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// Helper class to aggregate the collected in-memory stats to persistent
// storage.
#ifndef O3D_STATSREPORT_AGGREGATOR_H__
#define O3D_STATSREPORT_AGGREGATOR_H__

#include "metrics.h"

namespace stats_report {
// TODO: Refactor to avoid cross platform code duplication.

// Wrapper class and interface for metrics aggregation. This is a platform
// independent class and needs to be subclassed for various platforms and/or
// metrics persistence methods
class MetricsAggregator {
 public:
  // Aggregate all metrics in the associated collection
  // @returns true iff aggregation started successfully, false otherwise.
  bool AggregateMetrics();

 protected:
  MetricsAggregator();
  explicit MetricsAggregator(const MetricCollection &coll);
  virtual ~MetricsAggregator();

  // Start aggregation. Override this to grab locks, open files, whatever
  // needs to happen or can expedite the individual aggregate steps.
  // @return true on success, false on failure.
  // @note aggregation will not progress if this function returns false
  virtual bool StartAggregation();
  virtual void EndAggregation();

  virtual void Aggregate(CountMetric *metric) = 0;
  virtual void Aggregate(TimingMetric *metric) = 0;
  virtual void Aggregate(IntegerMetric *metric) = 0;
  virtual void Aggregate(BoolMetric *metric) = 0;

 private:
  const MetricCollection &coll_;

  DISALLOW_COPY_AND_ASSIGN(MetricsAggregator);
};

}  // namespace stats_report

#endif  // O3D_STATSREPORT_AGGREGATOR_H__