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(t->elem, key);
+ unsigned int v= cmp(key, t->elem);
if(v){
- if(next) next[(v>>31)^1]= t->elem;
- return av_tree_find(t->child[v>>31], key, cmp, next);
+ 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)){
+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);
- if(v){
- int i= v>>31;
+ 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];
- void *ret= av_tree_insert(child, key, cmp);
- if(!ret){
- t->state -= ((int)v>>31)|1;
- if(!(t->state&1)){
- if(t->state){
- if((*child)->state*2 == t->state){
- *tp= *child;
- *child= (*child)->child[i^1];
- (*tp)->child[i^1]= t;
- t->state= 0;
- }else{
- *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;
-
- i= (*tp)->state > 0;
- (*tp)->child[i ]->state= 0;
- (*tp)->child[i^1]->state= -(*tp)->state;
- }
+ 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;
}
- return key;
}
}
- return ret;
- }else{
- return t->elem;
+ if(!(*tp)->state ^ !!*next)
+ return key;
}
+ return ret;
}else{
- *tp= av_mallocz(sizeof(AVTreeNode));
- (*tp)->elem= key;
- return NULL;
+ *tp= *next; *next= NULL;
+ if(*tp){
+ (*tp)->elem= key;
+ return NULL;
+ }else
+ return key;
}
}
void av_tree_destroy(AVTreeNode *t){
- av_tree_destroy(t->child[0]);
- av_tree_destroy(t->child[1]);
- av_free(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);
+void av_tree_enumerate(AVTreeNode *t, void *opaque, int (*cmp)(void *opaque, void *elem), int (*enu)(void *opaque, void *elem)){
+ if(t){
+ int v= cmp ? cmp(opaque, t->elem) : 0;
+ if(v>=0) av_tree_enumerate(t->child[0], opaque, cmp, enu);
+ if(v==0) enu(opaque, t->elem);
+ if(v<=0) av_tree_enumerate(t->child[1], opaque, cmp, enu);
+ }
}
#endif
#ifdef TEST
+#include "lfg.h"
+
static int check(AVTreeNode *t){
if(t){
int left= check(t->child[0]);
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 %4d\n", t, t->state, t->elem);
+ 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");
}
-int cmp(const void *a, const void *b){
- return a-b;
+static int cmp(void *a, const void *b){
+ return (uint8_t*)a-(const uint8_t*)b;
}
int main(void){
- int i,j,k;
- AVTreeNode *root= NULL;
+ int i;
+ void *k;
+ AVTreeNode *root= NULL, *node=NULL;
+ AVLFG prng;
+
+ av_lfg_init(&prng, 1);
for(i=0; i<10000; i++){
- int j= (random()%863294);
+ 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);
- av_tree_insert(&root, (void*)(j+1), cmp);
+ 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;
}
projects / ffmpeg / blobdiff