warden_server.py 文件源码

def __exit__(self, exc_type, exc_val, exc_tb):
        """ Context manager protocol. If db exception is fired and
            self.retry_attempt is not zero, it is only logged and
            does not propagate, otherwise it propagates up. Also
            open transaction is rolled back.
            In case of no exception, transaction gets commited.
        """
        if not exc_type:
            self.con.commit()
            self.retry_attempt = 0
        else:
            try:
                if self.con:
                    self.con.rollback()
            except my.Error:
                pass
            try:
                self.close()
            except my.Error:
                pass
            if self.retry_attempt:
                self.log.info("Database error (%d attempts left): %s %s" % (self.retry_attempt, exc_type.__name__, exc_val))
                return True