usbloadergx/source/libntfs/ntfstime.h
2010-09-24 00:48:03 +00:00

119 lines
3.7 KiB
C

/*
* ntfstime.h - NTFS time related functions. Originated from the Linux-NTFS project.
*
* Copyright (c) 2005 Anton Altaparmakov
* Copyright (c) 2005 Yura Pakhuchiy
* Copyright (c) 2010 Jean-Pierre Andre
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the NTFS-3G
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _NTFS_NTFSTIME_H
#define _NTFS_NTFSTIME_H
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_GETTIMEOFDAY
#include <sys/time.h>
#endif
#include "types.h"
/*
* There are four times more conversions of internal representation
* to ntfs representation than any other conversion, so the most
* efficient internal representation is ntfs representation
* (with low endianness)
*/
typedef sle64 ntfs_time;
#define NTFS_TIME_OFFSET ((s64)(369 * 365 + 89) * 24 * 3600 * 10000000)
/**
* ntfs2timespec - Convert an NTFS time to Unix time
* @ntfs_time: An NTFS time in 100ns units since 1601
*
* NTFS stores times as the number of 100ns intervals since January 1st 1601 at
* 00:00 UTC. This system will not suffer from Y2K problems until ~57000AD.
*
* Return: A Unix time (number of seconds since 1970, and nanoseconds)
*/
static __inline__ struct timespec ntfs2timespec(ntfs_time ntfstime)
{
struct timespec spec;
s64 cputime;
cputime = sle64_to_cpu(ntfstime);
spec.tv_sec = (cputime - (NTFS_TIME_OFFSET)) / 10000000;
spec.tv_nsec = (cputime - (NTFS_TIME_OFFSET) - (s64) spec.tv_sec * 10000000) * 100;
/* force zero nsec for overflowing dates */
if ((spec.tv_nsec < 0) || (spec.tv_nsec > 999999999)) spec.tv_nsec = 0;
return (spec);
}
/**
* timespec2ntfs - Convert Linux time to NTFS time
* @utc_time: Linux time to convert to NTFS
*
* Convert the Linux time @utc_time to its corresponding NTFS time.
*
* Linux stores time in a long at present and measures it as the number of
* 1-second intervals since 1st January 1970, 00:00:00 UTC
* with a separated non-negative nanosecond value
*
* NTFS uses Microsoft's standard time format which is stored in a sle64 and is
* measured as the number of 100 nano-second intervals since 1st January 1601,
* 00:00:00 UTC.
*
* Return: An NTFS time (100ns units since Jan 1601)
*/
static __inline__ ntfs_time timespec2ntfs(struct timespec spec)
{
s64 units;
units = (s64) spec.tv_sec * 10000000 + NTFS_TIME_OFFSET + spec.tv_nsec / 100;
return (cpu_to_le64(units));
}
/*
* Return the current time in ntfs format
*/
static __inline__ ntfs_time ntfs_current_time(void)
{
struct timespec now;
#if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_SYS_CLOCK_GETTIME)
clock_gettime(CLOCK_REALTIME, &now);
#elif defined(HAVE_GETTIMEOFDAY)
struct timeval microseconds;
gettimeofday(&microseconds, (struct timezone*)NULL);
now.tv_sec = microseconds.tv_sec;
now.tv_nsec = microseconds.tv_usec*1000;
#else
now.tv_sec = time((time_t*) NULL);
now.tv_nsec = 0;
#endif
return (timespec2ntfs(now));
}
#endif /* _NTFS_NTFSTIME_H */