public void TestStablePoint()
{
var f = StableBloomFilter.NewDefaultStableBloomFilter(10000, 0.1);
for (int i = 0; i < 1000000; i++)
{
f.TestAndAdd(Encoding.ASCII.GetBytes(i.ToString()));
}
var zeros = 0;
for (uint i = 0; i < f.M; i++)
{
if (f.cells.Get(i) == 0)
{
zeros++;
}
}
var actual = Math.Round((double)((double)zeros / (double)f.M), 1, MidpointRounding.AwayFromZero);
var expected = Math.Round(f.StablePoint(), 1, MidpointRounding.AwayFromZero);
Assert.AreEqual(expected, actual);
// A classic Bloom filter is a special case of SBF where P is 0 and max is 1.
// It doesn't have a stable point.
var bf = StableBloomFilter.NewUnstableBloomFilter(1000, 0.1);
var stablePoint = bf.StablePoint();
if (stablePoint != 0)
{
Assert.Fail(string.Format("Expected stable point 0, got {0}", stablePoint));
}
}
public void Testinitialize()
{
n = 100000;
f = StableBloomFilter.NewDefaultStableBloomFilter(n, 0.01);
data = new byte[n][];
for (int i = 0; i < n; i++)
{
data[i] = Encoding.ASCII.GetBytes(i.ToString());
}
}
public void TestStableFalsePositiveRate()
{
var f = StableBloomFilter.NewDefaultStableBloomFilter(1000, 0.01);
var fps = Math.Round(f.FalsePositiveRate(), 2, MidpointRounding.AwayFromZero);
Assert.IsFalse(fps > 0.01);
// Classic Bloom filters have an unbound rate of false positives. Once they
// become full, every query returns a false positive.
var bf = StableBloomFilter.NewUnstableBloomFilter(1000, 0.01);
fps = bf.FalsePositiveRate();
Assert.AreEqual(1.0, fps);
}
public void TestStableReset()
{
var f = StableBloomFilter.NewDefaultStableBloomFilter(1000, 0.01);
for (int i = 0; i < 1000; i++)
{
f.TestAndAdd(Encoding.ASCII.GetBytes(i.ToString()));
}
var resetF = f.Reset();
Assert.AreSame(f, resetF, "Returned StableBloomFilter should be the same instance");
for (uint i = 0; i < f.M; i++)
{
var cell = f.cells.Get(i);
if (cell != 0)
{
Assert.Fail(string.Format("Expected zero cell, got {0}", cell));
}
}
}
public void TestStableTestAndAdd()
{
var f = StableBloomFilter.NewDefaultStableBloomFilter(10000, 0.01);
// 'a' is not in the filter.
if (f.Test(A_BYTES))
{
Assert.Fail("'a' should not be a member");
}
var addedF = f.Add(A_BYTES);
Assert.AreSame(f, addedF, "Returned StableBloomFilter should be the same instance");
// 'a' is now in the filter.
if (!f.Test(A_BYTES))
{
Assert.Fail("'a' should be a member");
}
// 'a' is still in the filter.
if (!f.TestAndAdd(A_BYTES))
{
Assert.Fail("'a' should be a member");
}
// 'b' is not in the filter.
if (f.TestAndAdd(B_BYTES))
{
Assert.Fail("'b' should not be a member");
}
// 'a' is still in the filter.
if (!f.Test(A_BYTES))
{
Assert.Fail("'a' should be a member");
}
// 'b' is now in the filter.
if (!f.Test(B_BYTES))
{
Assert.Fail("'b' should be a member");
}
// 'c' is not in the filter.
if (f.Test(C_BYTES))
{
Assert.Fail("'c' should not be a member");
}
for (int i = 0; i < 1000000; i++)
{
f.TestAndAdd(Encoding.ASCII.GetBytes(i.ToString()));
}
// 'a' should have been evicted
if (f.Test(A_BYTES))
{
Assert.Fail("'a' should not be a member");
}
}