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Diffstat (limited to 'fs/udf/udftime.c')
| -rw-r--r-- | fs/udf/udftime.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/fs/udf/udftime.c b/fs/udf/udftime.c new file mode 100644 index 000000000..77c331f1a --- /dev/null +++ b/fs/udf/udftime.c @@ -0,0 +1,170 @@ +/* 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 "udfdecl.h" + +#include <linux/types.h> +#include <linux/kernel.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) +}; + +#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 */ |