166 lines
2.9 KiB
C
166 lines
2.9 KiB
C
/*
|
|
* 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 "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 == NULL)
|
|
return p;
|
|
|
|
p->size = size;
|
|
p->nel = 0;
|
|
p->hash_value = hash_value;
|
|
p->keycmp = keycmp;
|
|
p->htable = kmalloc(sizeof(*(p->htable)) * size, GFP_KERNEL);
|
|
if (p->htable == NULL) {
|
|
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;
|
|
|
|
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 == NULL)
|
|
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 == NULL || (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;
|
|
}
|