net/batman-adv/hash.c

   1 /*
   2  * Copyright (C) 2006-2010 B.A.T.M.A.N. contributors:
   3  *
   4  * Simon Wunderlich, Marek Lindner
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "hash.h"
  24
  25 /* clears the hash */
  26 static void hash_init(struct hashtable_t *hash)
  27 {
  28         int i;
  29
  30         for (i = 0 ; i < hash->size; i++)
  31                 INIT_HLIST_HEAD(&hash->table[i]);
  32 }
  33
  34 /* free only the hashtable and the hash itself. */
  35 void hash_destroy(struct hashtable_t *hash)
  36 {
  37         kfree(hash->table);
  38         kfree(hash);
  39 }
  40
  41 /* allocates and clears the hash */
  42 struct hashtable_t *hash_new(int size)
  43 {
  44         struct hashtable_t *hash;
  45
  46         hash = kmalloc(sizeof(struct hashtable_t) , GFP_ATOMIC);
  47
  48         if (!hash)
  49                 return NULL;
  50
  51         hash->size = size;
  52         hash->table = kmalloc(sizeof(struct element_t *) * size, GFP_ATOMIC);
  53
  54         if (!hash->table) {
  55                 kfree(hash);
  56                 return NULL;
  57         }
  58
  59         hash_init(hash);
  60
  61         return hash;
  62 }