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1from __future__ import annotations
3import functools
4from collections.abc import Callable
5from time import perf_counter, sleep
6from typing import TYPE_CHECKING, TypeVar
8if TYPE_CHECKING:
9 from typing_extensions import ParamSpec
11 T = TypeVar("T")
12 P = ParamSpec("P")
15def retry(
16 wait: float, stop_after_delay: float
17) -> Callable[[Callable[P, T]], Callable[P, T]]:
18 """Decorator to automatically retry a function on error.
20 If the function raises, the function is recalled with the same arguments
21 until it returns or the time limit is reached. When the time limit is
22 surpassed, the last exception raised is reraised.
24 :param wait: The time to wait after an error before retrying, in seconds.
25 :param stop_after_delay: The time limit after which retries will cease,
26 in seconds.
27 """
29 def wrapper(func: Callable[P, T]) -> Callable[P, T]:
31 @functools.wraps(func)
32 def retry_wrapped(*args: P.args, **kwargs: P.kwargs) -> T:
33 # The performance counter is monotonic on all platforms we care
34 # about and has much better resolution than time.monotonic().
35 start_time = perf_counter()
36 while True:
37 try:
38 return func(*args, **kwargs)
39 except Exception:
40 if perf_counter() - start_time > stop_after_delay:
41 raise
42 sleep(wait)
44 return retry_wrapped
46 return wrapper