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 static inline void __hash_init(struct hlist_head *ht, unsigned int sz) 19 { 20 unsigned int i; 21 22 for (i = 0; i < sz; i++) 23 INIT_HLIST_HEAD(&ht[i]); 24 } 25 26 /** 27 * hash_init - initialize a hash table 28 * @table: hashtable to be initialized 29 * 30 * This has to be a macro since HASH_SIZE() will not work on pointers since 31 * it calculates the size during preprocessing. 32 */ 33 #define hash_init(table) __hash_init(table, HASH_SIZE(table)) 34 35 /** 36 * hash_add - add an object to a hashtable 37 * @table: hashtable to add to 38 * @node: the &struct hlist_node of the object to be added 39 * @key: the key of the object to be added 40 */ 41 #define hash_add(table, node, key) \ 42 hlist_add_head(node, hash_head(table, key)) 43 44 /** 45 * hash_del - remove an object from a hashtable 46 * @node: &struct hlist_node of the object to remove 47 */ 48 static inline void hash_del(struct hlist_node *node) 49 { 50 hlist_del_init(node); 51 } 52 53 /** 54 * hash_for_each - iterate over a hashtable 55 * @table: hashtable to iterate 56 * @obj: the type * to use as a loop cursor for each entry 57 * @member: the name of the hlist_node within the struct 58 */ 59 #define hash_for_each(table, obj, member) \ 60 for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ 61 hlist_for_each_entry(obj, &table[_bkt], member) 62 63 /** 64 * hash_for_each_safe - iterate over a hashtable safe against removal of 65 * hash entry 66 * @table: hashtable to iterate 67 * @obj: the type * to use as a loop cursor for each entry 68 * @tmp: a &struct hlist_node used for temporary storage 69 * @member: the name of the hlist_node within the struct 70 */ 71 #define hash_for_each_safe(table, obj, tmp, member) \ 72 for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ 73 hlist_for_each_entry_safe(obj, tmp, &table[_bkt], member) 74 75 /** 76 * hash_for_each_possible - iterate over all possible objects hashing to the 77 * same bucket 78 * @table: hashtable to iterate 79 * @obj: the type * to use as a loop cursor for each entry 80 * @member: the name of the hlist_node within the struct 81 * @key: the key of the objects to iterate over 82 */ 83 #define hash_for_each_possible(table, obj, member, key) \ 84 hlist_for_each_entry(obj, hash_head(table, key), member) 85 86 /** 87 * hash_for_each_possible_safe - iterate over all possible objects hashing to the 88 * same bucket safe against removals 89 * @table: hashtable to iterate 90 * @obj: the type * to use as a loop cursor for each entry 91 * @tmp: a &struct hlist_node used for temporary storage 92 * @member: the name of the hlist_node within the struct 93 * @key: the key of the objects to iterate over 94 */ 95 #define hash_for_each_possible_safe(table, obj, tmp, member, key) \ 96 hlist_for_each_entry_safe(obj, tmp, hash_head(table, key), member) 97 98 #endif /* HASHTABLE_H */ 99