class BloomFilter():
def __init__(self, *hash_functions, **kwds):
""" @param max_size: In bytes
"""
self.__bitset = BitSet()
if not hash_functions:
hash_functions = (object_hash, object_repr_hash, object_str_hash, object_id)
self.__hash_functions = hash_functions
max_size = kwds.get("max_size", 1024)
itemsize = self.__bitset.itemsize
self.__max_bits = int(itemsize * ceil(float(max_size) / itemsize)) << 3
def extend(self, values):
map(self.add, values)
def __get_bit_indexes_of(self, value):
return (hf(value) % self.__max_bits for hf in self.__hash_functions)
def add(self, value):
indexes_to_set = self.__get_bit_indexes_of(value)
self.__bitset.set_indexes(indexes_to_set)
def __contains__(self, value):
indexes_to_get = self.__get_bit_indexes_of(value)
bits = (index in self.__bitset for index in indexes_to_get)
return all(bits)
def __len__(self):
return len(self.__bitset) >> 3
def __repr__(self):
return "BloomFilter (%s bytes): %s" % (len(self), self.__bitset)
def __init__(self, *hash_functions, **kwds):
""" @param max_size: In bytes
"""
self.__bitset = BitSet()
if not hash_functions:
hash_functions = (object_hash, object_repr_hash, object_str_hash, object_id)
self.__hash_functions = hash_functions
max_size = kwds.get("max_size", 1024)
itemsize = self.__bitset.itemsize
self.__max_bits = int(itemsize * ceil(float(max_size) / itemsize)) << 3
def do_assignment(repeats=10, size=5000, m=16):
med = 0
maximals = []
print("Number of non-dominated BitStrings: ")
for _ in range(repeats):
bset = BitSet(size, m)
bset.find_dominated()
maximal = len(bset.no_dom)
maximals.append(maximal)
print(maximal, sep=' ', end=' ', flush=True)
print()
med = median(maximals)
print("Approximation of E[M_n]: ", med)
results = "Bits in a string: {}\nSet size: {}\nNumber of sets: {}\nApproximation of E[M_n]: {}\n----\n"
with open("generated.txt", "a+") as file:
file.write(results.format(m, size, repeats, med))
def load_name_index(cls, bits):
result = {} # string -> int
ver = bits.read_int32() # 0..3 Version
sig = bits.read_int32() # 4..7 Signature
age = bits.read_int32() # 8..11 Age
guid = bits.read_guid() # 12..27 GUID
#if ver != 20000404:
# raise PdbDebugException('Unsupported PDB Stream version {%u' % ver)
# Read string buffer.
buf = bits.read_int32() # 28..31 Bytes of Strings
beg = bits.position
nxt = bits.position + buf
bits.position = nxt
# Read map index.
cnt = bits.read_int32() # n+0..3 hash size.
mx = bits.read_int32() # n+4..7 maximum ni.
present = BitSet(bits)
deleted = BitSet(bits)
if not deleted.is_empty():
raise PdbDebugException('Unsupported PDB deleted bitset is not empty.')
j = 0;
for i in range(0, mx):
if present.is_set(i):
ns = bits.read_int32()
ni = bits.read_int32()
saved = bits.position
bits.position = beg + ns
name = bits.read_cstring()
bits.position = saved
result[name.upper()] = ni
j += 1
if j != cnt:
raise PdbDebugException('Count mismatch. (%u != %u)' % (j, cnt))
return (result, ver, sig, age, guid)
def load_name_index(cls, bits):
result = {} # string -> int
ver = bits.read_int32() # 0..3 Version
sig = bits.read_int32() # 4..7 Signature
age = bits.read_int32() # 8..11 Age
guid = bits.read_guid() # 12..27 GUID
#if ver != 20000404:
# raise PdbDebugException('Unsupported PDB Stream version {%u' % ver)
# Read string buffer.
buf = bits.read_int32() # 28..31 Bytes of Strings
beg = bits.position
nxt = bits.position + buf
bits.position = nxt
# Read map index.
cnt = bits.read_int32() # n+0..3 hash size.
mx = bits.read_int32() # n+4..7 maximum ni.
present = BitSet(bits)
deleted = BitSet(bits)
if not deleted.is_empty():
raise PdbDebugException(
'Unsupported PDB deleted bitset is not empty.')
j = 0
for i in range(0, mx):
if present.is_set(i):
ns = bits.read_int32()
ni = bits.read_int32()
saved = bits.position
bits.position = beg + ns
name = bits.read_cstring()
bits.position = saved
result[name.upper()] = ni
j += 1
if j != cnt:
raise PdbDebugException('Count mismatch. (%u != %u)' % (j, cnt))
return (result, ver, sig, age, guid)
def one_set():
bset = BitSet()
bset.find_dominated()
print(str(bset))
def dotest(l):
l.sort()
x = BitSet()
for i in l:
x[i] = 1
self.assertEqual(x.get_bits(), l)
def find_matches(self, inverted_index):
bitset = BitSet()
bitset.set_indexes(inverted_index.get_doc_ids_with(self._field_id, self._value))
return bitset