vlc/include/vlc_mtime.h
2007-02-09 18:24:06 +00:00

90 lines
4.4 KiB
C

/*****************************************************************************
* vlc_mtime.h: high resolution time management functions
*****************************************************************************
* This header provides portable high precision time management functions,
* which should be the only ones used in other segments of the program, since
* functions like gettimeofday() and ftime() are not always supported.
* Most functions are declared as inline or as macros since they are only
* interfaces to system calls and have to be called frequently.
* 'm' stands for 'micro', since maximum resolution is the microsecond.
* Functions prototyped are implemented in interface/mtime.c.
*****************************************************************************
* Copyright (C) 1996, 1997, 1998, 1999, 2000 the VideoLAN team
* $Id$
*
* Authors: Vincent Seguin <seguin@via.ecp.fr>
*
* This program 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 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; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#if !defined( __LIBVLC__ )
#error You are not libvlc or one of its plugins. You cannot include this file
#endif
/*****************************************************************************
* LAST_MDATE: date which will never happen
*****************************************************************************
* This date can be used as a 'never' date, to mark missing events in a function
* supposed to return a date, such as nothing to display in a function
* returning the date of the first image to be displayed. It can be used in
* comparaison with other values: all existing dates will be earlier.
*****************************************************************************/
#define LAST_MDATE ((mtime_t)((uint64_t)(-1)/2))
/*****************************************************************************
* MSTRTIME_MAX_SIZE: maximum possible size of mstrtime
*****************************************************************************
* This values is the maximal possible size of the string returned by the
* mstrtime() function, including '-' and the final '\0'. It should be used to
* allocate the buffer.
*****************************************************************************/
#define MSTRTIME_MAX_SIZE 22
/* Well, Duh? But it does clue us in that we are converting from
millisecond quantity to a second quantity or vice versa.
*/
#define MILLISECONDS_PER_SEC 1000
#define msecstotimestr(psz_buffer, msecs) \
secstotimestr( psz_buffer, (msecs / (int) MILLISECONDS_PER_SEC) )
/*****************************************************************************
* Prototypes
*****************************************************************************/
VLC_EXPORT( char *, mstrtime, ( char *psz_buffer, mtime_t date ) );
VLC_EXPORT( mtime_t, mdate, ( void ) );
VLC_EXPORT( void, mwait, ( mtime_t date ) );
VLC_EXPORT( void, msleep, ( mtime_t delay ) );
VLC_EXPORT( char *, secstotimestr, ( char *psz_buffer, int secs ) );
/*****************************************************************************
* date_t: date incrementation without long-term rounding errors
*****************************************************************************/
struct date_t
{
mtime_t date;
uint32_t i_divider_num;
uint32_t i_divider_den;
uint32_t i_remainder;
};
VLC_EXPORT( void, date_Init, ( date_t *, uint32_t, uint32_t ) );
VLC_EXPORT( void, date_Change, ( date_t *, uint32_t, uint32_t ) );
VLC_EXPORT( void, date_Set, ( date_t *, mtime_t ) );
VLC_EXPORT( mtime_t, date_Get, ( const date_t * ) );
VLC_EXPORT( void, date_Move, ( date_t *, mtime_t ) );
VLC_EXPORT( mtime_t, date_Increment, ( date_t *, uint32_t ) );
VLC_EXPORT( uint64_t, NTPtime64, ( void ) );