1 /* SPDX-License-Identifier: LGPL-2.1+ */
5 This file is part of systemd.
7 Copyright 2010 Lennart Poettering
8 Copyright 2014 Michal Schmidt
15 #include "hash-funcs.h"
20 * A hash table implementation. As a minor optimization a NULL hashmap object
21 * will be treated as empty hashmap for all read operations. That way it is not
22 * necessary to instantiate an object for each Hashmap use.
24 * If ENABLE_DEBUG_HASHMAP is defined (by configuring with --enable-debug=hashmap),
25 * the implemention will:
26 * - store extra data for debugging and statistics (see tools/gdb-sd_dump_hashmaps.py)
27 * - perform extra checks for invalid use of iterators
30 #define HASH_KEY_SIZE 16
32 /* The base type for all hashmap and set types. Many functions in the
33 * implementation take (HashmapBase*) parameters and are run-time polymorphic,
34 * though the API is not meant to be polymorphic (do not call functions
35 * internal_*() directly). */
36 typedef struct HashmapBase HashmapBase
;
38 /* Specific hashmap/set types */
39 typedef struct Hashmap Hashmap
; /* Maps keys to values */
40 typedef struct OrderedHashmap OrderedHashmap
; /* Like Hashmap, but also remembers entry insertion order */
41 typedef struct Set Set
; /* Stores just keys */
43 typedef struct IteratedCache IteratedCache
; /* Caches the iterated order of one of the above */
45 /* Ideally the Iterator would be an opaque struct, but it is instantiated
46 * by hashmap users, so the definition has to be here. Do not use its fields
49 unsigned idx
; /* index of an entry to be iterated next */
50 const void *next_key
; /* expected value of that entry's key pointer */
51 #if ENABLE_DEBUG_HASHMAP
52 unsigned put_count
; /* hashmap's put_count recorded at start of iteration */
53 unsigned rem_count
; /* hashmap's rem_count in previous iteration */
54 unsigned prev_idx
; /* idx in previous iteration */
58 #define _IDX_ITERATOR_FIRST (UINT_MAX - 1)
59 #define ITERATOR_FIRST ((Iterator) { .idx = _IDX_ITERATOR_FIRST, .next_key = NULL })
61 /* Macros for type checking */
62 #define PTR_COMPATIBLE_WITH_HASHMAP_BASE(h) \
63 (__builtin_types_compatible_p(typeof(h), HashmapBase*) || \
64 __builtin_types_compatible_p(typeof(h), Hashmap*) || \
65 __builtin_types_compatible_p(typeof(h), OrderedHashmap*) || \
66 __builtin_types_compatible_p(typeof(h), Set*))
68 #define PTR_COMPATIBLE_WITH_PLAIN_HASHMAP(h) \
69 (__builtin_types_compatible_p(typeof(h), Hashmap*) || \
70 __builtin_types_compatible_p(typeof(h), OrderedHashmap*)) \
72 #define HASHMAP_BASE(h) \
73 __builtin_choose_expr(PTR_COMPATIBLE_WITH_HASHMAP_BASE(h), \
77 #define PLAIN_HASHMAP(h) \
78 __builtin_choose_expr(PTR_COMPATIBLE_WITH_PLAIN_HASHMAP(h), \
82 #if ENABLE_DEBUG_HASHMAP
83 # define HASHMAP_DEBUG_PARAMS , const char *func, const char *file, int line
84 # define HASHMAP_DEBUG_SRC_ARGS , __func__, __FILE__, __LINE__
85 # define HASHMAP_DEBUG_PASS_ARGS , func, file, line
87 # define HASHMAP_DEBUG_PARAMS
88 # define HASHMAP_DEBUG_SRC_ARGS
89 # define HASHMAP_DEBUG_PASS_ARGS
92 Hashmap
*internal_hashmap_new(const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
);
93 OrderedHashmap
*internal_ordered_hashmap_new(const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
);
94 #define hashmap_new(ops) internal_hashmap_new(ops HASHMAP_DEBUG_SRC_ARGS)
95 #define ordered_hashmap_new(ops) internal_ordered_hashmap_new(ops HASHMAP_DEBUG_SRC_ARGS)
97 HashmapBase
*internal_hashmap_free(HashmapBase
*h
);
98 static inline Hashmap
*hashmap_free(Hashmap
*h
) {
99 return (void*)internal_hashmap_free(HASHMAP_BASE(h
));
101 static inline OrderedHashmap
*ordered_hashmap_free(OrderedHashmap
*h
) {
102 return (void*)internal_hashmap_free(HASHMAP_BASE(h
));
105 HashmapBase
*internal_hashmap_free_free(HashmapBase
*h
);
106 static inline Hashmap
*hashmap_free_free(Hashmap
*h
) {
107 return (void*)internal_hashmap_free_free(HASHMAP_BASE(h
));
109 static inline OrderedHashmap
*ordered_hashmap_free_free(OrderedHashmap
*h
) {
110 return (void*)internal_hashmap_free_free(HASHMAP_BASE(h
));
113 Hashmap
*hashmap_free_free_free(Hashmap
*h
);
114 static inline OrderedHashmap
*ordered_hashmap_free_free_free(OrderedHashmap
*h
) {
115 return (void*)hashmap_free_free_free(PLAIN_HASHMAP(h
));
118 IteratedCache
*iterated_cache_free(IteratedCache
*cache
);
119 int iterated_cache_get(IteratedCache
*cache
, const void ***res_keys
, const void ***res_values
, unsigned *res_n_entries
);
121 HashmapBase
*internal_hashmap_copy(HashmapBase
*h
);
122 static inline Hashmap
*hashmap_copy(Hashmap
*h
) {
123 return (Hashmap
*) internal_hashmap_copy(HASHMAP_BASE(h
));
125 static inline OrderedHashmap
*ordered_hashmap_copy(OrderedHashmap
*h
) {
126 return (OrderedHashmap
*) internal_hashmap_copy(HASHMAP_BASE(h
));
129 int internal_hashmap_ensure_allocated(Hashmap
**h
, const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
);
130 int internal_ordered_hashmap_ensure_allocated(OrderedHashmap
**h
, const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
);
131 #define hashmap_ensure_allocated(h, ops) internal_hashmap_ensure_allocated(h, ops HASHMAP_DEBUG_SRC_ARGS)
132 #define ordered_hashmap_ensure_allocated(h, ops) internal_ordered_hashmap_ensure_allocated(h, ops HASHMAP_DEBUG_SRC_ARGS)
134 IteratedCache
*internal_hashmap_iterated_cache_new(HashmapBase
*h
);
135 static inline IteratedCache
*hashmap_iterated_cache_new(Hashmap
*h
) {
136 return (IteratedCache
*) internal_hashmap_iterated_cache_new(HASHMAP_BASE(h
));
138 static inline IteratedCache
*ordered_hashmap_iterated_cache_new(OrderedHashmap
*h
) {
139 return (IteratedCache
*) internal_hashmap_iterated_cache_new(HASHMAP_BASE(h
));
142 int hashmap_put(Hashmap
*h
, const void *key
, void *value
);
143 static inline int ordered_hashmap_put(OrderedHashmap
*h
, const void *key
, void *value
) {
144 return hashmap_put(PLAIN_HASHMAP(h
), key
, value
);
147 int hashmap_update(Hashmap
*h
, const void *key
, void *value
);
148 static inline int ordered_hashmap_update(OrderedHashmap
*h
, const void *key
, void *value
) {
149 return hashmap_update(PLAIN_HASHMAP(h
), key
, value
);
152 int hashmap_replace(Hashmap
*h
, const void *key
, void *value
);
153 static inline int ordered_hashmap_replace(OrderedHashmap
*h
, const void *key
, void *value
) {
154 return hashmap_replace(PLAIN_HASHMAP(h
), key
, value
);
157 void *internal_hashmap_get(HashmapBase
*h
, const void *key
);
158 static inline void *hashmap_get(Hashmap
*h
, const void *key
) {
159 return internal_hashmap_get(HASHMAP_BASE(h
), key
);
161 static inline void *ordered_hashmap_get(OrderedHashmap
*h
, const void *key
) {
162 return internal_hashmap_get(HASHMAP_BASE(h
), key
);
165 void *hashmap_get2(Hashmap
*h
, const void *key
, void **rkey
);
166 static inline void *ordered_hashmap_get2(OrderedHashmap
*h
, const void *key
, void **rkey
) {
167 return hashmap_get2(PLAIN_HASHMAP(h
), key
, rkey
);
170 bool internal_hashmap_contains(HashmapBase
*h
, const void *key
);
171 static inline bool hashmap_contains(Hashmap
*h
, const void *key
) {
172 return internal_hashmap_contains(HASHMAP_BASE(h
), key
);
174 static inline bool ordered_hashmap_contains(OrderedHashmap
*h
, const void *key
) {
175 return internal_hashmap_contains(HASHMAP_BASE(h
), key
);
178 void *internal_hashmap_remove(HashmapBase
*h
, const void *key
);
179 static inline void *hashmap_remove(Hashmap
*h
, const void *key
) {
180 return internal_hashmap_remove(HASHMAP_BASE(h
), key
);
182 static inline void *ordered_hashmap_remove(OrderedHashmap
*h
, const void *key
) {
183 return internal_hashmap_remove(HASHMAP_BASE(h
), key
);
186 void *hashmap_remove2(Hashmap
*h
, const void *key
, void **rkey
);
187 static inline void *ordered_hashmap_remove2(OrderedHashmap
*h
, const void *key
, void **rkey
) {
188 return hashmap_remove2(PLAIN_HASHMAP(h
), key
, rkey
);
191 void *hashmap_remove_value(Hashmap
*h
, const void *key
, void *value
);
192 static inline void *ordered_hashmap_remove_value(OrderedHashmap
*h
, const void *key
, void *value
) {
193 return hashmap_remove_value(PLAIN_HASHMAP(h
), key
, value
);
196 int hashmap_remove_and_put(Hashmap
*h
, const void *old_key
, const void *new_key
, void *value
);
197 static inline int ordered_hashmap_remove_and_put(OrderedHashmap
*h
, const void *old_key
, const void *new_key
, void *value
) {
198 return hashmap_remove_and_put(PLAIN_HASHMAP(h
), old_key
, new_key
, value
);
201 int hashmap_remove_and_replace(Hashmap
*h
, const void *old_key
, const void *new_key
, void *value
);
202 static inline int ordered_hashmap_remove_and_replace(OrderedHashmap
*h
, const void *old_key
, const void *new_key
, void *value
) {
203 return hashmap_remove_and_replace(PLAIN_HASHMAP(h
), old_key
, new_key
, value
);
206 /* Since merging data from a OrderedHashmap into a Hashmap or vice-versa
207 * should just work, allow this by having looser type-checking here. */
208 int internal_hashmap_merge(Hashmap
*h
, Hashmap
*other
);
209 #define hashmap_merge(h, other) internal_hashmap_merge(PLAIN_HASHMAP(h), PLAIN_HASHMAP(other))
210 #define ordered_hashmap_merge(h, other) hashmap_merge(h, other)
212 int internal_hashmap_reserve(HashmapBase
*h
, unsigned entries_add
);
213 static inline int hashmap_reserve(Hashmap
*h
, unsigned entries_add
) {
214 return internal_hashmap_reserve(HASHMAP_BASE(h
), entries_add
);
216 static inline int ordered_hashmap_reserve(OrderedHashmap
*h
, unsigned entries_add
) {
217 return internal_hashmap_reserve(HASHMAP_BASE(h
), entries_add
);
220 int internal_hashmap_move(HashmapBase
*h
, HashmapBase
*other
);
221 /* Unlike hashmap_merge, hashmap_move does not allow mixing the types. */
222 static inline int hashmap_move(Hashmap
*h
, Hashmap
*other
) {
223 return internal_hashmap_move(HASHMAP_BASE(h
), HASHMAP_BASE(other
));
225 static inline int ordered_hashmap_move(OrderedHashmap
*h
, OrderedHashmap
*other
) {
226 return internal_hashmap_move(HASHMAP_BASE(h
), HASHMAP_BASE(other
));
229 int internal_hashmap_move_one(HashmapBase
*h
, HashmapBase
*other
, const void *key
);
230 static inline int hashmap_move_one(Hashmap
*h
, Hashmap
*other
, const void *key
) {
231 return internal_hashmap_move_one(HASHMAP_BASE(h
), HASHMAP_BASE(other
), key
);
233 static inline int ordered_hashmap_move_one(OrderedHashmap
*h
, OrderedHashmap
*other
, const void *key
) {
234 return internal_hashmap_move_one(HASHMAP_BASE(h
), HASHMAP_BASE(other
), key
);
237 unsigned internal_hashmap_size(HashmapBase
*h
) _pure_
;
238 static inline unsigned hashmap_size(Hashmap
*h
) {
239 return internal_hashmap_size(HASHMAP_BASE(h
));
241 static inline unsigned ordered_hashmap_size(OrderedHashmap
*h
) {
242 return internal_hashmap_size(HASHMAP_BASE(h
));
245 static inline bool hashmap_isempty(Hashmap
*h
) {
246 return hashmap_size(h
) == 0;
248 static inline bool ordered_hashmap_isempty(OrderedHashmap
*h
) {
249 return ordered_hashmap_size(h
) == 0;
252 unsigned internal_hashmap_buckets(HashmapBase
*h
) _pure_
;
253 static inline unsigned hashmap_buckets(Hashmap
*h
) {
254 return internal_hashmap_buckets(HASHMAP_BASE(h
));
256 static inline unsigned ordered_hashmap_buckets(OrderedHashmap
*h
) {
257 return internal_hashmap_buckets(HASHMAP_BASE(h
));
260 bool internal_hashmap_iterate(HashmapBase
*h
, Iterator
*i
, void **value
, const void **key
);
261 static inline bool hashmap_iterate(Hashmap
*h
, Iterator
*i
, void **value
, const void **key
) {
262 return internal_hashmap_iterate(HASHMAP_BASE(h
), i
, value
, key
);
264 static inline bool ordered_hashmap_iterate(OrderedHashmap
*h
, Iterator
*i
, void **value
, const void **key
) {
265 return internal_hashmap_iterate(HASHMAP_BASE(h
), i
, value
, key
);
268 void internal_hashmap_clear(HashmapBase
*h
);
269 static inline void hashmap_clear(Hashmap
*h
) {
270 internal_hashmap_clear(HASHMAP_BASE(h
));
272 static inline void ordered_hashmap_clear(OrderedHashmap
*h
) {
273 internal_hashmap_clear(HASHMAP_BASE(h
));
276 void internal_hashmap_clear_free(HashmapBase
*h
);
277 static inline void hashmap_clear_free(Hashmap
*h
) {
278 internal_hashmap_clear_free(HASHMAP_BASE(h
));
280 static inline void ordered_hashmap_clear_free(OrderedHashmap
*h
) {
281 internal_hashmap_clear_free(HASHMAP_BASE(h
));
284 void hashmap_clear_free_free(Hashmap
*h
);
285 static inline void ordered_hashmap_clear_free_free(OrderedHashmap
*h
) {
286 hashmap_clear_free_free(PLAIN_HASHMAP(h
));
290 * Note about all *_first*() functions
292 * For plain Hashmaps and Sets the order of entries is undefined.
293 * The functions find whatever entry is first in the implementation
296 * Only for OrderedHashmaps the order is well defined and finding
297 * the first entry is O(1).
300 void *internal_hashmap_steal_first(HashmapBase
*h
);
301 static inline void *hashmap_steal_first(Hashmap
*h
) {
302 return internal_hashmap_steal_first(HASHMAP_BASE(h
));
304 static inline void *ordered_hashmap_steal_first(OrderedHashmap
*h
) {
305 return internal_hashmap_steal_first(HASHMAP_BASE(h
));
308 void *internal_hashmap_steal_first_key(HashmapBase
*h
);
309 static inline void *hashmap_steal_first_key(Hashmap
*h
) {
310 return internal_hashmap_steal_first_key(HASHMAP_BASE(h
));
312 static inline void *ordered_hashmap_steal_first_key(OrderedHashmap
*h
) {
313 return internal_hashmap_steal_first_key(HASHMAP_BASE(h
));
316 void *internal_hashmap_first_key(HashmapBase
*h
) _pure_
;
317 static inline void *hashmap_first_key(Hashmap
*h
) {
318 return internal_hashmap_first_key(HASHMAP_BASE(h
));
320 static inline void *ordered_hashmap_first_key(OrderedHashmap
*h
) {
321 return internal_hashmap_first_key(HASHMAP_BASE(h
));
324 void *internal_hashmap_first(HashmapBase
*h
) _pure_
;
325 static inline void *hashmap_first(Hashmap
*h
) {
326 return internal_hashmap_first(HASHMAP_BASE(h
));
328 static inline void *ordered_hashmap_first(OrderedHashmap
*h
) {
329 return internal_hashmap_first(HASHMAP_BASE(h
));
332 #define hashmap_clear_with_destructor(_s, _f) \
335 while ((_item = hashmap_steal_first(_s))) \
338 #define hashmap_free_with_destructor(_s, _f) \
340 hashmap_clear_with_destructor(_s, _f); \
343 #define ordered_hashmap_clear_with_destructor(_s, _f) \
346 while ((_item = ordered_hashmap_steal_first(_s))) \
349 #define ordered_hashmap_free_with_destructor(_s, _f) \
351 ordered_hashmap_clear_with_destructor(_s, _f); \
352 ordered_hashmap_free(_s); \
355 /* no hashmap_next */
356 void *ordered_hashmap_next(OrderedHashmap
*h
, const void *key
);
358 char **internal_hashmap_get_strv(HashmapBase
*h
);
359 static inline char **hashmap_get_strv(Hashmap
*h
) {
360 return internal_hashmap_get_strv(HASHMAP_BASE(h
));
362 static inline char **ordered_hashmap_get_strv(OrderedHashmap
*h
) {
363 return internal_hashmap_get_strv(HASHMAP_BASE(h
));
367 * Hashmaps are iterated in unpredictable order.
368 * OrderedHashmaps are an exception to this. They are iterated in the order
369 * the entries were inserted.
370 * It is safe to remove the current entry.
372 #define HASHMAP_FOREACH(e, h, i) \
373 for ((i) = ITERATOR_FIRST; hashmap_iterate((h), &(i), (void**)&(e), NULL); )
375 #define ORDERED_HASHMAP_FOREACH(e, h, i) \
376 for ((i) = ITERATOR_FIRST; ordered_hashmap_iterate((h), &(i), (void**)&(e), NULL); )
378 #define HASHMAP_FOREACH_KEY(e, k, h, i) \
379 for ((i) = ITERATOR_FIRST; hashmap_iterate((h), &(i), (void**)&(e), (const void**) &(k)); )
381 #define ORDERED_HASHMAP_FOREACH_KEY(e, k, h, i) \
382 for ((i) = ITERATOR_FIRST; ordered_hashmap_iterate((h), &(i), (void**)&(e), (const void**) &(k)); )
384 DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap
*, hashmap_free
);
385 DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap
*, hashmap_free_free
);
386 DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap
*, hashmap_free_free_free
);
387 DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap
*, ordered_hashmap_free
);
388 DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap
*, ordered_hashmap_free_free
);
389 DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap
*, ordered_hashmap_free_free_free
);
391 #define _cleanup_hashmap_free_ _cleanup_(hashmap_freep)
392 #define _cleanup_hashmap_free_free_ _cleanup_(hashmap_free_freep)
393 #define _cleanup_hashmap_free_free_free_ _cleanup_(hashmap_free_free_freep)
394 #define _cleanup_ordered_hashmap_free_ _cleanup_(ordered_hashmap_freep)
395 #define _cleanup_ordered_hashmap_free_free_ _cleanup_(ordered_hashmap_free_freep)
396 #define _cleanup_ordered_hashmap_free_free_free_ _cleanup_(ordered_hashmap_free_free_freep)
398 DEFINE_TRIVIAL_CLEANUP_FUNC(IteratedCache
*, iterated_cache_free
);
400 #define _cleanup_iterated_cache_free_ _cleanup_(iterated_cache_freep)