def add(self, item):
'''Add an item to the filter'''
for i in range(self.function_count):
seed = i * BIP37_CONSTANT + self.tweak
hash = murmur3(item, seed=seed)
bit = hash % len(self.bit_field)
self.bit_field[bit] = 1
def add(self, item):
# We hash function_count number of times.
for i in range(self.function_count):
# This is the seed formula - page 215.
seed = i * BIP37_CONSTANT + self.tweak
# murmur3 returns a number, so we don't have to convert to an integer.
h = murmur3(item, seed=seed)
bit = h % len(self.bit_field)
self.bit_field[bit] = 1
def add(self, item):
'''Add an item to the filter'''
i = 0
for i in range(self.function_count):
# while i < self.function_count:
dat_spec_seed = i * BIP37_CONSTANT + self.tweak
h = murmur3(item, seed=dat_spec_seed)
bit = h % (self.size * 8)
self.bit_field[bit] = 1
def add(self, item):
'''Add an item to the filter'''
# iterate self.function_count number of times
for i in range(self.function_count):
# BIP0037 spec seed is i*BIP37_CONSTANT + self.tweak
seed = i * BIP37_CONSTANT + self.tweak
# get the murmur3 hash given that seed
h = murmur3(item, seed=seed)
# set the bit at the hash mod the bitfield size (self.size*8)
self.bit_field[h % (self.size * 8)] = 1
def add(self, item):
'''Add an item to the filter'''
# iterate self.function_count number of times
for i in range(self.function_count):
seed = i * BIP37_CONSTANT + tweak
h = murmur3(item, seed=seed)
bit = h % (self.size * 8)
self.bit_field[bit] = 1
# BIP0037 spec seed is i*BIP37_CONSTANT + self.tweak
# get the murmur3 hash given that seed
# set the bit at the hash mod the bitfield size (self.size*8)
# set the bit field at bit to be 1
raise NotImplementedError
def test_example_4(self):
field_size = 2
num_functions = 2
tweak = 42
bit_field_size = field_size * 8
bit_field = [0] * bit_field_size
for phrase in (b'hello world', b'goodbye'):
for i in range(num_functions):
seed = i * BIP37_CONSTANT + tweak
h = murmur3(phrase, seed=seed)
bit = h % bit_field_size
bit_field[bit] = 1
self.assertEqual(bit_field,
[0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0])
def test_exercise_1(self):
field_size = 10
function_count = 5
tweak = 99
items = (b'Hello World', b'Goodbye!')
bit_field_size = field_size * 8
bit_field = [0] * bit_field_size
for item in items:
for i in range(function_count):
seed = i * BIP37_CONSTANT + tweak
h = murmur3(item, seed=seed)
bit = h % bit_field_size
bit_field[bit] = 1
self.assertEqual(
bit_field_to_bytes(bit_field).hex(), '4000600a080000010940')
def add(self, item):
for i in range(self.function_count):
seed = i * BIP37_CONSTANT + self.tweak
h = murmur3(item, seed=seed)
bit = h % (self.size * 8)
self.bit_field[bit] = 1
from helper import murmur3
from bloomfilter import BIP37_CONSTANT
field_size = 10
num_functions = 5
tweak = 99
bit_field_size = field_size * 8
bit_field = [0] * bit_field_size
for phrase in (b'Hello World', b'Goodbye!'):
for i in range(num_functions):
seed = i * BIP37_CONSTANT + tweak
h = murmur3(phrase, seed=seed)
bit = h % bit_field_size
bit_field[bit] = 1
print(bit_field)
