2 This file is part of GNUnet.
3 (C) 2008 Christian Grothoff (and other contributing authors)
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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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"
31 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
34 * An entry in the hash map.
42 struct GNUNET_HashCode key;
50 * If there is a hash collision, we create a linked list.
52 struct MapEntry *next;
57 * Internal representation of the hash map.
59 struct GNUNET_CONTAINER_MultiHashMap
65 struct MapEntry **map;
68 * Number of entries in the map.
73 * Length of the "map" array.
75 unsigned int map_length;
80 * Create a multi hash map.
82 * @param len initial size (map will grow as needed)
83 * @param do_not_copy_keys GNUNET_NO is always safe and should be used by default;
84 * GNUNET_YES means that on 'put', the 'key' does not have
85 * to be copied as the destination of the pointer is
86 * guaranteed to be life as long as the value is stored in
87 * the hashmap. This can significantly reduce memory
88 * consumption, but of course is also a recipie for
89 * heap corruption if the assumption is not true. Only
90 * use this if (1) memory use is important in this case and
91 * (2) you have triple-checked that the invariant holds
92 * @return NULL on error
94 struct GNUNET_CONTAINER_MultiHashMap *
95 GNUNET_CONTAINER_multihashmap_create (unsigned int len,
98 struct GNUNET_CONTAINER_MultiHashMap *ret;
100 GNUNET_assert (len > 0);
101 ret = GNUNET_malloc (sizeof (struct GNUNET_CONTAINER_MultiHashMap));
102 ret->map = GNUNET_malloc (len * sizeof (struct MapEntry *));
103 ret->map_length = len;
109 * Destroy a hash map. Will not free any values
110 * stored in the hash map!
115 GNUNET_CONTAINER_multihashmap_destroy (struct GNUNET_CONTAINER_MultiHashMap
121 for (i = 0; i < map->map_length; i++)
123 while (NULL != (e = map->map[i]))
125 map->map[i] = e->next;
129 GNUNET_free (map->map);
135 * Compute the index of the bucket for the given key.
137 * @param m hash map for which to compute the index
138 * @param key what key should the index be computed for
139 * @return offset into the "map" array of "m"
142 idx_of (const struct GNUNET_CONTAINER_MultiHashMap *m,
143 const struct GNUNET_HashCode * key)
145 GNUNET_assert (m != NULL);
146 return (*(unsigned int *) key) % m->map_length;
151 * Get the number of key-value pairs in the map.
154 * @return the number of key value pairs
157 GNUNET_CONTAINER_multihashmap_size (const struct GNUNET_CONTAINER_MultiHashMap
165 * Given a key find a value in the map matching the key.
168 * @param key what to look for
169 * @return NULL if no value was found; note that
170 * this is indistinguishable from values that just
171 * happen to be NULL; use "contains" to test for
172 * key-value pairs with value NULL
175 GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap
176 *map, const struct GNUNET_HashCode * key)
180 e = map->map[idx_of (map, key)];
183 if (0 == memcmp (key, &e->key, sizeof (struct GNUNET_HashCode)))
192 * Iterate over all entries in the map.
195 * @param it function to call on each entry
196 * @param it_cls extra argument to it
197 * @return the number of key value pairs processed,
198 * GNUNET_SYSERR if it aborted iteration
201 GNUNET_CONTAINER_multihashmap_iterate (const struct
202 GNUNET_CONTAINER_MultiHashMap *map,
203 GNUNET_CONTAINER_HashMapIterator it,
210 struct GNUNET_HashCode kc;
213 GNUNET_assert (map != NULL);
214 for (i = 0; i < map->map_length; i++)
217 while (NULL != (e = n))
223 if (GNUNET_OK != it (it_cls, &kc, e->value))
224 return GNUNET_SYSERR;
234 * Remove the given key-value pair from the map. Note that if the
235 * key-value pair is in the map multiple times, only one of the pairs
239 * @param key key of the key-value pair
240 * @param value value of the key-value pair
241 * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
245 GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap *map,
246 const struct GNUNET_HashCode * key, void *value)
252 i = idx_of (map, key);
257 if ((0 == memcmp (key, &e->key, sizeof (struct GNUNET_HashCode))) &&
261 map->map[i] = e->next;
276 * Remove all entries for the given key from the map.
277 * Note that the values would not be "freed".
280 * @param key identifies values to be removed
281 * @return number of values removed
284 GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
285 *map, const struct GNUNET_HashCode * key)
293 i = idx_of (map, key);
298 if (0 == memcmp (key, &e->key, sizeof (struct GNUNET_HashCode)))
301 map->map[i] = e->next;
323 * Check if the map contains any value under the given
324 * key (including values that are NULL).
327 * @param key the key to test if a value exists for it
328 * @return GNUNET_YES if such a value exists,
332 GNUNET_CONTAINER_multihashmap_contains (const struct
333 GNUNET_CONTAINER_MultiHashMap *map,
334 const struct GNUNET_HashCode * key)
338 e = map->map[idx_of (map, key)];
341 if (0 == memcmp (key, &e->key, sizeof (struct GNUNET_HashCode)))
350 * Check if the map contains the given value under the given
354 * @param key the key to test if a value exists for it
355 * @param value value to test for
356 * @return GNUNET_YES if such a value exists,
360 GNUNET_CONTAINER_multihashmap_contains_value (const struct
361 GNUNET_CONTAINER_MultiHashMap
362 *map, const struct GNUNET_HashCode * key,
367 e = map->map[idx_of (map, key)];
370 if ((0 == memcmp (key, &e->key, sizeof (struct GNUNET_HashCode))) &&
380 * Grow the given map to a more appropriate size.
382 * @param map the hash map to grow
385 grow (struct GNUNET_CONTAINER_MultiHashMap *map)
387 struct MapEntry **old_map;
388 struct MapEntry **new_map;
390 unsigned int old_len;
391 unsigned int new_len;
396 old_len = map->map_length;
397 new_len = old_len * 2;
398 new_map = GNUNET_malloc (sizeof (struct MapEntry *) * new_len);
399 map->map_length = new_len;
401 for (i = 0; i < old_len; i++)
403 while (NULL != (e = old_map[i]))
405 old_map[i] = e->next;
406 idx = idx_of (map, &e->key);
407 e->next = new_map[idx];
411 GNUNET_free (old_map);
416 * Store a key-value pair in the map.
419 * @param key key to use
420 * @param value value to use
421 * @param opt options for put
422 * @return GNUNET_OK on success,
423 * GNUNET_NO if a value was replaced (with REPLACE)
424 * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
425 * value already exists
428 GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
429 const struct GNUNET_HashCode * key, void *value,
430 enum GNUNET_CONTAINER_MultiHashMapOption opt)
435 i = idx_of (map, key);
436 if ((opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE) &&
437 (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
442 if (0 == memcmp (key, &e->key, sizeof (struct GNUNET_HashCode)))
444 if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
445 return GNUNET_SYSERR;
452 if (map->size / 3 >= map->map_length / 4)
455 i = idx_of (map, key);
457 e = GNUNET_malloc (sizeof (struct MapEntry));
460 e->next = map->map[i];
468 * Iterate over all entries in the map that match a particular key.
471 * @param key key that the entries must correspond to
472 * @param it function to call on each entry
473 * @param it_cls extra argument to it
474 * @return the number of key value pairs processed,
475 * GNUNET_SYSERR if it aborted iteration
478 GNUNET_CONTAINER_multihashmap_get_multiple (const struct
479 GNUNET_CONTAINER_MultiHashMap *map,
480 const struct GNUNET_HashCode * key,
481 GNUNET_CONTAINER_HashMapIterator it,
489 n = map->map[idx_of (map, key)];
490 while (NULL != (e = n))
493 if (0 != memcmp (key, &e->key, sizeof (struct GNUNET_HashCode)))
495 if ((it != NULL) && (GNUNET_OK != it (it_cls, key, e->value)))
496 return GNUNET_SYSERR;
503 /* end of container_multihashmap.c */