#include "gnunet_crypto_lib.h"
/**
- *
+ * An entry in the hash map.
*/
struct MapEntry
{
+
+ /**
+ * Key for the entry.
+ */
GNUNET_HashCode key;
+
+ /**
+ * Value of the entry.
+ */
void *value;
+
+ /**
+ * If there is a hash collision, we create a linked list.
+ */
struct MapEntry *next;
+
};
/**
- *
+ * Internal representation of the hash map.
*/
struct GNUNET_CONTAINER_MultiHashMap
{
+ /**
+ * All of our buckets.
+ */
struct MapEntry **map;
+ /**
+ * Number of entries in the map.
+ */
unsigned int size;
+ /**
+ * Length of the "map" array.
+ */
unsigned int map_length;
};
+/**
+ * Create a multi hash map.
+ *
+ * @param len initial size (map will grow as needed)
+ * @return NULL on error
+ */
struct GNUNET_CONTAINER_MultiHashMap *
GNUNET_CONTAINER_multihashmap_create (unsigned int len)
{
struct GNUNET_CONTAINER_MultiHashMap *ret;
ret = GNUNET_malloc (sizeof (struct GNUNET_CONTAINER_MultiHashMap));
- ret->size = 0;
ret->map = GNUNET_malloc (len * sizeof (struct MapEntry *));
- memset (ret->map, 0, len * sizeof (struct MapEntry *));
ret->map_length = len;
return ret;
}
+/**
+ * Destroy a hash map. Will not free any values
+ * stored in the hash map!
+ *
+ * @param map the map
+ */
void
GNUNET_CONTAINER_multihashmap_destroy (struct GNUNET_CONTAINER_MultiHashMap
*map)
GNUNET_free (map);
}
+
+/**
+ * Compute the index of the bucket for the given key.
+ *
+ * @param m hash map for which to compute the index
+ * @param key what key should the index be computed for
+ * @return offset into the "map" array of "m"
+ */
static unsigned int
idx_of (const struct GNUNET_CONTAINER_MultiHashMap *m,
const GNUNET_HashCode * key)
}
+/**
+ * Get the number of key-value pairs in the map.
+ *
+ * @param map the map
+ * @return the number of key value pairs
+ */
unsigned int
GNUNET_CONTAINER_multihashmap_size (const struct GNUNET_CONTAINER_MultiHashMap
*map)
}
+/**
+ * Given a key find a value in the map matching the key.
+ *
+ * @param map the map
+ * @param key what to look for
+ * @return NULL if no value was found; note that
+ * this is indistinguishable from values that just
+ * happen to be NULL; use "contains" to test for
+ * key-value pairs with value NULL
+ */
void *
GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap
*map, const GNUNET_HashCode * key)
}
+/**
+ * Iterate over all entries in the map.
+ *
+ * @param map the map
+ * @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
+ */
int
GNUNET_CONTAINER_multihashmap_iterate (const struct
GNUNET_CONTAINER_MultiHashMap *map,
GNUNET_CONTAINER_HashMapIterator it,
- void *cls)
+ void *it_cls)
{
int count;
unsigned int i;
e = map->map[i];
while (e != NULL)
{
- if ((NULL != it) && (GNUNET_OK != it (cls, &e->key, e->value)))
+ if ( (NULL != it) &&
+ (GNUNET_OK != it (it_cls, &e->key, e->value)) )
return GNUNET_SYSERR;
count++;
e = e->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
+ * will be removed.
+ *
+ * @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
+ * is not in the map
+ */
int
GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap
*map, const GNUNET_HashCode * key,
e = map->map[i];
while (e != NULL)
{
- if ((0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode))) &&
- (value == e->value))
+ if ( (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode))) &&
+ (value == e->value))
{
if (p == NULL)
map->map[i] = e->next;
}
+/**
+ * Remove all entries for the given key from the map.
+ * Note that the values would not be "freed".
+ *
+ * @param map the map
+ * @param key identifies values to be removed
+ * @return number of values removed
+ */
int
GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
*map, const GNUNET_HashCode * key)
}
+/**
+ * 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
+ */
int
GNUNET_CONTAINER_multihashmap_contains (const struct
GNUNET_CONTAINER_MultiHashMap *map,
const GNUNET_HashCode * key)
{
struct MapEntry *e;
- unsigned int i;
- i = idx_of (map, key);
- e = map->map[i];
+ e = map->map[idx_of (map, key)];
while (e != NULL)
{
if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
}
+/**
+ * Grow the given map to a more appropriate size.
+ *
+ * @param map the hash map to grow
+ */
static void
grow (struct GNUNET_CONTAINER_MultiHashMap *map)
{
- struct MapEntry **old;
+ struct MapEntry **old_map;
+ struct MapEntry **new_map;
struct MapEntry *e;
+ unsigned int old_len;
+ unsigned int new_len;
+ unsigned int idx;
unsigned int i;
- unsigned int l;
-
- old = map->map;
- l = map->map_length;
- map->map_length *= 2;
- map->map = GNUNET_malloc (sizeof (struct MapEntry *) * map->map_length);
- memset (map->map, 0, sizeof (struct MapEntry *) * map->map_length);
- for (i = 0; i < l; i++)
+
+ old_map = map->map;
+ old_len = map->map_length;
+ new_len = old_len * 2;
+ new_map = GNUNET_malloc (sizeof (struct MapEntry *) * new_len);
+ map->map_length = new_len;
+ map->map = new_map;
+ for (i = 0; i < old_len; i++)
{
- while (NULL != (e = old[i]))
+ while (NULL != (e = old_map[i]))
{
- old[i] = e->next;
- e->next = map->map[idx_of (map, &e->key)];
- map->map[idx_of (map, &e->key)] = e;
+ old_map[i] = e->next;
+ idx = idx_of (map, &e->key);
+ e->next = new_map[idx];
+ new_map[idx] = e;
}
}
- GNUNET_free (old);
+ GNUNET_free (old_map);
}
+/**
+ * Store a key-value pair in the map.
+ *
+ * @param map the map
+ * @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
+ * value already exists
+ */
int
GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
const GNUNET_HashCode * key,
unsigned int i;
i = idx_of (map, key);
- if ((opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE) &&
- (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
+ if ( (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE) &&
+ (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST) )
{
e = map->map[i];
while (e != NULL)
{
- if ((0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode))) &&
- (value == e->value))
+ if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
{
if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
return GNUNET_SYSERR;
e = e->next;
}
}
- if (map->size / 3 > map->map_length / 4)
+ if (map->size / 3 >= map->map_length / 4)
grow (map);
e = GNUNET_malloc (sizeof (struct MapEntry));
e->key = *key;
}
+/**
+ * Iterate over all entries in the map that match a particular key.
+ *
+ * @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
+ * @return the number of key value pairs processed,
+ * GNUNET_SYSERR if it aborted iteration
+ */
int
GNUNET_CONTAINER_multihashmap_get_multiple (const struct
GNUNET_CONTAINER_MultiHashMap
*map, const GNUNET_HashCode * key,
GNUNET_CONTAINER_HashMapIterator
- it, void *cls)
+ it, void *it_cls)
{
int count;
struct MapEntry *e;
{
if (0 == memcmp (key, &e->key, sizeof (GNUNET_HashCode)))
{
- if ((it != NULL) && (GNUNET_OK != it (&e->key, e->value, cls)))
+ if ( (it != NULL) &&
+ (GNUNET_OK != it (it_cls, &e->key, e->value)) )
return GNUNET_SYSERR;
count++;
}
}
+/**
+ * Returns the stored value of a random non-null entry in the hash
+ * table. Returns only the first value, does not go inside bucket
+ * linked list (yet). Runs with a worst case time of N, so it's not
+ * efficient in any way shape or form!!!!.
+ *
+ * @param map the map
+ * @return value associated with a random key
+ */
void *
GNUNET_CONTAINER_multihashmap_get_random (const struct
GNUNET_CONTAINER_MultiHashMap *map)
{
unsigned int rand;
struct MapEntry *e;
- e = NULL;
if (map->size == 0)
return NULL;
-
- while (e == NULL)
+ while (1)
{
rand =
GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
map->map_length);
- e = map->map[rand];
+ if (NULL != (e = map->map[rand]))
+ return e->value;
}
-
return e->value;
}
+
/* end of container_multihashmap.c */
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