private function open()
{
if (!\Sauce\Path::check($this->filename, 'f', 'w')) {
if (!($this->file = fopen($this->filename, 'a'))) {
throw new \Exception('Log file is not writable (' . $this->filename . ').');
}
} else {
$this->file = fopen($this->filename, 'a');
}
if (!is_resource($this->file)) {
throw new \Exception('Log file resource is not valid anymore');
}
}
