commit bbe443f58ca5411d20b9aa436542f91c457112e1
Author: nolash <dev@holbrook.no>
Date: Thu, 29 Oct 2020 20:42:41 +0100
Initial commit, add v to filer
Diffstat:
| A | main.py | | | 40 | ++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 40 insertions(+), 0 deletions(-)
diff --git a/main.py b/main.py
@@ -0,0 +1,40 @@
+import numpy
+import hashlib
+import logging
+import math
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+
+class BloomFilter:
+
+ def __init__(self, bits, rounds):
+ self.bits = bits
+ self.bytes = int(bits / 8)
+ if self.bytes * 8 != self.bits:
+ raise ValueError('Need byte boundary bit value')
+ self.rounds = rounds
+ self.filter = numpy.zeros(self.bytes, dtype=numpy.uint8)
+
+
+ def add(self, s):
+ for i in range(self.rounds):
+ salt = str(i)
+ salt_str = salt.encode('utf-8')
+ logg.debug('hashing {} {}'.format(s, salt))
+ h = hashlib.sha256()
+ h.update(s.encode('utf-8'))
+ h.update(salt_str)
+ z = h.digest()
+ r = int.from_bytes(z, byteorder='big')
+ m = r % self.bits
+ bytepos = math.floor(m / 8)
+ bitpos = m % 8
+ self.filter[bytepos] |= 1 << bitpos
+ logg.debug('foo {} {}'.format(bytepos, bitpos))
+ return m
+
+
+f = BloomFilter(8192 * 8, 3)
+f.add('1024')
