/*
* Copyright (c) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup genericadt
* @{
*/
/** @file
*/
#ifndef KERN_BTREE_H_
#define KERN_BTREE_H_
#include <arch/types.h>
#include <typedefs.h>
#include <adt/list.h>
#define BTREE_M 5
#define BTREE_MAX_KEYS (BTREE_M - 1)
typedef uint64_t btree_key_t;
/** B-tree node structure. */
struct btree_node {
/** Number of keys. */
count_t keys;
/** Keys. We currently support only single keys. Additional room for one extra key is provided. */
btree_key_t key[BTREE_MAX_KEYS + 1];
/**
* Pointers to values. Sorted according to the key array. Defined only in leaf-level.
* There is room for storing value for the extra key.
*/
void *value[BTREE_MAX_KEYS + 1];
/**
* Pointers to descendants of this node sorted according to the key array.
* subtree[0] points to subtree with keys lesser than to key[0].
* subtree[1] points to subtree with keys greater than or equal to key[0] and lesser than key[1].
* ...
* There is room for storing a subtree pointer for the extra key.
*/
btree_node_t *subtree[BTREE_M + 1];
/** Pointer to parent node. Root node has NULL parent. */
btree_node_t *parent;
/** Link connecting leaf-level nodes. Defined only when this node is a leaf. */
link_t leaf_link;
/** Variables needed by btree_print(). */
link_t bfs_link;
int depth;
};
/** B-tree structure. */
struct btree {
btree_node_t *root; /**< B-tree root node pointer. */
link_t leaf_head; /**< Leaf-level list head. */
};
extern void btree_init(void);
extern void btree_create(btree_t *t);
extern void btree_destroy(btree_t *t);
extern void btree_insert(btree_t *t, btree_key_t key, void *value, btree_node_t *leaf_node);
extern void btree_remove(btree_t *t, btree_key_t key, btree_node_t *leaf_node);
extern void *btree_search(btree_t *t, btree_key_t key, btree_node_t **leaf_node);
extern btree_node_t *btree_leaf_node_left_neighbour(btree_t *t, btree_node_t *node);
extern btree_node_t *btree_leaf_node_right_neighbour(btree_t *t, btree_node_t *node);
extern void btree_print(btree_t *t);
#endif
/** @}
*/