mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-08-23 01:35:07 +02:00
214 lines
6.4 KiB
C
214 lines
6.4 KiB
C
/*
|
|
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "common.h"
|
|
#include "log.h"
|
|
#include "tree.h"
|
|
|
|
typedef struct AVTreeNode{
|
|
struct AVTreeNode *child[2];
|
|
void *elem;
|
|
int state;
|
|
}AVTreeNode;
|
|
|
|
const int av_tree_node_size = sizeof(AVTreeNode);
|
|
|
|
void *av_tree_find(const AVTreeNode *t, void *key, int (*cmp)(void *key, const void *b), void *next[2]){
|
|
if(t){
|
|
unsigned int v= cmp(key, t->elem);
|
|
if(v){
|
|
if(next) next[v>>31]= t->elem;
|
|
return av_tree_find(t->child[(v>>31)^1], key, cmp, next);
|
|
}else{
|
|
if(next){
|
|
av_tree_find(t->child[0], key, cmp, next);
|
|
av_tree_find(t->child[1], key, cmp, next);
|
|
}
|
|
return t->elem;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
void *av_tree_insert(AVTreeNode **tp, void *key, int (*cmp)(void *key, const void *b), AVTreeNode **next){
|
|
AVTreeNode *t= *tp;
|
|
if(t){
|
|
unsigned int v= cmp(t->elem, key);
|
|
void *ret;
|
|
if(!v){
|
|
if(*next)
|
|
return t->elem;
|
|
else if(t->child[0]||t->child[1]){
|
|
int i= !t->child[0];
|
|
void *next_elem[2];
|
|
av_tree_find(t->child[i], key, cmp, next_elem);
|
|
key= t->elem= next_elem[i];
|
|
v= -i;
|
|
}else{
|
|
*next= t;
|
|
*tp=NULL;
|
|
return NULL;
|
|
}
|
|
}
|
|
ret= av_tree_insert(&t->child[v>>31], key, cmp, next);
|
|
if(!ret){
|
|
int i= (v>>31) ^ !!*next;
|
|
AVTreeNode **child= &t->child[i];
|
|
t->state += 2*i - 1;
|
|
|
|
if(!(t->state&1)){
|
|
if(t->state){
|
|
/* The following code is equivalent to
|
|
if((*child)->state*2 == -t->state)
|
|
rotate(child, i^1);
|
|
rotate(tp, i);
|
|
|
|
with rotate():
|
|
static void rotate(AVTreeNode **tp, int i){
|
|
AVTreeNode *t= *tp;
|
|
|
|
*tp= t->child[i];
|
|
t->child[i]= t->child[i]->child[i^1];
|
|
(*tp)->child[i^1]= t;
|
|
i= 4*t->state + 2*(*tp)->state + 12;
|
|
t ->state= ((0x614586 >> i) & 3)-1;
|
|
(*tp)->state= ((*tp)->state>>1) + ((0x400EEA >> i) & 3)-1;
|
|
}
|
|
but such a rotate function is both bigger and slower
|
|
*/
|
|
if((*child)->state*2 == -t->state){
|
|
*tp= (*child)->child[i^1];
|
|
(*child)->child[i^1]= (*tp)->child[i];
|
|
(*tp)->child[i]= *child;
|
|
*child= (*tp)->child[i^1];
|
|
(*tp)->child[i^1]= t;
|
|
|
|
(*tp)->child[0]->state= -((*tp)->state>0);
|
|
(*tp)->child[1]->state= (*tp)->state<0 ;
|
|
(*tp)->state=0;
|
|
}else{
|
|
*tp= *child;
|
|
*child= (*child)->child[i^1];
|
|
(*tp)->child[i^1]= t;
|
|
if((*tp)->state) t->state = 0;
|
|
else t->state>>= 1;
|
|
(*tp)->state= -t->state;
|
|
}
|
|
}
|
|
}
|
|
if(!(*tp)->state ^ !!*next)
|
|
return key;
|
|
}
|
|
return ret;
|
|
}else{
|
|
*tp= *next; *next= NULL;
|
|
if(*tp){
|
|
(*tp)->elem= key;
|
|
return NULL;
|
|
}else
|
|
return key;
|
|
}
|
|
}
|
|
|
|
void av_tree_destroy(AVTreeNode *t){
|
|
if(t){
|
|
av_tree_destroy(t->child[0]);
|
|
av_tree_destroy(t->child[1]);
|
|
av_free(t);
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
void av_tree_enumerate(AVTreeNode *t, void *opaque, int (*f)(void *opaque, void *elem)){
|
|
int v= f(opaque, t->elem);
|
|
if(v>=0) av_tree_enumerate(t->child[0], opaque, f);
|
|
if(v<=0) av_tree_enumerate(t->child[1], opaque, f);
|
|
}
|
|
#endif
|
|
|
|
#ifdef TEST
|
|
|
|
#include "lfg.h"
|
|
|
|
static int check(AVTreeNode *t){
|
|
if(t){
|
|
int left= check(t->child[0]);
|
|
int right= check(t->child[1]);
|
|
|
|
if(left>999 || right>999)
|
|
return 1000;
|
|
if(right - left != t->state)
|
|
return 1000;
|
|
if(t->state>1 || t->state<-1)
|
|
return 1000;
|
|
return FFMAX(left, right)+1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void print(AVTreeNode *t, int depth){
|
|
int i;
|
|
for(i=0; i<depth*4; i++) av_log(NULL, AV_LOG_ERROR, " ");
|
|
if(t){
|
|
av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
|
|
print(t->child[0], depth+1);
|
|
print(t->child[1], depth+1);
|
|
}else
|
|
av_log(NULL, AV_LOG_ERROR, "NULL\n");
|
|
}
|
|
|
|
static int cmp(void *a, const void *b){
|
|
return (uint8_t*)a-(const uint8_t*)b;
|
|
}
|
|
|
|
int main(void){
|
|
int i;
|
|
void *k;
|
|
AVTreeNode *root= NULL, *node=NULL;
|
|
AVLFG prng;
|
|
|
|
av_lfg_init(&prng, 1);
|
|
|
|
for(i=0; i<10000; i++){
|
|
int j = av_lfg_get(&prng) % 86294;
|
|
if(check(root) > 999){
|
|
av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
|
|
print(root, 0);
|
|
return -1;
|
|
}
|
|
av_log(NULL, AV_LOG_ERROR, "inserting %4d\n", j);
|
|
if(!node)
|
|
node= av_mallocz(av_tree_node_size);
|
|
av_tree_insert(&root, (void*)(j+1), cmp, &node);
|
|
|
|
j = av_lfg_get(&prng) % 86294;
|
|
{
|
|
AVTreeNode *node2=NULL;
|
|
av_log(NULL, AV_LOG_ERROR, "removing %4d\n", j);
|
|
av_tree_insert(&root, (void*)(j+1), cmp, &node2);
|
|
k= av_tree_find(root, (void*)(j+1), cmp, NULL);
|
|
if(k)
|
|
av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|