Make pp_help a constant pointer to constant characters, moves it partially
[libav.git] / libavutil / tree.c
CommitLineData
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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
31void *av_tree_find(const AVTreeNode *t, void *key, int (*cmp)(void *key, const void *b), void *next[2]){
32 if(t){
33 unsigned int v= cmp(t->elem, key);
34 if(v){
35 if(next) next[(v>>31)^1]= t->elem;
36 return av_tree_find(t->child[v>>31], key, cmp, next);
37 }else{
38 return t->elem;
39 }
40 }
41 return NULL;
42}
43
44void *av_tree_insert(AVTreeNode **tp, void *key, int (*cmp)(void *key, const void *b)){
45 AVTreeNode *t= *tp;
46 if(t){
47 unsigned int v= cmp(t->elem, key);
48 if(v){
49 int i= v>>31;
50 AVTreeNode **child= &t->child[i];
51 void *ret= av_tree_insert(child, key, cmp);
52 if(!ret){
53 t->state -= ((int)v>>31)|1;
54 if(!(t->state&1)){
55 if(t->state){
56 if((*child)->state*2 == t->state){
57 *tp= *child;
58 *child= (*child)->child[i^1];
59 (*tp)->child[i^1]= t;
60 t->state= 0;
61 }else{
62 *tp= (*child)->child[i^1];
63 (*child)->child[i^1]= (*tp)->child[i];
64 (*tp)->child[i]= *child;
65 *child= (*tp)->child[i^1];
66 (*tp)->child[i^1]= t;
67
68 i= (*tp)->state > 0;
69 (*tp)->child[i ]->state= 0;
70 (*tp)->child[i^1]->state= -(*tp)->state;
71 }
72 (*tp)->state=0;
73 }
74 return key;
75 }
76 }
77 return ret;
78 }else{
79 return t->elem;
80 }
81 }else{
82 *tp= av_mallocz(sizeof(AVTreeNode));
83 (*tp)->elem= key;
84 return NULL;
85 }
86}
87
88void av_tree_destroy(AVTreeNode *t){
89 av_tree_destroy(t->child[0]);
90 av_tree_destroy(t->child[1]);
91 av_free(t);
92}
93
94#if 0
95void av_tree_enumerate(AVTreeNode *t, void *opaque, int (*f)(void *opaque, void *elem)){
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96 int v= f(opaque, t->elem);
97 if(v>=0) av_tree_enumerate(t->child[0], opaque, f);
98 if(v<=0) av_tree_enumerate(t->child[1], opaque, f);
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99}
100#endif
101
102#ifdef TEST
103
104static int check(AVTreeNode *t){
105 if(t){
106 int left= check(t->child[0]);
107 int right= check(t->child[1]);
108
109 if(left>999 || right>999)
110 return 1000;
111 if(right - left != t->state)
112 return 1000;
113 if(t->state>1 || t->state<-1)
114 return 1000;
115 return FFMAX(left, right)+1;
116 }
117 return 0;
118}
119
120static void print(AVTreeNode *t, int depth){
121 int i;
122 for(i=0; i<depth*4; i++) av_log(NULL, AV_LOG_ERROR, " ");
123 if(t){
124 av_log(NULL, AV_LOG_ERROR, "Node %p %2d %4d\n", t, t->state, t->elem);
125 print(t->child[0], depth+1);
126 print(t->child[1], depth+1);
127 }else
128 av_log(NULL, AV_LOG_ERROR, "NULL\n");
129}
130
131int cmp(const void *a, const void *b){
132 return a-b;
133}
134
f8a80fd6 135int main(void){
9eb88fde 136 int i,j,k;
eaaa48b2 137 AVTreeNode *root= NULL;
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138
139 for(i=0; i<10000; i++){
140 int j= (random()%863294);
141 if(check(root) > 999){
142 av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
143 print(root, 0);
144 return -1;
145 }
146 av_log(NULL, AV_LOG_ERROR, "inserting %4d\n", j);
147 av_tree_insert(&root, (void*)(j+1), cmp);
148 }
149 return 0;
150}
151#endif