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1/*
2 * Implementation of the hash table type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6#include <linux/kernel.h>
7#include <linux/slab.h>
8#include <linux/errno.h>
9#include <linux/sched.h>
10#include "hashtab.h"
11
12struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
13 int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
14 u32 size)
15{
16 struct hashtab *p;
17 u32 i;
18
19 p = kzalloc(sizeof(*p), GFP_KERNEL);
20 if (p == NULL)
21 return p;
22
23 p->size = size;
24 p->nel = 0;
25 p->hash_value = hash_value;
26 p->keycmp = keycmp;
27 p->htable = kmalloc(sizeof(*(p->htable)) * size, GFP_KERNEL);
28 if (p->htable == NULL) {
29 kfree(p);
30 return NULL;
31 }
32
33 for (i = 0; i < size; i++)
34 p->htable[i] = NULL;
35
36 return p;
37}
38
39int hashtab_insert(struct hashtab *h, void *key, void *datum)
40{
41 u32 hvalue;
42 struct hashtab_node *prev, *cur, *newnode;
43
44 cond_resched();
45
46 if (!h || h->nel == HASHTAB_MAX_NODES)
47 return -EINVAL;
48
49 hvalue = h->hash_value(h, key);
50 prev = NULL;
51 cur = h->htable[hvalue];
52 while (cur && h->keycmp(h, key, cur->key) > 0) {
53 prev = cur;
54 cur = cur->next;
55 }
56
57 if (cur && (h->keycmp(h, key, cur->key) == 0))
58 return -EEXIST;
59
60 newnode = kzalloc(sizeof(*newnode), GFP_KERNEL);
61 if (newnode == NULL)
62 return -ENOMEM;
63 newnode->key = key;
64 newnode->datum = datum;
65 if (prev) {
66 newnode->next = prev->next;
67 prev->next = newnode;
68 } else {
69 newnode->next = h->htable[hvalue];
70 h->htable[hvalue] = newnode;
71 }
72
73 h->nel++;
74 return 0;
75}
76
77void *hashtab_search(struct hashtab *h, const void *key)
78{
79 u32 hvalue;
80 struct hashtab_node *cur;
81
82 if (!h)
83 return NULL;
84
85 hvalue = h->hash_value(h, key);
86 cur = h->htable[hvalue];
87 while (cur && h->keycmp(h, key, cur->key) > 0)
88 cur = cur->next;
89
90 if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
91 return NULL;
92
93 return cur->datum;
94}
95
96void hashtab_destroy(struct hashtab *h)
97{
98 u32 i;
99 struct hashtab_node *cur, *temp;
100
101 if (!h)
102 return;
103
104 for (i = 0; i < h->size; i++) {
105 cur = h->htable[i];
106 while (cur) {
107 temp = cur;
108 cur = cur->next;
109 kfree(temp);
110 }
111 h->htable[i] = NULL;
112 }
113
114 kfree(h->htable);
115 h->htable = NULL;
116
117 kfree(h);
118}
119
120int hashtab_map(struct hashtab *h,
121 int (*apply)(void *k, void *d, void *args),
122 void *args)
123{
124 u32 i;
125 int ret;
126 struct hashtab_node *cur;
127
128 if (!h)
129 return 0;
130
131 for (i = 0; i < h->size; i++) {
132 cur = h->htable[i];
133 while (cur) {
134 ret = apply(cur->key, cur->datum, args);
135 if (ret)
136 return ret;
137 cur = cur->next;
138 }
139 }
140 return 0;
141}
142
143
144void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
145{
146 u32 i, chain_len, slots_used, max_chain_len;
147 struct hashtab_node *cur;
148
149 slots_used = 0;
150 max_chain_len = 0;
151 for (slots_used = max_chain_len = i = 0; i < h->size; i++) {
152 cur = h->htable[i];
153 if (cur) {
154 slots_used++;
155 chain_len = 0;
156 while (cur) {
157 chain_len++;
158 cur = cur->next;
159 }
160
161 if (chain_len > max_chain_len)
162 max_chain_len = chain_len;
163 }
164 }
165
166 info->slots_used = slots_used;
167 info->max_chain_len = max_chain_len;
168}
1/*
2 * Implementation of the hash table type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6#include <linux/kernel.h>
7#include <linux/slab.h>
8#include <linux/errno.h>
9#include "hashtab.h"
10
11struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
12 int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
13 u32 size)
14{
15 struct hashtab *p;
16 u32 i;
17
18 p = kzalloc(sizeof(*p), GFP_KERNEL);
19 if (p == NULL)
20 return p;
21
22 p->size = size;
23 p->nel = 0;
24 p->hash_value = hash_value;
25 p->keycmp = keycmp;
26 p->htable = kmalloc(sizeof(*(p->htable)) * size, GFP_KERNEL);
27 if (p->htable == NULL) {
28 kfree(p);
29 return NULL;
30 }
31
32 for (i = 0; i < size; i++)
33 p->htable[i] = NULL;
34
35 return p;
36}
37
38int hashtab_insert(struct hashtab *h, void *key, void *datum)
39{
40 u32 hvalue;
41 struct hashtab_node *prev, *cur, *newnode;
42
43 if (!h || h->nel == HASHTAB_MAX_NODES)
44 return -EINVAL;
45
46 hvalue = h->hash_value(h, key);
47 prev = NULL;
48 cur = h->htable[hvalue];
49 while (cur && h->keycmp(h, key, cur->key) > 0) {
50 prev = cur;
51 cur = cur->next;
52 }
53
54 if (cur && (h->keycmp(h, key, cur->key) == 0))
55 return -EEXIST;
56
57 newnode = kzalloc(sizeof(*newnode), GFP_KERNEL);
58 if (newnode == NULL)
59 return -ENOMEM;
60 newnode->key = key;
61 newnode->datum = datum;
62 if (prev) {
63 newnode->next = prev->next;
64 prev->next = newnode;
65 } else {
66 newnode->next = h->htable[hvalue];
67 h->htable[hvalue] = newnode;
68 }
69
70 h->nel++;
71 return 0;
72}
73
74void *hashtab_search(struct hashtab *h, const void *key)
75{
76 u32 hvalue;
77 struct hashtab_node *cur;
78
79 if (!h)
80 return NULL;
81
82 hvalue = h->hash_value(h, key);
83 cur = h->htable[hvalue];
84 while (cur && h->keycmp(h, key, cur->key) > 0)
85 cur = cur->next;
86
87 if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
88 return NULL;
89
90 return cur->datum;
91}
92
93void hashtab_destroy(struct hashtab *h)
94{
95 u32 i;
96 struct hashtab_node *cur, *temp;
97
98 if (!h)
99 return;
100
101 for (i = 0; i < h->size; i++) {
102 cur = h->htable[i];
103 while (cur) {
104 temp = cur;
105 cur = cur->next;
106 kfree(temp);
107 }
108 h->htable[i] = NULL;
109 }
110
111 kfree(h->htable);
112 h->htable = NULL;
113
114 kfree(h);
115}
116
117int hashtab_map(struct hashtab *h,
118 int (*apply)(void *k, void *d, void *args),
119 void *args)
120{
121 u32 i;
122 int ret;
123 struct hashtab_node *cur;
124
125 if (!h)
126 return 0;
127
128 for (i = 0; i < h->size; i++) {
129 cur = h->htable[i];
130 while (cur) {
131 ret = apply(cur->key, cur->datum, args);
132 if (ret)
133 return ret;
134 cur = cur->next;
135 }
136 }
137 return 0;
138}
139
140
141void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
142{
143 u32 i, chain_len, slots_used, max_chain_len;
144 struct hashtab_node *cur;
145
146 slots_used = 0;
147 max_chain_len = 0;
148 for (slots_used = max_chain_len = i = 0; i < h->size; i++) {
149 cur = h->htable[i];
150 if (cur) {
151 slots_used++;
152 chain_len = 0;
153 while (cur) {
154 chain_len++;
155 cur = cur->next;
156 }
157
158 if (chain_len > max_chain_len)
159 max_chain_len = chain_len;
160 }
161 }
162
163 info->slots_used = slots_used;
164 info->max_chain_len = max_chain_len;
165}