fix some remaining bugs with deleting nodes

diff --git a/common/rb_tree.c b/common/rb_tree.c
index 139bb1345f6b4deb26d326cf08995b9a1830b614..510f8b8650e30bbabc972881e0f048ea19504588 100644 (file)
--- a/common/rb_tree.c
+++ b/common/rb_tree.c
@@ -125,13 +125,55 @@ trbt_rotate_right(trbt_node_t *node)
 }
 
 /* NULL nodes are black by definition */
-static inline int trbt_color(trbt_node_t *node)
+static inline int trbt_get_color(trbt_node_t *node)
 {
        if (node==NULL) {
                return TRBT_BLACK;
        }
        return node->rb_color;
 }
+static inline int trbt_get_color_left(trbt_node_t *node)
+{
+       if (node==NULL) {
+               return TRBT_BLACK;
+       }
+       if (node->left==NULL) {
+               return TRBT_BLACK;
+       }
+       return node->left->rb_color;
+}
+static inline int trbt_get_color_right(trbt_node_t *node)
+{
+       if (node==NULL) {
+               return TRBT_BLACK;
+       }
+       if (node->right==NULL) {
+               return TRBT_BLACK;
+       }
+       return node->right->rb_color;
+}
+/* setting a NULL node to black is a nop */
+static inline void trbt_set_color(trbt_node_t *node, int color)
+{
+       if ( (node==NULL) && (color==TRBT_BLACK) ) {
+               return;
+       }
+       node->rb_color = color;
+}
+static inline void trbt_set_color_left(trbt_node_t *node, int color)
+{
+       if ( ((node==NULL)||(node->left==NULL)) && (color==TRBT_BLACK) ) {
+               return;
+       }
+       node->left->rb_color = color;
+}
+static inline void trbt_set_color_right(trbt_node_t *node, int color)
+{
+       if ( ((node==NULL)||(node->right==NULL)) && (color==TRBT_BLACK) ) {
+               return;
+       }
+       node->right->rb_color = color;
+}
 
 static inline void
 trbt_insert_case5(trbt_tree_t *tree, trbt_node_t *node)
@@ -252,13 +294,13 @@ trbt_delete_case6(trbt_node_t *node)
        sibling = trbt_sibling(node);
        parent  = trbt_parent(node);
 
-       sibling->rb_color = parent->rb_color;
-       parent->rb_color = TRBT_BLACK;
+       trbt_set_color(sibling, parent->rb_color);
+       trbt_set_color(parent, TRBT_BLACK);
        if (node == parent->left) {
-               sibling->right->rb_color = TRBT_BLACK;
+               trbt_set_color_right(sibling, TRBT_BLACK);
                trbt_rotate_left(parent);
        } else {
-               sibling->left->rb_color = TRBT_BLACK;
+               trbt_set_color_left(sibling, TRBT_BLACK);
                trbt_rotate_right(parent);
        }
 }
@@ -272,21 +314,21 @@ trbt_delete_case5(trbt_node_t *node)
        parent = trbt_parent(node);
        sibling = trbt_sibling(node);
        if ( (node == parent->left)
-          &&(trbt_color(sibling)        == TRBT_BLACK)
-          &&(trbt_color(sibling->left)  == TRBT_RED)
-          &&(trbt_color(sibling->right) == TRBT_BLACK) ){
-               sibling->rb_color = TRBT_RED;
-               sibling->left->rb_color = TRBT_BLACK;
+          &&(trbt_get_color(sibling)        == TRBT_BLACK)
+          &&(trbt_get_color_left(sibling)   == TRBT_RED)
+          &&(trbt_get_color_right(sibling)  == TRBT_BLACK) ){
+               trbt_set_color(sibling, TRBT_RED);
+               trbt_set_color_left(sibling, TRBT_BLACK);
                trbt_rotate_right(sibling);
                trbt_delete_case6(node);
                return;
-       }
+       } 
        if ( (node == parent->right)
-          &&(trbt_color(sibling)        == TRBT_BLACK)
-          &&(trbt_color(sibling->right) == TRBT_RED)
-          &&(trbt_color(sibling->left)  == TRBT_BLACK) ){
-               sibling->rb_color = TRBT_RED;
-               sibling->right->rb_color = TRBT_BLACK;
+          &&(trbt_get_color(sibling)        == TRBT_BLACK)
+          &&(trbt_get_color_right(sibling)  == TRBT_RED)
+          &&(trbt_get_color_left(sibling)   == TRBT_BLACK) ){
+               trbt_set_color(sibling, TRBT_RED);
+               trbt_set_color_right(sibling, TRBT_BLACK);
                trbt_rotate_left(sibling);
                trbt_delete_case6(node);
                return;
@@ -301,12 +343,12 @@ trbt_delete_case4(trbt_node_t *node)
        trbt_node_t *sibling;
 
        sibling = trbt_sibling(node);
-       if ( (trbt_color(node->parent)   == TRBT_RED)
-          &&(trbt_color(sibling)        == TRBT_BLACK)
-          &&(trbt_color(sibling->left)  == TRBT_BLACK)
-          &&(trbt_color(sibling->right) == TRBT_BLACK) ){
-               sibling->rb_color = TRBT_RED;
-               node->parent->rb_color = TRBT_BLACK;
+       if ( (trbt_get_color(node->parent)   == TRBT_RED)
+          &&(trbt_get_color(sibling)        == TRBT_BLACK)
+          &&(trbt_get_color_left(sibling)   == TRBT_BLACK)
+          &&(trbt_get_color_right(sibling)  == TRBT_BLACK) ){
+               trbt_set_color(sibling, TRBT_RED);
+               trbt_set_color(node->parent, TRBT_BLACK);
        } else {
                trbt_delete_case5(node);
        }
@@ -320,11 +362,11 @@ trbt_delete_case3(trbt_node_t *node)
        trbt_node_t *sibling;
 
        sibling = trbt_sibling(node);
-       if ( (trbt_color(node->parent)   == TRBT_BLACK)
-          &&(trbt_color(sibling)        == TRBT_BLACK)
-          &&(trbt_color(sibling->left)  == TRBT_BLACK)
-          &&(trbt_color(sibling->right) == TRBT_BLACK) ){
-               sibling->rb_color = TRBT_RED;
+       if ( (trbt_get_color(node->parent)   == TRBT_BLACK)
+          &&(trbt_get_color(sibling)        == TRBT_BLACK)
+          &&(trbt_get_color_left(sibling)   == TRBT_BLACK)
+          &&(trbt_get_color_right(sibling)  == TRBT_BLACK) ){
+               trbt_set_color(sibling, TRBT_RED);
                trbt_delete_case1(node->parent);
        } else {
                trbt_delete_case4(node);
@@ -337,7 +379,9 @@ trbt_delete_case2(trbt_node_t *node)
        trbt_node_t *sibling;
 
        sibling = trbt_sibling(node);
-       if (trbt_color(sibling) == TRBT_RED) {
+       if (trbt_get_color(sibling) == TRBT_RED) {
+               trbt_set_color(node->parent, TRBT_RED);
+               trbt_set_color(sibling, TRBT_BLACK);
                if (node == node->parent->left) {
                        trbt_rotate_left(node->parent);
                } else {
@@ -360,7 +404,7 @@ trbt_delete_case1(trbt_node_t *node)
 static void
 delete_node(trbt_node_t *node)
 {
-       trbt_node_t *child, *parent;
+       trbt_node_t *parent, *child, dc;
 
        if (node->left != NULL && node->right != NULL) {
                /* This node has two children, just copy the data */
@@ -385,36 +429,55 @@ delete_node(trbt_node_t *node)
                return;
        }
 
+
+
        /* There is at most one child to this node to be deleted */
        child = node->left;
        if (node->right) {
                child = node->right;
        }
 
+       /* we didnt have a proper child so create a dummy child */
+       if (!child) {
+               child = &dc;
+               child->tree = node->tree;
+               child->left=NULL;
+               child->right=NULL;
+               child->rb_color=TRBT_BLACK;
+               child->data=NULL;
+       }
+
        /* replace node with child */
-       parent=trbt_parent(node);
+       parent = trbt_parent(node);
        if (parent) {
                if (parent->left == node) {
                        parent->left = child;
                } else {
                        parent->right = child;
                }
-       } else {
-               node->tree->tree = child;
+//     } else {
+//             node->tree->tree = child;
        }
+       child->parent = node->parent;
 
-       if (child) {
-               child->parent = node->parent;
+       if (node->rb_color == TRBT_BLACK) {
+               if (trbt_get_color(child) == TRBT_RED) {
+                       child->rb_color = TRBT_BLACK;
+               } else {
+                       trbt_delete_case1(child);
+               }
+       }
 
-               if (node->rb_color == TRBT_BLACK) {
-                       if (child->rb_color == TRBT_RED) {
-                               child->rb_color = TRBT_BLACK;
-                       } else {
-                               trbt_delete_case1(child);
-                       }
+       if (child == &dc) {
+               if (child == child->parent->left) {
+                       child->parent->left = NULL;
+               } else {
+                       child->parent->right = NULL;
                }
        }
-       
+
+//     node->tree->tree->rb_color=TRBT_BLACK;
+
        talloc_free(node);
        return;
 }
@@ -583,23 +646,23 @@ test_tree(void)
        char *str;
        int i, ret;
        int NUM=15;
-
-       for(NUM=5;NUM<1000;NUM+=33)
-       {
-               tree=trbt_create(talloc_new(NULL));
-               printf("tree:0x%08x  %d nodes\n",(int)tree,NUM);
-               for(i=0;i<NUM;i++){
-                       str=talloc_asprintf(tree, "STRING#%d", i);
-                       ret=trbt_insert32(tree, i, str);
-               }
+       int cnt=0;
+
+       tree=trbt_create(talloc_new(NULL));
+       while(++cnt){
+               int i;
+               printf("iteration : %d\n",cnt);
+               i=random()%20;
+               printf("adding node %i\n",i);
+               trbt_insert32(tree, i, NULL);
                print_tree(tree);
-//             for(i=0;i<NUM;i++){
-               for(i=NUM-1;i>=0;i--){
-                       trbt_delete32(tree, i);
-                       print_tree(tree);
-               }
 
+               i=random()%20;
+               printf("deleting node %i\n",i);
+               trbt_delete32(tree, i);
+               print_tree(tree);
        }
+
 }
 
 #endif