ExecuteTimer::ExecuteTimer()
{
       memset(m_ctime, 0, sizeof(char)*32);
       //Reset the begin time.
       Reset();
}

ExecuteTimer::~ExecuteTimer()
{
}

char* ExecuteTimer::GetCTime()
{
       double lt = GetDTime();
       sprintf(m_ctime, "%.3fs", lt);
       return m_ctime;
}

double ExecuteTimer::GetDTime()
{
       struct timespec end;
       clock_gettime(CLOCK_REALTIME, &end);
       //trans. to second unit.
       double lt = (end.tv_sec - m_begin.tv_sec) + (end.tv_nsec - m_begin.tv_nsec) * 1.0e-9;
       return lt;
}

void ExecuteTimer::Reset()
{
       clock_gettime(CLOCK_REALTIME, &m_begin);
}

std::ostream& operator << (std::ostream& os, ExecuteTimer& obj)
{
       double lt = obj.GetDTime();
       //output formated string.
       char fmt[32] = {0};
       sprintf(fmt, "%.3fs", lt);
       os << fmt;
       return os;
}

std::ofstream& operator << (std::ofstream& ofs, ExecuteTimer& obj)
{
       double lt = obj.GetDTime();
       //output formated string.
       char fmt[32] = {0};
       sprintf(fmt, "%.3fs", lt);
       ofs << fmt;
       return ofs;
}