
LOCK_EX,
LOCK_UN,
LOCK_NB,
))) {
return flock($this->handle, $operation);
}
return TRUE;
}