omsbuff_isempty.c

linuxUNIX下跑的一套服务端程序

/* * 
 *  $Id: OMSbuff_isempty.c 79 2005-01-18 16:55:45Z shawill $
 *  
 *  This file is part of Fenice
 *
 *  Fenice -- Open Media Server
 *
 *  Copyright (C) 2004 by
 *  	
 *	- Giampaolo Mancini	<[e-mail]>
 *	- Francesco Varano	<[e-mail]>
 *	- Marco Penno		<[e-mail]>
 *	- Federico Ridolfo	<[e-mail]>
 *	- Eugenio Menegatti 	<[e-mail]>
 *	- Stefano Cau
 *	- Giuliano Emma
 *	- Stefano Oldrini
 * 
 *  Fenice 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.
 *
 *  Fenice 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 Fenice; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *  
 * */

#include <stdio.h>

#include <fenice/bufferpool.h>

/*! Check if buffer is empty for a given consumer. 
 *
 * Checks in this function are taken from <tt>OMSbuff_read()</tt> and not
 * optimized
 *
 * \param Consumer to be checked.
 * \return 1 if buffer is empty, 0 if not.
 * \return -1 on error.
 *
 * \see OMSbuff_read
 * */
int OMSbuff_isempty(OMSConsumer *cons)
{
	OMSSlot *last_read = cons->last_read_pos;
	// OMSSlot *next = cons->read_pos->next;
	OMSSlot *next = cons->read_pos;

	if ( !next->refs || (next->slot_seq < cons->last_seq) ) {
		// added some slots?
		if ( last_read && last_read->next->refs && (last_read->next->slot_seq > cons->last_seq) )
			return 0;
		else
			return 1;
	} else if (last_read && ( last_read->next->slot_seq < next->slot_seq ) )
			return 0;

	return 0;
}