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
|
/*
* Copyright (C) 2008 Stig Venaas <venaas@uninett.no>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*/
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include "list.h"
#include "hash.h"
/* allocates and initialises hash structure; returns NULL if malloc fails */
struct hash *hash_create() {
struct hash *h = malloc(sizeof(struct hash));
if (!h)
return NULL;
h->hashlist = list_create();
if (!h->hashlist) {
free(h);
return NULL;
}
pthread_mutex_init(&h->mutex, NULL);
return h;
}
/* frees all memory associated with the hash */
void hash_destroy(struct hash *h) {
struct list_node *ln;
if (!h)
return;
for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
free(((struct hash_entry *)ln->data)->key);
free(((struct hash_entry *)ln->data)->data);
}
list_destroy(h->hashlist);
pthread_mutex_destroy(&h->mutex);
}
/* insert entry in hash; returns 1 if ok, 0 if malloc fails */
int hash_insert(struct hash *h, void *key, uint32_t keylen, void *data) {
struct hash_entry *e;
if (!h)
return 0;
e = malloc(sizeof(struct hash_entry));
if (!e)
return 0;
memset(e, 0, sizeof(struct hash_entry));
e->key = malloc(keylen);
if (!e->key) {
free(e);
return 0;
}
memcpy(e->key, key, keylen);
e->keylen = keylen;
e->data = data;
pthread_mutex_lock(&h->mutex);
if (!list_push(h->hashlist, e)) {
pthread_mutex_unlock(&h->mutex);
free(e->key);
free(e);
return 0;
}
pthread_mutex_unlock(&h->mutex);
return 1;
}
/* reads entry from hash */
void *hash_read(struct hash *h, void *key, uint32_t keylen) {
struct list_node *ln;
struct hash_entry *e;
if (!h)
return 0;
pthread_mutex_lock(&h->mutex);
for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
e = (struct hash_entry *)ln->data;
if (e->keylen == keylen && !memcmp(e->key, key, keylen)) {
pthread_mutex_unlock(&h->mutex);
return e->data;
}
}
pthread_mutex_unlock(&h->mutex);
return NULL;
}
/* extracts entry from hash */
void *hash_extract(struct hash *h, void *key, uint32_t keylen) {
struct list_node *ln;
struct hash_entry *e;
if (!h)
return 0;
pthread_mutex_lock(&h->mutex);
for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
e = (struct hash_entry *)ln->data;
if (e->keylen == keylen && !memcmp(e->key, key, keylen)) {
free(e->key);
list_removedata(h->hashlist, e);
free(e);
pthread_mutex_unlock(&h->mutex);
return e->data;
}
}
pthread_mutex_unlock(&h->mutex);
return NULL;
}
/* returns first entry */
struct hash_entry *hash_first(struct hash *hash) {
struct list_node *ln;
struct hash_entry *e;
if (!hash || !((ln = list_first(hash->hashlist))))
return NULL;
e = (struct hash_entry *)ln->data;
e->next = ln->next;
return e;
}
/* returns the next node after the argument */
struct hash_entry *hash_next(struct hash_entry *entry) {
struct hash_entry *e;
if (!entry || !entry->next)
return NULL;
e = (struct hash_entry *)entry->next->data;
e->next = (struct list_node *)entry->next->next;
return e;
}
|
