1 /* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Paul Eggert (eggert@twinsun.com).
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
19
20 /*
21 * dgb 10/02/98: ripped this from glibc source to help convert timestamps to unix time
22 * 10/04/98: added new table-based lookup after seeing how ugly the gnu code is
23 * blf 09/27/99: ripped out all the old code and inserted new table from
24 * John Brockmeyer (without leap second corrections)
25 * rewrote udf_stamp_to_time and fixed timezone accounting in
26 udf_time_to_stamp.
27 */
28
29 /*
30 * We don't take into account leap seconds. This may be correct or incorrect.
31 * For more NIST information (especially dealing with leap seconds), see:
32 * http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
33 */
34
35 #include <linux/types.h>
36 #include <linux/kernel.h>
37 #include "udfdecl.h"
38
39 #define EPOCH_YEAR 1970
40
41 #ifndef __isleap
42 /* Nonzero if YEAR is a leap year (every 4 years,
43 except every 100th isn't, and every 400th is). */
44 #define __isleap(year) \
45 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
46 #endif
47
48 /* How many days come before each month (0-12). */
49 const unsigned short int __mon_yday[2][13] =
50 {
51 /* Normal years. */
52 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
53 /* Leap years. */
54 { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
55 };
56
57 #define MAX_YEAR_SECONDS 69
58 #define SPD 0x15180 /*3600*24*/
59 #define SPY(y,l,s) (SPD * (365*y+l)+s)
60
61 static time_t year_seconds[MAX_YEAR_SECONDS]= {
62 /*1970*/ SPY( 0, 0,0), SPY( 1, 0,0), SPY( 2, 0,0), SPY( 3, 1,0),
63 /*1974*/ SPY( 4, 1,0), SPY( 5, 1,0), SPY( 6, 1,0), SPY( 7, 2,0),
64 /*1978*/ SPY( 8, 2,0), SPY( 9, 2,0), SPY(10, 2,0), SPY(11, 3,0),
65 /*1982*/ SPY(12, 3,0), SPY(13, 3,0), SPY(14, 3,0), SPY(15, 4,0),
66 /*1986*/ SPY(16, 4,0), SPY(17, 4,0), SPY(18, 4,0), SPY(19, 5,0),
67 /*1990*/ SPY(20, 5,0), SPY(21, 5,0), SPY(22, 5,0), SPY(23, 6,0),
68 /*1994*/ SPY(24, 6,0), SPY(25, 6,0), SPY(26, 6,0), SPY(27, 7,0),
69 /*1998*/ SPY(28, 7,0), SPY(29, 7,0), SPY(30, 7,0), SPY(31, 8,0),
70 /*2002*/ SPY(32, 8,0), SPY(33, 8,0), SPY(34, 8,0), SPY(35, 9,0),
71 /*2006*/ SPY(36, 9,0), SPY(37, 9,0), SPY(38, 9,0), SPY(39,10,0),
72 /*2010*/ SPY(40,10,0), SPY(41,10,0), SPY(42,10,0), SPY(43,11,0),
73 /*2014*/ SPY(44,11,0), SPY(45,11,0), SPY(46,11,0), SPY(47,12,0),
74 /*2018*/ SPY(48,12,0), SPY(49,12,0), SPY(50,12,0), SPY(51,13,0),
75 /*2022*/ SPY(52,13,0), SPY(53,13,0), SPY(54,13,0), SPY(55,14,0),
76 /*2026*/ SPY(56,14,0), SPY(57,14,0), SPY(58,14,0), SPY(59,15,0),
77 /*2030*/ SPY(60,15,0), SPY(61,15,0), SPY(62,15,0), SPY(63,16,0),
78 /*2034*/ SPY(64,16,0), SPY(65,16,0), SPY(66,16,0), SPY(67,17,0),
79 /*2038*/ SPY(68,17,0)
80 };
81
82 extern struct timezone sys_tz;
83
84 #define SECS_PER_HOUR (60 * 60)
85 #define SECS_PER_DAY (SECS_PER_HOUR * 24)
86
87 time_t *
88 udf_stamp_to_time(time_t *dest, long *dest_usec, kernel_timestamp src)
89 {
90 int yday;
91 uint8_t type = src.typeAndTimezone >> 12;
92 int16_t offset;
93
94 if (type == 1)
95 {
96 offset = src.typeAndTimezone << 4;
97 /* sign extent offset */
98 offset = (offset >> 4);
99 if (offset == -2047) /* unspecified offset */
100 offset = 0;
101 }
102 else
103 offset = 0;
104
105 if ((src.year < EPOCH_YEAR) ||
106 (src.year > EPOCH_YEAR+MAX_YEAR_SECONDS))
107 {
108 *dest = -1;
109 *dest_usec = -1;
110 return NULL;
111 }
112 *dest = year_seconds[src.year - EPOCH_YEAR];
113 *dest -= offset * 60;
114
115 yday = ((__mon_yday[__isleap (src.year)]
116 [src.month-1]) + (src.day-1));
117 *dest += ( ( (yday* 24) + src.hour ) * 60 + src.minute ) * 60 + src.second;
118 *dest_usec = src.centiseconds * 10000 + src.hundredsOfMicroseconds * 100 + src.microseconds;
119 return dest;
120 }
121
122
123 kernel_timestamp *
124 udf_time_to_stamp(kernel_timestamp *dest, struct timespec ts)
125 {
126 long int days, rem, y;
127 const unsigned short int *ip;
128 int16_t offset;
129
130 offset = -sys_tz.tz_minuteswest;
131
132 if (!dest)
133 return NULL;
134
135 dest->typeAndTimezone = 0x1000 | (offset & 0x0FFF);
136
137 ts.tv_sec += offset * 60;
138 days = ts.tv_sec / SECS_PER_DAY;
139 rem = ts.tv_sec % SECS_PER_DAY;
140 dest->hour = rem / SECS_PER_HOUR;
141 rem %= SECS_PER_HOUR;
142 dest->minute = rem / 60;
143 dest->second = rem % 60;
144 y = 1970;
145
146 #define DIV(a,b) ((a) / (b) - ((a) % (b) < 0))
147 #define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
148
149 while (days < 0 || days >= (__isleap(y) ? 366 : 365))
150 {
151 long int yg = y + days / 365 - (days % 365 < 0);
152
153 /* Adjust DAYS and Y to match the guessed year. */
154 days -= ((yg - y) * 365
155 + LEAPS_THRU_END_OF (yg - 1)
156 - LEAPS_THRU_END_OF (y - 1));
157 y = yg;
158 }
159 dest->year = y;
160 ip = __mon_yday[__isleap(y)];
161 for (y = 11; days < (long int) ip[y]; --y)
162 continue;
163 days -= ip[y];
164 dest->month = y + 1;
165 dest->day = days + 1;
166
167 dest->centiseconds = ts.tv_nsec / 10000000;
168 dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000) / 100;
169 dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 -
170 dest->hundredsOfMicroseconds * 100);
171 return dest;
172 }
173
174 /* EOF */
175
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