/
ckms_quantiles.h
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/
ckms_quantiles.h
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#pragma once
#include <array>
#include <cstddef>
#include <functional>
#include <vector>
#include "prometheus/detail/core_export.h"
// IWYU pragma: private
namespace prometheus {
namespace detail {
class PROMETHEUS_CPP_CORE_EXPORT CKMSQuantiles {
public:
struct PROMETHEUS_CPP_CORE_EXPORT Quantile {
const double quantile;
const double error;
const double u;
const double v;
Quantile(double quantile, double error);
};
private:
struct Item {
/*const*/ double value;
int g;
/*const*/ int delta;
explicit Item(double value, int lower_delta, int delta);
};
public:
explicit CKMSQuantiles(const std::vector<Quantile>& quantiles);
void insert(double value);
double get(double q);
void reset();
private:
double allowableError(int rank);
bool insertBatch();
void compress();
private:
const std::reference_wrapper<const std::vector<Quantile>> quantiles_;
std::size_t count_;
std::vector<Item> sample_;
std::array<double, 500> buffer_;
std::size_t buffer_count_;
};
} // namespace detail
} // namespace prometheus