// Copyright 2019-2020 CERN and copyright holders of ALICE O2.

// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.

// All rights not expressly granted are reserved.

//

// This software is distributed under the terms of the GNU General Public

// License v3 (GPL Version 3), copied verbatim in the file "COPYING".

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

#ifndef _COUNTERSTATS_H

#define _COUNTERSTATS_H

#include <stdint.h>

#include <vector>

typedef uint64_t CounterValue;

class CounterStats

{

public:

CounterStats();

~CounterStats();

// do not mix set() and increment()

void set(CounterValue value); // assign new value

void increment(CounterValue value = 1); // increment new value

void reset(); // restore all stats to zero

CounterValue get(); // get latest value

CounterValue getTotal(); // get total of previous values set

double getAverage();

double getStdDev(); // get standard deviation (when histogram enabled)

CounterValue getMinimum();

CounterValue getMaximum();

CounterValue getCount();

void enableHistogram(unsigned int nbins, CounterValue vmin, CounterValue vmax, int logScale = 1);

void getHisto(std::vector<double>& x, std::vector<CounterValue>& count);

private:

CounterValue value; // last value set

// derived statistics

CounterValue sum; // sum of previous values set (to compute average)

CounterValue nValues; // number of time value was set (to compute average)

CounterValue min; // minimum value set

CounterValue max; // maximum value set

void updateStats(); // update statistics from latest value

std::vector<CounterValue> histoCounts; // store record of registered values

CounterValue histoVmin; // min value in histogram

CounterValue histoVmax; // max value in histogram

unsigned int histoNbin; // number of steps in histo

double histoStep; // step size (as a fraction of vmax)

double histoK1; // scaling factor

double histoK2; // scaling factor

int histoLogScale; // if set, using logarithmic scale on X

};

#endif // #ifndef _COUNTERSTATS_H