Commit | Line | Data |
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c6c8fea2 | 1 | /* |
64afe353 | 2 | * Copyright (C) 2006-2011 B.A.T.M.A.N. contributors: |
c6c8fea2 SE |
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 */ | |
7aadf889 | 31 | typedef int (*hashdata_compare_cb)(struct hlist_node *, void *); |
c6c8fea2 SE |
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 */ | |
36 | typedef int (*hashdata_choose_cb)(void *, int); | |
7aadf889 | 37 | typedef void (*hashdata_free_cb)(struct hlist_node *, void *); |
c6c8fea2 SE |
38 | |
39 | struct hashtable_t { | |
fb778ea1 ML |
40 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
41 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
c6c8fea2 SE |
42 | int size; /* size of hashtable */ |
43 | }; | |
44 | ||
45 | /* allocates and clears the hash */ | |
46 | struct hashtable_t *hash_new(int size); | |
47 | ||
c6c8fea2 SE |
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; | |
7aadf889 | 58 | struct hlist_node *node, *node_tmp; |
fb778ea1 | 59 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
60 | int i; |
61 | ||
62 | for (i = 0; i < hash->size; i++) { | |
63 | head = &hash->table[i]; | |
fb778ea1 | 64 | list_lock = &hash->list_locks[i]; |
c6c8fea2 | 65 | |
fb778ea1 | 66 | spin_lock_bh(list_lock); |
7aadf889 ML |
67 | hlist_for_each_safe(node, node_tmp, head) { |
68 | hlist_del_rcu(node); | |
c6c8fea2 | 69 | |
7aadf889 ML |
70 | if (free_cb) |
71 | free_cb(node, arg); | |
c6c8fea2 | 72 | } |
fb778ea1 | 73 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
74 | } |
75 | ||
76 | hash_destroy(hash); | |
77 | } | |
78 | ||
79 | /* adds data to the hashtable. returns 0 on success, -1 on error */ | |
80 | static inline int hash_add(struct hashtable_t *hash, | |
81 | hashdata_compare_cb compare, | |
7aadf889 ML |
82 | hashdata_choose_cb choose, |
83 | void *data, struct hlist_node *data_node) | |
c6c8fea2 SE |
84 | { |
85 | int index; | |
86 | struct hlist_head *head; | |
7aadf889 | 87 | struct hlist_node *node; |
fb778ea1 | 88 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
89 | |
90 | if (!hash) | |
fb778ea1 | 91 | goto err; |
c6c8fea2 SE |
92 | |
93 | index = choose(data, hash->size); | |
94 | head = &hash->table[index]; | |
fb778ea1 | 95 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 96 | |
fb778ea1 | 97 | rcu_read_lock(); |
7aadf889 ML |
98 | __hlist_for_each_rcu(node, head) { |
99 | if (!compare(node, data)) | |
100 | continue; | |
101 | ||
102 | goto err_unlock; | |
c6c8fea2 | 103 | } |
fb778ea1 | 104 | rcu_read_unlock(); |
c6c8fea2 SE |
105 | |
106 | /* no duplicate found in list, add new element */ | |
fb778ea1 | 107 | spin_lock_bh(list_lock); |
7aadf889 | 108 | hlist_add_head_rcu(data_node, head); |
fb778ea1 | 109 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
110 | |
111 | return 0; | |
fb778ea1 ML |
112 | |
113 | err_unlock: | |
114 | rcu_read_unlock(); | |
115 | err: | |
116 | return -1; | |
c6c8fea2 SE |
117 | } |
118 | ||
119 | /* removes data from hash, if found. returns pointer do data on success, so you | |
120 | * can remove the used structure yourself, or NULL on error . data could be the | |
121 | * structure you use with just the key filled, we just need the key for | |
122 | * comparing. */ | |
123 | static inline void *hash_remove(struct hashtable_t *hash, | |
124 | hashdata_compare_cb compare, | |
125 | hashdata_choose_cb choose, void *data) | |
126 | { | |
127 | size_t index; | |
7aadf889 | 128 | struct hlist_node *node; |
c6c8fea2 | 129 | struct hlist_head *head; |
fb778ea1 | 130 | void *data_save = NULL; |
c6c8fea2 SE |
131 | |
132 | index = choose(data, hash->size); | |
133 | head = &hash->table[index]; | |
134 | ||
fb778ea1 | 135 | spin_lock_bh(&hash->list_locks[index]); |
7aadf889 ML |
136 | hlist_for_each(node, head) { |
137 | if (!compare(node, data)) | |
138 | continue; | |
139 | ||
140 | data_save = node; | |
141 | hlist_del_rcu(node); | |
142 | break; | |
c6c8fea2 | 143 | } |
fb778ea1 | 144 | spin_unlock_bh(&hash->list_locks[index]); |
c6c8fea2 | 145 | |
fb778ea1 | 146 | return data_save; |
c6c8fea2 SE |
147 | } |
148 | ||
c6c8fea2 | 149 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |