1 | /* $NetBSD: clock_subr.c,v 1.27 2016/08/15 15:51:39 jakllsch Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1988 University of Utah. |
5 | * Copyright (c) 1982, 1990, 1993 |
6 | * The Regents of the University of California. All rights reserved. |
7 | * |
8 | * This code is derived from software contributed to Berkeley by |
9 | * the Systems Programming Group of the University of Utah Computer |
10 | * Science Department. |
11 | * |
12 | * Redistribution and use in source and binary forms, with or without |
13 | * modification, are permitted provided that the following conditions |
14 | * are met: |
15 | * 1. Redistributions of source code must retain the above copyright |
16 | * notice, this list of conditions and the following disclaimer. |
17 | * 2. Redistributions in binary form must reproduce the above copyright |
18 | * notice, this list of conditions and the following disclaimer in the |
19 | * documentation and/or other materials provided with the distribution. |
20 | * 3. Neither the name of the University nor the names of its contributors |
21 | * may be used to endorse or promote products derived from this software |
22 | * without specific prior written permission. |
23 | * |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
34 | * SUCH DAMAGE. |
35 | * |
36 | * from: Utah $Hdr: clock.c 1.18 91/01/21$ |
37 | * |
38 | * @(#)clock.c 8.2 (Berkeley) 1/12/94 |
39 | */ |
40 | |
41 | /* |
42 | * Generic routines to convert between a POSIX date |
43 | * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec |
44 | * Derived from arch/hp300/hp300/clock.c |
45 | */ |
46 | |
47 | #if HAVE_NBTOOL_CONFIG_H |
48 | #include "nbtool_config.h" |
49 | #endif /* HAVE_NBTOOL_CONFIG_H */ |
50 | |
51 | #ifdef _KERNEL |
52 | #include <sys/cdefs.h> |
53 | __KERNEL_RCSID(0, "$NetBSD: clock_subr.c,v 1.27 2016/08/15 15:51:39 jakllsch Exp $" ); |
54 | |
55 | #include <sys/param.h> |
56 | #include <sys/systm.h> |
57 | #include <sys/errno.h> |
58 | #else /* ! _KERNEL */ |
59 | #include <string.h> |
60 | #include <time.h> |
61 | #include <errno.h> |
62 | #endif /* ! _KERNEL */ |
63 | |
64 | #include "../sys/clock.h" |
65 | #include <dev/clock_subr.h> |
66 | |
67 | #define FEBRUARY 2 |
68 | |
69 | /* for easier alignment: |
70 | * time from the epoch to 2001 (there were 8 leap years): */ |
71 | #define DAYSTO2001 (365*31+8) |
72 | |
73 | /* 4 year intervals include 1 leap year */ |
74 | #define DAYS4YEARS (365*4+1) |
75 | |
76 | /* 100 year intervals include 24 leap years */ |
77 | #define DAYS100YEARS (365*100+24) |
78 | |
79 | /* 400 year intervals include 97 leap years */ |
80 | #define DAYS400YEARS (365*400+97) |
81 | |
82 | time_t |
83 | clock_ymdhms_to_secs(struct clock_ymdhms *dt) |
84 | { |
85 | uint64_t secs, i, year, days; |
86 | |
87 | year = dt->dt_year; |
88 | |
89 | /* |
90 | * Compute days since start of time |
91 | * First from years, then from months. |
92 | */ |
93 | if (year < POSIX_BASE_YEAR) |
94 | return -1; |
95 | days = 0; |
96 | if (is_leap_year(year) && dt->dt_mon > FEBRUARY) |
97 | days++; |
98 | |
99 | if (year < 2001) { |
100 | /* simple way for early years */ |
101 | for (i = POSIX_BASE_YEAR; i < year; i++) |
102 | days += days_per_year(i); |
103 | } else { |
104 | /* years are properly aligned */ |
105 | days += DAYSTO2001; |
106 | year -= 2001; |
107 | |
108 | i = year / 400; |
109 | days += i * DAYS400YEARS; |
110 | year -= i * 400; |
111 | |
112 | i = year / 100; |
113 | days += i * DAYS100YEARS; |
114 | year -= i * 100; |
115 | |
116 | i = year / 4; |
117 | days += i * DAYS4YEARS; |
118 | year -= i * 4; |
119 | |
120 | for (i = dt->dt_year-year; i < dt->dt_year; i++) |
121 | days += days_per_year(i); |
122 | } |
123 | |
124 | |
125 | /* Months */ |
126 | for (i = 1; i < dt->dt_mon; i++) |
127 | days += days_in_month(i); |
128 | days += (dt->dt_day - 1); |
129 | |
130 | /* Add hours, minutes, seconds. */ |
131 | secs = (((uint64_t)days |
132 | * 24 + dt->dt_hour) |
133 | * 60 + dt->dt_min) |
134 | * 60 + dt->dt_sec; |
135 | |
136 | if ((time_t)secs < 0 || secs > __type_max(time_t)) |
137 | return -1; |
138 | return secs; |
139 | } |
140 | |
141 | int |
142 | clock_secs_to_ymdhms(time_t secs, struct clock_ymdhms *dt) |
143 | { |
144 | int leap; |
145 | uint64_t i; |
146 | time_t days; |
147 | time_t rsec; /* remainder seconds */ |
148 | |
149 | if (secs < 0) |
150 | return EINVAL; |
151 | |
152 | days = secs / SECS_PER_DAY; |
153 | rsec = secs % SECS_PER_DAY; |
154 | |
155 | /* Day of week (Note: 1/1/1970 was a Thursday) */ |
156 | dt->dt_wday = (days + 4) % 7; |
157 | |
158 | if (days >= DAYSTO2001) { |
159 | days -= DAYSTO2001; |
160 | dt->dt_year = 2001; |
161 | |
162 | i = days / DAYS400YEARS; |
163 | days -= i*DAYS400YEARS; |
164 | dt->dt_year += i*400; |
165 | |
166 | i = days / DAYS100YEARS; |
167 | days -= i*DAYS100YEARS; |
168 | dt->dt_year += i*100; |
169 | |
170 | i = days / DAYS4YEARS; |
171 | days -= i*DAYS4YEARS; |
172 | dt->dt_year += i*4; |
173 | |
174 | for (i = dt->dt_year; days >= days_per_year(i); i++) |
175 | days -= days_per_year(i); |
176 | dt->dt_year = i; |
177 | } else { |
178 | /* Subtract out whole years, counting them in i. */ |
179 | for (i = POSIX_BASE_YEAR; days >= days_per_year(i); i++) |
180 | days -= days_per_year(i); |
181 | dt->dt_year = i; |
182 | } |
183 | |
184 | /* Subtract out whole months, counting them in i. */ |
185 | for (leap = 0, i = 1; days >= days_in_month(i)+leap; i++) { |
186 | days -= days_in_month(i)+leap; |
187 | if (i == 1 && is_leap_year(dt->dt_year)) |
188 | leap = 1; |
189 | else |
190 | leap = 0; |
191 | } |
192 | dt->dt_mon = i; |
193 | |
194 | /* Days are what is left over (+1) from all that. */ |
195 | dt->dt_day = days + 1; |
196 | |
197 | /* Hours, minutes, seconds are easy */ |
198 | dt->dt_hour = rsec / SECS_PER_HOUR; |
199 | rsec = rsec % SECS_PER_HOUR; |
200 | dt->dt_min = rsec / SECS_PER_MINUTE; |
201 | rsec = rsec % SECS_PER_MINUTE; |
202 | dt->dt_sec = rsec; |
203 | |
204 | return 0; |
205 | } |
206 | |