tlbmc/collector/monitoring_change_base.h

#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_COLLECTOR_MONITORING_CHANGE_BASE_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_COLLECTOR_MONITORING_CHANGE_BASE_H_

#include <optional>
#include <string_view>

namespace milotic_tlbmc {

// Sampling interval in milliseconds
using Interval = int;
// Interval used for stopping the monitoring of a sensor
constexpr Interval kStopMonitoring = 0;
// Interval used for resetting the monitoring of a sensor to the default
// ambient interval and batch size.
constexpr Interval kResetMonitoring = -1;
constexpr Interval kDefaultAmbientPollingIntervalMsec = 2000;
using BatchSize = int;
constexpr BatchSize kDefaultAmbientBatchSize = 1;

// A change to the monitoring configuration of a sensor.
struct Mutation {
  std::optional<Interval> interval;
  std::optional<BatchSize> batch_size;

  bool operator==(const Mutation&) const = default;
  bool operator!=(const Mutation&) const = default;

  void MergeWith(const Mutation& other) {
    if (other.interval.has_value()) {
      interval = other.interval;
    }
    if (other.batch_size.has_value()) {
      batch_size = other.batch_size;
    }
  }
};

// Transaction like object, capturing monitoring changes to be applied to a
// store or collector.
// Once create, one or more sensor mutations are added, then Apply() is called
// to apply the changes, after which the object is destroyed.
class MonitoringChangeBase {
 public:
  virtual ~MonitoringChangeBase() = default;
  virtual bool AddSensor(std::string_view sensor_key, Mutation mutation) & = 0;
  virtual void Apply() && = 0;
};

}  // namespace milotic_tlbmc

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_COLLECTOR_MONITORING_CHANGE_BASE_H_