2 * Routines for manipulating nstime_t structures
4 * Copyright (c) 2005 MX Telecom Ltd. <richardv@mxtelecom.com>
8 * Wireshark - Network traffic analyzer
9 * By Gerald Combs <gerald@wireshark.org>
10 * Copyright 1998 Gerald Combs
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
31 /* this is #defined so that we can clearly see that we have the right number of
32 zeros, rather than as a guard against the number of nanoseconds in a second
34 #define NS_PER_S 1000000000
36 /* set the given nstime_t to zero */
37 void nstime_set_zero(nstime_t *nstime)
43 /* is the given nstime_t currently zero? */
44 gboolean nstime_is_zero(nstime_t *nstime)
46 if(nstime->secs == 0 && nstime->nsecs == 0) {
55 * function: nstime_delta
59 void nstime_delta(nstime_t *delta, const nstime_t *b, const nstime_t *a )
61 if (b->secs == a->secs) {
62 /* The seconds part of b is the same as the seconds part of a, so if
63 the nanoseconds part of the first time is less than the nanoseconds
64 part of a, b is before a. The nanoseconds part of the delta should
65 just be the difference between the nanoseconds part of b and the
66 nanoseconds part of a; don't adjust the seconds part of the delta,
67 as it's OK if the nanoseconds part is negative, and an overflow
70 delta->nsecs = b->nsecs - a->nsecs;
71 } else if (b->secs <= a->secs) {
72 /* The seconds part of b is less than the seconds part of a, so b is
75 Both the "seconds" and "nanoseconds" value of the delta
76 should have the same sign, so if the difference between the
77 nanoseconds values would be *positive*, subtract 1,000,000,000
78 from it, and add one to the seconds value. */
79 delta->secs = b->secs - a->secs;
80 delta->nsecs = b->nsecs - a->nsecs;
81 if(delta->nsecs > 0) {
82 delta->nsecs -= NS_PER_S;
86 delta->secs = b->secs - a->secs;
87 delta->nsecs = b->nsecs - a->nsecs;
88 if(delta->nsecs < 0) {
89 delta->nsecs += NS_PER_S;
96 * function: nstime_sum
100 void nstime_sum(nstime_t *sum, const nstime_t *a, const nstime_t *b)
102 sum->secs = a->secs + b->secs;
103 sum->nsecs = a->nsecs + b->nsecs;
104 if(sum->nsecs>=NS_PER_S || (sum->nsecs>0 && sum->secs<0)){
105 sum->nsecs-=NS_PER_S;
107 } else if(sum->nsecs<=-NS_PER_S || (sum->nsecs<0 && sum->secs>0)) {
108 sum->nsecs+=NS_PER_S;
114 * function: nstime_to_msec
115 * converts nstime to double, time base is milli seconds
118 double nstime_to_msec(const nstime_t *time)
120 return ((double)time->secs*1000 + (double)time->nsecs/1000000);
124 * function: nstime_to_sec
125 * converts nstime to double, time base is seconds
128 double nstime_to_sec(const nstime_t *time)
130 return ((double)time->secs + (double)time->nsecs/1000000000);