/* *
* rb_tree_create - creates a new red-black tree, the 'compare' function
* is required and returns 'NULL' if failed.
*
* Note that, root->left should always point to the node that is the root
* of the tree. And nil points to a 'NULL' node which should always be
* black and may have arbitrary children and parent node.
* */
rb_tree *
rb_tree_create(int (*compare)(rb_node *node1, rb_node *node2)) {
assert(compare != NULL);
rb_tree *tree;
rb_node *nil, *root;
if ((tree = kmalloc(sizeof(rb_tree))) == NULL) {
goto bad_tree;
}
tree->compare = compare;
if ((nil = rb_node_create()) == NULL) {
goto bad_node_cleanup_tree;
}
nil->parent = nil->left = nil->right = nil;
nil->red = 0;
tree->nil = nil;
if ((root = rb_node_create()) == NULL) {
goto bad_node_cleanup_nil;
}
root->parent = root->left = root->right = nil;
root->red = 0;
tree->root = root;
return tree;
bad_node_cleanup_nil:
kfree(nil);
bad_node_cleanup_tree:
kfree(tree);
bad_tree:
return NULL;
}
// Creates (malloc'ates)
int
rb_tree_insert (struct rb_tree *self, void *value) {
return rb_tree_insert_node(self, rb_node_create(value));
}