#include "hyperloglog.h"
#include <util/generic/buffer.h>
#include <util/random/mersenne.h>
#include <util/stream/buffer.h>
#include <library/cpp/testing/unittest/registar.h>
#include <cmath>
Y_UNIT_TEST_SUITE(THyperLogLog) {
Y_UNIT_TEST(TestPrecision18) {
TMersenne<ui64> rand;
auto counter = THyperLogLog::Create(18);
static const std::pair<ui64, ui64> POINTS[] = {
{10, 10},
{100, 100},
{1000, 998},
{10000, 9978},
{100000, 99995},
{1000000, 997017},
{10000000, 9983891},
{100000000, 100315572},
{1000000000, 998791445},
//1:37: {10000000000, 10015943904}
};
ui64 unique = 0;
for (const auto& pnt : POINTS) {
while (unique < pnt.first) {
const auto val = rand();
counter.Update(val);
++unique;
}
const auto estimation = counter.Estimate();
const auto delta = i64(estimation) - i64(unique);
const auto error = double(delta) / unique;
UNIT_ASSERT(std::abs(error) < 0.0032);
UNIT_ASSERT_EQUAL(estimation, pnt.second);
}
{
auto counter2 = THyperLogLog::Create(18);
while (unique < 2000000000) {
const auto val = rand();
counter2.Update(val);
++unique;
}
const auto estimation = counter2.Estimate();
UNIT_ASSERT_EQUAL(estimation, 1000013484);
counter.Merge(counter2);
UNIT_ASSERT_EQUAL(counter.Estimate(), 1998488794);
}
{
TBufferStream stream;
counter.Save(stream);
UNIT_ASSERT_EQUAL(stream.Buffer().Size(), 1 + (1 << 18));
stream.Rewind();
const auto copy = THyperLogLog::Load(stream);
UNIT_ASSERT_EQUAL(counter.Estimate(), copy.Estimate());
}
}
}