Subversion Repositories HelenOS

Rev

Rev 1147 | Rev 1164 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1101 jermar 1
/*
2
 * Copyright (C) 2006 Jakub Jermar
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
29
#ifndef __BTREE_H__
30
#define __BTREE_H__
31
 
32
#include <arch/types.h>
33
#include <typedefs.h>
34
#include <adt/list.h>
35
 
1140 jermar 36
#define BTREE_M     5
1101 jermar 37
#define BTREE_MAX_KEYS  (BTREE_M - 1)
38
 
39
/** B-tree node structure. */
40
struct btree_node {
41
    /** Number of keys. */
42
    count_t keys;
43
 
44
    /** Keys. We currently support only single keys. Additional room for one extra key is provided. */
45
    __native key[BTREE_MAX_KEYS + 1];
46
 
47
    /**
48
     * Pointers to values. Sorted according to the key array. Defined only in leaf-level.
49
     * There is room for storing value for the extra key.
50
     */
51
    void *value[BTREE_MAX_KEYS + 1];
52
 
53
    /**
54
     * Pointers to descendants of this node sorted according to the key array.
1140 jermar 55
     * subtree[0] points to subtree with keys lesser than to key[0].
56
     * subtree[1] points to subtree with keys greater than or equal to key[0] and lesser than key[1].
1101 jermar 57
     * ...
58
     * There is room for storing a subtree pointer for the extra key.
59
     */
60
    btree_node_t *subtree[BTREE_M + 1];
61
 
62
    /** Pointer to parent node. Root node has NULL parent. */
63
    btree_node_t *parent;
64
 
65
    /** Link connecting leaf-level nodes. Defined only when this node is a leaf. */
66
    link_t leaf_link;
67
 
68
    /** Variables needed by btree_print(). */  
69
    link_t bfs_link;
70
    int depth;
71
};
72
 
73
/** B-tree structure. */
74
struct btree {
75
    btree_node_t *root; /**< B-tree root node pointer. */
76
    link_t leaf_head;   /**< Leaf-level list head. */
77
};
78
 
79
extern void btree_create(btree_t *t);
80
extern void btree_destroy(btree_t *t);
81
 
82
extern void btree_insert(btree_t *t, __native key, void *value, btree_node_t *leaf_node);
1140 jermar 83
extern void btree_remove(btree_t *t, __native key, btree_node_t *leaf_node);
1101 jermar 84
extern void *btree_search(btree_t *t, __native key, btree_node_t **leaf_node);
85
 
1150 jermar 86
extern btree_node_t *btree_leaf_node_left_neighbour(btree_t *t, btree_node_t *node);
87
extern btree_node_t *btree_leaf_node_right_neighbour(btree_t *t, btree_node_t *node);
1147 jermar 88
 
1101 jermar 89
extern void btree_print(btree_t *t);
90
#endif