1 | /* $NetBSD: clock.h,v 1.3 2014/11/17 17:11:29 christos Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 1996 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Gordon W. Ross |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | #ifndef _SYS_CLOCK_H_ |
33 | #define _SYS_CLOCK_H_ |
34 | |
35 | /* Some handy constants. */ |
36 | #define SECS_PER_MINUTE 60 |
37 | #define SECS_PER_HOUR 3600 |
38 | #define SECS_PER_DAY 86400 |
39 | #define DAYS_PER_COMMON_YEAR 365 |
40 | #define DAYS_PER_LEAP_YEAR 366 |
41 | #define SECS_PER_COMMON_YEAR (SECS_PER_DAY * DAYS_PER_COMMON_YEAR) |
42 | #define SECS_PER_LEAP_YEAR (SECS_PER_DAY * DAYS_PER_LEAP_YEAR) |
43 | |
44 | /* Traditional POSIX base year */ |
45 | #define POSIX_BASE_YEAR 1970 |
46 | |
47 | /* Some handy functions */ |
48 | static inline int |
49 | days_in_month(int m) |
50 | { |
51 | switch (m) { |
52 | case 2: |
53 | return 28; |
54 | case 4: case 6: case 9: case 11: |
55 | return 30; |
56 | case 1: case 3: case 5: case 7: case 8: case 10: case 12: |
57 | return 31; |
58 | default: |
59 | return -1; |
60 | } |
61 | } |
62 | |
63 | /* |
64 | * This inline avoids some unnecessary modulo operations |
65 | * as compared with the usual macro: |
66 | * ( ((year % 4) == 0 && |
67 | * (year % 100) != 0) || |
68 | * ((year % 400) == 0) ) |
69 | * It is otherwise equivalent. |
70 | */ |
71 | static inline int |
72 | is_leap_year(uint64_t year) |
73 | { |
74 | if ((year & 3) != 0) |
75 | return 0; |
76 | |
77 | if (__predict_false((year % 100) != 0)) |
78 | return 1; |
79 | |
80 | return __predict_false((year % 400) == 0); |
81 | } |
82 | |
83 | static inline int |
84 | days_per_year(uint64_t year) |
85 | { |
86 | return is_leap_year(year) ? DAYS_PER_LEAP_YEAR : DAYS_PER_COMMON_YEAR; |
87 | } |
88 | |
89 | #endif /* _SYS_CLOCK_H_ */ |
90 | |