gauge.h

#pragma once
 
#include <atomic>
 
#include "prometheus/client_metric.h"
#include "prometheus/detail/builder.h"  // IWYU pragma: export
#include "prometheus/detail/core_export.h"
#include "prometheus/metric_type.h"
 
namespace prometheus {

class PROMETHEUS_CPP_CORE_EXPORT Gauge {
 public:
  static const MetricType metric_type{MetricType::Gauge};

  Gauge() = default;

  Gauge(double);

  void Increment();

  void Increment(double);

  void Decrement();

  void Decrement(double);

  void Set(double);

  void SetToCurrentTime();

  double Value() const;

  ClientMetric Collect() const;
 
 private:
  void Change(double);
  std::atomic<double> value_{0.0};
};

PROMETHEUS_CPP_CORE_EXPORT detail::Builder<Gauge> BuildGauge();
 
}  // namespace prometheus