/*
This file is part of GNUnet.
- (C) 2008 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2008 GNUnet e.V.
- GNUnet is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 3, or (at your
- option) any later version.
+ GNUnet is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
+ Affero General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file util/container_multihashmap32.c
*/
#include "platform.h"
-#include "gnunet_util_lib.h"
+#include "gnunet_container_lib.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "util-container-multihashmap32", __VA_ARGS__)
+
-#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+/**
+ * Maximum recursion depth for callbacks of
+ * #GNUNET_CONTAINER_multihashmap_get_multiple() themselves
+ * again calling #GNUNET_CONTAINER_multihashmap_get_multiple().
+ * Should be totally excessive, but if violated we die.
+ */
+#define NEXT_CACHE_SIZE 16
/**
* An entry in the hash map.
unsigned int size;
/**
- * Length of the "map" array.
+ * Length of the @e map array.
*/
unsigned int map_length;
+
+ /**
+ * Counts the destructive modifications (grow, remove)
+ * to the map, so that iterators can check if they are still valid.
+ */
+ unsigned int modification_counter;
+
+ /**
+ * Map entries indicating iteration positions currently
+ * in use by #GNUNET_CONTAINER_multihashmap_get_multiple().
+ * Only used up to @e next_cache_off.
+ */
+ struct MapEntry *next_cache[NEXT_CACHE_SIZE];
+
+ /**
+ * Offset of @e next_cache entries in use, must be smaller
+ * than #NEXT_CACHE_SIZE.
+ */
+ unsigned int next_cache_off;
+};
+
+
+/**
+ * Cursor into a multihashmap.
+ * Allows to enumerate elements asynchronously.
+ */
+struct GNUNET_CONTAINER_MultiHashMap32Iterator
+{
+ /**
+ * Position in the bucket @e idx
+ */
+ struct MapEntry *me;
+
+ /**
+ * Current bucket index.
+ */
+ unsigned int idx;
+
+ /**
+ * Modification counter as observed on the map when the iterator
+ * was created.
+ */
+ unsigned int modification_counter;
+
+ /**
+ * Map that we are iterating over.
+ */
+ const struct GNUNET_CONTAINER_MultiHashMap32 *map;
};
GNUNET_assert (len > 0);
ret = GNUNET_new (struct GNUNET_CONTAINER_MultiHashMap32);
- ret->map = GNUNET_malloc (len * sizeof (struct MapEntry *));
+ ret->map = GNUNET_malloc_large (len *
+ sizeof (struct MapEntry *));
+ if (NULL == ret->map)
+ {
+ GNUNET_free (ret);
+ return NULL;
+ }
ret->map_length = len;
return ret;
}
* @param map the map
*/
void
-GNUNET_CONTAINER_multihashmap32_destroy (struct GNUNET_CONTAINER_MultiHashMap32
- *map)
+GNUNET_CONTAINER_multihashmap32_destroy (struct GNUNET_CONTAINER_MultiHashMap32 *map)
{
- unsigned int i;
struct MapEntry *e;
- for (i = 0; i < map->map_length; i++)
+ for (unsigned int i = 0; i < map->map_length; i++)
{
while (NULL != (e = map->map[i]))
{
idx_of (const struct GNUNET_CONTAINER_MultiHashMap32 *m,
const uint32_t key)
{
- GNUNET_assert (m != NULL);
+ GNUNET_assert (NULL != m);
return ((unsigned int) key) % m->map_length;
}
* @return the number of key value pairs
*/
unsigned int
-GNUNET_CONTAINER_multihashmap32_size (const struct
- GNUNET_CONTAINER_MultiHashMap32 *map)
+GNUNET_CONTAINER_multihashmap32_size (const struct GNUNET_CONTAINER_MultiHashMap32 *map)
{
return map->size;
}
* key-value pairs with value NULL
*/
void *
-GNUNET_CONTAINER_multihashmap32_get (const struct
- GNUNET_CONTAINER_MultiHashMap32 *map,
+GNUNET_CONTAINER_multihashmap32_get (const struct GNUNET_CONTAINER_MultiHashMap32 *map,
uint32_t key)
{
struct MapEntry *e;
e = map->map[idx_of (map, key)];
- while (e != NULL)
+ while (NULL != e)
{
if (key == e->key)
return e->value;
*
* @param map the map
* @param it function to call on each entry
- * @param it_cls extra argument to it
+ * @param it_cls extra argument to @a it
* @return the number of key value pairs processed,
- * GNUNET_SYSERR if it aborted iteration
+ * #GNUNET_SYSERR if it aborted iteration
*/
int
-GNUNET_CONTAINER_multihashmap32_iterate (const struct
- GNUNET_CONTAINER_MultiHashMap32 *map,
- GNUNET_CONTAINER_HashMapIterator32 it,
+GNUNET_CONTAINER_multihashmap32_iterate (struct GNUNET_CONTAINER_MultiHashMap32 *map,
+ GNUNET_CONTAINER_HashMapIterator32 it,
void *it_cls)
{
int count;
- unsigned int i;
- struct MapEntry *e;
- struct MapEntry *n;
+ struct MapEntry **ce;
count = 0;
- GNUNET_assert (map != NULL);
- for (i = 0; i < map->map_length; i++)
+ GNUNET_assert (NULL != map);
+ ce = &map->next_cache[map->next_cache_off];
+ GNUNET_assert (++map->next_cache_off < NEXT_CACHE_SIZE);
+ for (unsigned int i = 0; i < map->map_length; i++)
{
- n = map->map[i];
- while (NULL != (e = n))
+ struct MapEntry *e;
+
+ *ce = map->map[i];
+ while (NULL != (e = *ce))
{
- n = e->next;
+ *ce = e->next;
if (NULL != it)
{
- if (GNUNET_OK != it (it_cls, e->key, e->value))
+ if (GNUNET_OK != it (it_cls,
+ e->key,
+ e->value))
+ {
+ GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
return GNUNET_SYSERR;
+ }
}
count++;
}
}
+ GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
return count;
}
+/**
+ * We are about to free() the @a bme, make sure it is not in
+ * the list of next values for any iterator in the @a map's next_cache.
+ *
+ * @param map the map to check
+ * @param bme the entry that is about to be free'd
+ */
+static void
+update_next_cache (struct GNUNET_CONTAINER_MultiHashMap32 *map,
+ const struct MapEntry *me)
+{
+ for (unsigned int i=0;i<map->next_cache_off;i++)
+ if (map->next_cache[i] == me)
+ map->next_cache[i] = me->next;
+}
+
+
/**
* Remove the given key-value pair from the map. Note that if the
* key-value pair is in the map multiple times, only one of the pairs
* @param map the map
* @param key key of the key-value pair
* @param value value of the key-value pair
- * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
+ * @return #GNUNET_YES on success, #GNUNET_NO if the key-value pair
* is not in the map
*/
int
-GNUNET_CONTAINER_multihashmap32_remove (struct GNUNET_CONTAINER_MultiHashMap32
- *map,
- uint32_t key, const void *value)
+GNUNET_CONTAINER_multihashmap32_remove (struct GNUNET_CONTAINER_MultiHashMap32 *map,
+ uint32_t key,
+ const void *value)
{
struct MapEntry *e;
struct MapEntry *p;
unsigned int i;
+ map->modification_counter++;
+
i = idx_of (map, key);
p = NULL;
e = map->map[i];
map->map[i] = e->next;
else
p->next = e->next;
+ update_next_cache (map,
+ e);
GNUNET_free (e);
map->size--;
return GNUNET_YES;
* @return number of values removed
*/
int
-GNUNET_CONTAINER_multihashmap32_remove_all (struct
- GNUNET_CONTAINER_MultiHashMap32
- *map,
+GNUNET_CONTAINER_multihashmap32_remove_all (struct GNUNET_CONTAINER_MultiHashMap32 *map,
uint32_t key)
{
struct MapEntry *e;
unsigned int i;
int ret;
+ map->modification_counter++;
+
ret = 0;
i = idx_of (map, key);
p = NULL;
map->map[i] = e->next;
else
p->next = e->next;
+ update_next_cache (map,
+ e);
GNUNET_free (e);
map->size--;
if (p == NULL)
*
* @param map the map
* @param key the key to test if a value exists for it
- * @return GNUNET_YES if such a value exists,
- * GNUNET_NO if not
+ * @return #GNUNET_YES if such a value exists,
+ * #GNUNET_NO if not
*/
int
-GNUNET_CONTAINER_multihashmap32_contains (const struct
- GNUNET_CONTAINER_MultiHashMap32 *map,
+GNUNET_CONTAINER_multihashmap32_contains (const struct GNUNET_CONTAINER_MultiHashMap32 *map,
uint32_t key)
{
struct MapEntry *e;
* @param map the map
* @param key the key to test if a value exists for it
* @param value value to test for
- * @return GNUNET_YES if such a value exists,
- * GNUNET_NO if not
+ * @return #GNUNET_YES if such a value exists,
+ * #GNUNET_NO if not
*/
int
-GNUNET_CONTAINER_multihashmap32_contains_value (const struct
- GNUNET_CONTAINER_MultiHashMap32
- *map,
+GNUNET_CONTAINER_multihashmap32_contains_value (const struct GNUNET_CONTAINER_MultiHashMap32 *map,
uint32_t key,
const void *value)
{
unsigned int old_len;
unsigned int new_len;
unsigned int idx;
- unsigned int i;
old_map = map->map;
old_len = map->map_length;
new_len = old_len * 2;
- new_map = GNUNET_malloc (sizeof (struct MapEntry *) * new_len);
+ if (0 == new_len) /* 2^31 * 2 == 0 */
+ new_len = old_len; /* never use 0 */
+ if (new_len == old_len)
+ return; /* nothing changed */
+ new_map = GNUNET_malloc_large (new_len *
+ sizeof (struct MapEntry *));
+ if (NULL == new_map)
+ return; /* grow not possible */
+ map->modification_counter++;
map->map_length = new_len;
map->map = new_map;
- for (i = 0; i < old_len; i++)
+ for (unsigned int i = 0; i < old_len; i++)
{
while (NULL != (e = old_map[i]))
{
* @param key key to use
* @param value value to use
* @param opt options for put
- * @return GNUNET_OK on success,
- * GNUNET_NO if a value was replaced (with REPLACE)
- * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
+ * @return #GNUNET_OK on success,
+ * #GNUNET_NO if a value was replaced (with REPLACE)
+ * #GNUNET_SYSERR if UNIQUE_ONLY was the option and the
* value already exists
*/
int
* @param map the map
* @param key key that the entries must correspond to
* @param it function to call on each entry
- * @param it_cls extra argument to it
+ * @param it_cls extra argument to @a it
* @return the number of key value pairs processed,
* GNUNET_SYSERR if it aborted iteration
*/
int
-GNUNET_CONTAINER_multihashmap32_get_multiple (const struct
- GNUNET_CONTAINER_MultiHashMap32
- *map, uint32_t key,
- GNUNET_CONTAINER_HashMapIterator32
- it, void *it_cls)
+GNUNET_CONTAINER_multihashmap32_get_multiple (struct GNUNET_CONTAINER_MultiHashMap32 *map,
+ uint32_t key,
+ GNUNET_CONTAINER_HashMapIterator32 it,
+ void *it_cls)
{
int count;
struct MapEntry *e;
- struct MapEntry *n;
+ struct MapEntry **ce;
count = 0;
- n = map->map[idx_of (map, key)];
- while (NULL != (e = n))
+ ce = &map->next_cache[map->next_cache_off];
+ GNUNET_assert (++map->next_cache_off < NEXT_CACHE_SIZE);
+
+ *ce = map->map[idx_of (map, key)];
+ while (NULL != (e = *ce))
{
- n = e->next;
+ *ce = e->next;
if (key != e->key)
continue;
- if ((it != NULL) && (GNUNET_OK != it (it_cls, key, e->value)))
- return GNUNET_SYSERR;
+ if ( (NULL != it) &&
+ (GNUNET_OK != it (it_cls,
+ key,
+ e->value)) )
+ {
+ GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
+ return GNUNET_SYSERR;
+ }
count++;
}
+ GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
return count;
}
+/**
+ * Create an iterator for a multihashmap.
+ * The iterator can be used to retrieve all the elements in the multihashmap
+ * one by one, without having to handle all elements at once (in contrast to
+ * GNUNET_CONTAINER_multihashmap_iterate()). Note that the iterator can not be
+ * used anymore if elements have been removed from 'map' after the creation of
+ * the iterator, or 'map' has been destroyed. Adding elements to 'map' may
+ * result in skipped or repeated elements.
+ *
+ * @param map the map to create an iterator for
+ * @return an iterator over the given multihashmap @a map
+ */
+struct GNUNET_CONTAINER_MultiHashMap32Iterator *
+GNUNET_CONTAINER_multihashmap32_iterator_create (const struct GNUNET_CONTAINER_MultiHashMap32 *map)
+{
+ struct GNUNET_CONTAINER_MultiHashMap32Iterator *iter;
+
+ iter = GNUNET_new (struct GNUNET_CONTAINER_MultiHashMap32Iterator);
+ iter->map = map;
+ iter->modification_counter = map->modification_counter;
+ iter->me = map->map[0];
+ return iter;
+}
+
+
+/**
+ * Retrieve the next element from the hash map at the iterator's position.
+ * If there are no elements left, GNUNET_NO is returned, and 'key' and 'value'
+ * are not modified.
+ * This operation is only allowed if no elements have been removed from the
+ * multihashmap since the creation of 'iter', and the map has not been destroyed.
+ * Adding elements may result in repeating or skipping elements.
+ *
+ * @param iter the iterator to get the next element from
+ * @param key pointer to store the key in, can be NULL
+ * @param value pointer to store the value in, can be NULL
+ * @return #GNUNET_YES we returned an element,
+ * #GNUNET_NO if we are out of elements
+ */
+int
+GNUNET_CONTAINER_multihashmap32_iterator_next (struct GNUNET_CONTAINER_MultiHashMap32Iterator *iter,
+ uint32_t *key,
+ const void **value)
+{
+ /* make sure the map has not been modified */
+ GNUNET_assert (iter->modification_counter == iter->map->modification_counter);
+
+ /* look for the next entry, skipping empty buckets */
+ while (1)
+ {
+ if (iter->idx >= iter->map->map_length)
+ return GNUNET_NO;
+ if (NULL != iter->me)
+ {
+ if (NULL != key)
+ *key = iter->me->key;
+ if (NULL != value)
+ *value = iter->me->value;
+ iter->me = iter->me->next;
+ return GNUNET_YES;
+ }
+ iter->idx += 1;
+ if (iter->idx < iter->map->map_length)
+ iter->me = iter->map->map[iter->idx];
+ }
+}
+
+
+/**
+ * Destroy a multihashmap iterator.
+ *
+ * @param iter the iterator to destroy
+ */
+void
+GNUNET_CONTAINER_multihashmap32_iterator_destroy (struct GNUNET_CONTAINER_MultiHashMapIterator *iter)
+{
+ GNUNET_free (iter);
+}
+
+
/* end of container_multihashmap.c */
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