#ifndef _URCU_RCULFHASH_H
#define _URCU_RCULFHASH_H
+/*
+ * urcu/rculfhash.h
+ *
+ * Userspace RCU library - Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
#include <stdint.h>
#include <urcu-call-rcu.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * struct rcu_ht_node and struct _rcu_ht_node should be aligned on
+ * 4-bytes boundaries because the two lower bits are used as flags.
+ */
+
+struct _rcu_ht_node {
+ struct rcu_ht_node *next; /* ptr | DUMMY_FLAG | REMOVED_FLAG */
+ unsigned long reverse_hash;
+};
+
struct rcu_ht_node {
- struct rcu_ht_node *next;
+ /* cache-hot for iteration */
+ struct _rcu_ht_node p; /* needs to be first field */
void *key;
- unsigned long hash;
- unsigned long reverse_hash;
- unsigned int dummy;
- void *value;
+ unsigned int key_len;
+ /* cache-cold for iteration */
struct rcu_head head;
};
* Ensure reader and writer threads are registered as urcu readers.
*/
-typedef unsigned long (*ht_hash_fct)(void *hashseed, void *key);
+typedef unsigned long (*ht_hash_fct)(void *key, size_t length,
+ unsigned long seed);
+typedef unsigned long (*ht_compare_fct)(void *key1, size_t key1_len,
+ void *key2, size_t key2_len);
+/*
+ * ht_node_init - initialize a hash table node
+ */
static inline
-void ht_node_init(struct rcu_ht_node *node, void *key, void *value)
+void ht_node_init(struct rcu_ht_node *node, void *key,
+ size_t key_len)
{
node->key = key;
- node->value = value;
- node->dummy = 0;
+ node->key_len = key_len;
}
/*
+ * ht_new - allocate a hash table.
+ *
* init_size must be power of two.
*/
struct rcu_ht *ht_new(ht_hash_fct hash_fct,
- void *hashseed,
+ ht_compare_fct compare_fct,
+ unsigned long hash_seed,
unsigned long init_size,
void (*ht_call_rcu)(struct rcu_head *head,
void (*func)(struct rcu_head *head)));
+/*
+ * ht_destroy - destroy a hash table.
+ */
int ht_destroy(struct rcu_ht *ht);
-/* Call with rcu_read_lock held. */
-struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key);
+/*
+ * ht_count_nodes - count the number of nodes in the hash table.
+ *
+ * Call with rcu_read_lock held.
+ */
+void ht_count_nodes(struct rcu_ht *ht,
+ unsigned long *count,
+ unsigned long *removed);
+
+/*
+ * ht_lookup - lookup a node by key.
+ *
+ * Returns NULL if not found.
+ * Call with rcu_read_lock held.
+ */
+struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len);
-/* Call with rcu_read_lock held. */
-int ht_add(struct rcu_ht *ht, struct rcu_ht_node *node);
+/*
+ * ht_next - get the next item with same key (after a lookup).
+ *
+ * Returns NULL if no following node exists with same key.
+ * RCU read-side lock must be held across ht_lookup and ht_next calls, and also
+ * between ht_next calls using the node returned by a previous ht_next.
+ * Call with rcu_read_lock held.
+ */
+struct rcu_ht_node *ht_next(struct rcu_ht *ht, struct rcu_ht_node *node);
-/* Call with rcu_read_lock held. */
+/*
+ * ht_add - add a node to the hash table.
+ *
+ * Call with rcu_read_lock held.
+ */
+void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node);
+
+/*
+ * ht_add_unique - add a node to hash table, if key is not present.
+ *
+ * Returns the node added upon success.
+ * Returns the unique node already present upon failure. If ht_add_unique fails,
+ * the node passed as parameter should be freed by the caller.
+ * Call with rcu_read_lock held.
+ */
+struct rcu_ht_node *ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node);
+
+/*
+ * ht_remove - remove node from hash table.
+ *
+ * Node can be looked up with ht_lookup. RCU read-side lock must be held between
+ * lookup and removal.
+ * Call with rcu_read_lock held.
+ */
int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node);
+/*
+ * ht_resize - Force a hash table resize
+ * @growth: growth order (current size is multiplied by 2^growth)
+ *
+ * Currently, only expand operation is supported (growth >= 0).
+ */
void ht_resize(struct rcu_ht *ht, int growth);
+#ifdef __cplusplus
+}
+#endif
+
#endif /* _URCU_RCULFHASH_H */
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