public CountMinSketchState(
CountMinSketchStateHashes hashes,
CountMinSketchStateTopk topk)
{
Hashes = hashes;
Topk = topk;
}
private void Add(
CountMinSketchStateHashes state,
string item,
long count)
{
state.Add(GetBytes(item), count);
}
public static CountMinSketchState MakeState(CountMinSketchSpec spec)
{
var hashes = CountMinSketchStateHashes.MakeState(spec.HashesSpec);
CountMinSketchStateTopk topk = null;
if (spec.TopkSpec != null && spec.TopkSpec > 0) {
topk = new CountMinSketchStateTopk(spec.TopkSpec.Value);
}
return new CountMinSketchState(hashes, topk);
}
public void TestSimpleFlow()
{
var state = CountMinSketchStateHashes.MakeState(DefaultSpec);
Add(state, "hello", 100);
Assert.AreEqual(100, EstimateCount(state, "hello"));
Add(state, "text", 1);
Assert.AreEqual(1, EstimateCount(state, "text"));
Add(state, "hello", 3);
Assert.AreEqual(103, EstimateCount(state, "hello"));
Assert.AreEqual(1, EstimateCount(state, "text"));
}
private long EstimateCount(
CountMinSketchStateHashes state,
string item)
{
return(state.EstimateCount(GetBytes(item)));
}
public void TestSpace()
{
var eps = 0.001;
var confidence = 0.999;
var space = 2000;
var points = 100000;
var randomized = true;
var random = new Random();
var spec = new CountMinSketchSpecHashes(eps, confidence, 123456);
var state = CountMinSketchStateHashes.MakeState(spec);
IDictionary <ByteBuffer, long> sent = new Dictionary <ByteBuffer, long>();
for (var i = 0; i < points; i++)
{
ByteBuffer bytes;
if (randomized)
{
bytes = TestCountMinSketchStateTopK.GenerateBytesRandom(random, space);
}
else
{
bytes = TestCountMinSketchStateTopK.GenerateBytesModulo(i, space);
}
state.Add(bytes.Array, 1);
if (!sent.TryGetValue(bytes, out var count))
{
sent.Put(bytes, 1L);
}
else
{
sent.Put(bytes, count + 1);
}
if (i > 0 && i % 100000 == 0)
{
Console.Out.WriteLine("Completed " + i);
}
}
// compare
var errors = 0;
foreach (var entry in sent)
{
var frequency = state.EstimateCount(entry.Key.Array);
if (frequency != entry.Value)
{
Console.Out.WriteLine("Expected " + entry.Value + " received " + frequency);
errors++;
}
}
Console.Out.WriteLine("Found " + errors + " errors at space " + space + " sent " + points);
Assert.That(eps * points, Is.GreaterThan(errors));
}
