66 lines
1.7 KiB
Python
66 lines
1.7 KiB
Python
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from __future__ import annotations
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import asyncio
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import random
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import time
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from dataclasses import dataclass
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@dataclass
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class BackoffConfig:
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base_seconds: float = 5.0
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max_seconds: float = 300.0
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jitter_pct: float = 0.2
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multiplier: float = 2.0
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class ExponentialBackoff:
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def __init__(self, config: BackoffConfig | None = None):
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self._config = config or BackoffConfig()
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self._attempt = 0
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self._last_attempt_time: float = 0
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@property
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def attempt(self) -> int:
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return self._attempt
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@property
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def next_delay(self) -> float:
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if self._attempt == 0:
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return 0
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base = min(
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self._config.base_seconds * (self._config.multiplier ** (self._attempt - 1)),
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self._config.max_seconds,
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)
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jitter = base * self._config.jitter_pct * (random.random() * 2 - 1)
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return base + jitter
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def reset(self) -> None:
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self._attempt = 0
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self._last_attempt_time = 0
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def mark_attempt(self) -> None:
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self._attempt += 1
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self._last_attempt_time = time.monotonic()
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async def wait(self) -> None:
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delay = self.next_delay
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if delay > 0:
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await asyncio.sleep(delay)
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async def execute(self, func, *args, **kwargs):
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while True:
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try:
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self.mark_attempt()
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return await func(*args, **kwargs)
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except Exception as e:
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if not _is_retryable(e):
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raise
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if self.next_delay >= self._config.max_seconds:
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raise
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await self.wait()
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def _is_retryable(exception: Exception) -> bool:
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return getattr(exception, "retryable", False)
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