1 /*
2 * SysDB - src/include/utils/avltree.h
3 * Copyright (C) 2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. 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 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #ifndef SDB_UTILS_AVLTREE_H
29 #define SDB_UTILS_AVLTREE_H 1
31 #include "core/object.h"
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
37 /*
38 * An AVL tree implements Adelson-Velskii and Landis' self-balancing search
39 * tree. It supports search, insert, and delete operations in average and
40 * worst-case time-complexity O(log n).
41 */
42 struct sdb_avltree;
43 typedef struct sdb_avltree sdb_avltree_t;
45 struct sdb_avltree_iter;
46 typedef struct sdb_avltree_iter sdb_avltree_iter_t;
48 /*
49 * sdb_avltree_create:
50 * Creates an AVL tree. Objects will be compared by their names.
51 */
52 sdb_avltree_t *
53 sdb_avltree_create(void);
55 /*
56 * sdb_avltree_destroy:
57 * Destroy the specified AVL tree and release all included objects (decrement
58 * the ref-count).
59 */
60 void
61 sdb_avltree_destroy(sdb_avltree_t *tree);
63 /*
64 * sdb_avltree_clear:
65 * Remove all nodes from the tree, releasing the included objects (decrement
66 * the ref-count).
67 */
68 void
69 sdb_avltree_clear(sdb_avltree_t *tree);
71 /*
72 * sdb_avltree_insert:
73 * Insert a new node into the tree. Each object must be unique. This operation
74 * may change the structure of the tree by rebalancing subtrees which no
75 * longer comply with the rules of AVL.
76 *
77 * Returns:
78 * - 0 on success
79 * - a negative value else
80 */
81 int
82 sdb_avltree_insert(sdb_avltree_t *tree, sdb_object_t *obj);
84 /*
85 * sdb_avltree_lookup:
86 * Lookup an object from a tree by name.
87 *
88 * Returns:
89 * - the requested object
90 * - NULL if no such object exists
91 */
92 sdb_object_t *
93 sdb_avltree_lookup(sdb_avltree_t *tree, const char *name);
95 /*
96 * sdb_avltree_get_iter, sdb_avltree_iter_has_next, sdb_avltree_iter_get_next,
97 * sdb_avltree_iter_destroy:
98 * Iterate through all nodes of the tree. The iterator will start at the
99 * smallest element (based on the name) and then iterate through the sorted
100 * sequence of all nodes.
101 *
102 * sdb_avltree_iter_get_next returns NULL if there is no next element.
103 */
104 sdb_avltree_iter_t *
105 sdb_avltree_get_iter(sdb_avltree_t *tree);
106 void
107 sdb_avltree_iter_destroy(sdb_avltree_iter_t *iter);
109 _Bool
110 sdb_avltree_iter_has_next(sdb_avltree_iter_t *iter);
111 sdb_object_t *
112 sdb_avltree_iter_get_next(sdb_avltree_iter_t *iter);
114 /*
115 * sdb_avltree_size:
116 * Returns the number of nodes in the tree.
117 */
118 size_t
119 sdb_avltree_size(sdb_avltree_t *tree);
121 /*
122 * sdb_avltree_valid:
123 * Validate a tree, checking if all rules of AVL are met. All errors will be
124 * reported through the logging sub-system. This function is mainly intended
125 * for debugging and (unit) testing.
126 *
127 * Returns:
128 * - true if the tree is valid
129 * - false else
130 */
131 _Bool
132 sdb_avltree_valid(sdb_avltree_t *tree);
134 #ifdef __cplusplus
135 } /* extern "C" */
136 #endif
138 #endif /* ! SDB_UTILS_AVLTREE_H */
140 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */