ntfstime.h revision 7e7bd3dccbfe8f79e25e5c1554b5bc3a9aaca321
/*
* ntfstime.h - NTFS time related functions. Part of the Linux-NTFS project.
*
* Copyright (c) 2005 Anton Altaparmakov
* Copyright (c) 2005-2007 Yura Pakhuchiy
*
* 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 Linux-NTFS
* 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
#include "types.h"
#define NTFS_TIME_OFFSET ((s64)(369 * 365 + 89) * 24 * 3600 * 10000000)
/**
* ntfs2utc - 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: n A Unix time (number of seconds since 1970)
*/
static __inline__ time_t ntfs2utc(sle64 ntfs_time)
{
return (sle64_to_cpu(ntfs_time) - (NTFS_TIME_OFFSET)) / 10000000;
}
/**
* utc2ntfs - 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.
*
* NTFS uses Microsoft's standard time format which is stored in a s64 and is
* measured as the number of 100 nano-second intervals since 1st January 1601,
* 00:00:00 UTC.
*
* Return: n An NTFS time (100ns units since Jan 1601)
*/
static __inline__ sle64 utc2ntfs(time_t utc_time)
{
/* Convert to 100ns intervals and then add the NTFS time offset. */
return cpu_to_sle64((s64)utc_time * 10000000 + NTFS_TIME_OFFSET);
}
#endif /* _NTFS_NTFSTIME_H */