histogram.h

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

class PROMETHEUS_CPP_CORE_EXPORT Histogram {
 public:
  using BucketBoundaries = std::vector<double>;
 
  static const MetricType metric_type{MetricType::Histogram};

  Histogram(const BucketBoundaries& buckets);

  void Observe(double value);

  void ObserveMultiple(const std::vector<double>& bucket_increments,
                       const double sum_of_values);

  ClientMetric Collect() const;
 
 private:
  const BucketBoundaries bucket_boundaries_;
  mutable std::mutex mutex_;
  std::vector<Counter> bucket_counts_;
  Gauge sum_;
};

PROMETHEUS_CPP_CORE_EXPORT detail::Builder<Histogram> BuildHistogram();
 
}  // namespace prometheus