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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /net/batman-adv/hash.h | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'net/batman-adv/hash.h')
-rw-r--r-- | net/batman-adv/hash.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/net/batman-adv/hash.h b/net/batman-adv/hash.h new file mode 100644 index 00000000..d4bd7862 --- /dev/null +++ b/net/batman-adv/hash.h @@ -0,0 +1,163 @@ +/* + * Copyright (C) 2006-2012 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 + * 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA + * + */ + +#ifndef _NET_BATMAN_ADV_HASH_H_ +#define _NET_BATMAN_ADV_HASH_H_ + +#include <linux/list.h> + +/* callback to a compare function. should + * compare 2 element datas for their keys, + * return 0 if same and not 0 if not + * same */ +typedef int (*hashdata_compare_cb)(const struct hlist_node *, const void *); + +/* the hashfunction, should return an index + * based on the key in the data of the first + * argument and the size the second */ +typedef uint32_t (*hashdata_choose_cb)(const void *, uint32_t); +typedef void (*hashdata_free_cb)(struct hlist_node *, void *); + +struct hashtable_t { + struct hlist_head *table; /* the hashtable itself with the buckets */ + spinlock_t *list_locks; /* spinlock for each hash list entry */ + uint32_t size; /* size of hashtable */ +}; + +/* allocates and clears the hash */ +struct hashtable_t *hash_new(uint32_t size); + +/* free only the hashtable and the hash itself. */ +void hash_destroy(struct hashtable_t *hash); + +/* 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. */ +static inline void hash_delete(struct hashtable_t *hash, + hashdata_free_cb free_cb, void *arg) +{ + struct hlist_head *head; + struct hlist_node *node, *node_tmp; + spinlock_t *list_lock; /* spinlock to protect write access */ + uint32_t i; + + for (i = 0; i < hash->size; i++) { + head = &hash->table[i]; + list_lock = &hash->list_locks[i]; + + spin_lock_bh(list_lock); + hlist_for_each_safe(node, node_tmp, head) { + hlist_del_rcu(node); + + if (free_cb) + free_cb(node, arg); + } + spin_unlock_bh(list_lock); + } + + hash_destroy(hash); +} + +/** + * hash_add - adds data to the hashtable + * @hash: storage hash table + * @compare: callback to determine if 2 hash elements are identical + * @choose: callback calculating the hash index + * @data: data passed to the aforementioned callbacks as argument + * @data_node: to be added element + * + * Returns 0 on success, 1 if the element already is in the hash + * and -1 on error. + */ + +static inline int hash_add(struct hashtable_t *hash, + hashdata_compare_cb compare, + hashdata_choose_cb choose, + const void *data, struct hlist_node *data_node) +{ + uint32_t index; + int ret = -1; + struct hlist_head *head; + struct hlist_node *node; + spinlock_t *list_lock; /* spinlock to protect write access */ + + if (!hash) + goto out; + + index = choose(data, hash->size); + head = &hash->table[index]; + list_lock = &hash->list_locks[index]; + + rcu_read_lock(); + __hlist_for_each_rcu(node, head) { + if (!compare(node, data)) + continue; + + ret = 1; + goto err_unlock; + } + rcu_read_unlock(); + + /* no duplicate found in list, add new element */ + spin_lock_bh(list_lock); + hlist_add_head_rcu(data_node, head); + spin_unlock_bh(list_lock); + + ret = 0; + goto out; + +err_unlock: + rcu_read_unlock(); +out: + return ret; +} + +/* 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. */ +static inline void *hash_remove(struct hashtable_t *hash, + hashdata_compare_cb compare, + hashdata_choose_cb choose, void *data) +{ + uint32_t index; + struct hlist_node *node; + struct hlist_head *head; + void *data_save = NULL; + + index = choose(data, hash->size); + head = &hash->table[index]; + + spin_lock_bh(&hash->list_locks[index]); + hlist_for_each(node, head) { + if (!compare(node, data)) + continue; + + data_save = node; + hlist_del_rcu(node); + break; + } + spin_unlock_bh(&hash->list_locks[index]); + + return data_save; +} + +#endif /* _NET_BATMAN_ADV_HASH_H_ */ |