X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=src%2Futils_avltree.c;h=830b711f8f9713d45bfe5b898995b2ac5f85b7ae;hb=f4c3e684850315991f0760e90f5d845af4615d5f;hp=f6b15b153844ec177eef8ea51eb68a65c89152e5;hpb=312e8cdc9c83155cd1fa0eab1509d0cc25d7a8e6;p=collectd.git

diff --git a/src/utils_avltree.c b/src/utils_avltree.c
index f6b15b15..830b711f 100644
--- a/src/utils_avltree.c
+++ b/src/utils_avltree.c
@@ -58,7 +58,7 @@ struct avl_iterator_s
 /*
  * private functions
  */
-#if 1
+#if 0
 static void verify_tree (avl_node_t *n)
 {
 	if (n == NULL)
@@ -230,17 +230,17 @@ static void rebalance (avl_tree_t *t, avl_node_t *n)
 		{
 			assert (n->right != NULL);
 			b_bottom = BALANCE (n->right);
-			assert ((b_bottom == -1) || (b_bottom == 1));
-			if (b_bottom == -1)
-				n = rotate_left (t, n);
-			else
+			assert ((b_bottom >= -1) || (b_bottom <= 1));
+			if (b_bottom == 1)
 				n = rotate_right_left (t, n);
+			else
+				n = rotate_left (t, n);
 		}
 		else if (b_top == 2)
 		{
 			assert (n->left != NULL);
 			b_bottom = BALANCE (n->left);
-			assert ((b_bottom == -1) || (b_bottom == 1));
+			assert ((b_bottom >= -1) || (b_bottom <= 1));
 			if (b_bottom == -1)
 				n = rotate_left_right (t, n);
 			else
@@ -332,12 +332,38 @@ void *avl_node_prev (avl_tree_t *t, avl_node_t *n)
 	}
 
 	return (r);
-}
+} /* void *avl_node_prev */
 
 static int _remove (avl_tree_t *t, avl_node_t *n)
 {
 	assert ((t != NULL) && (n != NULL));
 
+	if ((n->left != NULL) && (n->right != NULL))
+	{
+		avl_node_t *r; /* replacement node */
+		if (BALANCE (n) > 0) /* left subtree is higher */
+		{
+			assert (n->left != NULL);
+			r = avl_node_prev (t, n);
+			
+		}
+		else /* right subtree is higher */
+		{
+			assert (n->right != NULL);
+			r = avl_node_next (t, n);
+		}
+
+		assert ((r->left == NULL) || (r->right == NULL));
+
+		/* copy content */
+		n->key   = r->key;
+		n->value = r->value;
+
+		n = r;
+	}
+
+	assert ((n->left == NULL) || (n->right == NULL));
+
 	if ((n->left == NULL) && (n->right == NULL))
 	{
 		/* Deleting a leave is easy */
@@ -360,25 +386,59 @@ static int _remove (avl_tree_t *t, avl_node_t *n)
 
 		free_node (n);
 	}
-	else
+	else if (n->left == NULL)
 	{
-		avl_node_t *r; /* replacement node */
-		if (BALANCE (n) > 0)
+		assert (BALANCE (n) == -1);
+		assert ((n->parent == NULL) || (n->parent->left == n) || (n->parent->right == n));
+		if (n->parent == NULL)
 		{
-			assert (n->left != NULL);
-			r = avl_node_prev (t, n);
+			assert (t->root == n);
+			t->root = n->right;
+		}
+		else if (n->parent->left == n)
+		{
+			n->parent->left = n->right;
 		}
 		else
 		{
-			assert (n->right != NULL);
-			r = avl_node_next (t, n);
+			n->parent->right = n->right;
 		}
+		n->right->parent = n->parent;
 
-		/* copy content */
-		n->key   = r->key;
-		n->value = r->value;
+		if (n->parent != NULL)
+			rebalance (t, n->parent);
 
-		_remove (t, r);
+		n->right = NULL;
+		free_node (n);
+	}
+	else if (n->right == NULL)
+	{
+		assert (BALANCE (n) == 1);
+		assert ((n->parent == NULL) || (n->parent->left == n) || (n->parent->right == n));
+		if (n->parent == NULL)
+		{
+			assert (t->root == n);
+			t->root = n->left;
+		}
+		else if (n->parent->left == n)
+		{
+			n->parent->left = n->left;
+		}
+		else
+		{
+			n->parent->right = n->left;
+		}
+		n->left->parent = n->parent;
+
+		if (n->parent != NULL)
+			rebalance (t, n->parent);
+
+		n->left = NULL;
+		free_node (n);
+	}
+	else
+	{
+		assert (0);
 	}
 
 	return (0);
@@ -523,6 +583,44 @@ avl_iterator_t *avl_get_iterator (avl_tree_t *t)
 	return (avl_create_iterator (t, n));
 } /* avl_iterator_t *avl_get_iterator */
 
+int avl_pick (avl_tree_t *t, void **key, void **value)
+{
+	avl_node_t *n;
+	avl_node_t *p;
+
+	assert ((key != NULL) && (value != NULL));
+	if (t->root == NULL)
+		return (-1);
+
+	n = t->root;
+	while ((n->left != NULL) || (n->right != NULL))
+	{
+		int height_left  = (n->left  == NULL) ? 0 : n->left->height;
+		int height_right = (n->right == NULL) ? 0 : n->right->height;
+
+		if (height_left > height_right)
+			n = n->left;
+		else
+			n = n->right;
+	}
+
+	p = n->parent;
+	if (p == NULL)
+		t->root = NULL;
+	else if (p->left == n)
+		p->left = NULL;
+	else
+		p->right = NULL;
+
+	*key   = n->key;
+	*value = n->value;
+
+	free_node (n);
+	rebalance (t, p);
+
+	return (0);
+} /* int avl_pick */
+
 void *avl_iterator_next (avl_iterator_t *iter)
 {
 	avl_node_t *n;