pqueue.c

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/* crypto/pqueue/pqueue.c */
/* 
 * DTLS implementation written by Nagendra Modadugu
 * ([email protected]) 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
 *    [email protected].
 *
 * 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
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */

#include "cryptlib.h"
#include <openssl/bn.h>
#include "pqueue.h"

typedef struct _pqueue
    {
    pitem *items;
    int count;
    } pqueue_s;

pitem *
pitem_new(unsigned char *prio64be, void *data)
    {
    pitem *item = (pitem *) OPENSSL_malloc(sizeof(pitem));
    if (item == NULL) return NULL;

    memcpy(item->priority,prio64be,sizeof(item->priority));

    item->data = data;
    item->next = NULL;

    return item;
    }

void
pitem_free(pitem *item)
    {
    if (item == NULL) return;

    OPENSSL_free(item);
    }

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;
    }

void
pqueue_free(pqueue_s *pq)
    {
    if (pq == NULL) return;

    OPENSSL_free(pq);
    }

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)
        {
        /* we can compare 64-bit value in big-endian encoding
         * with memcmp:-) */
        int cmp = memcmp(next->priority, item->priority,8);
        if (cmp > 0)        /* next > item */
            {
            item->next = next;

            if (curr == NULL) 
                pq->items = item;
            else  
                curr->next = item;

            return item;
            }
        
        else if (cmp == 0)  /* duplicates not allowed */
            return NULL;
        }

    item->next = NULL;
    curr->next = item;

    return item;
    }

pitem *
pqueue_peek(pqueue_s *pq)
    {
    return pq->items;
    }

pitem *
pqueue_pop(pqueue_s *pq)
    {
    pitem *item = pq->items;

    if (pq->items != NULL)
        pq->items = pq->items->next;

    return item;
    }

pitem *
pqueue_find(pqueue_s *pq, unsigned char *prio64be)
    {
    pitem *next;
    pitem *found = NULL;

    if ( pq->items == NULL)
        return NULL;

    for ( next = pq->items; next->next != NULL; next = next->next)
        {
        if ( memcmp(next->priority, prio64be,8) == 0)
            {
            found = next;
            break;
            }
        }
    
    /* check the one last node */
    if ( memcmp(next->priority, prio64be,8) ==0)
        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;
    }

void
pqueue_print(pqueue_s *pq)
    {
    pitem *item = pq->items;

    while(item != NULL)
        {
        printf("item\t%02x%02x%02x%02x%02x%02x%02x%02x\n",
            item->priority[0],item->priority[1],
            item->priority[2],item->priority[3],
            item->priority[4],item->priority[5],
            item->priority[6],item->priority[7]);
        item = item->next;
        }
    }

pitem *
pqueue_iterator(pqueue_s *pq)
    {
    return pqueue_peek(pq);
    }

pitem *
pqueue_next(pitem **item)
    {
    pitem *ret;

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


    /* *item != NULL */
    ret = *item;
    *item = (*item)->next;

    return ret;
    }

int
pqueue_size(pqueue_s *pq)
{
    pitem *item = pq->items;
    int count = 0;
    
    while(item != NULL)
    {
        count++;
        item = item->next;
    }
    return count;
}