public void Add_WithCounterAtMaxValue_ShouldRemainConstant()
{
var filter = new CountingBloomFilter <int>(50, 0.01);
while (filter.CounterAt(42) < byte.MaxValue)
{
filter.Add(42);
}
filter.Add(42); // one additional add to attempt to roll over byte.maxvalue
Assert.True(filter.Contains(42));
}
public void Remove_RemovedItemIsNotPresent()
{
CountingBloomFilter bf = new CountingBloomFilter(10, 0.001);
bf.Add("a");
bf.Add("a");
Assert.IsTrue(bf.IsPresent("a"));
bf.Remove("a");
Assert.IsFalse(bf.IsPresent("a"));
}
public void Remove_WithItemInCollection_ShouldReturnTrue()
{
var filter = new CountingBloomFilter <int>(100, 0.2);
filter.Add(27);
Assert.True(filter.Remove(27));
}
public void Contains_WhenItemHasBeenAdded_ShouldReturnTrue()
{
var filter = new CountingBloomFilter <int>(50, 0.02);
filter.Add(42);
Assert.True(filter.Contains(42));
}
public void AddAndCheck_WhenItemHasBeenAddedBefore_ShouldReturnTrue()
{
var filter = new CountingBloomFilter <int>(50, 0.02);
filter.Add(42);
Assert.True(filter.AddAndCheck(42));
}
public void Remove_WithItemInCollection_ShouldRemoveItemFromCollection()
{
var filter = new CountingBloomFilter <int>(100, 0.2);
filter.Add(27);
filter.Remove(27);
Assert.False(filter.Contains(27));
}
public Property Remove_WithItemInCollection_ShouldReturnTrue()
{
return(Prop.ForAll(Arb.Default.Int32(), testData =>
{
var filter = new CountingBloomFilter <int>(100, 0.2, ByteConverter);
filter.Add(testData);
return filter.Remove(testData).ToProperty();
}));
}
public Property Contains_WhenItemHasBeenAdded_ShouldReturnTrue()
{
return(Prop.ForAll(Arb.Default.Int32(), testData =>
{
var filter = new CountingBloomFilter <int>(50, 0.02, ByteConverter);
filter.Add(testData);
return filter.Contains(testData).ToProperty();
}));
}
public Property AddAndCheck_WhenItemHasBeenAddedBefore_ShouldReturnTrue()
{
return(Prop.ForAll(Arb.Default.Int32(), testData =>
{
var filter = new CountingBloomFilter <int>(50, 0.02, ByteConverter);
filter.Add(testData);
(filter.AddAndCheck(testData)).ToProperty();
}));
}
public void CountingBloomFilter()
{
CountingBloomFilter <int> filter = new CountingBloomFilter <int>(10, 2);
Assert.IsFalse(filter.Add(10));
Assert.IsTrue(filter.Contains(10));
Assert.IsTrue(filter.Remove(10));
Assert.IsFalse(filter.Contains(10));
}
public void CountingBloomFilter()
{
CountingBloomFilter<int> filter = new CountingBloomFilter<int>(10, 2);
Assert.IsFalse(filter.Add(10));
Assert.IsTrue(filter.Contains(10));
Assert.IsTrue(filter.Remove(10));
Assert.IsFalse(filter.Contains(10));
}
public void Contains_With5PercentFalsePositives_ShouldHaveLessThan5PercentErrors(int stepRange, double errorRate)
{
var filter = new CountingBloomFilter <int>(stepRange, errorRate);
foreach (var num in Enumerable.Range(1, stepRange))
{
filter.Add(num);
}
var errorCount = Enumerable.Range(stepRange + 1, stepRange * 2).Count(num => filter.Contains(num));
Assert.InRange(errorCount, 0d, errorRate * stepRange);
}
public void Contains_WhenItemHasBeenAdded_AndFilterHasBeenSerializedAndUnserialized_ShouldReturnTrue()
{
using (var stream = new MemoryStream())
{
var filterOld = new CountingBloomFilter <int>(50, 0.02);
filterOld.Add(42);
IFormatter formatter = new BinaryFormatter();
formatter.Serialize(stream, filterOld);
stream.Flush();
stream.Position = 0;
CountingBloomFilter <int> filterNew = (CountingBloomFilter <int>)formatter.Deserialize(stream);
Assert.True(filterNew.Contains(42));
}
}
public Property Contains_With5PercentFalsePositives_ShouldHaveLessThan5PercentErrors()
{
return(Prop.ForAll(Arb.From(Gen.Choose(1, 5000)), Arb.From(Gen.Choose(1, 99)), (stepRange, errorRate) =>
{
var filter = new CountingBloomFilter <int>(stepRange, errorRate / 100d, ByteConverter);
foreach (var num in Enumerable.Range(1, stepRange))
{
filter.Add(num);
}
var errorCount = Enumerable.Range(stepRange + 1, stepRange * 2).Count(num => filter.Contains(num));
var highError = errorRate * stepRange;
(0 <= errorCount && errorCount <= highError).ToProperty();
}));
}
public void RollbackWhenRemovingANonExistantItem()
{
var a = new CountingBloomFilter <int>(1000, 0.01f);
for (var i = 0; i < 1000; i++)
{
a.Add(i);
}
byte[] copy = (byte[])a.Array.Clone();
Assert.IsFalse(a.Remove(1001));
for (int i = 0; i < a.Array.Length; i++)
{
Assert.AreEqual(a.Array[i], copy[i]);
}
}
public void Remove_RemovedItemIsNotPresent()
{
CountingBloomFilter bf = new CountingBloomFilter(10, 0.001);
bf.Add("a");
bf.Add("a");
Assert.IsTrue(bf.IsPresent("a"));
bf.Remove("a");
Assert.IsFalse(bf.IsPresent("a"));
}