/* nstime.c
* Routines for manipulating nstime_t structures
*
* Copyright (c) 2005 MX Telecom Ltd.
*
* Wireshark - Network traffic analyzer
* By Gerald Combs
* Copyright 1998 Gerald Combs
*
* 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.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include
#include "nstime.h"
/* this is #defined so that we can clearly see that we have the right number of
zeros, rather than as a guard against the number of nanoseconds in a second
changing ;) */
#define NS_PER_S 1000000000
/* set the given nstime_t to zero */
void nstime_set_zero(nstime_t *nstime)
{
nstime->secs = 0;
nstime->nsecs = 0;
}
/* is the given nstime_t currently zero? */
gboolean nstime_is_zero(nstime_t *nstime)
{
if(nstime->secs == 0 && nstime->nsecs == 0) {
return TRUE;
} else {
return FALSE;
}
}
/* set the given nstime_t to (0,maxint) to mark it as "unset"
* That way we can find the first frame even when a timestamp
* is zero (fix for bug 1056)
*/
void nstime_set_unset(nstime_t *nstime)
{
nstime->secs = 0;
nstime->nsecs = G_MAXINT;
}
/* is the given nstime_t currently (0,maxint)? */
gboolean nstime_is_unset(const nstime_t *nstime)
{
if(nstime->secs == 0 && nstime->nsecs == G_MAXINT) {
return TRUE;
} else {
return FALSE;
}
}
/** funcion: nstime_copy
*
* a = b
*/
void nstime_copy(nstime_t *a, const nstime_t *b)
{
a->secs = b->secs;
a->nsecs = b->nsecs;
}
/*
* function: nstime_delta
* delta = b - a
*/
void nstime_delta(nstime_t *delta, const nstime_t *b, const nstime_t *a )
{
if (b->secs == a->secs) {
/* The seconds part of b is the same as the seconds part of a, so if
the nanoseconds part of the first time is less than the nanoseconds
part of a, b is before a. The nanoseconds part of the delta should
just be the difference between the nanoseconds part of b and the
nanoseconds part of a; don't adjust the seconds part of the delta,
as it's OK if the nanoseconds part is negative, and an overflow
can never result. */
delta->secs = 0;
delta->nsecs = b->nsecs - a->nsecs;
} else if (b->secs <= a->secs) {
/* The seconds part of b is less than the seconds part of a, so b is
before a.
Both the "seconds" and "nanoseconds" value of the delta
should have the same sign, so if the difference between the
nanoseconds values would be *positive*, subtract 1,000,000,000
from it, and add one to the seconds value. */
delta->secs = b->secs - a->secs;
delta->nsecs = b->nsecs - a->nsecs;
if(delta->nsecs > 0) {
delta->nsecs -= NS_PER_S;
delta->secs ++;
}
} else {
delta->secs = b->secs - a->secs;
delta->nsecs = b->nsecs - a->nsecs;
if(delta->nsecs < 0) {
delta->nsecs += NS_PER_S;
delta->secs --;
}
}
}
/*
* function: nstime_sum
* sum = a + b
*/
void nstime_sum(nstime_t *sum, const nstime_t *a, const nstime_t *b)
{
sum->secs = a->secs + b->secs;
sum->nsecs = a->nsecs + b->nsecs;
if(sum->nsecs>=NS_PER_S || (sum->nsecs>0 && sum->secs<0)){
sum->nsecs-=NS_PER_S;
sum->secs++;
} else if(sum->nsecs<=-NS_PER_S || (sum->nsecs<0 && sum->secs>0)) {
sum->nsecs+=NS_PER_S;
sum->secs--;
}
}
/*
* function: nstime_cmp
*
* a > b : > 0
* a = b : 0
* a < b : < 0
*/
int nstime_cmp (const nstime_t *a, const nstime_t *b )
{
if (G_UNLIKELY(nstime_is_unset(a))) {
if (G_UNLIKELY(nstime_is_unset(b))) {
return 0; /* "no time stamp" is "equal" to "no time stamp" */
} else {
return -1; /* and is less than all time stamps */
}
} else {
if (G_UNLIKELY(nstime_is_unset(b))) {
return 1;
}
}
if (a->secs == b->secs) {
return a->nsecs - b->nsecs;
} else {
return (int) (a->secs - b->secs);
}
}
/*
* function: nstime_to_msec
* converts nstime to double, time base is milli seconds
*/
double nstime_to_msec(const nstime_t *nstime)
{
return ((double)nstime->secs*1000 + (double)nstime->nsecs/1000000);
}
/*
* function: nstime_to_sec
* converts nstime to double, time base is seconds
*/
double nstime_to_sec(const nstime_t *nstime)
{
return ((double)nstime->secs + (double)nstime->nsecs/1000000000);
}
/*
* Number of seconds between the UN*X epoch (January 1, 1970, 00:00:00 GMT)
* and the Windows NT epoch (January 1, 1601 in the proleptic Gregorian
* calendar, 00:00:00 "GMT")
*
* This is
*
* 369*365.25*24*60*60-(3*24*60*60+6*60*60)
*
* 1970-1601 is 369; 365.25 is the average length of a year in days,
* including leap years.
*
* 3 days are subtracted because 1700, 1800, and 1900 were not leap
* years, as, while they're all evenly divisible by 4, they're also
* evently divisible by 100, but not evently divisible by 400, so
* we need to compensate for using the average length of a year in
* days, which assumes a leap year every 4 years, *including* every
* 100 years.
*
* I'm not sure what the extra 6 hours are that are being subtracted.
*/
#define TIME_FIXUP_CONSTANT G_GUINT64_CONSTANT(11644473600)
#ifndef TIME_T_MIN
#define TIME_T_MIN ((time_t) ((time_t)0 < (time_t) -1 ? (time_t) 0 \
: ~ (time_t) 0 << (sizeof (time_t) * CHAR_BIT - 1)))
#endif
#ifndef TIME_T_MAX
#define TIME_T_MAX ((time_t) (~ (time_t) 0 - TIME_T_MIN))
#endif
/*
* function: filetime_to_nstime
* converts a Windows FILETIME value to an nstime_t
* returns TRUE if the conversion succeeds, FALSE if it doesn't
* (for example, with a 32-bit time_t, the time overflows or
* underflows time_t)
*/
gboolean
filetime_to_nstime(nstime_t *nstime, guint64 filetime)
{
/*
* This code is based on the Samba code:
*
* Unix SMB/Netbios implementation.
* Version 1.9.
* time handling functions
* Copyright (C) Andrew Tridgell 1992-1998
*/
gint64 secs;
int nsecs;
/* The next two lines are a fix needed for the
broken SCO compiler. JRA. */
time_t l_time_min = TIME_T_MIN;
time_t l_time_max = TIME_T_MAX;
/* Split into seconds and nanoseconds. */
secs = filetime / 10000000;
nsecs = (int)((filetime % 10000000)*100);
/* Now adjust the seconds. */
secs -= TIME_FIXUP_CONSTANT;
if (!(l_time_min <= secs && secs <= l_time_max)) {
/* The result won't fit in a time_t */
return FALSE;
}
/*
* Get the time as seconds and nanoseconds.
*/
nstime->secs = (time_t) secs;
nstime->nsecs = nsecs;
return TRUE;
}
/*
* Editor modelines
*
* Local Variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/