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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tv.c,v 1.4 1999/05/17 20:37:52 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 |
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25 | * License along with mLib; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
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28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: tv.c,v $ |
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33 | * Revision 1.4 1999/05/17 20:37:52 mdw |
34 | * New function `tv_addl' to add a literal to a time value. Use magical |
35 | * `MILLION' constant in place of 1000000 for ease of reading. |
36 | * |
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37 | * Revision 1.3 1999/05/06 19:51:36 mdw |
38 | * Reformatted the LGPL notice a little bit. |
39 | * |
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40 | * Revision 1.2 1999/05/05 18:50:31 mdw |
41 | * Change licensing conditions to LGPL. |
42 | * |
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43 | * Revision 1.1 1998/11/25 23:30:01 mdw |
44 | * New file. |
45 | * |
46 | */ |
47 | |
48 | /*----- Header files ------------------------------------------------------*/ |
49 | |
50 | #include <sys/time.h> |
51 | #include "tv.h" |
52 | |
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53 | /*----- A macro to make reading easier ------------------------------------*/ |
54 | |
55 | #define MILLION 1000000 |
56 | |
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57 | /*----- Main code ---------------------------------------------------------*/ |
58 | |
59 | /* --- @tv_add@ --- * |
60 | * |
61 | * Arguments: @struct timeval *dst@ = destination block |
62 | * @const struct timeval *a, *b@ = source blocks |
63 | * |
64 | * Returns: --- |
65 | * |
66 | * Use: Adds two timevals. |
67 | */ |
68 | |
69 | void tv_add(struct timeval *dst, |
70 | const struct timeval *a, const struct timeval *b) |
71 | { |
72 | dst->tv_sec = a->tv_sec + b->tv_sec; |
73 | dst->tv_usec = a->tv_usec + b->tv_usec; |
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74 | if (dst->tv_usec >= MILLION) { |
75 | dst->tv_usec -= MILLION; |
76 | dst->tv_sec++; |
77 | } |
78 | } |
79 | |
80 | /* --- @tv_addl@ --- * |
81 | * |
82 | * Arguments: @struct timeval *dst@ = destination block |
83 | * @const struct timeval *a@ = source blocks |
84 | * @time_t sec@, @unsigned long usec@ = time to add |
85 | * |
86 | * Returns: --- |
87 | * |
88 | * Use: Adds a literal time in seconds and microseconds. |
89 | */ |
90 | |
91 | void tv_addl(struct timeval *dst, const struct timeval *a, |
92 | time_t sec, unsigned long usec) |
93 | { |
94 | dst->tv_sec = a->tv_sec + sec; |
95 | dst->tv_usec = a->tv_usec + usec; |
96 | if (dst->tv_usec >= MILLION) { |
97 | dst->tv_usec -= MILLION; |
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98 | dst->tv_sec++; |
99 | } |
100 | } |
101 | |
102 | /* --- @tv_sub@ --- * |
103 | * |
104 | * Arguments: @struct timeval *dst@ = destination block |
105 | * @const struct timeval *a, *b@ = source blocks |
106 | * |
107 | * Returns: --- |
108 | * |
109 | * Use: Subtracts two timevals. |
110 | */ |
111 | |
112 | void tv_sub(struct timeval *dst, |
113 | const struct timeval *a, const struct timeval *b) |
114 | { |
115 | dst->tv_sec = a->tv_sec - b->tv_sec; |
116 | if (a->tv_usec >= b->tv_usec) |
117 | dst->tv_usec = a->tv_usec - b->tv_usec; |
118 | else { |
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119 | dst->tv_usec = a->tv_usec + MILLION - b->tv_usec; |
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120 | dst->tv_sec--; |
121 | } |
122 | } |
123 | |
124 | /* --- @tv_cmp@ --- * |
125 | * |
126 | * Arguments: @const struct timeval *a, *b@ = source blocks |
127 | * |
128 | * Returns: Less than, equal to, or greater than zero. |
129 | * |
130 | * Use: Compares two timevals. |
131 | */ |
132 | |
133 | int tv_cmp(const struct timeval *a, const struct timeval *b) |
134 | { |
135 | if (a->tv_sec > b->tv_sec) |
136 | return (1); |
137 | else if (a->tv_sec < b->tv_sec) |
138 | return (-1); |
139 | else if (a->tv_usec > b->tv_usec) |
140 | return (1); |
141 | else if (a->tv_usec < b->tv_usec) |
142 | return (-1); |
143 | else |
144 | return (0); |
145 | } |
146 | |
147 | /*----- That's all, folks -------------------------------------------------*/ |