/**
 * \file
 * \author Thomas Fischer
 * \author Wenqing Wang
 * \date   2012-05-10, 2014-10.10
 * \brief  Definition of the RunTime class.
 *
 * \copyright
 * Copyright (c) 2012-2020, OpenGeoSys Community (http://www.opengeosys.org)
 *            Distributed under a Modified BSD License.
 *              See accompanying file LICENSE.txt or
 *              http://www.opengeosys.org/project/license
 */

#pragma once

#ifdef USE_MPI
#include <mpi.h>
#else
#include <chrono>
#endif

namespace BaseLib
{

/// Count the running time.
class RunTime
{
    public:
        /// Start the timer.
        void start()
        {
#ifdef USE_MPI
            _start_time = MPI_Wtime();
#else
            _start_time = std::chrono::system_clock::now();
#endif
        }

        /// Get the elapsed time in seconds.
        double elapsed() const
        {
#ifdef USE_MPI
            return MPI_Wtime() - _start_time;
#else
            using namespace std::chrono;
            return duration<double>(system_clock::now() - _start_time).count();
#endif
        }

    private:
#ifdef USE_MPI
        double _start_time = std::numeric_limits<double>::quiet_NaN();
#else
        std::chrono::time_point<std::chrono::system_clock> _start_time;
#endif
};

} // end namespace BaseLib