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
159
160
161
162
163
164
165
166
167
168
|
/*
* Implementation of the hash table type.
*
* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include "hashtab.h"
struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
u32 size)
{
struct hashtab *p;
u32 i;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return p;
p->size = size;
p->nel = 0;
p->hash_value = hash_value;
p->keycmp = keycmp;
p->htable = kmalloc_array(size, sizeof(*p->htable), GFP_KERNEL);
if (!p->htable) {
kfree(p);
return NULL;
}
for (i = 0; i < size; i++)
p->htable[i] = NULL;
return p;
}
int hashtab_insert(struct hashtab *h, void *key, void *datum)
{
u32 hvalue;
struct hashtab_node *prev, *cur, *newnode;
cond_resched();
if (!h || h->nel == HASHTAB_MAX_NODES)
return -EINVAL;
hvalue = h->hash_value(h, key);
prev = NULL;
cur = h->htable[hvalue];
while (cur && h->keycmp(h, key, cur->key) > 0) {
prev = cur;
cur = cur->next;
}
if (cur && (h->keycmp(h, key, cur->key) == 0))
return -EEXIST;
newnode = kzalloc(sizeof(*newnode), GFP_KERNEL);
if (!newnode)
return -ENOMEM;
newnode->key = key;
newnode->datum = datum;
if (prev) {
newnode->next = prev->next;
prev->next = newnode;
} else {
newnode->next = h->htable[hvalue];
h->htable[hvalue] = newnode;
}
h->nel++;
return 0;
}
void *hashtab_search(struct hashtab *h, const void *key)
{
u32 hvalue;
struct hashtab_node *cur;
if (!h)
return NULL;
hvalue = h->hash_value(h, key);
cur = h->htable[hvalue];
while (cur && h->keycmp(h, key, cur->key) > 0)
cur = cur->next;
if (!cur || (h->keycmp(h, key, cur->key) != 0))
return NULL;
return cur->datum;
}
void hashtab_destroy(struct hashtab *h)
{
u32 i;
struct hashtab_node *cur, *temp;
if (!h)
return;
for (i = 0; i < h->size; i++) {
cur = h->htable[i];
while (cur) {
temp = cur;
cur = cur->next;
kfree(temp);
}
h->htable[i] = NULL;
}
kfree(h->htable);
h->htable = NULL;
kfree(h);
}
int hashtab_map(struct hashtab *h,
int (*apply)(void *k, void *d, void *args),
void *args)
{
u32 i;
int ret;
struct hashtab_node *cur;
if (!h)
return 0;
for (i = 0; i < h->size; i++) {
cur = h->htable[i];
while (cur) {
ret = apply(cur->key, cur->datum, args);
if (ret)
return ret;
cur = cur->next;
}
}
return 0;
}
void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
{
u32 i, chain_len, slots_used, max_chain_len;
struct hashtab_node *cur;
slots_used = 0;
max_chain_len = 0;
for (slots_used = max_chain_len = i = 0; i < h->size; i++) {
cur = h->htable[i];
if (cur) {
slots_used++;
chain_len = 0;
while (cur) {
chain_len++;
cur = cur->next;
}
if (chain_len > max_chain_len)
max_chain_len = chain_len;
}
}
info->slots_used = slots_used;
info->max_chain_len = max_chain_len;
}
|
