/*

 * Copyright 2011 Free Software Foundation, Inc.

 *

 * This file is part of GNU Radio

 *

 * GNU Radio is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3, or (at your option)

 * any later version.

 *

 * GNU Radio is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifndef INCLUDED_GRUEL_HIGH_RES_TIMER_H

#define INCLUDED_GRUEL_HIGH_RES_TIMER_H

namespace gruel {

    //! Typedef for the timer tick count

    typedef signed long long high_res_timer_type;

    //! Get the current time in ticks

    high_res_timer_type high_res_timer_now(void);

    //! Get the number of ticks per second

    high_res_timer_type high_res_timer_tps(void);

    //! Get the tick count at the epoch

    high_res_timer_type high_res_timer_epoch(void);

} /* namespace gruel */

////////////////////////////////////////////////////////////////////////

// Use architecture defines to determine the implementation

////////////////////////////////////////////////////////////////////////

#if defined(linux) || defined(__linux) || defined(__linux__)

    #define GRUEL_HRT_USE_CLOCK_GETTIME

#elif defined(_WIN32) || defined(__WIN32__) || defined(WIN32)

    #define GRUEL_HRT_USE_QUERY_PERFORMANCE_COUNTER

#elif defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)

    #define GRUEL_HRT_USE_MACH_ABSOLUTE_TIME

#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)

    #define GRUEL_HRT_USE_CLOCK_GETTIME

#else

    #define GRUEL_HRT_USE_MICROSEC_CLOCK

#endif

////////////////////////////////////////////////////////////////////////

#ifdef GRUEL_HRT_USE_CLOCK_GETTIME

    #include <ctime>

    inline gruel::high_res_timer_type gruel::high_res_timer_now(void){

        timespec ts;

        clock_gettime(CLOCK_MONOTONIC, &ts);

        return ts.tv_sec*high_res_timer_tps() + ts.tv_nsec;

    }

    inline gruel::high_res_timer_type gruel::high_res_timer_tps(void){

        return 1000000000UL;

    }

#endif /* GRUEL_HRT_USE_CLOCK_GETTIME */

////////////////////////////////////////////////////////////////////////

#ifdef GRUEL_HRT_USE_MACH_ABSOLUTE_TIME

    #include <mach/mach_time.h>

    inline gruel::high_res_timer_type gruel::high_res_timer_now(void){

        return mach_absolute_time();

    }

    inline gruel::high_res_timer_type gruel::high_res_timer_tps(void){

        mach_timebase_info_data_t info;

        mach_timebase_info(&info);

        return gruel::high_res_timer_type(info.numer*1000000000UL)/info.denom;

    }

#endif

////////////////////////////////////////////////////////////////////////

#ifdef GRUEL_HRT_USE_QUERY_PERFORMANCE_COUNTER

    #include <Windows.h>

    inline gruel::high_res_timer_type gruel::high_res_timer_now(void){

        LARGE_INTEGER counts;

        QueryPerformanceCounter(&counts);

        return counts.QuadPart;

    }

    inline gruel::high_res_timer_type gruel::high_res_timer_tps(void){

        LARGE_INTEGER freq;

        QueryPerformanceFrequency(&freq);

        return freq.QuadPart;

    }

#endif

////////////////////////////////////////////////////////////////////////

#ifdef GRUEL_HRT_USE_MICROSEC_CLOCK

    #include <boost/date_time/posix_time/posix_time.hpp>

    inline gruel::high_res_timer_type gruel::high_res_timer_now(void){

        static const boost::posix_time::ptime epoch(boost::posix_time::from_time_t(0));

        return (boost::posix_time::microsec_clock::universal_time() - epoch).ticks();

    }

    inline gruel::high_res_timer_type gruel::high_res_timer_tps(void){

        return boost::posix_time::time_duration::ticks_per_second();

    }

#endif

////////////////////////////////////////////////////////////////////////

#include <boost/date_time/posix_time/posix_time.hpp>

inline gruel::high_res_timer_type gruel::high_res_timer_epoch(void){

    static const double hrt_ticks_per_utc_ticks = gruel::high_res_timer_tps()/double(boost::posix_time::time_duration::ticks_per_second());

    boost::posix_time::time_duration utc = boost::posix_time::microsec_clock::universal_time() - boost::posix_time::from_time_t(0);

    return gruel::high_res_timer_now() - utc.ticks()*hrt_ticks_per_utc_ticks;

}

#endif /* INCLUDED_GRUEL_HIGH_RES_TIMER_H */