xref: /linux/scripts/include/hashtable.h (revision 0d6ccfe6b319d56da63b7d7cfbcecd92780a680d)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef HASHTABLE_H
3 #define HASHTABLE_H
4 
5 #include "array_size.h"
6 #include "list.h"
7 
8 #define HASH_SIZE(name) (ARRAY_SIZE(name))
9 
10 #define HASHTABLE_DECLARE(name, size)		struct hlist_head name[size]
11 
12 #define HASHTABLE_DEFINE(name, size)						\
13 	HASHTABLE_DECLARE(name, size) =						\
14 			{ [0 ... ((size) - 1)] = HLIST_HEAD_INIT }
15 
16 #define hash_head(table, key)		(&(table)[(key) % HASH_SIZE(table)])
17 
18 /**
19  * hash_add - add an object to a hashtable
20  * @table: hashtable to add to
21  * @node: the &struct hlist_node of the object to be added
22  * @key: the key of the object to be added
23  */
24 #define hash_add(table, node, key)						\
25 	hlist_add_head(node, hash_head(table, key))
26 
27 /**
28  * hash_for_each - iterate over a hashtable
29  * @table: hashtable to iterate
30  * @obj: the type * to use as a loop cursor for each entry
31  * @member: the name of the hlist_node within the struct
32  */
33 #define hash_for_each(table, obj, member)				\
34 	for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++)		\
35 		hlist_for_each_entry(obj, &table[_bkt], member)
36 
37 /**
38  * hash_for_each_possible - iterate over all possible objects hashing to the
39  * same bucket
40  * @table: hashtable to iterate
41  * @obj: the type * to use as a loop cursor for each entry
42  * @member: the name of the hlist_node within the struct
43  * @key: the key of the objects to iterate over
44  */
45 #define hash_for_each_possible(table, obj, member, key)			\
46 	hlist_for_each_entry(obj, hash_head(table, key), member)
47 
48 #endif /* HASHTABLE_H */
49