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/*
* (C) 2006-2007 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Description: generic hash table implementation
*/
#include "hash.h"
#include "slist.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
struct hashtable_node *hashtable_alloc_node(int datasize, void *data)
{
struct hashtable_node *n;
int size = sizeof(struct hashtable_node) + datasize;
n = malloc(size);
if (!n)
return NULL;
memset(n, 0, size);
memcpy(n->data, data, datasize);
return n;
}
void hashtable_destroy_node(struct hashtable_node *h)
{
free(h);
}
struct hashtable *
hashtable_create(int hashsize, int limit, int datasize,
uint32_t (*hash)(const void *data, struct hashtable *table),
int (*compare)(const void *data1, const void *data2))
{
int i;
struct hashtable *h;
int size = sizeof(struct hashtable)
+ hashsize * sizeof(struct slist_head);
h = (struct hashtable *) malloc(size);
if (!h) {
errno = ENOMEM;
return NULL;
}
memset(h, 0, size);
for (i=0; i<hashsize; i++)
INIT_SLIST_HEAD(h->members[i]);
h->hashsize = hashsize;
h->limit = limit;
h->datasize = datasize;
h->hash = hash;
h->compare = compare;
return h;
}
void hashtable_destroy(struct hashtable *h)
{
hashtable_flush(h);
free(h);
}
void *hashtable_add(struct hashtable *table, void *data)
{
struct slist_head *e;
struct hashtable_node *n;
uint32_t id;
/* hash table is full */
if (table->count >= table->limit) {
errno = ENOSPC;
return NULL;
}
id = table->hash(data, table);
slist_for_each(e, &table->members[id]) {
n = slist_entry(e, struct hashtable_node, head);
if (table->compare(n->data, data)) {
errno = EEXIST;
return NULL;
}
}
n = hashtable_alloc_node(table->datasize, data);
if (n == NULL) {
errno = ENOMEM;
return NULL;
}
slist_add(&table->members[id], &n->head);
table->count++;
return n->data;
}
void *hashtable_test(struct hashtable *table, const void *data)
{
struct slist_head *e;
uint32_t id;
struct hashtable_node *n;
id = table->hash(data, table);
slist_for_each(e, &table->members[id]) {
n = slist_entry(e, struct hashtable_node, head);
if (table->compare(n->data, data))
return n->data;
}
errno = ENOENT;
return NULL;
}
int hashtable_del(struct hashtable *table, void *data)
{
struct slist_head *e, *next, *prev;
uint32_t id;
struct hashtable_node *n;
id = table->hash(data, table);
slist_for_each_safe(e, prev, next, &table->members[id]) {
n = slist_entry(e, struct hashtable_node, head);
if (table->compare(n->data, data)) {
slist_del(e, prev);
hashtable_destroy_node(n);
table->count--;
return 0;
}
}
errno = ENOENT;
return -1;
}
int hashtable_flush(struct hashtable *table)
{
uint32_t i;
struct slist_head *e, *next, *prev;
struct hashtable_node *n;
for (i=0; i < table->hashsize; i++)
slist_for_each_safe(e, prev, next, &table->members[i]) {
n = slist_entry(e, struct hashtable_node, head);
slist_del(e, prev);
hashtable_destroy_node(n);
}
table->count = 0;
return 0;
}
int hashtable_iterate(struct hashtable *table, void *data,
int (*iterate)(void *data1, void *data2))
{
uint32_t i;
struct slist_head *e, *next, *prev;
struct hashtable_node *n;
for (i=0; i < table->hashsize; i++) {
slist_for_each_safe(e, prev, next, &table->members[i]) {
n = slist_entry(e, struct hashtable_node, head);
if (iterate(data, n->data) == -1)
return -1;
}
}
return 0;
}
unsigned int hashtable_counter(const struct hashtable *table)
{
return table->count;
}
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