ARM: remove needless .text/.align directives
[ffmpeg.git] / libavutil / tree.c
index f4b9af1..067e5b0 100644 (file)
@@ -1,24 +1,23 @@
 /*
  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; 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"
 
@@ -28,79 +27,126 @@ typedef struct AVTreeNode{
     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]);
@@ -121,30 +167,46 @@ 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 %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;
 }