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| Rev | Author | Line No. | Line |
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| 1101 | jermar | 1 | /* |
| 2 | * Copyright (C) 2006 Jakub Jermar |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | #ifndef __BTREE_H__ |
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| 30 | #define __BTREE_H__ |
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| 31 | |||
| 32 | #include <arch/types.h> |
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| 33 | #include <typedefs.h> |
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| 34 | #include <adt/list.h> |
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| 35 | |||
| 1140 | jermar | 36 | #define BTREE_M 5 |
| 1101 | jermar | 37 | #define BTREE_MAX_KEYS (BTREE_M - 1) |
| 38 | |||
| 1177 | jermar | 39 | typedef __u64 btree_key_t; |
| 40 | |||
| 1101 | jermar | 41 | /** B-tree node structure. */ |
| 42 | struct btree_node { |
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| 43 | /** Number of keys. */ |
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| 44 | count_t keys; |
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| 45 | |||
| 46 | /** Keys. We currently support only single keys. Additional room for one extra key is provided. */ |
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| 1177 | jermar | 47 | btree_key_t key[BTREE_MAX_KEYS + 1]; |
| 1101 | jermar | 48 | |
| 49 | /** |
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| 50 | * Pointers to values. Sorted according to the key array. Defined only in leaf-level. |
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| 51 | * There is room for storing value for the extra key. |
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| 52 | */ |
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| 53 | void *value[BTREE_MAX_KEYS + 1]; |
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| 54 | |||
| 55 | /** |
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| 56 | * Pointers to descendants of this node sorted according to the key array. |
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| 1140 | jermar | 57 | * subtree[0] points to subtree with keys lesser than to key[0]. |
| 58 | * subtree[1] points to subtree with keys greater than or equal to key[0] and lesser than key[1]. |
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| 1101 | jermar | 59 | * ... |
| 60 | * There is room for storing a subtree pointer for the extra key. |
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| 61 | */ |
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| 62 | btree_node_t *subtree[BTREE_M + 1]; |
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| 63 | |||
| 64 | /** Pointer to parent node. Root node has NULL parent. */ |
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| 65 | btree_node_t *parent; |
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| 66 | |||
| 67 | /** Link connecting leaf-level nodes. Defined only when this node is a leaf. */ |
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| 68 | link_t leaf_link; |
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| 69 | |||
| 70 | /** Variables needed by btree_print(). */ |
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| 71 | link_t bfs_link; |
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| 72 | int depth; |
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| 73 | }; |
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| 74 | |||
| 75 | /** B-tree structure. */ |
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| 76 | struct btree { |
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| 77 | btree_node_t *root; /**< B-tree root node pointer. */ |
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| 78 | link_t leaf_head; /**< Leaf-level list head. */ |
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| 79 | }; |
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| 80 | |||
| 1164 | jermar | 81 | extern void btree_init(void); |
| 82 | |||
| 1101 | jermar | 83 | extern void btree_create(btree_t *t); |
| 84 | extern void btree_destroy(btree_t *t); |
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| 85 | |||
| 1177 | jermar | 86 | extern void btree_insert(btree_t *t, btree_key_t key, void *value, btree_node_t *leaf_node); |
| 87 | extern void btree_remove(btree_t *t, btree_key_t key, btree_node_t *leaf_node); |
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| 88 | extern void *btree_search(btree_t *t, btree_key_t key, btree_node_t **leaf_node); |
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| 1101 | jermar | 89 | |
| 1150 | jermar | 90 | extern btree_node_t *btree_leaf_node_left_neighbour(btree_t *t, btree_node_t *node); |
| 91 | extern btree_node_t *btree_leaf_node_right_neighbour(btree_t *t, btree_node_t *node); |
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| 1147 | jermar | 92 | |
| 1101 | jermar | 93 | extern void btree_print(btree_t *t); |
| 94 | #endif |