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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tv.c,v 1.2 1999/05/05 18:50:31 mdw Exp $ |
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4 | * |
5 | * Manipulation of timeval structures |
6 | * |
7 | * (c) 1998 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the mLib utilities library. |
13 | * |
14 | * mLib is free software; you can redistribute it and/or modify |
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15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
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18 | * |
19 | * mLib is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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22 | * GNU Library General Public License for more details. |
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23 | * |
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24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with mLib; if not, write to the Free Software |
26 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: tv.c,v $ |
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32 | * Revision 1.2 1999/05/05 18:50:31 mdw |
33 | * Change licensing conditions to LGPL. |
34 | * |
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35 | * Revision 1.1 1998/11/25 23:30:01 mdw |
36 | * New file. |
37 | * |
38 | */ |
39 | |
40 | /*----- Header files ------------------------------------------------------*/ |
41 | |
42 | #include <sys/time.h> |
43 | #include "tv.h" |
44 | |
45 | /*----- Main code ---------------------------------------------------------*/ |
46 | |
47 | /* --- @tv_add@ --- * |
48 | * |
49 | * Arguments: @struct timeval *dst@ = destination block |
50 | * @const struct timeval *a, *b@ = source blocks |
51 | * |
52 | * Returns: --- |
53 | * |
54 | * Use: Adds two timevals. |
55 | */ |
56 | |
57 | void tv_add(struct timeval *dst, |
58 | const struct timeval *a, const struct timeval *b) |
59 | { |
60 | dst->tv_sec = a->tv_sec + b->tv_sec; |
61 | dst->tv_usec = a->tv_usec + b->tv_usec; |
62 | if (dst->tv_usec >= 1000000) { |
63 | dst->tv_usec -= 1000000; |
64 | dst->tv_sec++; |
65 | } |
66 | } |
67 | |
68 | /* --- @tv_sub@ --- * |
69 | * |
70 | * Arguments: @struct timeval *dst@ = destination block |
71 | * @const struct timeval *a, *b@ = source blocks |
72 | * |
73 | * Returns: --- |
74 | * |
75 | * Use: Subtracts two timevals. |
76 | */ |
77 | |
78 | void tv_sub(struct timeval *dst, |
79 | const struct timeval *a, const struct timeval *b) |
80 | { |
81 | dst->tv_sec = a->tv_sec - b->tv_sec; |
82 | if (a->tv_usec >= b->tv_usec) |
83 | dst->tv_usec = a->tv_usec - b->tv_usec; |
84 | else { |
85 | dst->tv_usec = a->tv_usec + 1000000 - b->tv_usec; |
86 | dst->tv_sec--; |
87 | } |
88 | } |
89 | |
90 | /* --- @tv_cmp@ --- * |
91 | * |
92 | * Arguments: @const struct timeval *a, *b@ = source blocks |
93 | * |
94 | * Returns: Less than, equal to, or greater than zero. |
95 | * |
96 | * Use: Compares two timevals. |
97 | */ |
98 | |
99 | int tv_cmp(const struct timeval *a, const struct timeval *b) |
100 | { |
101 | if (a->tv_sec > b->tv_sec) |
102 | return (1); |
103 | else if (a->tv_sec < b->tv_sec) |
104 | return (-1); |
105 | else if (a->tv_usec > b->tv_usec) |
106 | return (1); |
107 | else if (a->tv_usec < b->tv_usec) |
108 | return (-1); |
109 | else |
110 | return (0); |
111 | } |
112 | |
113 | /*----- That's all, folks -------------------------------------------------*/ |