- 根目录:
- fs
- udf
- udftime.c
/* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Eggert (eggert@twinsun.com).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/*
* dgb 10/02/98: ripped this from glibc source to help convert timestamps
* to unix time
* 10/04/98: added new table-based lookup after seeing how ugly
* the gnu code is
* blf 09/27/99: ripped out all the old code and inserted new table from
* John Brockmeyer (without leap second corrections)
* rewrote udf_stamp_to_time and fixed timezone accounting in
* udf_time_to_stamp.
*/
/*
* We don't take into account leap seconds. This may be correct or incorrect.
* For more NIST information (especially dealing with leap seconds), see:
* http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include "udfdecl.h"
#define EPOCH_YEAR 1970
#ifndef __isleap
/* Nonzero if YEAR is a leap year (every 4 years,
except every 100th isn't, and every 400th is). */
#define __isleap(year) \
((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
#endif
/* How many days come before each month (0-12). */
static const unsigned short int __mon_yday[2][13] = {
/* Normal years. */
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
/* Leap years. */
{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
};
#define MAX_YEAR_SECONDS 69
#define SPD 0x15180 /*3600*24 */
#define SPY(y, l, s) (SPD * (365 * y + l) + s)
static time_t year_seconds[MAX_YEAR_SECONDS] = {
/*1970*/ SPY(0, 0, 0), SPY(1, 0, 0), SPY(2, 0, 0), SPY(3, 1, 0),
/*1974*/ SPY(4, 1, 0), SPY(5, 1, 0), SPY(6, 1, 0), SPY(7, 2, 0),
/*1978*/ SPY(8, 2, 0), SPY(9, 2, 0), SPY(10, 2, 0), SPY(11, 3, 0),
/*1982*/ SPY(12, 3, 0), SPY(13, 3, 0), SPY(14, 3, 0), SPY(15, 4, 0),
/*1986*/ SPY(16, 4, 0), SPY(17, 4, 0), SPY(18, 4, 0), SPY(19, 5, 0),
/*1990*/ SPY(20, 5, 0), SPY(21, 5, 0), SPY(22, 5, 0), SPY(23, 6, 0),
/*1994*/ SPY(24, 6, 0), SPY(25, 6, 0), SPY(26, 6, 0), SPY(27, 7, 0),
/*1998*/ SPY(28, 7, 0), SPY(29, 7, 0), SPY(30, 7, 0), SPY(31, 8, 0),
/*2002*/ SPY(32, 8, 0), SPY(33, 8, 0), SPY(34, 8, 0), SPY(35, 9, 0),
/*2006*/ SPY(36, 9, 0), SPY(37, 9, 0), SPY(38, 9, 0), SPY(39, 10, 0),
/*2010*/ SPY(40, 10, 0), SPY(41, 10, 0), SPY(42, 10, 0), SPY(43, 11, 0),
/*2014*/ SPY(44, 11, 0), SPY(45, 11, 0), SPY(46, 11, 0), SPY(47, 12, 0),
/*2018*/ SPY(48, 12, 0), SPY(49, 12, 0), SPY(50, 12, 0), SPY(51, 13, 0),
/*2022*/ SPY(52, 13, 0), SPY(53, 13, 0), SPY(54, 13, 0), SPY(55, 14, 0),
/*2026*/ SPY(56, 14, 0), SPY(57, 14, 0), SPY(58, 14, 0), SPY(59, 15, 0),
/*2030*/ SPY(60, 15, 0), SPY(61, 15, 0), SPY(62, 15, 0), SPY(63, 16, 0),
/*2034*/ SPY(64, 16, 0), SPY(65, 16, 0), SPY(66, 16, 0), SPY(67, 17, 0),
/*2038*/ SPY(68, 17, 0)
};
extern struct timezone sys_tz;
#define SECS_PER_HOUR (60 * 60)
#define SECS_PER_DAY (SECS_PER_HOUR * 24)
struct timespec *
udf_disk_stamp_to_time(struct timespec *dest, struct timestamp src)
{
int yday;
u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone);
u16 year = le16_to_cpu(src.year);
uint8_t type = typeAndTimezone >> 12;
int16_t offset;
if (type == 1) {
offset = typeAndTimezone << 4;
/* sign extent offset */
offset = (offset >> 4);
if (offset == -2047) /* unspecified offset */
offset = 0;
} else
offset = 0;
if ((year < EPOCH_YEAR) ||
(year >= EPOCH_YEAR + MAX_YEAR_SECONDS)) {
return NULL;
}
dest->tv_sec = year_seconds[year - EPOCH_YEAR];
dest->tv_sec -= offset * 60;
yday = ((__mon_yday[__isleap(year)][src.month - 1]) + src.day - 1);
dest->tv_sec += (((yday * 24) + src.hour) * 60 + src.minute) * 60 + src.second;
dest->tv_nsec = 1000 * (src.centiseconds * 10000 +
src.hundredsOfMicroseconds * 100 + src.microseconds);
return dest;
}
struct timestamp *
udf_time_to_disk_stamp(struct timestamp *dest, struct timespec ts)
{
long int days, rem, y;
const unsigned short int *ip;
int16_t offset;
offset = -sys_tz.tz_minuteswest;
if (!dest)
return NULL;
dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF));
ts.tv_sec += offset * 60;
days = ts.tv_sec / SECS_PER_DAY;
rem = ts.tv_sec % SECS_PER_DAY;
dest->hour = rem / SECS_PER_HOUR;
rem %= SECS_PER_HOUR;
dest->minute = rem / 60;
dest->second = rem % 60;
y = 1970;
#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
while (days < 0 || days >= (__isleap(y) ? 366 : 365)) {
long int yg = y + days / 365 - (days % 365 < 0);
/* Adjust DAYS and Y to match the guessed year. */
days -= ((yg - y) * 365
+ LEAPS_THRU_END_OF(yg - 1)
- LEAPS_THRU_END_OF(y - 1));
y = yg;
}
dest->year = cpu_to_le16(y);
ip = __mon_yday[__isleap(y)];
for (y = 11; days < (long int)ip[y]; --y)
continue;
days -= ip[y];
dest->month = y + 1;
dest->day = days + 1;
dest->centiseconds = ts.tv_nsec / 10000000;
dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 -
dest->centiseconds * 10000) / 100;
dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 -
dest->hundredsOfMicroseconds * 100);
return dest;
}
/* EOF */