hslot.c

用来作为linux中SIP SERVER,完成VOIP网络电话中服务器的功能

/* 
 * $Id: hslot.c,v 1.6 2004/08/24 09:00:46 janakj Exp $ 
 *
 * Hash table collision slot related functions
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    [e-mail]
 *
 * ser 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "hslot.h"


/*
 * Initialize cache slot structure
 */
int init_slot(struct udomain* _d, hslot_t* _s)
{
	_s->n = 0;
	_s->first = 0;
	_s->last = 0;
	_s->d = _d;
	return 0;
}


/*
 * Deinitialize given slot structure
 */
void deinit_slot(hslot_t* _s)
{
	struct urecord* ptr;
	
	     /* Remove all elements */
	while(_s->first) {
		ptr = _s->first;
		_s->first = _s->first->s_ll.next;
		free_urecord(ptr);
	}
	
	_s->n = 0;
	_s->last = 0;
        _s->d = 0;
}


/*
 * Add an element to an slot's linked list
 */
void slot_add(hslot_t* _s, struct urecord* _r)
{
	if (_s->n == 0) {
		_s->first = _s->last = _r;
	} else {
		_r->s_ll.prev = _s->last;
		_s->last->s_ll.next = _r;
		_s->last = _r;
	}
	_s->n++;
	_r->slot = _s;
}


/*
 * Remove an element from slot linked list
 */
void slot_rem(hslot_t* _s, struct urecord* _r)
{
	if (_r->s_ll.prev) {
		_r->s_ll.prev->s_ll.next = _r->s_ll.next;
	} else {
		_s->first = _r->s_ll.next;
	}

	if (_r->s_ll.next) {
		_r->s_ll.next->s_ll.prev = _r->s_ll.prev;
	} else {
		_s->last = _r->s_ll.prev;
	}

	_r->s_ll.prev = _r->s_ll.next = 0;
	_r->slot = 0;
	_s->n--;
}