/* $Id: hash.c,v 1.8 2004/04/05 12:47:07 armin Exp $ */
/*
 * Copyright (c) 2003,2004 Armin Wolfermann
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <config.h>
#include "dnsproxy.h"

#define HASHSIZE 10
#define HASH(id) (id & ((1 << HASHSIZE) - 1))

static struct request *request_hash[1 << HASHSIZE];

void
hash_add_request(struct request *req)
{
	struct request **p = &request_hash[HASH(req->id)];

	if ((req->next = *p) != NULL) {
		(*p)->prev = &req->next;
		++hash_collisions;
	}
	*p = req;
	req->prev = p;

	++active_queries;
}

void
hash_remove_request(struct request *req)
{
	if (!req->prev) return;
	if (req->next)
		req->next->prev = req->prev;
	*req->prev = req->next;
	req->prev = NULL;

	--active_queries;
}

struct request *
hash_find_request(unsigned short id)
{
	struct request *req = request_hash[HASH(id)];

	for (;;) {
		if (!req) break;
		if (req->id == id) break;
		req = req->next;
	}

	return req;
}