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 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
*/
#include "platform.h"
-#include "gnunet_common.h"
-#include "gnunet_container_lib.h"
-#include "gnunet_crypto_lib.h"
+#include "gnunet_util_lib.h"
#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
* If there is a hash collision, we create a linked list.
*/
struct SmallMapEntry *next;
-
+
/**
* Key for the entry.
*/
*/
struct GNUNET_CONTAINER_MultiHashMap
{
-
/**
* All of our buckets.
*/
* GNUNET_YES if the map entries are of type 'struct SmallMapEntry'.
*/
int use_small_entries;
+
+ /**
+ * Counts the destructive modifications (grow, remove)
+ * to the map, so that iterators can check if they are still valid.
+ */
+ unsigned int modification_counter;
+};
+
+
+/**
+ * Cursor into a multihashmap.
+ * Allows to enumerate elements asynchronously.
+ */
+struct GNUNET_CONTAINER_MultiHashMapIterator
+{
+ /**
+ * Position in the bucket 'idx'
+ */
+ union 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_MultiHashMap *map;
};
* @param len initial size (map will grow as needed)
* @param do_not_copy_keys GNUNET_NO is always safe and should be used by default;
* GNUNET_YES means that on 'put', the 'key' does not have
- * to be copied as the destination of the pointer is
+ * to be copied as the destination of the pointer is
* guaranteed to be life as long as the value is stored in
- * the hashmap. This can significantly reduce memory
- * consumption, but of course is also a recipie for
+ * the hashmap. This can significantly reduce memory
+ * consumption, but of course is also a recipie for
* heap corruption if the assumption is not true. Only
* use this if (1) memory use is important in this case and
* (2) you have triple-checked that the invariant holds
struct GNUNET_CONTAINER_MultiHashMap *map;
GNUNET_assert (len > 0);
- map = GNUNET_malloc (sizeof (struct GNUNET_CONTAINER_MultiHashMap));
+ map = GNUNET_new (struct GNUNET_CONTAINER_MultiHashMap);
map->map = GNUNET_malloc (len * sizeof (union MapEntry));
map->map_length = len;
map->use_small_entries = do_not_copy_keys;
struct SmallMapEntry *sme;
struct SmallMapEntry *nxt;
- nxt = me.sme;
+ nxt = me.sme;
while (NULL != (sme = nxt))
{
nxt = sme->next;
struct BigMapEntry *bme;
struct BigMapEntry *nxt;
- nxt = me.bme;
+ nxt = me.bme;
while (NULL != (bme = nxt))
{
nxt = bme->next;
*/
int
GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap *map,
- const struct GNUNET_HashCode *key,
- void *value)
+ const struct GNUNET_HashCode *key,
+ const void *value)
{
union MapEntry me;
unsigned int i;
+ map->modification_counter++;
+
i = idx_of (map, key);
me = map->map[i];
if (map->use_small_entries)
- {
+ {
struct SmallMapEntry *sme;
struct SmallMapEntry *p;
unsigned int i;
int ret;
+ map->modification_counter++;
+
ret = 0;
i = idx_of (map, key);
me = map->map[i];
if (map->use_small_entries)
- {
+ {
struct SmallMapEntry *sme;
struct SmallMapEntry *p;
unsigned int idx;
unsigned int i;
+ map->modification_counter++;
+
old_map = map->map;
old_len = map->map_length;
new_len = old_len * 2;
*/
int
GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
- const struct GNUNET_HashCode *key,
+ const struct GNUNET_HashCode *key,
void *value,
enum GNUNET_CONTAINER_MultiHashMapOption opt)
{
{
struct SmallMapEntry *sme;
- for (sme = me.sme; NULL != sme; sme = sme->next)
+ for (sme = me.sme; NULL != sme; sme = sme->next)
if (0 == memcmp (key, sme->key, sizeof (struct GNUNET_HashCode)))
{
if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
{
struct BigMapEntry *bme;
- for (bme = me.bme; NULL != bme; bme = bme->next)
+ for (bme = me.bme; NULL != bme; bme = bme->next)
if (0 == memcmp (key, &bme->key, sizeof (struct GNUNET_HashCode)))
{
if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
if (map->use_small_entries)
{
struct SmallMapEntry *sme;
-
- sme = GNUNET_malloc (sizeof (struct SmallMapEntry));
+
+ sme = GNUNET_new (struct SmallMapEntry);
sme->key = key;
sme->value = value;
sme->next = map->map[i].sme;
else
{
struct BigMapEntry *bme;
-
- bme = GNUNET_malloc (sizeof (struct BigMapEntry));
+
+ bme = GNUNET_new (struct BigMapEntry);
bme->key = *key;
bme->value = value;
bme->next = map->map[i].bme;
me = map->map[idx_of (map, key)];
if (map->use_small_entries)
{
- struct SmallMapEntry *sme;
+ struct SmallMapEntry *sme;
struct SmallMapEntry *nxt;
-
+
nxt = me.sme;
while (NULL != (sme = nxt))
{
}
else
{
- struct BigMapEntry *bme;
+ struct BigMapEntry *bme;
struct BigMapEntry *nxt;
-
+
nxt = me.bme;
while (NULL != (bme = nxt))
{
}
+/**
+ * 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 'map'
+ */
+struct GNUNET_CONTAINER_MultiHashMapIterator *
+GNUNET_CONTAINER_multihashmap_iterator_create (const struct GNUNET_CONTAINER_MultiHashMap *map)
+{
+ struct GNUNET_CONTAINER_MultiHashMapIterator *iter;
+
+ iter = GNUNET_new (struct GNUNET_CONTAINER_MultiHashMapIterator);
+ 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_multihashmap_iterator_next (struct GNUNET_CONTAINER_MultiHashMapIterator *iter,
+ struct GNUNET_HashCode *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 (GNUNET_YES == iter->map->use_small_entries)
+ {
+ if (NULL != iter->me.sme)
+ {
+ if (NULL != key)
+ *key = *iter->me.sme->key;
+ if (NULL != value)
+ *value = iter->me.sme->value;
+ iter->me.sme = iter->me.sme->next;
+ return GNUNET_YES;
+ }
+ }
+ else
+ {
+ if (NULL != iter->me.bme)
+ {
+ if (NULL != key)
+ *key = iter->me.bme->key;
+ if (NULL != value)
+ *value = iter->me.bme->value;
+ iter->me.bme = iter->me.bme->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_multihashmap_iterator_destroy (struct GNUNET_CONTAINER_MultiHashMapIterator *iter)
+{
+ GNUNET_free (iter);
+}
+
+
/* end of container_multihashmap.c */
projects / oweals / gnunet.git / blobdiff