// ======================================================================
//
// Copyright (c) 1997 The CGAL Consortium
//
// This software and related documentation is part of an INTERNAL release
// of the Computational Geometry Algorithms Library (CGAL). It is not
// intended for general use.
//
// ----------------------------------------------------------------------
//
// release       : 
// release_date  : 
//
// file          : include/CGAL/Timer.h
// package       : Timer (1.9)
// maintainer    : Matthias Baesken <baesken@informatik.uni-trier.de>
// revision      : 1.9
// revision_date : 4 April 2001 
// author(s)     : Lutz Kettner  <kettner@inf.ethz.ch>  
//                 Matthias Baesken <baesken@informatik.uni-halle.de>
// coordinator   : INRIA, Sophia Antipolis
//
// A timer class to measure cpu time of user-processes.
// ======================================================================

#ifndef CGAL_TIMER_H
#define CGAL_TIMER_H 1

#ifndef CGAL_BASIC_H
#include <CGAL/basic.h>
#endif
#ifndef CGAL_PROTECT_CSTDLIB
#include <cstdlib>
#define CGAL_PROTECT_CSTDLIB
#endif
#ifndef CGAL_PROTECT_CLIMITS
#include <climits>
#define CGAL_PROTECT_CLIMITS
#endif

// used for clock()
#ifndef CGAL_PROTECT_CTIME
#include <ctime>
#define CGAL_PROTECT_CTIME
#endif

CGAL_BEGIN_NAMESPACE

// SECTION: A Timer for User-Process Time
// ========================================================================
// 
// DEFINITION
// 
// A timer `t' of type Timer is an object with a state. It is either
// running or it is stopped. The state is controlled with `t.start()'
// and `t.stop()'. The timer counts the time elapsed since its creation
// or last reset. It counts only the time where it is in the running
// state. The time information is given in seconds.

class Timer {
private:
    CGAL_CLIB_STD::clock_t  elapsed;
    CGAL_CLIB_STD::clock_t  started;
    int           interv;
    bool          running;

public:
    Timer() : elapsed(0), started(0), interv(0), running(false) {}

    void     start();
    void     stop ();
    void     reset();
    bool     is_running() const { return running; }

    double   time()       const;
    int      intervals()  const { return interv; }
    double   precision()  const { return 0.01; }
    double   max() const        { return 2146.0;}
};


/*****************************************************************************/

// Member functions Timer
// ===========================

inline void Timer::start() {
    CGAL_assertion( ! running);
    started = CGAL_CLIB_STD::clock();
    if (started == (CGAL_CLIB_STD::clock_t)-1) {
        // possible on Solaris according to man-page
#if defined (_MSC_VER)
	std::cout << "Timer error: CGAL_CLIB_STD::clock() returned -1.\n";
#else
	std::cerr << "Timer error: CGAL_CLIB_STD::clock() returned -1.\n";
#endif
	CGAL_CLIB_STD::abort();
    }
    running = true;
    ++ interv;
}

inline void Timer::stop() {
    CGAL_assertion( running);
    elapsed += CGAL_CLIB_STD::clock() - started;
    running  = false;
}

inline void Timer::reset() {
    interv = 0;
    elapsed = 0;
    if (running) {
	started = CGAL_CLIB_STD::clock();
	++ interv;
    }
}

inline double Timer::time() const {
    if (running) {
	return double( elapsed  + CGAL_CLIB_STD::clock() - started) / CLOCKS_PER_SEC;
    }
    return double(elapsed) / CLOCKS_PER_SEC;
}

CGAL_END_NAMESPACE

#endif // CGAL_TIMER_H //
// EOF //