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/*
* 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). */
#ifndef OPENSSL_HEADER_PQUEUE_H
#define OPENSSL_HEADER_PQUEUE_H
#include <openssl/base.h>
#if defined(__cplusplus)
extern "C" {
#endif
/* Priority queue.
*
* The priority queue maintains a linked-list of nodes, each with a unique,
* 64-bit priority, in ascending priority order. */
typedef struct _pqueue *pqueue;
typedef struct _pitem {
uint8_t priority[8]; /* 64-bit value in big-endian encoding */
void *data;
struct _pitem *next;
} pitem;
typedef struct _pitem *piterator;
/* Creating and freeing queues. */
/* pqueue_new allocates a fresh, empty priority queue object and returns it, or
* NULL on error. */
pqueue pqueue_new();
/* pqueue_free frees |pq| but not any of the items it points to. Thus |pq| must
* be empty or a memory leak will occur. */
void pqueue_free(pqueue pq);
/* Creating and freeing items. */
/* pitem_new allocates a fresh priority queue item that points at |data| and
* has a priority given by |prio64be|, which is a 64-bit, unsigned number
* expressed in big-endian form. It returns the fresh item, or NULL on
* error. */
pitem *pitem_new(uint8_t prio64be[8], void *data);
/* pitem_free frees |item|, but not any data that it points to. */
void pitem_free(pitem *item);
/* Queue accessor functions */
/* pqueue_peek returns the item with the smallest priority from |pq|, or NULL
* if empty. */
pitem *pqueue_peek(pqueue pq);
/* pqueue_find returns the item whose priority matches |prio64be| or NULL if no
* such item exists. */
pitem *pqueue_find(pqueue pq, unsigned char *prio64be);
/* Queue mutation functions */
/* pqueue_insert inserts |item| into |pq| and returns item. */
pitem *pqueue_insert(pqueue pq, pitem *item);
/* pqueue_pop takes the item with the least priority from |pq| and returns it,
* or NULL if |pq| is empty. */
pitem *pqueue_pop(pqueue pq);
/* pqueue_size returns the number of items in |pq|. */
size_t pqueue_size(pqueue pq);
/* Iterating */
/* pqueue_iterator returns an iterator that can be used to iterate over the
* contents of the queue. */
pitem *pqueue_iterator(pqueue pq);
/* pqueue_next returns the current value of |iter| and advances it to the next
* position. If the iterator has advanced over all the elements, it returns
* NULL. */
pitem *pqueue_next(piterator *iter);
#if defined(__cplusplus)
} /* extern C */
#endif
#endif /* OPENSSL_HEADER_PQUEUE_H */