twisted.py 文件源码

def retries(timeout=30, intervals=1, clock=reactor):
    """Helper for retrying something, sleeping between attempts.

    Returns a generator that yields ``(elapsed, remaining, wait)`` tuples,
    giving times in seconds. The last item, `wait`, is the suggested amount of
    time to sleep before trying again.

    :param timeout: From now, how long to keep iterating, in seconds. This can
        be specified as a number, or as an iterable. In the latter case, the
        iterator is advanced each time an interval is needed. This allows for
        back-off strategies.
    :param intervals: The sleep between each iteration, in seconds, an an
        iterable from which to obtain intervals.
    :param clock: An optional `IReactorTime` provider. Defaults to the
        installed reactor.
    """
    start = clock.seconds()
    end = start + timeout

    if isinstance(intervals, Iterable):
        intervals = iter(intervals)
    else:
        intervals = repeat(intervals)

    return gen_retries(start, end, intervals, clock)