summaryrefslogtreecommitdiff
path: root/ssl/pqueue.c
blob: 548a7a443d914545cfaba504a7583f388d8df2f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/*
 * Copyright 2005-2018 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the OpenSSL license (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#include "ssl_locl.h"
#include <openssl/bn.h>

struct pqueue_st {
    pitem *items;
    int count;
};

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

    if (item == NULL) {
        SSLerr(SSL_F_PITEM_NEW, ERR_R_MALLOC_FAILURE);
        return NULL;
    }

    memcpy(item->priority, prio64be, sizeof(item->priority));
    item->data = data;
    item->next = NULL;
    return item;
}

void pitem_free(pitem *item)
{
    OPENSSL_free(item);
}

pqueue *pqueue_new(void)
{
    pqueue *pq = OPENSSL_zalloc(sizeof(*pq));

    if (pq == NULL)
        SSLerr(SSL_F_PQUEUE_NEW, ERR_R_MALLOC_FAILURE);

    return pq;
}

void pqueue_free(pqueue *pq)
{
    OPENSSL_free(pq);
}

pitem *pqueue_insert(pqueue *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 *pq)
{
    return pq->items;
}

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

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

    return item;
}

pitem *pqueue_find(pqueue *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;

    return found;
}

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

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

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

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

    return ret;
}

size_t pqueue_size(pqueue *pq)
{
    pitem *item = pq->items;
    size_t count = 0;

    while (item != NULL) {
        count++;
        item = item->next;
    }
    return count;
}