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* Copyright (C) 2006-2010 B.A.T.M.A.N. contributors:
* Simon Wunderlich, Marek Lindner
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
#ifndef _BATMAN_HASH_H
#define _BATMAN_HASH_H
#define HASHIT(name) struct hash_it_t name = { \
.index = -1, .bucket = NULL, \
.prev_bucket = NULL, \
.first_bucket = NULL }
typedef int (*hashdata_compare_cb)(void *, void *);
typedef int (*hashdata_choose_cb)(void *, int);
typedef void (*hashdata_free_cb)(void *);
struct element_t {
void *data; /* pointer to the data */
struct element_t *next; /* overflow bucket pointer */
struct hash_it_t {
int index;
struct element_t *bucket;
struct element_t *prev_bucket;
struct element_t **first_bucket;
struct hashtable_t {
struct element_t **table; /* the hashtable itself, with the buckets */
int elements; /* number of elements registered */
int size; /* size of hashtable */
hashdata_compare_cb compare;/* callback to a compare function. should
* compare 2 element datas for their keys,
* return 0 if same and not 0 if not
* same */
hashdata_choose_cb choose; /* the hashfunction, should return an index
* based on the key in the data of the first
* argument and the size the second */
/* clears the hash */
void hash_init(struct hashtable_t *hash);
/* allocates and clears the hash */
struct hashtable_t *hash_new(int size, hashdata_compare_cb compare,
hashdata_choose_cb choose);
/* remove bucket (this might be used in hash_iterate() if you already found the
* bucket you want to delete and don't need the overhead to find it again with
* hash_remove(). But usually, you don't want to use this function, as it
* fiddles with hash-internals. */
void *hash_remove_bucket(struct hashtable_t *hash, struct hash_it_t *hash_it_t);
/* remove the hash structure. if hashdata_free_cb != NULL, this function will be
* called to remove the elements inside of the hash. if you don't remove the
* elements, memory might be leaked. */
void hash_delete(struct hashtable_t *hash, hashdata_free_cb free_cb);
/* free only the hashtable and the hash itself. */
void hash_destroy(struct hashtable_t *hash);
/* adds data to the hashtable. returns 0 on success, -1 on error */
int hash_add(struct hashtable_t *hash, void *data);
/* removes data from hash, if found. returns pointer do data on success, so you
* can remove the used structure yourself, or NULL on error . data could be the
* structure you use with just the key filled, we just need the key for
* comparing. */
void *hash_remove(struct hashtable_t *hash, void *data);
/* finds data, based on the key in keydata. returns the found data on success,
* or NULL on error */
void *hash_find(struct hashtable_t *hash, void *keydata);
/* resize the hash, returns the pointer to the new hash or NULL on
* error. removes the old hash on success */
struct hashtable_t *hash_resize(struct hashtable_t *hash, int size);
/* iterate though the hash. first element is selected with iter_in NULL. use
* the returned iterator to access the elements until hash_it_t returns NULL. */
struct hash_it_t *hash_iterate(struct hashtable_t *hash,
struct hash_it_t *iter_in);
/* print the hash table for debugging */
void hash_debug(struct hashtable_t *hash);