forked from LBRYCommunity/lbry-sdk
24 lines
759 B
Python
24 lines
759 B
Python
from lbrynet.dht import constants
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class Distance:
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"""Calculate the XOR result between two string variables.
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Frequently we re-use one of the points so as an optimization
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we pre-calculate the value of that point.
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"""
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def __init__(self, key: bytes):
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if len(key) != constants.hash_length:
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raise ValueError("invalid key length: %i" % len(key))
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self.key = key
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self.val_key_one = int.from_bytes(key, 'big')
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def __call__(self, key_two: bytes) -> int:
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val_key_two = int.from_bytes(key_two, 'big')
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return self.val_key_one ^ val_key_two
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def is_closer(self, a: bytes, b: bytes) -> bool:
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"""Returns true is `a` is closer to `key` than `b` is"""
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return self(a) < self(b)
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