2 This file is part of GNUnet.
3 (C) 2008 Christian Grothoff (and other contributing authors)
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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
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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.
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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"
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,
199 for (i = 0; i < map->map_length; i++)
202 while (NULL != (e = n))
205 if ((NULL != it) && (GNUNET_OK != it (it_cls, &e->key, e->value)))
206 return GNUNET_SYSERR;
215 * Remove the given key-value pair from the map. Note that if the
216 * key-value pair is in the map multiple times, only one of the pairs
220 * @param key key of the key-value pair
221 * @param value value of the key-value pair
222 * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
226 GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap
227 *map, const GNUNET_HashCode * key,
234 i = idx_of (map, key);
239 if ((0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode))) &&
243 map->map[i] = e->next;
258 * Remove all entries for the given key from the map.
259 * Note that the values would not be "freed".
262 * @param key identifies values to be removed
263 * @return number of values removed
266 GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
267 *map, const GNUNET_HashCode * key)
275 i = idx_of (map, key);
280 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
283 map->map[i] = e->next;
305 * Check if the map contains any value under the given
306 * key (including values that are NULL).
309 * @param key the key to test if a value exists for it
310 * @return GNUNET_YES if such a value exists,
314 GNUNET_CONTAINER_multihashmap_contains (const struct
315 GNUNET_CONTAINER_MultiHashMap *map,
316 const GNUNET_HashCode * key)
320 e = map->map[idx_of (map, key)];
323 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
332 * Grow the given map to a more appropriate size.
334 * @param map the hash map to grow
337 grow (struct GNUNET_CONTAINER_MultiHashMap *map)
339 struct MapEntry **old_map;
340 struct MapEntry **new_map;
342 unsigned int old_len;
343 unsigned int new_len;
348 old_len = map->map_length;
349 new_len = old_len * 2;
350 new_map = GNUNET_malloc (sizeof (struct MapEntry *) * new_len);
351 map->map_length = new_len;
353 for (i = 0; i < old_len; i++)
355 while (NULL != (e = old_map[i]))
357 old_map[i] = e->next;
358 idx = idx_of (map, &e->key);
359 e->next = new_map[idx];
363 GNUNET_free (old_map);
368 * Store a key-value pair in the map.
371 * @param key key to use
372 * @param value value to use
373 * @param opt options for put
374 * @return GNUNET_OK on success,
375 * GNUNET_NO if a value was replaced (with REPLACE)
376 * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
377 * value already exists
380 GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
381 const GNUNET_HashCode * key,
383 enum GNUNET_CONTAINER_MultiHashMapOption
389 i = idx_of (map, key);
390 if ((opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE) &&
391 (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
396 if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
398 if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
399 return GNUNET_SYSERR;
406 if (map->size / 3 >= map->map_length / 4)
409 i = idx_of (map, key);
411 e = GNUNET_malloc (sizeof (struct MapEntry));
414 e->next = map->map[i];
422 * Iterate over all entries in the map that match a particular key.
425 * @param key key that the entries must correspond to
426 * @param it function to call on each entry
427 * @param it_cls extra argument to it
428 * @return the number of key value pairs processed,
429 * GNUNET_SYSERR if it aborted iteration
432 GNUNET_CONTAINER_multihashmap_get_multiple (const struct
433 GNUNET_CONTAINER_MultiHashMap
434 *map, const GNUNET_HashCode * key,
435 GNUNET_CONTAINER_HashMapIterator
443 n = map->map[idx_of (map, key)];
444 while (NULL != (e = n))
447 if (0 != memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
449 if ((it != NULL) && (GNUNET_OK != it (it_cls, &e->key, e->value)))
450 return GNUNET_SYSERR;
457 /* end of container_multihashmap.c */