xref: /dragonfly/contrib/file/src/cdf_time.c (revision 73e0051e)
1 /*-
2  * Copyright (c) 2008 Christos Zoulas
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
15  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
16  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
18  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24  * POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "file.h"
28 
29 #ifndef lint
30 FILE_RCSID("@(#)$File: cdf_time.c,v 1.6 2009/03/10 11:44:29 christos Exp $")
31 #endif
32 
33 #include <time.h>
34 #ifdef TEST
35 #include <err.h>
36 #endif
37 #include <string.h>
38 
39 #include "cdf.h"
40 
41 #define isleap(y) ((((y) % 4) == 0) && \
42     ((((y) % 100) != 0) || (((y) % 400) == 0)))
43 
44 static const int mdays[] = {
45     31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
46 };
47 
48 /*
49  * Return the number of days between jan 01 1601 and jan 01 of year.
50  */
51 static int
52 cdf_getdays(int year)
53 {
54 	int days = 0;
55 	int y;
56 
57 	for (y = CDF_BASE_YEAR; y < year; y++)
58 		days += isleap(y) + 365;
59 
60 	return days;
61 }
62 
63 /*
64  * Return the day within the month
65  */
66 static int
67 cdf_getday(int year, int days)
68 {
69 	size_t m;
70 
71 	for (m = 0; m < sizeof(mdays) / sizeof(mdays[0]); m++) {
72 		int sub = mdays[m] + (m == 1 && isleap(year));
73 		if (days < sub)
74 			return days;
75 		days -= sub;
76 	}
77 	return days;
78 }
79 
80 /*
81  * Return the 0...11 month number.
82  */
83 static int
84 cdf_getmonth(int year, int days)
85 {
86 	size_t m;
87 
88 	for (m = 0; m < sizeof(mdays) / sizeof(mdays[0]); m++) {
89 		days -= mdays[m];
90 		if (m == 1 && isleap(year))
91 			days--;
92 		if (days <= 0)
93 			return (int)m;
94 	}
95 	return (int)m;
96 }
97 
98 int
99 cdf_timestamp_to_timespec(struct timespec *ts, cdf_timestamp_t t)
100 {
101 	struct tm tm;
102 #ifdef HAVE_STRUCT_TM_TM_ZONE
103 	static char UTC[] = "UTC";
104 #endif
105 	int rdays;
106 
107 	/* Unit is 100's of nanoseconds */
108 	ts->tv_nsec = (t % CDF_TIME_PREC) * 100;
109 
110 	t /= CDF_TIME_PREC;
111 	tm.tm_sec = t % 60;
112 	t /= 60;
113 
114 	tm.tm_min = t % 60;
115 	t /= 60;
116 
117 	tm.tm_hour = t % 24;
118 	t /= 24;
119 
120 	// XXX: Approx
121 	tm.tm_year = CDF_BASE_YEAR + (t / 365);
122 
123 	rdays = cdf_getdays(tm.tm_year);
124 	t -= rdays;
125 	tm.tm_mday = cdf_getday(tm.tm_year, t);
126 	tm.tm_mon = cdf_getmonth(tm.tm_year, t);
127 	tm.tm_wday = 0;
128 	tm.tm_yday = 0;
129 	tm.tm_isdst = 0;
130 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
131 	tm.tm_gmtoff = 0;
132 #endif
133 #ifdef HAVE_STRUCT_TM_TM_ZONE
134 	tm.tm_zone = UTC;
135 #endif
136 	tm.tm_year -= 1900;
137 	ts->tv_sec = mktime(&tm);
138 	if (ts->tv_sec == -1) {
139 		errno = EINVAL;
140 		return -1;
141 	}
142 	return 0;
143 }
144 
145 int
146 cdf_timespec_to_timestamp(cdf_timestamp_t *t, const struct timespec *ts)
147 {
148 	(void)&t;
149 	(void)&ts;
150 #ifdef notyet
151 	struct tm tm;
152 	if (gmtime_r(&ts->ts_sec, &tm) == NULL) {
153 		errno = EINVAL;
154 		return -1;
155 	}
156 	*t = (ts->ts_nsec / 100) * CDF_TIME_PREC;
157 	*t = tm.tm_sec;
158 	*t += tm.tm_min * 60;
159 	*t += tm.tm_hour * 60 * 60;
160 	*t += tm.tm_mday * 60 * 60 * 24;
161 #endif
162 	return 0;
163 }
164 
165 
166 #ifdef TEST
167 int
168 main(int argc, char *argv[])
169 {
170 	struct timespec ts;
171 	static const cdf_timestamp_t tst = 0x01A5E403C2D59C00ULL;
172 	static const char *ref = "Sat Apr 23 01:30:00 1977";
173 	char *p, *q;
174 
175 	cdf_timestamp_to_timespec(&ts, tst);
176 	p = ctime(&ts.tv_sec);
177 	if ((q = strchr(p, '\n')) != NULL)
178 		*q = '\0';
179 	if (strcmp(ref, p) != 0)
180 		errx(1, "Error date %s != %s\n", ref, p);
181 	return 0;
182 }
183 #endif
184