1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
4 * Generic non-thread safe hash map implementation.
6 * Copyright (c) 2019 Facebook
8 #ifndef __LIBBPF_HASHMAP_H
9 #define __LIBBPF_HASHMAP_H
15 #define __WORDSIZE (__SIZEOF_LONG__ * 8)
18 static inline size_t hash_bits(size_t h, int bits)
20 /* shuffle bits and return requested number of upper bits */
21 return (h * 11400714819323198485llu) >> (__WORDSIZE - bits);
24 typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx);
25 typedef bool (*hashmap_equal_fn)(const void *key1, const void *key2, void *ctx);
27 struct hashmap_entry {
30 struct hashmap_entry *next;
34 hashmap_hash_fn hash_fn;
35 hashmap_equal_fn equal_fn;
38 struct hashmap_entry **buckets;
44 #define HASHMAP_INIT(hash_fn, equal_fn, ctx) { \
45 .hash_fn = (hash_fn), \
46 .equal_fn = (equal_fn), \
54 void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
55 hashmap_equal_fn equal_fn, void *ctx);
56 struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
57 hashmap_equal_fn equal_fn,
59 void hashmap__clear(struct hashmap *map);
60 void hashmap__free(struct hashmap *map);
62 size_t hashmap__size(const struct hashmap *map);
63 size_t hashmap__capacity(const struct hashmap *map);
66 * Hashmap insertion strategy:
67 * - HASHMAP_ADD - only add key/value if key doesn't exist yet;
68 * - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise,
70 * - HASHMAP_UPDATE - update value, if key already exists; otherwise, do
71 * nothing and return -ENOENT;
72 * - HASHMAP_APPEND - always add key/value pair, even if key already exists.
73 * This turns hashmap into a multimap by allowing multiple values to be
74 * associated with the same key. Most useful read API for such hashmap is
75 * hashmap__for_each_key_entry() iteration. If hashmap__find() is still
76 * used, it will return last inserted key/value entry (first in a bucket
79 enum hashmap_insert_strategy {
87 * hashmap__insert() adds key/value entry w/ various semantics, depending on
88 * provided strategy value. If a given key/value pair replaced already
89 * existing key/value pair, both old key and old value will be returned
90 * through old_key and old_value to allow calling code do proper memory
93 int hashmap__insert(struct hashmap *map, const void *key, void *value,
94 enum hashmap_insert_strategy strategy,
95 const void **old_key, void **old_value);
97 static inline int hashmap__add(struct hashmap *map,
98 const void *key, void *value)
100 return hashmap__insert(map, key, value, HASHMAP_ADD, NULL, NULL);
103 static inline int hashmap__set(struct hashmap *map,
104 const void *key, void *value,
105 const void **old_key, void **old_value)
107 return hashmap__insert(map, key, value, HASHMAP_SET,
111 static inline int hashmap__update(struct hashmap *map,
112 const void *key, void *value,
113 const void **old_key, void **old_value)
115 return hashmap__insert(map, key, value, HASHMAP_UPDATE,
119 static inline int hashmap__append(struct hashmap *map,
120 const void *key, void *value)
122 return hashmap__insert(map, key, value, HASHMAP_APPEND, NULL, NULL);
125 bool hashmap__delete(struct hashmap *map, const void *key,
126 const void **old_key, void **old_value);
128 bool hashmap__find(const struct hashmap *map, const void *key, void **value);
131 * hashmap__for_each_entry - iterate over all entries in hashmap
132 * @map: hashmap to iterate
133 * @cur: struct hashmap_entry * used as a loop cursor
134 * @bkt: integer used as a bucket loop cursor
136 #define hashmap__for_each_entry(map, cur, bkt) \
137 for (bkt = 0; bkt < map->cap; bkt++) \
138 for (cur = map->buckets[bkt]; cur; cur = cur->next)
141 * hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe
143 * @map: hashmap to iterate
144 * @cur: struct hashmap_entry * used as a loop cursor
145 * @tmp: struct hashmap_entry * used as a temporary next cursor storage
146 * @bkt: integer used as a bucket loop cursor
148 #define hashmap__for_each_entry_safe(map, cur, tmp, bkt) \
149 for (bkt = 0; bkt < map->cap; bkt++) \
150 for (cur = map->buckets[bkt]; \
151 cur && ({tmp = cur->next; true; }); \
155 * hashmap__for_each_key_entry - iterate over entries associated with given key
156 * @map: hashmap to iterate
157 * @cur: struct hashmap_entry * used as a loop cursor
158 * @key: key to iterate entries for
160 #define hashmap__for_each_key_entry(map, cur, _key) \
161 for (cur = ({ size_t bkt = hash_bits(map->hash_fn((_key), map->ctx),\
163 map->buckets ? map->buckets[bkt] : NULL; }); \
166 if (map->equal_fn(cur->key, (_key), map->ctx))
168 #define hashmap__for_each_key_entry_safe(map, cur, tmp, _key) \
169 for (cur = ({ size_t bkt = hash_bits(map->hash_fn((_key), map->ctx),\
171 cur = map->buckets ? map->buckets[bkt] : NULL; }); \
172 cur && ({ tmp = cur->next; true; }); \
174 if (map->equal_fn(cur->key, (_key), map->ctx))
176 #endif /* __LIBBPF_HASHMAP_H */