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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 | |||
| 1702 | cejka | 29 | /** @addtogroup genericadt |
| 30 | * @{ |
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| 31 | */ |
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| 32 | /** @file |
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| 33 | */ |
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| 34 | |||
| 1101 | jermar | 35 | #ifndef __BTREE_H__ |
| 36 | #define __BTREE_H__ |
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| 37 | |||
| 38 | #include <arch/types.h> |
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| 39 | #include <typedefs.h> |
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| 40 | #include <adt/list.h> |
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| 41 | |||
| 1140 | jermar | 42 | #define BTREE_M 5 |
| 1101 | jermar | 43 | #define BTREE_MAX_KEYS (BTREE_M - 1) |
| 44 | |||
| 1177 | jermar | 45 | typedef __u64 btree_key_t; |
| 46 | |||
| 1101 | jermar | 47 | /** B-tree node structure. */ |
| 48 | struct btree_node { |
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| 49 | /** Number of keys. */ |
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| 50 | count_t keys; |
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| 51 | |||
| 52 | /** Keys. We currently support only single keys. Additional room for one extra key is provided. */ |
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| 1177 | jermar | 53 | btree_key_t key[BTREE_MAX_KEYS + 1]; |
| 1101 | jermar | 54 | |
| 55 | /** |
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| 56 | * Pointers to values. Sorted according to the key array. Defined only in leaf-level. |
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| 57 | * There is room for storing value for the extra key. |
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| 58 | */ |
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| 59 | void *value[BTREE_MAX_KEYS + 1]; |
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| 60 | |||
| 61 | /** |
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| 62 | * Pointers to descendants of this node sorted according to the key array. |
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| 1140 | jermar | 63 | * subtree[0] points to subtree with keys lesser than to key[0]. |
| 64 | * 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 | 65 | * ... |
| 66 | * There is room for storing a subtree pointer for the extra key. |
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| 67 | */ |
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| 68 | btree_node_t *subtree[BTREE_M + 1]; |
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| 69 | |||
| 70 | /** Pointer to parent node. Root node has NULL parent. */ |
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| 71 | btree_node_t *parent; |
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| 72 | |||
| 73 | /** Link connecting leaf-level nodes. Defined only when this node is a leaf. */ |
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| 74 | link_t leaf_link; |
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| 75 | |||
| 76 | /** Variables needed by btree_print(). */ |
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| 77 | link_t bfs_link; |
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| 78 | int depth; |
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| 79 | }; |
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| 80 | |||
| 81 | /** B-tree structure. */ |
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| 82 | struct btree { |
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| 83 | btree_node_t *root; /**< B-tree root node pointer. */ |
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| 84 | link_t leaf_head; /**< Leaf-level list head. */ |
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| 85 | }; |
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| 86 | |||
| 1164 | jermar | 87 | extern void btree_init(void); |
| 88 | |||
| 1101 | jermar | 89 | extern void btree_create(btree_t *t); |
| 90 | extern void btree_destroy(btree_t *t); |
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| 91 | |||
| 1177 | jermar | 92 | extern void btree_insert(btree_t *t, btree_key_t key, void *value, btree_node_t *leaf_node); |
| 93 | extern void btree_remove(btree_t *t, btree_key_t key, btree_node_t *leaf_node); |
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| 94 | extern void *btree_search(btree_t *t, btree_key_t key, btree_node_t **leaf_node); |
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| 1101 | jermar | 95 | |
| 1150 | jermar | 96 | extern btree_node_t *btree_leaf_node_left_neighbour(btree_t *t, btree_node_t *node); |
| 97 | extern btree_node_t *btree_leaf_node_right_neighbour(btree_t *t, btree_node_t *node); |
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| 1147 | jermar | 98 | |
| 1101 | jermar | 99 | extern void btree_print(btree_t *t); |
| 100 | #endif |
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| 1702 | cejka | 101 | |
| 102 | /** @} |
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| 103 | */ |
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| 104 |