void rb_tree_insert_case4(RBTree *tree, RBTreeNode *node)
{
RBTreeNode *next_node;
RBTreeNodeSide side;
/* Note that at this point, by implication from case 3, we know
* that the parent is red, but the uncle is black. We therefore
* only need to examine what side the node is on relative
* to its parent, and the side the parent is on relative to
* the grandparent. */
side = rb_tree_node_side(node);
if (side != rb_tree_node_side(node->parent)) {
/* After the rotation, we will continue to case 5, but
* the parent node will be at the bottom. */
next_node = node->parent;
/* Rotate around the parent in the opposite direction
* to side. */
rb_tree_rotate(tree, node->parent, 1-side);
} else {
next_node = node;
}
rb_tree_insert_case5(tree, next_node);
}
static void rb_tree_insert_case4(rb_node_t *node)
{
rb_node_t *g = grandparent(node);
/*
LOG_DBG("inserting case 4 parent_c=%d uncle_c=%d\n",
node->parent->color, uncle(node) ? uncle(node)->color : 0);
*/
if (node->parent->right == node && node->parent == g->left) {
rb_tree_rotate_left_side_left(node->parent);
node = node->left;
} else if (node->parent->left == node && node->parent == g->right) {
rb_tree_rotate_right_side_right(node->parent);
node = node->right;
}
if (node)
rb_tree_insert_case5(node);
}
