src/time.c

/*
 * Time calculation functions.
 *
 * Copyright 2000-2006 Willy Tarreau <w@1wt.eu>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */

#include <sys/time.h>

#include <common/config.h>
#include <common/standard.h>
#include <common/time.h>

struct timeval now;             /* the current date at any moment */
struct timeval start_date;      /* the process's start date */

/*
 * adds <ms> ms to <from>, set the result to <tv> and returns a pointer <tv>
 */
REGPRM3 struct timeval *tv_delayfrom(struct timeval *tv, const struct timeval *from, int ms)
{
	if (!tv || !from)
		return NULL;
	tv->tv_usec = from->tv_usec + (ms%1000)*1000;
	tv->tv_sec  = from->tv_sec  + (ms/1000);
	while (tv->tv_usec >= 1000000) {
		tv->tv_usec -= 1000000;
		tv->tv_sec++;
	}
	return tv;
}

/*
 * compares <tv1> and <tv2> modulo 1ms: returns 0 if equal, -1 if tv1 < tv2, 1 if tv1 > tv2
 * Must not be used when either argument is eternity. Use tv_cmp2_ms() for that.
 */
REGPRM2 int tv_cmp_ms(const struct timeval *tv1, const struct timeval *tv2)
{
	if ((unsigned)tv1->tv_sec == (unsigned)tv2->tv_sec) {
		if ((unsigned)tv2->tv_usec >= (unsigned)tv1->tv_usec + 1000)
			return -1;
		else if ((unsigned)tv1->tv_usec >= (unsigned)tv2->tv_usec + 1000)
			return 1;
		else
			return 0;
	}
	else if (((unsigned)tv2->tv_sec > (unsigned)tv1->tv_sec + 1) ||
		 (((unsigned)tv2->tv_sec == (unsigned)tv1->tv_sec + 1) &&
		  ((unsigned)tv2->tv_usec + 1000000 >= (unsigned)tv1->tv_usec + 1000)))
		return -1;
	else if (((unsigned)tv1->tv_sec > (unsigned)tv2->tv_sec + 1) ||
		 (((unsigned)tv1->tv_sec == (unsigned)tv2->tv_sec + 1) &&
		  ((unsigned)tv1->tv_usec + 1000000 >= (unsigned)tv2->tv_usec + 1000)))
		return 1;
	else
		return 0;
}

/*
 * compares <tv1> and <tv2> modulo 1 ms: returns 0 if equal, -1 if tv1 < tv2, 1 if tv1 > tv2,
 * assuming that TV_ETERNITY is greater than everything.
 */
REGPRM2 int tv_cmp2_ms(const struct timeval *tv1, const struct timeval *tv2)
{
	if (tv_iseternity(tv1))
		if (tv_iseternity(tv2))
			return 0; /* same */
		else
			return 1; /* tv1 later than tv2 */
	else if (tv_iseternity(tv2))
		return -1; /* tv2 later than tv1 */
    
	if ((unsigned)tv1->tv_sec == (unsigned)tv2->tv_sec) {
		if ((unsigned)tv1->tv_usec >= (unsigned)tv2->tv_usec + 1000)
			return 1;
		else if ((unsigned)tv2->tv_usec >= (unsigned)tv1->tv_usec + 1000)
			return -1;
		else
			return 0;
	}
	else if (((unsigned)tv1->tv_sec > (unsigned)tv2->tv_sec + 1) ||
		 (((unsigned)tv1->tv_sec == (unsigned)tv2->tv_sec + 1) &&
		  ((unsigned)tv1->tv_usec + 1000000 >= (unsigned)tv2->tv_usec + 1000)))
		return 1;
	else if (((unsigned)tv2->tv_sec > (unsigned)tv1->tv_sec + 1) ||
		 (((unsigned)tv2->tv_sec == (unsigned)tv1->tv_sec + 1) &&
		  ((unsigned)tv2->tv_usec + 1000000 >= (unsigned)tv1->tv_usec + 1000)))
		return -1;
	else
		return 0;
}

/*
 * compares <tv1> and <tv2> modulo 1 ms: returns 1 if tv1 <= tv2, 0 if tv1 > tv2,
 * assuming that TV_ETERNITY is greater than everything. Returns 0 if tv1 is
 * TV_ETERNITY, and always assumes that tv2 != TV_ETERNITY. Designed to replace
 * occurrences of (tv_cmp2_ms(tv,now) <= 0).
 */
REGPRM2 int tv_cmp2_le(const struct timeval *tv1, const struct timeval *tv2)
{
	if (likely((unsigned)tv1->tv_sec > (unsigned)tv2->tv_sec + 1))
		return 0;

	if (likely((unsigned)tv1->tv_sec < (unsigned)tv2->tv_sec))
		return 1;

	if (likely((unsigned)tv1->tv_sec == (unsigned)tv2->tv_sec)) {
		if ((unsigned)tv2->tv_usec >= (unsigned)tv1->tv_usec + 1000)
			return 1;
		else
			return 0;
	}

	if (unlikely(((unsigned)tv1->tv_sec == (unsigned)tv2->tv_sec + 1) &&
		     ((unsigned)tv1->tv_usec + 1000000 >= (unsigned)tv2->tv_usec + 1000)))
		return 0;
	else
		return 1;
}

/*
 * returns the remaining time between tv1=now and event=tv2
 * if tv2 is passed, 0 is returned.
 * Returns TIME_ETERNITY if tv2 is eternity.
 */
REGPRM2 unsigned long tv_remain2(const struct timeval *tv1, const struct timeval *tv2)
{
	unsigned long ret;

	if (tv_iseternity(tv2))
		return TIME_ETERNITY;

	if (tv_cmp_ms(tv1, tv2) >= 0)
		return 0; /* event elapsed */

	ret = (tv2->tv_sec - tv1->tv_sec) * 1000;
	if ((unsigned)tv2->tv_usec > (unsigned)tv1->tv_usec)
		ret += (tv2->tv_usec - tv1->tv_usec) / 1000;
	else
		ret -= (tv1->tv_usec - tv2->tv_usec) / 1000;
	return (unsigned long) ret;
}


/*
 * returns the absolute difference, in ms, between tv1 and tv2
 * Must not be used when either argument is eternity.
 */
REGPRM2 unsigned long tv_delta(const struct timeval *tv1, const struct timeval *tv2)
{
	int cmp;
	unsigned long ret;
  

	cmp = tv_cmp(tv1, tv2);
	if (!cmp)
		return 0; /* same dates, null diff */
	else if (cmp < 0) {
		const struct timeval *tmp = tv1;
		tv1 = tv2;
		tv2 = tmp;
	}
	ret = (tv1->tv_sec - tv2->tv_sec) * 1000;
	if ((unsigned)tv1->tv_usec > (unsigned)tv2->tv_usec)
		ret += (tv1->tv_usec - tv2->tv_usec) / 1000;
	else
		ret -= (tv2->tv_usec - tv1->tv_usec) / 1000;
	return (unsigned long) ret;
}

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */