55 lines
1.8 KiB
Python
55 lines
1.8 KiB
Python
import socket
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from time import sleep
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from redis.exceptions import ConnectionError, TimeoutError
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class Retry:
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"""Retry a specific number of times after a failure"""
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def __init__(
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self,
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backoff,
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retries,
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supported_errors=(ConnectionError, TimeoutError, socket.timeout),
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):
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"""
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Initialize a `Retry` object with a `Backoff` object
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that retries a maximum of `retries` times.
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`retries` can be negative to retry forever.
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You can specify the types of supported errors which trigger
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a retry with the `supported_errors` parameter.
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"""
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self._backoff = backoff
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self._retries = retries
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self._supported_errors = supported_errors
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def update_supported_errors(self, specified_errors: list):
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"""
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Updates the supported errors with the specified error types
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"""
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self._supported_errors = tuple(
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set(self._supported_errors + tuple(specified_errors))
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)
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def call_with_retry(self, do, fail):
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"""
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Execute an operation that might fail and returns its result, or
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raise the exception that was thrown depending on the `Backoff` object.
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`do`: the operation to call. Expects no argument.
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`fail`: the failure handler, expects the last error that was thrown
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"""
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self._backoff.reset()
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failures = 0
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while True:
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try:
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return do()
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except self._supported_errors as error:
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failures += 1
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fail(error)
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if self._retries >= 0 and failures > self._retries:
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raise error
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backoff = self._backoff.compute(failures)
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if backoff > 0:
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sleep(backoff)
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