179 строки
3.2 KiB
C
179 строки
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Implementation of the hash table type.
|
|
*
|
|
* Author : Stephen Smalley, <sds@tycho.nsa.gov>
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/sched.h>
|
|
#include "hashtab.h"
|
|
|
|
static struct kmem_cache *hashtab_node_cachep;
|
|
|
|
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 = kmem_cache_zalloc(hashtab_node_cachep, 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;
|
|
kmem_cache_free(hashtab_node_cachep, 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 (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;
|
|
}
|
|
|
|
void __init hashtab_cache_init(void)
|
|
{
|
|
hashtab_node_cachep = kmem_cache_create("hashtab_node",
|
|
sizeof(struct hashtab_node),
|
|
0, SLAB_PANIC, NULL);
|
|
}
|