| 1 | /* $NetBSD: clock.h,v 1.7 2023/10/27 14:34:58 jschauma 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 | #if !defined(_KERNEL) && !defined(_STANDALONE) |
| 36 | #include <stdint.h> |
| 37 | #endif |
| 38 | |
| 39 | /* Some handy constants. */ |
| 40 | #define SECS_PER_MINUTE 60 |
| 41 | #define SECS_PER_HOUR 3600 |
| 42 | #define SECS_PER_DAY 86400 |
| 43 | #define DAYS_PER_COMMON_YEAR 365 |
| 44 | #define DAYS_PER_LEAP_YEAR 366 |
| 45 | #define SECS_PER_COMMON_YEAR (SECS_PER_DAY * DAYS_PER_COMMON_YEAR) |
| 46 | #define SECS_PER_LEAP_YEAR (SECS_PER_DAY * DAYS_PER_LEAP_YEAR) |
| 47 | |
| 48 | /* Traditional POSIX base year */ |
| 49 | #define POSIX_BASE_YEAR 1970 |
| 50 | |
| 51 | /* Some handy functions */ |
| 52 | static __inline int |
| 53 | days_in_month(int m) |
| 54 | { |
| 55 | switch (m) { |
| 56 | case 2: |
| 57 | return 28; |
| 58 | case 4: case 6: case 9: case 11: |
| 59 | return 30; |
| 60 | case 1: case 3: case 5: case 7: case 8: case 10: case 12: |
| 61 | return 31; |
| 62 | default: |
| 63 | return -1; |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * This inline avoids some unnecessary modulo operations |
| 69 | * as compared with the usual macro: |
| 70 | * ( ((year % 4) == 0 && |
| 71 | * (year % 100) != 0) || |
| 72 | * ((year % 400) == 0) ) |
| 73 | * It is otherwise equivalent. |
| 74 | */ |
| 75 | static __inline int |
| 76 | is_leap_year(uint64_t year) |
| 77 | { |
| 78 | if ((year & 3) != 0) |
| 79 | return 0; |
| 80 | |
| 81 | if (__predict_false((year % 100) != 0)) |
| 82 | return 1; |
| 83 | |
| 84 | return __predict_false((year % 400) == 0); |
| 85 | } |
| 86 | |
| 87 | static __inline int |
| 88 | days_per_year(uint64_t year) |
| 89 | { |
| 90 | return is_leap_year(year) ? DAYS_PER_LEAP_YEAR : DAYS_PER_COMMON_YEAR; |
| 91 | } |
| 92 | |
| 93 | #endif /* _SYS_CLOCK_H_ */ |