static unsigned int verify_redblack(dnode_t *nil, dnode_t *root)
{
unsigned height_left, height_right;
if (root != nil) {
height_left = verify_redblack(nil, root->left);
height_right = verify_redblack(nil, root->right);
if (height_left == 0 || height_right == 0)
return 0;
if (height_left != height_right)
return 0;
if (root->color == dnode_red) {
if (root->left->color != dnode_black)
return 0;
if (root->right->color != dnode_black)
return 0;
return height_left;
}
if (root->color != dnode_black)
return 0;
return height_left + 1;
}
return 1;
}
int dict_verify(dict_t *dict)
{
dnode_t *nil = dict_nil(dict), *root = dict_root(dict);
/* check that the sentinel node and root node are black */
if (root->color != dnode_black)
return 0;
if (nil->color != dnode_black)
return 0;
if (nil->right != nil)
return 0;
/* nil->left is the root node; check that its parent pointer is nil */
if (nil->left->parent != nil)
return 0;
/* perform a weak test that the tree is a binary search tree */
if (!verify_bintree(dict))
return 0;
/* verify that the tree is a red-black tree */
if (!verify_redblack(nil, root))
return 0;
if (verify_node_count(nil, root) != dict_count(dict))
return 0;
return 1;
}
