Timer.cpp

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// Timer.cpp
// =========
// High Resolution Timer.
// This timer is able to measure the elapsed time with 1 micro-second accuracy
// in both Windows, Linux and Unix system
//
//  AUTHOR: Song Ho Ahn ([email protected])
// CREATED: 2003-01-13
// UPDATED: 2006-01-13
//
// Copyright (c) 2003 Song Ho Ahn

#include "util/Timer.hpp"
#include <cstdlib>

// constructor
Timer::Timer(bool bStart)
{
    clear();

    // FT: Added this part:
    //
    if (bStart) start();
}

// distructor
Timer::~Timer()
{
}

// start timer.
// startCount will be set at this point.
void Timer::start()
{
    stopped = 0; // reset stop flag
#ifdef WIN32
    QueryPerformanceCounter(&startCount);
#else
    gettimeofday(&startCount, nullptr);
#endif
}

// stop the timer.
// endCount will be set at this point.
void Timer::stop()
{
    stopped = 1; // set timer stopped flag

#ifdef WIN32
    QueryPerformanceCounter(&endCount);
#else
    gettimeofday(&endCount, nullptr);
#endif
}

// Clear: stop the timer and clear the contents.
void Timer::clear()
{
#ifdef WIN32
    QueryPerformanceFrequency(&frequency);
    startCount.QuadPart = 0;
    endCount.QuadPart = 0;
#else
    startCount.tv_sec = startCount.tv_usec = 0;
    endCount.tv_sec = endCount.tv_usec = 0;
#endif

    stopped = 0;
    startTimeInMicroSec = 0;
    endTimeInMicroSec = 0;
}

// compute elapsed time in micro-second resolution.
// other getElapsedTime will call this first, then convert to correspond
// resolution.
double Timer::getElapsedTimeInMicroSec()
{
#ifdef WIN32
    if (!stopped) QueryPerformanceCounter(&endCount);

    startTimeInMicroSec =
        startCount.QuadPart * (1000000.0 / frequency.QuadPart);
    endTimeInMicroSec = endCount.QuadPart * (1000000.0 / frequency.QuadPart);
#else
    if (!stopped) gettimeofday(&endCount, nullptr);

    startTimeInMicroSec = (startCount.tv_sec * 1000000.0) + startCount.tv_usec;
    endTimeInMicroSec = (endCount.tv_sec * 1000000.0) + endCount.tv_usec;
#endif

    return endTimeInMicroSec - startTimeInMicroSec;
}

// divide elapsedTimeInMicroSec by 1000
double Timer::getElapsedTimeInMilliSec()
{
    return getElapsedTimeInMicroSec() * 0.001;
}

// divide elapsedTimeInMicroSec by 1000000
double Timer::getElapsedTimeInSec()
{
    return getElapsedTimeInMicroSec() * 0.000001;
}

// same as getElapsedTimeInSec()
double Timer::getElapsedTime()
{
    return getElapsedTimeInSec();
}