237 lines
7.1 KiB
C
237 lines
7.1 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 "log.h"
|
|
#include "mem.h"
|
|
#include "tree.h"
|
|
|
|
typedef struct AVTreeNode {
|
|
struct AVTreeNode *child[2];
|
|
void *elem;
|
|
int state;
|
|
} AVTreeNode;
|
|
|
|
const int av_tree_node_size = sizeof(AVTreeNode);
|
|
|
|
struct AVTreeNode *av_tree_node_alloc(void)
|
|
{
|
|
return av_mallocz(sizeof(struct 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);
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
#ifdef TEST
|
|
|
|
#include "common.h"
|
|
#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++) {
|
|
intptr_t 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_tree_node_alloc();
|
|
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
|