MetricBuilder.hpp

#pragma once
 
#include "util/prometheus/MetricBase.hpp"
 
#include <cstdint>
#include <memory>
#include <string>
#include <vector>
 
namespace util::prometheus {

struct MetricBuilderInterface {
    virtual ~MetricBuilderInterface() = default;

    virtual std::unique_ptr<MetricBase>
    operator()(
        std::string name,
        std::string labelsString,
        MetricType type,
        std::vector<std::int64_t> const& buckets = {}
    ) = 0;

    virtual std::unique_ptr<MetricBase>
    operator()(
        std::string name,
        std::string labelsString,
        MetricType type,
        std::vector<double> const& buckets
    ) = 0;
};

class MetricBuilder : public MetricBuilderInterface {
public:
    std::unique_ptr<MetricBase>
    operator()(
        std::string name,
        std::string labelsString,
        MetricType type,
        std::vector<std::int64_t> const& buckets = {}
    ) override;
 
    std::unique_ptr<MetricBase>
    operator()(
        std::string name,
        std::string labelsString,
        MetricType type,
        std::vector<double> const& buckets
    ) override;
 
private:
    static std::unique_ptr<MetricBase>
    makeMetric(std::string name, std::string labelsString, MetricType type);
 
    template <typename ValueType>
        requires std::same_as<ValueType, std::int64_t> || std::same_as<ValueType, double>
    std::unique_ptr<MetricBase>
    makeHistogram(
        std::string name,
        std::string labelsString,
        MetricType type,
        std::vector<ValueType> const& buckets
    );
};
 
}  // namespace util::prometheus