43 lines
1.1 KiB
Python
43 lines
1.1 KiB
Python
from ..logger import getLogger
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MAX_FACTOR = 20 # avoid weirdness with python's arbitary integer precision
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MAX_WAIT = 60 * 60 # 1 hour
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logger = getLogger(__name__)
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class Backoff():
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def __init__(self, initial=None, base=2, exp=2, max=MAX_WAIT, attempts=None):
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self._attempts = attempts
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self._initial = initial
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self._start = base
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self._max = max
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self._exp = exp
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self._counter = 0
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def reset(self):
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self._counter = 0
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def peek(self):
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exp = self._counter - 1
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if self._counter == 1 and self._initial is not None:
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return self._initial
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elif self._initial is not None:
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exp -= 1
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exp = min(exp, MAX_FACTOR)
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computed = self._start * pow(self._exp, exp)
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if self._max:
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computed = min(self._max, computed)
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return computed
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def backoff(self, error):
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if self._attempts and self._counter >= self._attempts:
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raise error
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self._counter += 1
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return self.peek()
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def maxOut(self):
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self._counter = 100
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