49 lines
1.5 KiB
Python
49 lines
1.5 KiB
Python
import random
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def expo(n: int, base=2, factor=1, max_value=None):
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"""Exponential decay.
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Adapted from https://github.com/litl/backoff/blob/master/backoff.py (MIT License)
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Args:
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base: The mathematical base of the exponentiation operation
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factor: Factor to multiply the exponentation by.
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max_value: The maximum value to yield. Once the value in the
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true exponential sequence exceeds this, the value
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of max_value will forever after be yielded.
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"""
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a = factor * base ** n
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if max_value is None or a < max_value:
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return a
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else:
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return max_value
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def random_jitter(value, jitter=1):
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"""Jitter the value a random number of milliseconds.
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Copied from https://github.com/litl/backoff/blob/master/backoff.py (MIT License)
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This adds up to 1 second of additional time to the original value.
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Prior to backoff version 1.2 this was the default jitter behavior.
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Args:
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value: The unadulterated backoff value.
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"""
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return value + random.uniform(0, jitter)
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def full_jitter(value):
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"""Jitter the value across the full range (0 to value).
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Copied from https://github.com/litl/backoff/blob/master/backoff.py (MIT License)
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This corresponds to the "Full Jitter" algorithm specified in the
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AWS blog's post on the performance of various jitter algorithms.
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(http://www.awsarchitectureblog.com/2015/03/backoff.html)
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Args:
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value: The unadulterated backoff value.
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"""
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return random.uniform(0, value)
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