stopwatch.cxx

#include "stopwatch.h"
 
#include <iostream>
#include <ctime>
#ifdef _WIN32
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <windows.h>
#endif
 
namespace cgv {
    namespace utils {
 
#ifdef _WIN32
static long long frequency;
static bool queried_perfcounter = false;
#else
constexpr auto S_TO_NS=1000000000LL;
constexpr auto NS_TO_S=(1.0/double(S_TO_NS));
#endif
 
void stopwatch::init()
{
#ifdef _WIN32
    if (!queried_perfcounter) {
        QueryPerformanceFrequency((LARGE_INTEGER*) &frequency);
        queried_perfcounter = true;
    }
    QueryPerformanceCounter((LARGE_INTEGER*) &start);
#else
    timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    start = ((long long)ts.tv_sec)*S_TO_NS + (long long)ts.tv_nsec;
#endif
}
 
//standard constructor starts time measurement
stopwatch::stopwatch(bool silent) : silent(silent)
{
    resultd = 0;
    init();
} 
 
//start counting time
stopwatch::stopwatch(double *result, bool silent) : silent(silent)
{
    this->resultd = result;
    init();
}
 
double stopwatch::get_current_time(long long& end) const
{
    double time;
#ifdef _WIN32
    QueryPerformanceCounter((LARGE_INTEGER*) &end);
    time =(end-start)/(double)frequency;
#else
    timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    end = ((long long)ts.tv_sec)*S_TO_NS + (long long)ts.tv_nsec;
    time = double(end - start)*NS_TO_S;
#endif
    return time;
}

double stopwatch::get_elapsed_time() const
{
    long long end;
    return get_current_time(end);
}

double stopwatch::restart()
{
    long long end;
    double time = get_current_time(end);
    start = end;
    return time;    
}
 
// add_time adds the time ellapsed thus far
void stopwatch::add_time()
{
    double time = restart();
    
    if(resultd)
        *resultd += time;   
    else if(!silent)
        std::cout << "elapsed time in seconds: " << time << std::endl;
}
 
//destructor stops time measurement and puts the result into cout
stopwatch::~stopwatch()
{
    add_time();
}
 
    }
}