2 This file is part of GNUnet.
3 (C) 2008 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
21 * @file util/container_multihashmap.c
22 * @brief hash map where the same key may be present multiple times
23 * @author Christian Grothoff
27 #include "gnunet_common.h"
28 #include "gnunet_container_lib.h"
29 #include "gnunet_crypto_lib.h"
32 * An entry in the hash map.
48 * If there is a hash collision, we create a linked list.
50 struct MapEntry *next;
55 * Internal representation of the hash map.
57 struct GNUNET_CONTAINER_MultiHashMap
63 struct MapEntry **map;
66 * Number of entries in the map.
71 * Length of the "map" array.
73 unsigned int map_length;
78 * Create a multi hash map.
80 * @param len initial size (map will grow as needed)
81 * @return NULL on error
83 struct GNUNET_CONTAINER_MultiHashMap *
84 GNUNET_CONTAINER_multihashmap_create (unsigned int len)
86 struct GNUNET_CONTAINER_MultiHashMap *ret;
88 GNUNET_assert (len > 0);
89 ret = GNUNET_malloc (sizeof (struct GNUNET_CONTAINER_MultiHashMap));
90 ret->map = GNUNET_malloc (len * sizeof (struct MapEntry *));
91 ret->map_length = len;
97 * Destroy a hash map. Will not free any values
98 * stored in the hash map!
103 GNUNET_CONTAINER_multihashmap_destroy (struct GNUNET_CONTAINER_MultiHashMap
109 for (i = 0; i < map->map_length; i++)
111 while (NULL != (e = map->map[i]))
113 map->map[i] = e->next;
117 GNUNET_free (map->map);
123 * Compute the index of the bucket for the given key.
125 * @param m hash map for which to compute the index
126 * @param key what key should the index be computed for
127 * @return offset into the "map" array of "m"
130 idx_of (const struct GNUNET_CONTAINER_MultiHashMap *m,
131 const GNUNET_HashCode * key)
133 return (*(unsigned int *) key) % m->map_length;
138 * Get the number of key-value pairs in the map.
141 * @return the number of key value pairs
144 GNUNET_CONTAINER_multihashmap_size (const struct GNUNET_CONTAINER_MultiHashMap
152 * Given a key find a value in the map matching the key.
155 * @param key what to look for
156 * @return NULL if no value was found; note that
157 * this is indistinguishable from values that just
158 * happen to be NULL; use "contains" to test for
159 * key-value pairs with value NULL
162 GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap
163 *map, const GNUNET_HashCode * key)
167 e = map->map[idx_of (map, key)];
170 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
179 * Iterate over all entries in the map.
182 * @param it function to call on each entry
183 * @param it_cls extra argument to it
184 * @return the number of key value pairs processed,
185 * GNUNET_SYSERR if it aborted iteration
188 GNUNET_CONTAINER_multihashmap_iterate (const struct
189 GNUNET_CONTAINER_MultiHashMap *map,
190 GNUNET_CONTAINER_HashMapIterator it,
200 GNUNET_assert(map!=NULL);
202 for (i = 0; i < map->map_length; i++)
205 while (NULL != (e = n))
211 if (GNUNET_OK != it (it_cls, &kc, e->value))
212 return GNUNET_SYSERR;
222 * Remove the given key-value pair from the map. Note that if the
223 * key-value pair is in the map multiple times, only one of the pairs
227 * @param key key of the key-value pair
228 * @param value value of the key-value pair
229 * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
233 GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap
234 *map, const GNUNET_HashCode * key,
241 i = idx_of (map, key);
246 if ((0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode))) &&
250 map->map[i] = e->next;
265 * Remove all entries for the given key from the map.
266 * Note that the values would not be "freed".
269 * @param key identifies values to be removed
270 * @return number of values removed
273 GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
274 *map, const GNUNET_HashCode * key)
282 i = idx_of (map, key);
287 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
290 map->map[i] = e->next;
312 * Check if the map contains any value under the given
313 * key (including values that are NULL).
316 * @param key the key to test if a value exists for it
317 * @return GNUNET_YES if such a value exists,
321 GNUNET_CONTAINER_multihashmap_contains (const struct
322 GNUNET_CONTAINER_MultiHashMap *map,
323 const GNUNET_HashCode * key)
327 e = map->map[idx_of (map, key)];
330 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
339 * Grow the given map to a more appropriate size.
341 * @param map the hash map to grow
344 grow (struct GNUNET_CONTAINER_MultiHashMap *map)
346 struct MapEntry **old_map;
347 struct MapEntry **new_map;
349 unsigned int old_len;
350 unsigned int new_len;
355 old_len = map->map_length;
356 new_len = old_len * 2;
357 new_map = GNUNET_malloc (sizeof (struct MapEntry *) * new_len);
358 map->map_length = new_len;
360 for (i = 0; i < old_len; i++)
362 while (NULL != (e = old_map[i]))
364 old_map[i] = e->next;
365 idx = idx_of (map, &e->key);
366 e->next = new_map[idx];
370 GNUNET_free (old_map);
375 * Store a key-value pair in the map.
378 * @param key key to use
379 * @param value value to use
380 * @param opt options for put
381 * @return GNUNET_OK on success,
382 * GNUNET_NO if a value was replaced (with REPLACE)
383 * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
384 * value already exists
387 GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
388 const GNUNET_HashCode * key,
390 enum GNUNET_CONTAINER_MultiHashMapOption
396 i = idx_of (map, key);
397 if ((opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE) &&
398 (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
403 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
405 if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
406 return GNUNET_SYSERR;
413 if (map->size / 3 >= map->map_length / 4)
416 i = idx_of (map, key);
418 e = GNUNET_malloc (sizeof (struct MapEntry));
421 e->next = map->map[i];
429 * Iterate over all entries in the map that match a particular key.
432 * @param key key that the entries must correspond to
433 * @param it function to call on each entry
434 * @param it_cls extra argument to it
435 * @return the number of key value pairs processed,
436 * GNUNET_SYSERR if it aborted iteration
439 GNUNET_CONTAINER_multihashmap_get_multiple (const struct
440 GNUNET_CONTAINER_MultiHashMap
441 *map, const GNUNET_HashCode * key,
442 GNUNET_CONTAINER_HashMapIterator
450 n = map->map[idx_of (map, key)];
451 while (NULL != (e = n))
454 if (0 != memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
456 if ((it != NULL) && (GNUNET_OK != it (it_cls, key, e->value)))
457 return GNUNET_SYSERR;
464 /* end of container_multihashmap.c */