Flip key and element so types match, not that it matters for any code
[libav.git] / libavutil / tree.c
CommitLineData
9eb88fde
MN
1/*
2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg 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.
10 *
11 * FFmpeg 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.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "common.h"
22#include "log.h"
23#include "tree.h"
24
25typedef struct AVTreeNode{
26 struct AVTreeNode *child[2];
27 void *elem;
28 int state;
29}AVTreeNode;
30
6e8b982b
MN
31const int av_tree_node_size = sizeof(AVTreeNode);
32
9eb88fde
MN
33void *av_tree_find(const AVTreeNode *t, void *key, int (*cmp)(void *key, const void *b), void *next[2]){
34 if(t){
2e1d2873 35 unsigned int v= cmp(key, t->elem);
9eb88fde 36 if(v){
2e1d2873
MN
37 if(next) next[v>>31]= t->elem;
38 return av_tree_find(t->child[(v>>31)^1], key, cmp, next);
9eb88fde 39 }else{
116d15cc
MN
40 if(next){
41 av_tree_find(t->child[0], key, cmp, next);
42 av_tree_find(t->child[1], key, cmp, next);
43 }
9eb88fde
MN
44 return t->elem;
45 }
46 }
47 return NULL;
48}
49
6e8b982b 50void *av_tree_insert(AVTreeNode **tp, void *key, int (*cmp)(void *key, const void *b), AVTreeNode **next){
9eb88fde
MN
51 AVTreeNode *t= *tp;
52 if(t){
53 unsigned int v= cmp(t->elem, key);
f05dda3b
MN
54 void *ret;
55 if(!v){
56 if(*next)
57 return t->elem;
58 else if(t->child[0]||t->child[1]){
59 int i= !t->child[0];
60 AVTreeNode **child= &t->child[i];
61 void *next_elem[2];
62 av_tree_find(*child, key, cmp, next_elem);
63 key= t->elem= next_elem[i];
64 v= -i;
65 }else{
66 *next= t;
67 *tp=NULL;
68 return NULL;
69 }
70 }
71 ret= av_tree_insert(&t->child[v>>31], key, cmp, next);
9eb88fde 72 if(!ret){
f05dda3b
MN
73 int i= (v>>31) ^ !!*next;
74 AVTreeNode **child= &t->child[i];
75 t->state += 2*i - 1;
76
9eb88fde
MN
77 if(!(t->state&1)){
78 if(t->state){
f05dda3b 79 if((*child)->state*2 == -t->state){
9eb88fde
MN
80 *tp= (*child)->child[i^1];
81 (*child)->child[i^1]= (*tp)->child[i];
82 (*tp)->child[i]= *child;
83 *child= (*tp)->child[i^1];
84 (*tp)->child[i^1]= t;
85
f05dda3b
MN
86 (*tp)->child[0]->state= -((*tp)->state>0);
87 (*tp)->child[1]->state= (*tp)->state<0 ;
88 (*tp)->state=0;
89 }else{
90 *tp= *child;
91 *child= (*child)->child[i^1];
92 (*tp)->child[i^1]= t;
93 if((*tp)->state) t->state = 0;
94 else t->state>>= 1;
95 (*tp)->state= -t->state;
9eb88fde 96 }
9eb88fde 97 }
9eb88fde 98 }
f05dda3b
MN
99 if(!(*tp)->state ^ !!*next)
100 return key;
9eb88fde
MN
101 }
102 return ret;
9eb88fde 103 }else{
6e8b982b 104 *tp= *next; *next= NULL;
9eb88fde
MN
105 (*tp)->elem= key;
106 return NULL;
107 }
108}
109
110void av_tree_destroy(AVTreeNode *t){
111 av_tree_destroy(t->child[0]);
112 av_tree_destroy(t->child[1]);
113 av_free(t);
114}
115
116#if 0
117void av_tree_enumerate(AVTreeNode *t, void *opaque, int (*f)(void *opaque, void *elem)){
33206876
MN
118 int v= f(opaque, t->elem);
119 if(v>=0) av_tree_enumerate(t->child[0], opaque, f);
120 if(v<=0) av_tree_enumerate(t->child[1], opaque, f);
9eb88fde
MN
121}
122#endif
123
124#ifdef TEST
d5cb5fe8 125#undef random
9eb88fde
MN
126static int check(AVTreeNode *t){
127 if(t){
128 int left= check(t->child[0]);
129 int right= check(t->child[1]);
130
131 if(left>999 || right>999)
132 return 1000;
133 if(right - left != t->state)
134 return 1000;
135 if(t->state>1 || t->state<-1)
136 return 1000;
137 return FFMAX(left, right)+1;
138 }
139 return 0;
140}
141
142static void print(AVTreeNode *t, int depth){
143 int i;
144 for(i=0; i<depth*4; i++) av_log(NULL, AV_LOG_ERROR, " ");
145 if(t){
146 av_log(NULL, AV_LOG_ERROR, "Node %p %2d %4d\n", t, t->state, t->elem);
147 print(t->child[0], depth+1);
148 print(t->child[1], depth+1);
149 }else
150 av_log(NULL, AV_LOG_ERROR, "NULL\n");
151}
152
153int cmp(const void *a, const void *b){
154 return a-b;
155}
156
f8a80fd6 157int main(void){
9eb88fde 158 int i,j,k;
f05dda3b 159 AVTreeNode *root= NULL, *node=NULL;
9eb88fde
MN
160
161 for(i=0; i<10000; i++){
f05dda3b 162 int j= (random()%86294);
9eb88fde
MN
163 if(check(root) > 999){
164 av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
165 print(root, 0);
166 return -1;
167 }
168 av_log(NULL, AV_LOG_ERROR, "inserting %4d\n", j);
f05dda3b
MN
169 if(!node)
170 node= av_mallocz(av_tree_node_size);
171 av_tree_insert(&root, (void*)(j+1), cmp, &node);
172
173 j= (random()%86294);
174 k= av_tree_find(root, (void*)(j+1), cmp, NULL);
175 if(k){
176 AVTreeNode *node2=NULL;
177 av_tree_insert(&root, (void*)(j+1), cmp, &node2);
178 k= av_tree_find(root, (void*)(j+1), cmp, NULL);
179 if(k)
180 av_log(NULL, AV_LOG_ERROR, "removial failure %d\n", i);
181 }
9eb88fde
MN
182 }
183 return 0;
184}
185#endif