coreutils/lib/xtime.h
2005-02-21 08:05:49 +00:00

88 lines
2.3 KiB
C

/* xtime -- extended-resolution integer time stamps
Copyright (C) 2005 Free Software Foundation, Inc.
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, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Paul Eggert. */
#ifndef XTIME_H_
#define XTIME_H_ 1
/* xtime_t is a signed type used for time stamps. It is an integer
type that is a count of nanoseconds -- except for obsolescent hosts
without sufficiently-wide integers, where it is a count of
seconds. */
#if HAVE_LONG_LONG
typedef long long int xtime_t;
# define XTIME_PRECISION 1000000000LL
#else
# include <limits.h>
typedef long int xtime_t;
# if LONG_MAX >> 31 >> 31 == 0
# define XTIME_PRECISION 1L
# else
# define XTIME_PRECISION 1000000000L
# endif
#endif
/* Return an extended time value that contains S seconds and NS
nanoseconds, without any overflow checking. */
static inline xtime_t
xtime_make (xtime_t s, int ns)
{
if (XTIME_PRECISION == 1)
return s;
else
return XTIME_PRECISION * s + ns;
}
/* Return the number of seconds in T, which must be nonnegative. */
static inline xtime_t
xtime_nonnegative_sec (xtime_t t)
{
return t / XTIME_PRECISION;
}
/* Return the number of seconds in T. */
static inline xtime_t
xtime_sec (xtime_t t)
{
return (XTIME_PRECISION == 1
? t
: t < 0
? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1
: xtime_nonnegative_sec (t));
}
/* Return the number of nanoseconds in T, which must be nonnegative. */
static inline int
xtime_nonnegative_nsec (xtime_t t)
{
return t % XTIME_PRECISION;
}
/* Return the number of nanoseconds in T. */
static inline int
xtime_nsec (xtime_t t)
{
int ns = t % XTIME_PRECISION;
if (ns < 0)
ns += XTIME_PRECISION;
return ns;
}
#endif