//
// Simple class to allow events to be timed
//
// Copyright (C) J. Belson	2001.12.06
//
// $Author: jon $ : $Date: 2003/06/03 16:46:53 $
//


#ifndef _STOPWATCH_H_
#define _STOPWATCH_H_

#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>


/**
 * Measure the user time (not elapsed time) taken by an application
 */
class stopwatch {

private:
	struct timeval t1, t2;
public:
	stopwatch(void) {
		reset();
	};

	void reset(void) {
		struct rusage ru;
		getrusage(RUSAGE_SELF, &ru);
		t1 = ru.ru_utime;
	}

	void start(void) {
		struct rusage ru;
		getrusage(RUSAGE_SELF, &ru);
		t1 = ru.ru_utime;
	}

	// Number of microseconds since stopwatch started
	long get_time(void) {
		struct rusage ru;
		getrusage(RUSAGE_SELF, &ru);
		t2 = ru.ru_utime;

		// Adjust if necessary to ensure t2-t1 is meaningful
		if (t1.tv_usec > t2.tv_usec) {
			t2.tv_sec--;
			t2.tv_usec+=1000000;
		}
		long int secs = t2.tv_sec - t1.tv_sec;
		unsigned long int centi = (t2.tv_usec - t1.tv_usec)/10000;

		long int time = secs*100 + centi;

		return time;
	}
};

#endif	// _STOPWATCH_