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
25 typedef struct AVTreeNode {
26 struct AVTreeNode *child[2];
31 #if FF_API_CONTEXT_SIZE
32 const int av_tree_node_size = sizeof(AVTreeNode);
35 struct AVTreeNode *av_tree_node_alloc(void)
37 return av_mallocz(sizeof(struct AVTreeNode));
40 void *av_tree_find(const AVTreeNode *t, void *key,
41 int (*cmp)(void *key, const void *b), void *next[2])
44 unsigned int v = cmp(key, t->elem);
46 if (next) next[v >> 31] = t->elem;
47 return av_tree_find(t->child[(v >> 31) ^ 1], key, cmp, next);
50 av_tree_find(t->child[0], key, cmp, next);
51 av_tree_find(t->child[1], key, cmp, next);
59 void *av_tree_insert(AVTreeNode **tp, void *key,
60 int (*cmp)(void *key, const void *b), AVTreeNode **next)
64 unsigned int v = cmp(t->elem, key);
69 else if (t->child[0] || t->child[1]) {
72 av_tree_find(t->child[i], key, cmp, next_elem);
73 key = t->elem = next_elem[i];
81 ret = av_tree_insert(&t->child[v >> 31], key, cmp, next);
83 int i = (v >> 31) ^ !!*next;
84 AVTreeNode **child = &t->child[i];
85 t->state += 2 * i - 1;
87 if (!(t->state & 1)) {
89 /* The following code is equivalent to
90 if((*child)->state*2 == -t->state)
95 static void rotate(AVTreeNode **tp, int i) {
99 t->child[i]= t->child[i]->child[i^1];
100 (*tp)->child[i^1]= t;
101 i= 4*t->state + 2*(*tp)->state + 12;
102 t ->state= ((0x614586 >> i) & 3)-1;
103 (*tp)->state= ((*tp)->state>>1) + ((0x400EEA >> i) & 3)-1;
105 but such a rotate function is both bigger and slower
107 if (( *child )->state * 2 == -t->state) {
108 *tp = (*child)->child[i ^ 1];
109 (*child)->child[i ^ 1] = (*tp)->child[i];
110 (*tp)->child[i] = *child;
111 *child = ( *tp )->child[i ^ 1];
112 (*tp)->child[i ^ 1] = t;
114 (*tp)->child[0]->state = -((*tp)->state > 0);
115 (*tp)->child[1]->state = (*tp)->state < 0;
119 *child = (*child)->child[i ^ 1];
120 (*tp)->child[i ^ 1] = t;
121 if ((*tp)->state) t->state = 0;
123 (*tp)->state = -t->state;
127 if (!(*tp)->state ^ !!*next)
142 void av_tree_destroy(AVTreeNode *t)
145 av_tree_destroy(t->child[0]);
146 av_tree_destroy(t->child[1]);
151 void av_tree_enumerate(AVTreeNode *t, void *opaque,
152 int (*cmp)(void *opaque, void *elem),
153 int (*enu)(void *opaque, void *elem))
156 int v = cmp ? cmp(opaque, t->elem) : 0;
158 av_tree_enumerate(t->child[0], opaque, cmp, enu);
160 enu(opaque, t->elem);
162 av_tree_enumerate(t->child[1], opaque, cmp, enu);
171 static int check(AVTreeNode *t)
174 int left = check(t->child[0]);
175 int right = check(t->child[1]);
177 if (left>999 || right>999)
179 if (right - left != t->state)
181 if (t->state>1 || t->state<-1)
183 return FFMAX(left, right) + 1;
188 static void print(AVTreeNode *t, int depth)
191 for (i = 0; i < depth * 4; i++) av_log(NULL, AV_LOG_ERROR, " ");
193 av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
194 print(t->child[0], depth + 1);
195 print(t->child[1], depth + 1);
197 av_log(NULL, AV_LOG_ERROR, "NULL\n");
200 static int cmp(void *a, const void *b)
202 return (uint8_t *) a - (const uint8_t *) b;
209 AVTreeNode *root = NULL, *node = NULL;
212 av_lfg_init(&prng, 1);
214 for (i = 0; i < 10000; i++) {
215 int j = av_lfg_get(&prng) % 86294;
216 if (check(root) > 999) {
217 av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
221 av_log(NULL, AV_LOG_ERROR, "inserting %4d\n", j);
223 node = av_tree_node_alloc();
224 av_tree_insert(&root, (void *) (j + 1), cmp, &node);
226 j = av_lfg_get(&prng) % 86294;
228 AVTreeNode *node2 = NULL;
229 av_log(NULL, AV_LOG_ERROR, "removing %4d\n", j);
230 av_tree_insert(&root, (void *) (j + 1), cmp, &node2);
231 k = av_tree_find(root, (void *) (j + 1), cmp, NULL);
233 av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);