如何检查我的Yii2应用程序中的Web进程是否可以写入sqlite数据库文件？

Question

I am developing an Yii2 application and at times, the Sqlite3 file which I use for database, becomes "read only" (due to other stuff happening on the server) and users are getting nasty PHP exception errors instead of a nicely displayed error message. I am trying to use the "beforeSave()" function to check if the databse is writable, but I don't know the best way to check if the web process (www-data) has write access to it. Anyone any ideas? I have the following two functions in my base model:

    public function beforeSave($insert)
    {
        if (parent::beforeSave($insert)) {
            // Check if database is writable
            if($this->attemptDBWrite())
                return true;
            else
            {
                \Yii::$app->getSession()->setFlash('error', 'Database is not writable by the application user');
                return false;
            }
        } else {
            return false;
        }
    }

And the "attemptDBWrite()" function:

    public function attemptDBWrite()
    {
        try {
            $connection = \Yii::$app->db;
            // SOME CODE NEEDED HERE TO CHECK <<<=========
        } catch (\yii\db\Exception $e) {
            \Yii::$app->getSession()->setFlash('error', var_dump($e));
            return false;
        }
    }

Answer 1

 public function attemptDBWrite()
    {
        try {
            $connection = \Yii::$app->db;
            if (is_writable($database_source_path)) {
                return false;
              }
        } catch (\yii\db\Exception $e) {
            \Yii::$app->getSession()->setFlash('error', var_dump($e));
            return false;
        }
    }

$database_source_path - is path of sqlite database file