timer.cpp

#include "timer.h"
/*
  start();  starts the clock running from the current time
  currtime();  returns the current time
  stop();  stops the clock without reseting its value
  reset();  stops the clock and resets the timer to 0
*/

Timer::Timer(){
    elapsedTime_=0;
    isstop_=true;

#if PLATFORM == WINDOWS
    starttime_=0;
    stoptime_=0;    
#else
    clock_gettime(CLOCK_MONOTONIC_RAW, &starttime_);
    stoptime_=starttime_;
#endif


}
void Timer::reset(){
#if PLATFORM == WINDOWS
    starttime_=0;
    stoptime_=0;    
#else
    clock_gettime(CLOCK_MONOTONIC_RAW, &starttime_);
    stoptime_=starttime_;
#endif
    elapsedTime_=0;
    isstop_=true;
}
void Timer::start(){
#if PLATFORM == WINDOWS
    clock_t curr=clock();
    if(isstop_){
        starttime_=(stoptime_==0)?curr:starttime_+(curr-stoptime_);
        isstop_=false;
    }
    else{
        starttime_=curr;   //its like hitting reset and start
    }
#else
    struct timespec curr;
    clock_gettime(CLOCK_MONOTONIC_RAW, &curr);
    if(isstop_){
        starttime_=curr;
        isstop_=false;
    }
    else{
        clock_gettime(CLOCK_MONOTONIC_RAW, &starttime_);
        stoptime_=starttime_;
        elapsedTime_=0;
    }
#endif

}
void Timer::stop(){
#if PLATFORM == WINDOWS
    stoptime_=clock();
#else
    clock_gettime(CLOCK_MONOTONIC_RAW, &stoptime_);
    elapsedTime_ += (stoptime_.tv_nsec - starttime_.tv_nsec) / 1000000000.0 + 
            (stoptime_.tv_sec  - starttime_.tv_sec);
#endif
    isstop_=true;
}
double Timer::currtime(){
    double rc;
#if PLATFORM == WINDOWS
    clock_t curr=clock();
    clock_t elapse=(isstop_)?stoptime_-starttime_:curr-starttime_;
    rc= double(elapse)/CLOCKS_PER_SEC;
#else
    struct timespec curr;
    clock_gettime(CLOCK_MONOTONIC_RAW,&curr);
    if(isstop_){
        rc=elapsedTime_;
    }
    else{
        rc=elapsedTime_ + (curr.tv_nsec - starttime_.tv_nsec) / 1000000000.0 + 
            (curr.tv_sec  - starttime_.tv_sec);
    }    
#endif
    return rc;
}
double Timer::starttime(){
#if PLATFORM == WINDOWS
    return (double)starttime_;
#else
    return starttime_.tv_nsec/ 1000000000.0 + starttime_.tv_sec;
#endif
}