def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def _ignoring_sigint(self):
        with self._ignore_sigint_lock:
            self._check_sigint_gate_is_correct()
            self._threads_ignoring_sigint += 1
        try:
            yield
        finally:
            with self._ignore_sigint_lock:
                self._threads_ignoring_sigint -= 1
                self._check_sigint_gate_is_correct()