1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
33 struct hashmap_entry {
36 struct hashmap_entry *bucket_next, *bucket_previous;
37 struct hashmap_entry *iterate_next, *iterate_previous;
41 hash_func_t hash_func;
42 compare_func_t compare_func;
44 struct hashmap_entry *iterate_list_head, *iterate_list_tail;
48 #define BY_HASH(h) ((struct hashmap_entry**) ((uint8_t*) (h) + ALIGN(sizeof(Hashmap))))
50 unsigned string_hash_func(const void *p) {
55 hash = 31 * hash + (unsigned) *c;
60 int string_compare_func(const void *a, const void *b) {
64 unsigned trivial_hash_func(const void *p) {
65 return PTR_TO_UINT(p);
68 int trivial_compare_func(const void *a, const void *b) {
69 return a < b ? -1 : (a > b ? 1 : 0);
72 Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func) {
75 if (!(h = malloc0(ALIGN(sizeof(Hashmap)) + NBUCKETS * ALIGN(sizeof(struct hashmap_entry*)))))
78 h->hash_func = hash_func ? hash_func : trivial_hash_func;
79 h->compare_func = compare_func ? compare_func : trivial_compare_func;
82 h->iterate_list_head = h->iterate_list_tail = NULL;
87 int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t compare_func) {
93 if (!(*h = hashmap_new(hash_func, compare_func)))
99 static void link_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) {
103 /* Insert into hash table */
104 e->bucket_next = BY_HASH(h)[hash];
105 e->bucket_previous = NULL;
106 if (BY_HASH(h)[hash])
107 BY_HASH(h)[hash]->bucket_previous = e;
108 BY_HASH(h)[hash] = e;
110 /* Insert into iteration list */
111 e->iterate_previous = h->iterate_list_tail;
112 e->iterate_next = NULL;
113 if (h->iterate_list_tail) {
114 assert(h->iterate_list_head);
115 h->iterate_list_tail->iterate_next = e;
117 assert(!h->iterate_list_head);
118 h->iterate_list_head = e;
120 h->iterate_list_tail = e;
123 assert(h->n_entries >= 1);
126 static void unlink_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) {
130 /* Remove from iteration list */
132 e->iterate_next->iterate_previous = e->iterate_previous;
134 h->iterate_list_tail = e->iterate_previous;
136 if (e->iterate_previous)
137 e->iterate_previous->iterate_next = e->iterate_next;
139 h->iterate_list_head = e->iterate_next;
141 /* Remove from hash table bucket list */
143 e->bucket_next->bucket_previous = e->bucket_previous;
145 if (e->bucket_previous)
146 e->bucket_previous->bucket_next = e->bucket_next;
148 BY_HASH(h)[hash] = e->bucket_next;
150 assert(h->n_entries >= 1);
154 static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
160 hash = h->hash_func(e->key) % NBUCKETS;
162 unlink_entry(h, e, hash);
166 void hashmap_free(Hashmap*h) {
176 void hashmap_clear(Hashmap *h) {
180 while (h->iterate_list_head)
181 remove_entry(h, h->iterate_list_head);
184 static struct hashmap_entry *hash_scan(Hashmap *h, unsigned hash, const void *key) {
185 struct hashmap_entry *e;
187 assert(hash < NBUCKETS);
189 for (e = BY_HASH(h)[hash]; e; e = e->bucket_next)
190 if (h->compare_func(e->key, key) == 0)
196 int hashmap_put(Hashmap *h, const void *key, void *value) {
197 struct hashmap_entry *e;
202 hash = h->hash_func(key) % NBUCKETS;
204 if ((e = hash_scan(h, hash, key))) {
206 if (e->value == value)
212 if (!(e = new(struct hashmap_entry, 1)))
218 link_entry(h, e, hash);
223 int hashmap_replace(Hashmap *h, const void *key, void *value) {
224 struct hashmap_entry *e;
229 hash = h->hash_func(key) % NBUCKETS;
231 if ((e = hash_scan(h, hash, key))) {
237 return hashmap_put(h, key, value);
240 void* hashmap_get(Hashmap *h, const void *key) {
242 struct hashmap_entry *e;
247 hash = h->hash_func(key) % NBUCKETS;
249 if (!(e = hash_scan(h, hash, key)))
255 void* hashmap_remove(Hashmap *h, const void *key) {
256 struct hashmap_entry *e;
263 hash = h->hash_func(key) % NBUCKETS;
265 if (!(e = hash_scan(h, hash, key)))
274 int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value) {
275 struct hashmap_entry *e;
276 unsigned old_hash, new_hash;
281 old_hash = h->hash_func(old_key) % NBUCKETS;
282 if (!(e = hash_scan(h, old_hash, old_key)))
285 new_hash = h->hash_func(new_key) % NBUCKETS;
286 if (hash_scan(h, new_hash, new_key))
289 unlink_entry(h, e, old_hash);
294 link_entry(h, e, new_hash);
299 void* hashmap_remove_value(Hashmap *h, const void *key, void *value) {
300 struct hashmap_entry *e;
306 hash = h->hash_func(key) % NBUCKETS;
308 if (!(e = hash_scan(h, hash, key)))
311 if (e->value != value)
319 void *hashmap_iterate(Hashmap *h, Iterator *i, const void **key) {
320 struct hashmap_entry *e;
327 if (*i == ITERATOR_LAST)
330 if (*i == ITERATOR_FIRST && !h->iterate_list_head)
333 e = *i == ITERATOR_FIRST ? h->iterate_list_head : (struct hashmap_entry*) *i;
336 *i = (Iterator) e->iterate_next;
354 void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key) {
355 struct hashmap_entry *e;
362 if (*i == ITERATOR_FIRST)
365 if (*i == ITERATOR_LAST && !h->iterate_list_tail)
368 e = *i == ITERATOR_LAST ? h->iterate_list_tail : (struct hashmap_entry*) *i;
370 if (e->iterate_previous)
371 *i = (Iterator) e->iterate_previous;
389 void *hashmap_iterate_skip(Hashmap *h, const void *key, Iterator *i) {
391 struct hashmap_entry *e;
396 hash = h->hash_func(key) % NBUCKETS;
398 if (!(e = hash_scan(h, hash, key)))
406 void* hashmap_first(Hashmap *h) {
411 if (!h->iterate_list_head)
414 return h->iterate_list_head->value;
417 void* hashmap_last(Hashmap *h) {
422 if (!h->iterate_list_tail)
425 return h->iterate_list_tail->value;
428 void* hashmap_steal_first(Hashmap *h) {
434 if (!h->iterate_list_head)
437 data = h->iterate_list_head->value;
438 remove_entry(h, h->iterate_list_head);
443 unsigned hashmap_size(Hashmap *h) {
451 bool hashmap_isempty(Hashmap *h) {
456 return h->n_entries == 0;
459 int hashmap_merge(Hashmap *h, Hashmap *other) {
460 struct hashmap_entry *e;
467 for (e = other->iterate_list_head; e; e = e->iterate_next) {
470 if ((r = hashmap_put(h, e->key, e->value)) < 0)
478 void hashmap_move(Hashmap *h, Hashmap *other) {
479 struct hashmap_entry *e, *n;
483 /* The same as hashmap_merge(), but every new item from other
484 * is moved to h. This function is guaranteed to succeed. */
489 for (e = other->iterate_list_head; e; e = n) {
490 unsigned h_hash, other_hash;
494 h_hash = h->hash_func(e->key) % NBUCKETS;
496 if (hash_scan(h, h_hash, e->key))
499 other_hash = other->hash_func(e->key) % NBUCKETS;
501 unlink_entry(other, e, other_hash);
502 link_entry(h, e, h_hash);
506 int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key) {
507 unsigned h_hash, other_hash;
508 struct hashmap_entry *e;
515 h_hash = h->hash_func(key) % NBUCKETS;
516 if (hash_scan(h, h_hash, key))
519 other_hash = other->hash_func(key) % NBUCKETS;
520 if (!(e = hash_scan(other, other_hash, key)))
523 unlink_entry(other, e, other_hash);
524 link_entry(h, e, h_hash);
529 Hashmap *hashmap_copy(Hashmap *h) {
534 if (!(copy = hashmap_new(h->hash_func, h->compare_func)))
537 if (hashmap_merge(copy, h) < 0) {