示例#1
0
def test_repr():
    bf = BloomFilter(8000, 3)

    assert repr(bf) == "<BloomFilter (length: 8000, hashes: 3)>"

    bf = BloomFilter.create_from_capacity(5000, 0.02)

    assert repr(bf) == "<BloomFilter (length: 40712, hashes: 5)>"
示例#2
0
def test_count_when_full():
    length = 8
    num_of_hashes = 2

    bf = BloomFilter(length, num_of_hashes)

    # We index 20 strings to kind of guarantee that
    # filter of length 8 is full afterwards.
    # NOTE: In perfect situation, only 4 items are required,
    # but we don't know which ones.
    for i in range(20):
        bf.add("test{}".format(i))

    assert bf.count() == length / num_of_hashes
示例#3
0
def test_init_from_capacity():
    bf = BloomFilter.create_from_capacity(5000, 0.02)
    assert bf.sizeof() == 5089, "Unexpected size in bytes"

    with pytest.raises(ValueError) as excinfo:
        bf = BloomFilter.create_from_capacity(5000, 2)
    assert str(excinfo.value) == 'Error rate shell be in (0, 1)'

    with pytest.raises(ValueError) as excinfo:
        bf = BloomFilter.create_from_capacity(0, 0.02)
    assert str(excinfo.value) == 'Filter capacity can\'t be 0 or negative'

    bf = BloomFilter.create_from_capacity(5000, 0.999)
    assert len(bf) == 16
示例#4
0
def test_init():
    bf = BloomFilter(8000, 3)
    assert bf.sizeof() == 1000, "Unexpected size in bytes"

    with pytest.raises(ValueError) as excinfo:
        bf = BloomFilter(8000, 0)
    assert str(excinfo.value) == 'At least one hash function is required'

    with pytest.raises(ValueError) as excinfo:
        bf = BloomFilter(0, 5)
    assert str(excinfo.value) == 'Filter length can\'t be 0 or negative'
示例#5
0
def test_len():
    bf = BloomFilter(8000, 3)
    assert len(bf) == 8000

    bf = BloomFilter(8001, 3)
    assert len(bf) == 8008
示例#6
0
def test_count():
    bf = BloomFilter(8000, 3)
    assert bf.count() == 0

    bf.add("test")
    assert bf.count() == 1

    bf.add("test")
    assert bf.count() == 1

    bf.add("test2")
    assert bf.count() == 2
示例#7
0
def test_lookup():
    bf = BloomFilter(8000, 3)

    bf.add("test")
    assert bf.test("test") == 1, "Can't find recently added element"
    assert bf.test("test_test") == 0, "False positive detected"
示例#8
0
def test_add():
    bf = BloomFilter(8000, 3)

    for word in ["test", 1, {"hello": "world"}]:
        bf.add(word)
        assert bf.test(word) == 1, "Can't find recently added element"
示例#9
0
"""Example how to use Classical Bloom Filter."""

from pdsa.membership.bloom_filter import BloomFilter

LOREM_IPSUM = (
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit."
    " Mauris consequat leo ut vehicula placerat. In lacinia, nisl"
    " id maximus auctor, sem elit interdum urna, at efficitur tellus"
    " turpis at quam. Pellentesque eget iaculis turpis. Nam ac ligula"
    " ut nunc porttitor pharetra in non lorem. In purus metus,"
    " sollicitudin tristique sapien.")

if __name__ == '__main__':
    bf = BloomFilter(80000, 4)

    print(bf)
    print("Bloom filter uses {} bytes in the memory".format(bf.sizeof()))

    print("Filter contains approx. {} unique elements".format(bf.count()))

    print("'Lorem' {} in the filter".format(
        "is" if bf.test("Lorem") else "is not"))

    words = set(LOREM_IPSUM.split())
    for word in words:
        bf.add(word.strip(" .,"))

    print("Added {} words, in the filter approx. {} unique elements".format(
        len(words), bf.count()))

    print("'Lorem' {} in the filter".format(