Ticket #3504: monotone_timer_better_rollover.cpp

#include <TimerTraits.h>

#include <Assert.h>
#include <CheckedInt64.h>

#include <windows.h>

namespace {

    LONGLONG GetPerfFreq()
    {
        LARGE_INTEGER large_int;

        ASSERT(::QueryPerformanceFrequency(&large_int));

        return large_int.QuadPart;
    }
}

boost::int64_t TimerTraits::performance_freq_ = GetPerfFreq();

TimerTraits::time_type TimerTraits::now()
{
    LARGE_INTEGER large_int;

    ::QueryPerformanceCounter(&large_int);

    time_type result;
    result.ticks_ = large_int.QuadPart;
    return result;
}

boost::posix_time::time_duration TimerTraits::to_posix_duration(
    const TimerTraits::duration_type& d)
{
    CheckedInt64 counts(d.ticks_);
    CheckedInt64 freq(performance_freq_);

    // Convert the counts from the performance
    // counter

    counts.ScaleEq(CheckedInt64(1000), freq);

    // Assert that there is no error in the conversion

    ASSERT(counts.GetError() == CheckedInt64::NONE);

    return boost::posix_time::milliseconds(counts.GetValue());
}

boost::int64_t
TimerTraits::milliseconds_to_duration(boost::uint32_t milliseconds)
{
    CheckedInt64 counts(milliseconds);
    CheckedInt64 freq(performance_freq_);

    // Convert the counts from milliseconds
    // into the performance counter frequency

    counts.ScaleEq(freq, CheckedInt64(1000));

    // Assert that there is no error in the conversion

    ASSERT(counts.GetError() == CheckedInt64::NONE);

    return counts.GetValue();
}


} // namespace Details
} // namespace AVCPlat