__init__.py 文件源码

def _get_waiting_in_secs(waiting_in_secs,
                             num_retries,
                             max_waiting_in_secs):
        """Retrieve the waiting time in seconds.

        This method uses exponential back-off in figuring out the number of
        seconds to wait; however, the max wait time shouldn't be more than
        what is specified via max_waiting_in_seconds.

        Args:
            waiting_in_secs: waiting time in seconds.
            num_retries: number of retries, starting from 0.
            max_waiting_in_secs: maximum waiting time in seconds.

        Returns:
            The number of seconds to wait.

        """
        # make the backoff going up even faster
        waiting_in_secs *= 2**num_retries
        jitter = waiting_in_secs * 0.2
        waiting_in_secs += random.triangular(-jitter, jitter)
        return min(waiting_in_secs, max_waiting_in_secs)