1 /*
2 * Copyright (C) 2010 Joseph Adams <joeyadams3.14159@gmail.com>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23 #ifndef CCAN_AVL_H
24 #define CCAN_AVL_H
25
26 #include <stdbool.h>
27 #include <stddef.h>
28
29 struct sm_state;
30
31 typedef struct AvlNode AvlNode;
32 typedef struct AvlIter AvlIter;
33
34 struct stree {
35 AvlNode *root;
36 struct stree *base_stree;
37 char *has_states;
38 size_t count;
39 int stree_id;
40 int references;
41 };
42
43 void free_stree(struct stree **avl);
44 /* Free an stree tree. */
45
46 struct sm_state *avl_lookup(const struct stree *avl, const struct sm_state *sm);
47 /* O(log n). Lookup a sm. Return NULL if the sm is not present. */
48
49 #define avl_member(avl, sm) (!!avl_lookup_node(avl, sm))
50 /* O(log n). See if a sm is present. */
51
52 size_t stree_count(const struct stree *avl);
53 /* O(1). Return the number of elements in the tree. */
54
55 bool avl_insert(struct stree **avl, const struct sm_state *sm);
56 /*
57 * O(log n). Insert an sm or replace it if already present.
58 *
59 * Return false if the insertion replaced an existing sm.
60 */
61
62 bool avl_remove(struct stree **avl, const struct sm_state *sm);
63 /*
64 * O(log n). Remove an sm (if present).
65 *
66 * Return true if it was removed.
67 */
68
69 bool avl_check_invariants(struct stree *avl);
70 /* For testing purposes. This function will always return true :-) */
71
72
73 /************************* Traversal *************************/
74
75 #define avl_foreach(iter, avl) avl_traverse(iter, avl, FORWARD)
76 /*
77 * O(n). Traverse an stree tree in order.
78 *
79 * Example:
80 *
81 * AvlIter i;
82 *
83 * avl_foreach(i, avl)
84 * printf("%s -> %s\n", i.sm->name, i.sm->state->name);
85 */
86
87 #define FOR_EACH_SM(avl, _sm) { \
88 AvlIter _i; \
89 avl_foreach(_i, avl) { \
90 _sm = _i.sm;
91
92 #define END_FOR_EACH_SM(_sm) }}
93
94 #define FOR_EACH_MY_SM(_owner, avl, _sm) { \
95 AvlIter _i; \
96 avl_foreach(_i, avl) { \
97 _sm = _i.sm; \
98 if (_sm->owner != _owner) \
99 continue; \
100
101 #define avl_foreach_reverse(iter, avl) avl_traverse(iter, avl, BACKWARD)
102 /* O(n). Traverse an stree tree in reverse order. */
103
104 typedef enum AvlDirection {FORWARD = 0, BACKWARD = 1} AvlDirection;
105
106 struct AvlIter {
107 struct sm_state *sm;
108 AvlNode *node;
109
110 /* private */
111 AvlNode *stack[100];
112 int stack_index;
113 AvlDirection direction;
114 };
115
116 void avl_iter_begin(AvlIter *iter, struct stree *avl, AvlDirection dir);
117 void avl_iter_next(AvlIter *iter);
118 #define avl_traverse(iter, avl, direction) \
119 for (avl_iter_begin(&(iter), avl, direction); \
120 (iter).node != NULL; \
121 avl_iter_next(&iter))
122
123
124 /***************** Internal data structures ******************/
125
126 struct AvlNode {
127 const struct sm_state *sm;
128
129 AvlNode *lr[2];
130 int balance; /* -1, 0, or 1 */
131 };
132
133 AvlNode *avl_lookup_node(const struct stree *avl, const struct sm_state *sm);
134 /* O(log n). Lookup an stree node by sm. Return NULL if not present. */
135
136 struct stree *clone_stree(struct stree *orig);
137
138 void set_stree_id(struct stree **stree, int id);
139 int get_stree_id(struct stree *stree);
140
141 #endif