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* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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typedef struct AVTreeNode{
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struct AVTreeNode *child[2];
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const int av_tree_node_size = sizeof(AVTreeNode);
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void *av_tree_find(const AVTreeNode *t, void *key, int (*cmp)(void *key, const void *b), void *next[2]){
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unsigned int v= cmp(key, t->elem);
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if(next) next[v>>31]= t->elem;
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return av_tree_find(t->child[(v>>31)^1], key, cmp, next);
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av_tree_find(t->child[0], key, cmp, next);
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av_tree_find(t->child[1], key, cmp, next);
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void *av_tree_insert(AVTreeNode **tp, void *key, int (*cmp)(void *key, const void *b), AVTreeNode **next){
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unsigned int v= cmp(t->elem, key);
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else if(t->child[0]||t->child[1]){
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av_tree_find(t->child[i], key, cmp, next_elem);
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key= t->elem= next_elem[i];
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ret= av_tree_insert(&t->child[v>>31], key, cmp, next);
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int i= (v>>31) ^ !!*next;
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AVTreeNode **child= &t->child[i];
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/* The following code is equivalent to
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if((*child)->state*2 == -t->state)
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static void rotate(AVTreeNode **tp, int i){
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t->child[i]= t->child[i]->child[i^1];
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i= 4*t->state + 2*(*tp)->state + 12;
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t ->state= ((0x614586 >> i) & 3)-1;
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(*tp)->state= ((*tp)->state>>1) + ((0x400EEA >> i) & 3)-1;
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but such a rotate function is both bigger and slower
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if((*child)->state*2 == -t->state){
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*tp= (*child)->child[i^1];
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(*child)->child[i^1]= (*tp)->child[i];
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(*tp)->child[i]= *child;
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*child= (*tp)->child[i^1];
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(*tp)->child[i^1]= t;
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(*tp)->child[0]->state= -((*tp)->state>0);
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(*tp)->child[1]->state= (*tp)->state<0 ;
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*child= (*child)->child[i^1];
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(*tp)->child[i^1]= t;
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if((*tp)->state) t->state = 0;
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(*tp)->state= -t->state;
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if(!(*tp)->state ^ !!*next)
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*tp= *next; *next= NULL;
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void av_tree_destroy(AVTreeNode *t){
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av_tree_destroy(t->child[0]);
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av_tree_destroy(t->child[1]);
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void av_tree_enumerate(AVTreeNode *t, void *opaque, int (*cmp)(void *opaque, void *elem), int (*enu)(void *opaque, void *elem)){
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int v= cmp ? cmp(opaque, t->elem) : 0;
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if(v>=0) av_tree_enumerate(t->child[0], opaque, cmp, enu);
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if(v==0) enu(opaque, t->elem);
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if(v<=0) av_tree_enumerate(t->child[1], opaque, cmp, enu);
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static int check(AVTreeNode *t){
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int left= check(t->child[0]);
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int right= check(t->child[1]);
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if(left>999 || right>999)
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if(right - left != t->state)
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if(t->state>1 || t->state<-1)
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return FFMAX(left, right)+1;
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static void print(AVTreeNode *t, int depth){
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for(i=0; i<depth*4; i++) av_log(NULL, AV_LOG_ERROR, " ");
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av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
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print(t->child[0], depth+1);
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print(t->child[1], depth+1);
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av_log(NULL, AV_LOG_ERROR, "NULL\n");
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static int cmp(void *a, const void *b){
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return (uint8_t*)a-(const uint8_t*)b;
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AVTreeNode *root= NULL, *node=NULL;
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av_lfg_init(&prng, 1);
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for(i=0; i<10000; i++){
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int j = av_lfg_get(&prng) % 86294;
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if(check(root) > 999){
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av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
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av_log(NULL, AV_LOG_ERROR, "inserting %4d\n", j);
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node= av_mallocz(av_tree_node_size);
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av_tree_insert(&root, (void*)(j+1), cmp, &node);
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j = av_lfg_get(&prng) % 86294;
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AVTreeNode *node2=NULL;
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av_log(NULL, AV_LOG_ERROR, "removing %4d\n", j);
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av_tree_insert(&root, (void*)(j+1), cmp, &node2);
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k= av_tree_find(root, (void*)(j+1), cmp, NULL);
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av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);