1/*	$NetBSD: cdf_time.c,v 1.12 2023/08/18 19:00:11 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2008 Christos Zoulas
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "file.h"
30
31#ifndef lint
32#if 0
33FILE_RCSID("@(#)$File: cdf_time.c,v 1.24 2023/07/17 15:54:44 christos Exp $")
34#else
35__RCSID("$NetBSD: cdf_time.c,v 1.12 2023/08/18 19:00:11 christos Exp $");
36#endif
37#endif
38
39#include <time.h>
40#ifdef TEST
41#include <err.h>
42#endif
43#include <string.h>
44
45#include "cdf.h"
46
47#define isleap(y) ((((y) % 4) == 0) && \
48    ((((y) % 100) != 0) || (((y) % 400) == 0)))
49
50static const int mdays[] = {
51    31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
52};
53
54/*
55 * Return the number of days between jan 01 1601 and jan 01 of year.
56 */
57static int
58cdf_getdays(int year)
59{
60	int days = 0;
61	int y;
62
63	for (y = CDF_BASE_YEAR; y < year; y++)
64		days += isleap(y) + 365;
65
66	return days;
67}
68
69/*
70 * Return the day within the month
71 */
72static int
73cdf_getday(int year, int days)
74{
75	size_t m;
76
77	for (m = 0; m < __arraycount(mdays); m++) {
78		int sub = mdays[m] + (m == 1 && isleap(year));
79		if (days < sub)
80			return days;
81		days -= sub;
82	}
83	return days;
84}
85
86/*
87 * Return the 0...11 month number.
88 */
89static int
90cdf_getmonth(int year, int days)
91{
92	size_t m;
93
94	for (m = 0; m < __arraycount(mdays); m++) {
95		days -= mdays[m];
96		if (m == 1 && isleap(year))
97			days--;
98		if (days <= 0)
99			return CAST(int, m);
100	}
101	return CAST(int, m);
102}
103
104int
105cdf_timestamp_to_timespec(struct timespec *ts, cdf_timestamp_t t)
106{
107	struct tm tm;
108#ifdef HAVE_STRUCT_TM_TM_ZONE
109	static char UTC[] = "UTC";
110#endif
111	int rdays;
112
113	/* Unit is 100's of nanoseconds */
114	ts->tv_nsec = (t % CDF_TIME_PREC) * 100;
115
116	t /= CDF_TIME_PREC;
117	tm.tm_sec = CAST(int, t % 60);
118	t /= 60;
119
120	tm.tm_min = CAST(int, t % 60);
121	t /= 60;
122
123	tm.tm_hour = CAST(int, t % 24);
124	t /= 24;
125
126	/* XXX: Approx */
127	tm.tm_year = CAST(int, CDF_BASE_YEAR + (t / 365));
128
129	rdays = cdf_getdays(tm.tm_year);
130	t -= rdays - 1;
131	tm.tm_mday = cdf_getday(tm.tm_year, CAST(int, t));
132	tm.tm_mon = cdf_getmonth(tm.tm_year, CAST(int, t));
133	tm.tm_wday = 0;
134	tm.tm_yday = 0;
135	tm.tm_isdst = 0;
136#ifdef HAVE_STRUCT_TM_TM_GMTOFF
137	tm.tm_gmtoff = 0;
138#endif
139#ifdef HAVE_STRUCT_TM_TM_ZONE
140	tm.tm_zone = UTC;
141#endif
142	tm.tm_year -= 1900;
143	ts->tv_sec = mktime(&tm);
144	if (ts->tv_sec == -1) {
145		errno = EINVAL;
146		return -1;
147	}
148	return 0;
149}
150
151int
152/*ARGSUSED*/
153cdf_timespec_to_timestamp(cdf_timestamp_t *t, const struct timespec *ts)
154{
155#ifndef __lint__
156	(void)&t;
157	(void)&ts;
158#endif
159#ifdef notyet
160	struct tm tm;
161	if (gmtime_r(&ts->ts_sec, &tm) == NULL) {
162		errno = EINVAL;
163		return -1;
164	}
165	*t = (ts->ts_nsec / 100) * CDF_TIME_PREC;
166	*t += tm.tm_sec;
167	*t += tm.tm_min * 60;
168	*t += tm.tm_hour * 60 * 60;
169	*t += tm.tm_mday * 60 * 60 * 24;
170#endif
171	return 0;
172}
173
174char *
175cdf_ctime(const time_t *sec, char *buf)
176{
177	char *ptr = *sec > MAX_CTIME ? NULL : ctime_r(sec, buf);
178	if (ptr != NULL)
179		return buf;
180#ifdef WIN32
181	(void)snprintf(buf, 26, "*Bad* 0x%16.16I64x\n",
182	    CAST(long long, *sec));
183#else
184	(void)snprintf(buf, 26, "*Bad* %#16.16" INT64_T_FORMAT "x\n",
185	    CAST(long long, *sec));
186#endif
187	return buf;
188}
189
190
191#ifdef TEST_TIME
192int
193main(int argc, char *argv[])
194{
195	struct timespec ts;
196	char buf[25];
197	static const cdf_timestamp_t tst = 0x01A5E403C2D59C00ULL;
198	static const char *ref = "Sat Apr 23 01:30:00 1977";
199	char *p, *q;
200
201	cdf_timestamp_to_timespec(&ts, tst);
202	p = cdf_ctime(&ts.tv_sec, buf);
203	if ((q = strchr(p, '\n')) != NULL)
204		*q = '\0';
205	if (strcmp(ref, p) != 0)
206		errx(1, "Error date %s != %s\n", ref, p);
207	return 0;
208}
209#endif
210