/* crypto/pqueue/pqueue.c */

/* 

 * DTLS implementation written by Nagendra Modadugu

 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  

 */

/* ====================================================================

 * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer. 

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include "cryptlib.h"

#include <openssl/bn.h>

#include <pqueue.h> 

typedef struct _pqueue

	{

	pitem *items;

	int count;

	} pqueue_s;

EXPORT_C pitem *

pitem_new(PQ_64BIT priority, void *data)

	{

	pitem *item = (pitem *) OPENSSL_malloc(sizeof(pitem));

	if (item == NULL) return NULL;

	pq_64bit_init(&(item->priority));

	pq_64bit_assign(&item->priority, &priority);

	item->data = data;

	item->next = NULL;

	return item;

	}

EXPORT_C void

pitem_free(pitem *item)

	{

	if (item == NULL) return;

	pq_64bit_free(&(item->priority));

	OPENSSL_free(item);

	}

EXPORT_C pqueue_s *

pqueue_new()

	{

	pqueue_s *pq = (pqueue_s *) OPENSSL_malloc(sizeof(pqueue_s));

	if (pq == NULL) return NULL;

	memset(pq, 0x00, sizeof(pqueue_s));

	return pq;

	}

EXPORT_C void

pqueue_free(pqueue_s *pq)

	{

	if (pq == NULL) return;

	OPENSSL_free(pq);

	}

EXPORT_C pitem *

pqueue_insert(pqueue_s *pq, pitem *item)

	{

	pitem *curr, *next;

	if (pq->items == NULL)

		{

		pq->items = item;

		return item;

		}

	for(curr = NULL, next = pq->items; 

		next != NULL;

		curr = next, next = next->next)

		{

		if (pq_64bit_gt(&(next->priority), &(item->priority)))

			{

			item->next = next;

			if (curr == NULL) 

				pq->items = item;

			else  

				curr->next = item;

			return item;

			}

		/* duplicates not allowed */

		if (pq_64bit_eq(&(item->priority), &(next->priority)))

			return NULL;

		}

	item->next = NULL;

	curr->next = item;

	return item;

	}

EXPORT_C pitem *

pqueue_peek(pqueue_s *pq)

	{

	return pq->items;

	}

EXPORT_C pitem *

pqueue_pop(pqueue_s *pq)

	{

	pitem *item = pq->items;

	if (pq->items != NULL)

		pq->items = pq->items->next;

	return item;

	}

EXPORT_C pitem *

pqueue_find(pqueue_s *pq, PQ_64BIT priority)

	{

	pitem *next, *prev = NULL;

	pitem *found = NULL;

	if ( pq->items == NULL)

		return NULL;

	for ( next = pq->items; next->next != NULL; 

		  prev = next, next = next->next)

		{

		if ( pq_64bit_eq(&(next->priority), &priority))

			{

			found = next;

			break;

			}

		}

	/* check the one last node */

	if ( pq_64bit_eq(&(next->priority), &priority))

		found = next;

	if ( ! found)

		return NULL;

#if 0 /* find works in peek mode */

	if ( prev == NULL)

		pq->items = next->next;

	else

		prev->next = next->next;

#endif

	return found;

	}

#if PQ_64BIT_IS_INTEGER

EXPORT_C void

pqueue_print(pqueue_s *pq)

	{

	pitem *item = pq->items;

	while(item != NULL)

		{

		printf("item\t" PQ_64BIT_PRINT "\n", item->priority);

		item = item->next;

		}

	}

#endif

EXPORT_C pitem *

pqueue_iterator(pqueue_s *pq)

	{

	return pqueue_peek(pq);

	}

EXPORT_C pitem *

pqueue_next(pitem **item)

	{

	pitem *ret;

	if ( item == NULL || *item == NULL)

		return NULL;

	/* *item != NULL */

	ret = *item;

	*item = (*item)->next;

	return ret;

	}