Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 1 | /* |
Sven Eckelmann | 567db7b | 2012-01-01 00:41:38 +0100 | [diff] [blame] | 2 | * Copyright (C) 2006-2012 B.A.T.M.A.N. contributors: |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 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 | #ifndef _NET_BATMAN_ADV_HASH_H_ |
| 23 | #define _NET_BATMAN_ADV_HASH_H_ |
| 24 | |
| 25 | #include <linux/list.h> |
| 26 | |
| 27 | /* callback to a compare function. should |
| 28 | * compare 2 element datas for their keys, |
| 29 | * return 0 if same and not 0 if not |
| 30 | * same */ |
Sven Eckelmann | 747e422 | 2011-05-14 23:14:50 +0200 | [diff] [blame] | 31 | typedef int (*hashdata_compare_cb)(const struct hlist_node *, const void *); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 32 | |
| 33 | /* the hashfunction, should return an index |
| 34 | * based on the key in the data of the first |
| 35 | * argument and the size the second */ |
Antonio Quartulli | c90681b | 2011-10-05 17:05:25 +0200 | [diff] [blame] | 36 | typedef uint32_t (*hashdata_choose_cb)(const void *, uint32_t); |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 37 | typedef void (*hashdata_free_cb)(struct hlist_node *, void *); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 38 | |
| 39 | struct hashtable_t { |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 40 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
| 41 | spinlock_t *list_locks; /* spinlock for each hash list entry */ |
Antonio Quartulli | c90681b | 2011-10-05 17:05:25 +0200 | [diff] [blame] | 42 | uint32_t size; /* size of hashtable */ |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 43 | }; |
| 44 | |
| 45 | /* allocates and clears the hash */ |
Antonio Quartulli | c90681b | 2011-10-05 17:05:25 +0200 | [diff] [blame] | 46 | struct hashtable_t *hash_new(uint32_t size); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 47 | |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 48 | /* free only the hashtable and the hash itself. */ |
| 49 | void hash_destroy(struct hashtable_t *hash); |
| 50 | |
| 51 | /* remove the hash structure. if hashdata_free_cb != NULL, this function will be |
| 52 | * called to remove the elements inside of the hash. if you don't remove the |
| 53 | * elements, memory might be leaked. */ |
| 54 | static inline void hash_delete(struct hashtable_t *hash, |
| 55 | hashdata_free_cb free_cb, void *arg) |
| 56 | { |
| 57 | struct hlist_head *head; |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 58 | struct hlist_node *node, *node_tmp; |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 59 | spinlock_t *list_lock; /* spinlock to protect write access */ |
Antonio Quartulli | c90681b | 2011-10-05 17:05:25 +0200 | [diff] [blame] | 60 | uint32_t i; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 61 | |
| 62 | for (i = 0; i < hash->size; i++) { |
| 63 | head = &hash->table[i]; |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 64 | list_lock = &hash->list_locks[i]; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 65 | |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 66 | spin_lock_bh(list_lock); |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 67 | hlist_for_each_safe(node, node_tmp, head) { |
| 68 | hlist_del_rcu(node); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 69 | |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 70 | if (free_cb) |
| 71 | free_cb(node, arg); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 72 | } |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 73 | spin_unlock_bh(list_lock); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 74 | } |
| 75 | |
| 76 | hash_destroy(hash); |
| 77 | } |
| 78 | |
Antonio Quartulli | 1a1f37d | 2011-07-10 00:36:36 +0200 | [diff] [blame] | 79 | /** |
| 80 | * hash_add - adds data to the hashtable |
| 81 | * @hash: storage hash table |
| 82 | * @compare: callback to determine if 2 hash elements are identical |
| 83 | * @choose: callback calculating the hash index |
| 84 | * @data: data passed to the aforementioned callbacks as argument |
| 85 | * @data_node: to be added element |
| 86 | * |
| 87 | * Returns 0 on success, 1 if the element already is in the hash |
| 88 | * and -1 on error. |
| 89 | */ |
| 90 | |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 91 | static inline int hash_add(struct hashtable_t *hash, |
| 92 | hashdata_compare_cb compare, |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 93 | hashdata_choose_cb choose, |
Sven Eckelmann | 747e422 | 2011-05-14 23:14:50 +0200 | [diff] [blame] | 94 | const void *data, struct hlist_node *data_node) |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 95 | { |
Antonio Quartulli | c90681b | 2011-10-05 17:05:25 +0200 | [diff] [blame] | 96 | uint32_t index; |
| 97 | int ret = -1; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 98 | struct hlist_head *head; |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 99 | struct hlist_node *node; |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 100 | spinlock_t *list_lock; /* spinlock to protect write access */ |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 101 | |
| 102 | if (!hash) |
Antonio Quartulli | 1a1f37d | 2011-07-10 00:36:36 +0200 | [diff] [blame] | 103 | goto out; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 104 | |
| 105 | index = choose(data, hash->size); |
| 106 | head = &hash->table[index]; |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 107 | list_lock = &hash->list_locks[index]; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 108 | |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 109 | rcu_read_lock(); |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 110 | __hlist_for_each_rcu(node, head) { |
| 111 | if (!compare(node, data)) |
| 112 | continue; |
| 113 | |
Antonio Quartulli | 1a1f37d | 2011-07-10 00:36:36 +0200 | [diff] [blame] | 114 | ret = 1; |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 115 | goto err_unlock; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 116 | } |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 117 | rcu_read_unlock(); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 118 | |
| 119 | /* no duplicate found in list, add new element */ |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 120 | spin_lock_bh(list_lock); |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 121 | hlist_add_head_rcu(data_node, head); |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 122 | spin_unlock_bh(list_lock); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 123 | |
Antonio Quartulli | 1a1f37d | 2011-07-10 00:36:36 +0200 | [diff] [blame] | 124 | ret = 0; |
| 125 | goto out; |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 126 | |
| 127 | err_unlock: |
| 128 | rcu_read_unlock(); |
Antonio Quartulli | 1a1f37d | 2011-07-10 00:36:36 +0200 | [diff] [blame] | 129 | out: |
| 130 | return ret; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 131 | } |
| 132 | |
| 133 | /* removes data from hash, if found. returns pointer do data on success, so you |
| 134 | * can remove the used structure yourself, or NULL on error . data could be the |
| 135 | * structure you use with just the key filled, we just need the key for |
| 136 | * comparing. */ |
| 137 | static inline void *hash_remove(struct hashtable_t *hash, |
| 138 | hashdata_compare_cb compare, |
| 139 | hashdata_choose_cb choose, void *data) |
| 140 | { |
Antonio Quartulli | c90681b | 2011-10-05 17:05:25 +0200 | [diff] [blame] | 141 | uint32_t index; |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 142 | struct hlist_node *node; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 143 | struct hlist_head *head; |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 144 | void *data_save = NULL; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 145 | |
| 146 | index = choose(data, hash->size); |
| 147 | head = &hash->table[index]; |
| 148 | |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 149 | spin_lock_bh(&hash->list_locks[index]); |
Marek Lindner | 7aadf88 | 2011-02-18 12:28:09 +0000 | [diff] [blame] | 150 | hlist_for_each(node, head) { |
| 151 | if (!compare(node, data)) |
| 152 | continue; |
| 153 | |
| 154 | data_save = node; |
| 155 | hlist_del_rcu(node); |
| 156 | break; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 157 | } |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 158 | spin_unlock_bh(&hash->list_locks[index]); |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 159 | |
Marek Lindner | fb778ea | 2011-01-19 20:01:40 +0000 | [diff] [blame] | 160 | return data_save; |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 161 | } |
| 162 | |
Sven Eckelmann | c6c8fea | 2010-12-13 11:19:28 +0000 | [diff] [blame] | 163 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |