2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 typedef struct AVTreeNode {
27 struct AVTreeNode *child[2];
32 #if FF_API_CONTEXT_SIZE
33 const int av_tree_node_size = sizeof(AVTreeNode);
36 struct AVTreeNode *av_tree_node_alloc(void)
38 return av_mallocz(sizeof(struct AVTreeNode));
41 void *av_tree_find(const AVTreeNode *t, void *key,
42 int (*cmp)(void *key, const void *b), void *next[2])
45 unsigned int v = cmp(key, t->elem);
48 next[v >> 31] = t->elem;
49 return av_tree_find(t->child[(v >> 31) ^ 1], key, cmp, next);
52 av_tree_find(t->child[0], key, cmp, next);
53 av_tree_find(t->child[1], key, cmp, next);
61 void *av_tree_insert(AVTreeNode **tp, void *key,
62 int (*cmp)(void *key, const void *b), AVTreeNode **next)
66 unsigned int v = cmp(t->elem, key);
71 else if (t->child[0] || t->child[1]) {
74 av_tree_find(t->child[i], key, cmp, next_elem);
75 key = t->elem = next_elem[i];
83 ret = av_tree_insert(&t->child[v >> 31], key, cmp, next);
85 int i = (v >> 31) ^ !!*next;
86 AVTreeNode **child = &t->child[i];
87 t->state += 2 * i - 1;
89 if (!(t->state & 1)) {
91 /* The following code is equivalent to
92 * if ((*child)->state * 2 == -t->state)
93 * rotate(child, i ^ 1);
97 * static void rotate(AVTreeNode **tp, int i)
102 * t->child[i] = t->child[i]->child[i ^ 1];
103 * (*tp)->child[i ^ 1] = t;
104 * i = 4 * t->state + 2 * (*tp)->state + 12;
105 * t->state = ((0x614586 >> i) & 3) - 1;
106 * (*tp)->state = ((0x400EEA >> i) & 3) - 1 +
107 * ((*tp)->state >> 1);
109 * but such a rotate function is both bigger and slower
111 if ((*child)->state * 2 == -t->state) {
112 *tp = (*child)->child[i ^ 1];
113 (*child)->child[i ^ 1] = (*tp)->child[i];
114 (*tp)->child[i] = *child;
115 *child = (*tp)->child[i ^ 1];
116 (*tp)->child[i ^ 1] = t;
118 (*tp)->child[0]->state = -((*tp)->state > 0);
119 (*tp)->child[1]->state = (*tp)->state < 0;
123 *child = (*child)->child[i ^ 1];
124 (*tp)->child[i ^ 1] = t;
129 (*tp)->state = -t->state;
133 if (!(*tp)->state ^ !!*next)
148 void av_tree_destroy(AVTreeNode *t)
151 av_tree_destroy(t->child[0]);
152 av_tree_destroy(t->child[1]);
157 void av_tree_enumerate(AVTreeNode *t, void *opaque,
158 int (*cmp)(void *opaque, void *elem),
159 int (*enu)(void *opaque, void *elem))
162 int v = cmp ? cmp(opaque, t->elem) : 0;
164 av_tree_enumerate(t->child[0], opaque, cmp, enu);
166 enu(opaque, t->elem);
168 av_tree_enumerate(t->child[1], opaque, cmp, enu);
177 static int check(AVTreeNode *t)
180 int left = check(t->child[0]);
181 int right = check(t->child[1]);
183 if (left > 999 || right > 999)
185 if (right - left != t->state)
187 if (t->state > 1 || t->state < -1)
189 return FFMAX(left, right) + 1;
194 static void print(AVTreeNode *t, int depth)
197 for (i = 0; i < depth * 4; i++)
198 av_log(NULL, AV_LOG_ERROR, " ");
200 av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
201 print(t->child[0], depth + 1);
202 print(t->child[1], depth + 1);
204 av_log(NULL, AV_LOG_ERROR, "NULL\n");
207 static int cmp(void *a, const void *b)
209 return (uint8_t *) a - (const uint8_t *) b;
215 AVTreeNode *root = NULL, *node = NULL;
218 av_lfg_init(&prng, 1);
220 for (i = 0; i < 10000; i++) {
221 AVTreeNode *node2 = NULL;
222 intptr_t j = av_lfg_get(&prng) % 86294;
223 void *ret, *jj = (void *)(j + 1);
225 while (ret = av_tree_find(root, jj, cmp, NULL)) {
226 j = av_lfg_get(&prng) % 86294;
227 jj = (void *)(j + 1);
230 if (check(root) > 999) {
231 av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
237 node = av_tree_node_alloc();
239 av_log(NULL, AV_LOG_ERROR, "Memory allocation failure.\n");
242 av_tree_insert(&root, jj, cmp, &node);
244 while (ret = av_tree_find(root, jj, cmp, NULL)) {
245 j = av_lfg_get(&prng) % 86294;
246 jj = (void *)(j + 1);
249 ret = av_tree_insert(&root, jj, cmp, &node2);
251 av_tree_destroy(node2);
252 ret = av_tree_find(root, jj, cmp, NULL);
254 av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);
257 av_tree_destroy(root);