/*
This file is part of GNUnet.
- (C) 2008, 2012 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2008, 2012 Christian Grothoff (and other contributing authors)
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"
#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.
*/
unsigned int map_length;
/**
- * GNUNET_NO if the map entries are of type 'struct BigMapEntry',
- * GNUNET_YES if the map entries are of type 'struct SmallMapEntry'.
+ * #GNUNET_NO if the map entries are of type 'struct BigMapEntry',
+ * #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;
};
* Create a multi hash 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
+ * @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
* 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;
* key-value pairs with value NULL
*/
void *
-GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap
- *map, const struct GNUNET_HashCode *key)
+GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap *map,
+ const struct GNUNET_HashCode *key)
{
union MapEntry me;
*
* @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_multihashmap_iterate (const struct
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;
* @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_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;
* @return number of values removed
*/
int
-GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
- *map, const struct GNUNET_HashCode *key)
+GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap *map,
+ const struct GNUNET_HashCode *key)
{
union MapEntry me;
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;
sme = map->map[i].sme;
else
sme = p->next;
- ret++;
+ ret++;
}
else
{
}
+/**
+ * Callback used to remove all entries from the map.
+ *
+ * @param cls the `struct GNUNET_CONTAINER_MultiHashMap`
+ * @param key the key
+ * @param value the value
+ * @return #GNUNET_OK (continue to iterate)
+ */
+static int
+remove_all (void *cls,
+ const struct GNUNET_HashCode *key,
+ void *value)
+{
+ struct GNUNET_CONTAINER_MultiHashMap *map = cls;
+
+ GNUNET_CONTAINER_multihashmap_remove (map,
+ key,
+ value);
+ return GNUNET_OK;
+}
+
+
+/**
+ * @ingroup hashmap
+ * Remove all entries from the map.
+ * Note that the values would not be "freed".
+ *
+ * @param map the map
+ * @return number of values removed
+ */
+unsigned int
+GNUNET_CONTAINER_multihashmap_clear (struct GNUNET_CONTAINER_MultiHashMap *map)
+{
+ unsigned int ret;
+
+ ret = map->size;
+ GNUNET_CONTAINER_multihashmap_iterate (map,
+ &remove_all,
+ map);
+ return ret;
+}
+
+
/**
* Check if the map contains any value under the given
* key (including values that are 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_multihashmap_contains (const struct
* @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_multihashmap_contains_value (const struct
unsigned int idx;
unsigned int i;
+ map->modification_counter++;
+
old_map = map->map;
old_len = map->map_length;
new_len = old_len * 2;
struct BigMapEntry *bme;
while (NULL != (bme = old_map[i].bme))
- {
+ {
old_map[i].bme = bme->next;
idx = idx_of (map, &bme->key);
bme->next = new_map[idx].bme;
* @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
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;
* @param it function to call on each entry
* @param it_cls extra argument to it
* @return the number of key value pairs processed,
- * GNUNET_SYSERR if it aborted iteration
+ * #GNUNET_SYSERR if it aborted iteration
*/
int
GNUNET_CONTAINER_multihashmap_get_multiple (const struct
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))
{
}
+/**
+ * @ingroup hashmap
+ * Call @a it on a random value from the map, or not at all
+ * if the map is empty. Note that this function has linear
+ * complexity (in the size of the map).
+ *
+ * @param map the map
+ * @param it function to call on a random entry
+ * @param it_cls extra argument to @a it
+ * @return the number of key value pairs processed, zero or one.
+ */
+unsigned int
+GNUNET_CONTAINER_multihashmap_get_random (const struct GNUNET_CONTAINER_MultiHashMap *map,
+ GNUNET_CONTAINER_HashMapIterator it,
+ void *it_cls)
+{
+ unsigned int off;
+ unsigned int idx;
+ union MapEntry me;
+
+ if (0 == map->size)
+ return 0;
+ if (NULL == it)
+ return 1;
+ off = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
+ map->size);
+ for (idx = 0; idx < map->map_length; idx++)
+ {
+ me = map->map[idx];
+ if (map->use_small_entries)
+ {
+ struct SmallMapEntry *sme;
+ struct SmallMapEntry *nxt;
+
+ nxt = me.sme;
+ while (NULL != (sme = nxt))
+ {
+ nxt = sme->next;
+ if (0 == off)
+ {
+ if (GNUNET_OK != it (it_cls,
+ sme->key,
+ sme->value))
+ return GNUNET_SYSERR;
+ return 1;
+ }
+ off--;
+ }
+ }
+ else
+ {
+ struct BigMapEntry *bme;
+ struct BigMapEntry *nxt;
+
+ nxt = me.bme;
+ while (NULL != (bme = nxt))
+ {
+ nxt = bme->next;
+ if (0 == off)
+ {
+ if (GNUNET_OK != it (it_cls,
+ &bme->key, bme->value))
+ return GNUNET_SYSERR;
+ return 1;
+ }
+ off--;
+ }
+ }
+ }
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+}
+
+
+/**
+ * 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 */
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