prometheus-cpp/core/src/gauge.cc

#include "prometheus/gauge.h"

#include "detail/builder.impl.h"
#include "family.impl.h"
#include "registry.impl.h"

#include <ctime>

namespace prometheus {

Gauge::Gauge(const double value) : value_{value} {}

void Gauge::Increment() { Increment(1.0); }

void Gauge::Increment(const double value) {
  if (value < 0.0) {
    return;
  }
  Change(value);
}

void Gauge::Decrement() { Decrement(1.0); }

void Gauge::Decrement(const double value) {
  if (value < 0.0) {
    return;
  }
  Change(-1.0 * value);
}

void Gauge::Set(const double value) { value_.store(value); }

void Gauge::Change(const double value) {
  auto current = value_.load();
  while (!value_.compare_exchange_weak(current, current + value))
    ;
}

void Gauge::SetToCurrentTime() {
  const auto time = std::time(nullptr);
  Set(static_cast<double>(time));
}

double Gauge::Value() const { return value_; }

ClientMetric Gauge::Collect() const {
  ClientMetric metric;
  metric.gauge.value = Value();
  return metric;
}

template class Family<Gauge>;
template class detail::Builder<Gauge>;

template Family<Gauge>& Registry::Add(
    const std::string& name, const std::string& help,
    const std::map<std::string, std::string>& labels);

detail::Builder<Gauge> BuildGauge() { return {}; }

}  // namespace prometheus