vlc_mtime.h

Go to the documentation of this file.

/*****************************************************************************
 * 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 VLC authors and VideoLAN
 * $Id: 311eb670eb7b9f35668196b78c9fa3c5cf1779db $
 *
 * 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 Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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.
 *****************************************************************************/
 
#ifndef __VLC_MTIME_H
# define __VLC_MTIME_H 1
 
/*****************************************************************************
 * 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
 
/*****************************************************************************
 * Prototypes
 *****************************************************************************/
VLC_API char * secstotimestr( char *psz_buffer, int32_t 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_API void date_Init( date_t *, uint32_t, uint32_t );
VLC_API void date_Change( date_t *, uint32_t, uint32_t );
VLC_API void date_Set( date_t *, mtime_t );
VLC_API mtime_t date_Get( const date_t * );
VLC_API void date_Move( date_t *, mtime_t );
VLC_API mtime_t date_Increment( date_t *, uint32_t );
VLC_API mtime_t date_Decrement( date_t *, uint32_t );
VLC_API uint64_t NTPtime64( void );
#endif /* !__VLC_MTIME_ */