lbry-sdk/lbrynet/dht/distance.py
Lex Berezhny 10b34d6b33
unnecessary list() added during py3 port
instead of recursive bytes2unicode use a proper JSONEncoder to conver bytes->unicode for json.dumps()
removing excessive isinstance(data, bytes) checks
py3: / -> // and list() around .items() that gets modified in loop
moved lbrynet.undecorated to where its actually used and hopefully we can delete it eventually
removed build/upload_assets.py, travis can do all this now
2018-08-24 11:40:43 -04:00

29 lines
885 B
Python

from binascii import hexlify
from lbrynet.dht import constants
class Distance:
"""Calculate the XOR result between two string variables.
Frequently we re-use one of the points so as an optimization
we pre-calculate the value of that point.
"""
def __init__(self, key):
if len(key) != constants.key_bits // 8:
raise ValueError("invalid key length: %i" % len(key))
self.key = key
self.val_key_one = int(hexlify(key), 16)
def __call__(self, key_two):
val_key_two = int(hexlify(key_two), 16)
return self.val_key_one ^ val_key_two
def is_closer(self, a, b):
"""Returns true is `a` is closer to `key` than `b` is"""
return self(a) < self(b)
def to_contact(self, contact):
"""A convenience function for calculating the distance to a contact"""
return self(contact.id)