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venv/lib/python3.9/site-packages/pip/_internal/utils/retry.py

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+import functools
+from time import perf_counter, sleep
+from typing import Callable, TypeVar
+
+from pip._vendor.typing_extensions import ParamSpec
+
+T = TypeVar("T")
+P = ParamSpec("P")
+
+
+def retry(
+    wait: float, stop_after_delay: float
+) -> Callable[[Callable[P, T]], Callable[P, T]]:
+    """Decorator to automatically retry a function on error.
+
+    If the function raises, the function is recalled with the same arguments
+    until it returns or the time limit is reached. When the time limit is
+    surpassed, the last exception raised is reraised.
+
+    :param wait: The time to wait after an error before retrying, in seconds.
+    :param stop_after_delay: The time limit after which retries will cease,
+        in seconds.
+    """
+
+    def wrapper(func: Callable[P, T]) -> Callable[P, T]:
+
+        @functools.wraps(func)
+        def retry_wrapped(*args: P.args, **kwargs: P.kwargs) -> T:
+            # The performance counter is monotonic on all platforms we care
+            # about and has much better resolution than time.monotonic().
+            start_time = perf_counter()
+            while True:
+                try:
+                    return func(*args, **kwargs)
+                except Exception:
+                    if perf_counter() - start_time > stop_after_delay:
+                        raise
+                    sleep(wait)
+
+        return retry_wrapped
+
+    return wrapper