void rbtree_node::remove(rbtree_node** root)
{
rbtree_node* node = this;
rbtree_node* child;
rbtree_node* parent;
int color;
//
// Satisfy Precondition: node has at most one non-null child
//
if (!node->left) {
child = node->right;
} else if (!node->right) {
child = node->left;
} else {
rbtree_node* old = node;
//
// Locate a node that satisfies the precondition to swap with the node to be removed
//
node = node->right;
while (node->left)
node = node->left;
//
// Node satisfies precondition
//
child = node->right;
//
// Swap nodes (swap <-> (node <-> child))
//
parent = node->parent();
color = node->color();
if (child)
child->parent(parent);
if (parent == old) {
parent->right = child;
parent = node;
} else {
parent->left = child;
}
node->_parent = old->_parent;
node->left = old->left;
node->right = old->right;
if (old->parent()) {
UL_ASSERT((old->parent()->right == old) || (old->parent()->left == old));
if (old->parent()->left == old) {
old->parent()->left = node;
} else {
old->parent()->right = node;
}
} else {
*root = node;
}
old->left->parent(node);
if (old->right)
old->right->parent(node);
goto rm_color;
}
//
// Replace Node with Child
//
parent = node->parent();
color = node->color();
if (child) {
child->parent(parent);
}
if (parent) {
UL_ASSERT((parent->right == node) || (parent->left == node));
if (parent->left == node) {
parent->left = child;
} else {
parent->right = child;
}
} else {
*root = child;
}
rm_color:
//
// Adjust Red-Black tree properties if node is black
//
if (color == black) {
remove_color(child, parent, root);
}
UL_ASSERT(!*root || (*root)->color() == black);
//
// Bug prevention
//
this->_parent = 0;
this->left = nullptr;
this->right = nullptr;
}
static void remove_color(ul::rbtree_node* node, ul::rbtree_node* parent, ul::rbtree_node** root)
{
ul::rbtree_node* sibling;
//
// Case 1
//
if (node && node->color() == ul::rbtree_node::red) {
node->color(ul::rbtree_node::black);
//
// Cases: 2, 3, 4, 5, 6
//
// To reduce a number of repeated comparisions for the sibling, the code was duplicated and,
// as a result, dead code paths were removed.
//
} else while (parent) {
UL_ASSERT((node == parent->left) || (node == parent->right));
if (node == parent->left) {
sibling = parent->right;
if (sibling->color() == ul::rbtree_node::red) {
parent->color(ul::rbtree_node::red);
sibling->color(ul::rbtree_node::black);
rotate_left(parent, root);
sibling = parent->right;
}
if (sibling->color() == ul::rbtree_node::black) {
if (!sibling->right || sibling->right->color() == ul::rbtree_node::black) {
if (!sibling->left || sibling->left->color() == ul::rbtree_node::black) {
if (parent->color() == ul::rbtree_node::black) {
sibling->color(ul::rbtree_node::red);
node = parent;
parent = node->parent();
continue;
} else {
sibling->color(ul::rbtree_node::red);
parent->color(ul::rbtree_node::black);
break;
}
} else {
sibling->color(ul::rbtree_node::red);
sibling->left->color(ul::rbtree_node::black);
rotate_right(sibling, root);
sibling = parent->right;
}
}
sibling->color(parent->color());
parent->color(ul::rbtree_node::black);
if (sibling->right)
sibling->right->color(ul::rbtree_node::black);
rotate_left(parent, root);
}
} else {
sibling = parent->left;
if (sibling->color() == ul::rbtree_node::red) {
parent->color(ul::rbtree_node::red);
sibling->color(ul::rbtree_node::black);
rotate_right(parent, root);
sibling = parent->left;
}
if (sibling->color() == ul::rbtree_node::black) {
if (!sibling->left || sibling->left->color() == ul::rbtree_node::black) {
if (!sibling->right || sibling->right->color() == ul::rbtree_node::black) {
if (parent->color() == ul::rbtree_node::black) {
sibling->color(ul::rbtree_node::red);
node = parent;
parent = node->parent();
continue;
} else {
sibling->color(ul::rbtree_node::red);
parent->color(ul::rbtree_node::black);
break;
}
} else {
sibling->color(ul::rbtree_node::red);
sibling->right->color(ul::rbtree_node::black);
rotate_left(sibling, root);
sibling = parent->left;
}
}
sibling->color(parent->color());
parent->color(ul::rbtree_node::black);
if (sibling->left) sibling->left->color(ul::rbtree_node::black);
rotate_right(parent, root);
}
}
break;
}
}
ViewableObjectFactory* HistoryManager::GetFactory(ID id)
{
UL_ASSERT(data.find(id) != data.end());
UL_ASSERT(data[id].factory != NULL);
return data[id].factory;
}
int HistoryManager::GetModifiedTime(ID id)
{
UL_ASSERT(data.find(id) != data.end());
return data[id].modifiedTime;
}
std::string HistoryManager::GetValue(ID id)
{
UL_ASSERT(data.find(id) != data.end());
return data[id].value;
}
void HistoryManager::SetFactory(ID id, ViewableObjectFactory* factory)
{
UL_ASSERT(data.find(id) != data.end());
data[id].factory = factory;
}
void HistoryManager::SetValue(ID id, std::string value)
{
UL_ASSERT(data.find(id) != data.end());
data[id].value = value;
}
void HistoryManager::SetHistory(ID id, std::set<ValueID> history)
{
UL_ASSERT(data.find(id) != data.end());
data[id].history = history;
data[id].modifiedTime = time;
}
void HistoryManager::SetVisible(ID id, bool visible)
{
UL_ASSERT(data.find(id) != data.end());
data[id].visible = visible;
}
bool HistoryManager::IsVisible(ID id)
{
UL_ASSERT(data.find(id) != data.end());
return data[id].visible;
}
std::set<ValueID> HistoryManager::GetHistory(ID id)
{
UL_ASSERT(data.find(id) != data.end());
return data[id].history;
}
