357 lines
12 KiB
C#
357 lines
12 KiB
C#
|
using System;
|
||
|
|
|
||
|
|
namespace Ryujinx.Common.Collections
|
||
|
|
{
|
||
|
|
/// <summary>
|
||
|
|
/// Tree that provides the ability for O(logN) lookups for keys that exist in the tree, and O(logN) lookups for keys immediately greater than or less than a specified key.
|
||
|
|
/// </summary>
|
||
|
|
/// <typeparam name="T">Derived node type</typeparam>
|
||
|
|
public class IntrusiveRedBlackTreeImpl<T> where T : IntrusiveRedBlackTreeNode<T>
|
||
|
|
{
|
||
|
|
protected const bool Black = true;
|
||
|
|
protected const bool Red = false;
|
||
|
|
protected T Root = null;
|
||
|
|
|
||
|
|
internal T RootNode => Root;
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Number of nodes on the tree.
|
||
|
|
/// </summary>
|
||
|
|
public int Count { get; protected set; }
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Removes all nodes on the tree.
|
||
|
|
/// </summary>
|
||
|
|
public void Clear()
|
||
|
|
{
|
||
|
|
Root = null;
|
||
|
|
Count = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Finds the node whose key is immediately greater than <paramref name="node"/>.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node to find the successor of</param>
|
||
|
|
/// <returns>Successor of <paramref name="node"/></returns>
|
||
|
|
internal static T SuccessorOf(T node)
|
||
|
|
{
|
||
|
|
if (node.Right != null)
|
||
|
|
{
|
||
|
|
return Minimum(node.Right);
|
||
|
|
}
|
||
|
|
T parent = node.Parent;
|
||
|
|
while (parent != null && node == parent.Right)
|
||
|
|
{
|
||
|
|
node = parent;
|
||
|
|
parent = parent.Parent;
|
||
|
|
}
|
||
|
|
return parent;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Finds the node whose key is immediately less than <paramref name="node"/>.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node to find the predecessor of</param>
|
||
|
|
/// <returns>Predecessor of <paramref name="node"/></returns>
|
||
|
|
internal static T PredecessorOf(T node)
|
||
|
|
{
|
||
|
|
if (node.Left != null)
|
||
|
|
{
|
||
|
|
return Maximum(node.Left);
|
||
|
|
}
|
||
|
|
T parent = node.Parent;
|
||
|
|
while (parent != null && node == parent.Left)
|
||
|
|
{
|
||
|
|
node = parent;
|
||
|
|
parent = parent.Parent;
|
||
|
|
}
|
||
|
|
return parent;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Returns the node with the largest key where <paramref name="node"/> is considered the root node.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Root node</param>
|
||
|
|
/// <returns>Node with the maximum key in the tree of <paramref name="node"/></returns>
|
||
|
|
protected static T Maximum(T node)
|
||
|
|
{
|
||
|
|
T tmp = node;
|
||
|
|
while (tmp.Right != null)
|
||
|
|
{
|
||
|
|
tmp = tmp.Right;
|
||
|
|
}
|
||
|
|
|
||
|
|
return tmp;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Returns the node with the smallest key where <paramref name="node"/> is considered the root node.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Root node</param>
|
||
|
|
/// <returns>Node with the minimum key in the tree of <paramref name="node"/></returns>
|
||
|
|
/// <exception cref="ArgumentNullException"><paramref name="node"/> is null</exception>
|
||
|
|
protected static T Minimum(T node)
|
||
|
|
{
|
||
|
|
if (node == null)
|
||
|
|
{
|
||
|
|
throw new ArgumentNullException(nameof(node));
|
||
|
|
}
|
||
|
|
T tmp = node;
|
||
|
|
while (tmp.Left != null)
|
||
|
|
{
|
||
|
|
tmp = tmp.Left;
|
||
|
|
}
|
||
|
|
|
||
|
|
return tmp;
|
||
|
|
}
|
||
|
|
|
||
|
|
protected void RestoreBalanceAfterRemoval(T balanceNode)
|
||
|
|
{
|
||
|
|
T ptr = balanceNode;
|
||
|
|
|
||
|
|
while (ptr != Root && ColorOf(ptr) == Black)
|
||
|
|
{
|
||
|
|
if (ptr == LeftOf(ParentOf(ptr)))
|
||
|
|
{
|
||
|
|
T sibling = RightOf(ParentOf(ptr));
|
||
|
|
|
||
|
|
if (ColorOf(sibling) == Red)
|
||
|
|
{
|
||
|
|
SetColor(sibling, Black);
|
||
|
|
SetColor(ParentOf(ptr), Red);
|
||
|
|
RotateLeft(ParentOf(ptr));
|
||
|
|
sibling = RightOf(ParentOf(ptr));
|
||
|
|
}
|
||
|
|
if (ColorOf(LeftOf(sibling)) == Black && ColorOf(RightOf(sibling)) == Black)
|
||
|
|
{
|
||
|
|
SetColor(sibling, Red);
|
||
|
|
ptr = ParentOf(ptr);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
if (ColorOf(RightOf(sibling)) == Black)
|
||
|
|
{
|
||
|
|
SetColor(LeftOf(sibling), Black);
|
||
|
|
SetColor(sibling, Red);
|
||
|
|
RotateRight(sibling);
|
||
|
|
sibling = RightOf(ParentOf(ptr));
|
||
|
|
}
|
||
|
|
SetColor(sibling, ColorOf(ParentOf(ptr)));
|
||
|
|
SetColor(ParentOf(ptr), Black);
|
||
|
|
SetColor(RightOf(sibling), Black);
|
||
|
|
RotateLeft(ParentOf(ptr));
|
||
|
|
ptr = Root;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
T sibling = LeftOf(ParentOf(ptr));
|
||
|
|
|
||
|
|
if (ColorOf(sibling) == Red)
|
||
|
|
{
|
||
|
|
SetColor(sibling, Black);
|
||
|
|
SetColor(ParentOf(ptr), Red);
|
||
|
|
RotateRight(ParentOf(ptr));
|
||
|
|
sibling = LeftOf(ParentOf(ptr));
|
||
|
|
}
|
||
|
|
if (ColorOf(RightOf(sibling)) == Black && ColorOf(LeftOf(sibling)) == Black)
|
||
|
|
{
|
||
|
|
SetColor(sibling, Red);
|
||
|
|
ptr = ParentOf(ptr);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
if (ColorOf(LeftOf(sibling)) == Black)
|
||
|
|
{
|
||
|
|
SetColor(RightOf(sibling), Black);
|
||
|
|
SetColor(sibling, Red);
|
||
|
|
RotateLeft(sibling);
|
||
|
|
sibling = LeftOf(ParentOf(ptr));
|
||
|
|
}
|
||
|
|
SetColor(sibling, ColorOf(ParentOf(ptr)));
|
||
|
|
SetColor(ParentOf(ptr), Black);
|
||
|
|
SetColor(LeftOf(sibling), Black);
|
||
|
|
RotateRight(ParentOf(ptr));
|
||
|
|
ptr = Root;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
SetColor(ptr, Black);
|
||
|
|
}
|
||
|
|
|
||
|
|
protected void RestoreBalanceAfterInsertion(T balanceNode)
|
||
|
|
{
|
||
|
|
SetColor(balanceNode, Red);
|
||
|
|
while (balanceNode != null && balanceNode != Root && ColorOf(ParentOf(balanceNode)) == Red)
|
||
|
|
{
|
||
|
|
if (ParentOf(balanceNode) == LeftOf(ParentOf(ParentOf(balanceNode))))
|
||
|
|
{
|
||
|
|
T sibling = RightOf(ParentOf(ParentOf(balanceNode)));
|
||
|
|
|
||
|
|
if (ColorOf(sibling) == Red)
|
||
|
|
{
|
||
|
|
SetColor(ParentOf(balanceNode), Black);
|
||
|
|
SetColor(sibling, Black);
|
||
|
|
SetColor(ParentOf(ParentOf(balanceNode)), Red);
|
||
|
|
balanceNode = ParentOf(ParentOf(balanceNode));
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
if (balanceNode == RightOf(ParentOf(balanceNode)))
|
||
|
|
{
|
||
|
|
balanceNode = ParentOf(balanceNode);
|
||
|
|
RotateLeft(balanceNode);
|
||
|
|
}
|
||
|
|
SetColor(ParentOf(balanceNode), Black);
|
||
|
|
SetColor(ParentOf(ParentOf(balanceNode)), Red);
|
||
|
|
RotateRight(ParentOf(ParentOf(balanceNode)));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
T sibling = LeftOf(ParentOf(ParentOf(balanceNode)));
|
||
|
|
|
||
|
|
if (ColorOf(sibling) == Red)
|
||
|
|
{
|
||
|
|
SetColor(ParentOf(balanceNode), Black);
|
||
|
|
SetColor(sibling, Black);
|
||
|
|
SetColor(ParentOf(ParentOf(balanceNode)), Red);
|
||
|
|
balanceNode = ParentOf(ParentOf(balanceNode));
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
if (balanceNode == LeftOf(ParentOf(balanceNode)))
|
||
|
|
{
|
||
|
|
balanceNode = ParentOf(balanceNode);
|
||
|
|
RotateRight(balanceNode);
|
||
|
|
}
|
||
|
|
SetColor(ParentOf(balanceNode), Black);
|
||
|
|
SetColor(ParentOf(ParentOf(balanceNode)), Red);
|
||
|
|
RotateLeft(ParentOf(ParentOf(balanceNode)));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
SetColor(Root, Black);
|
||
|
|
}
|
||
|
|
|
||
|
|
protected virtual void RotateLeft(T node)
|
||
|
|
{
|
||
|
|
if (node != null)
|
||
|
|
{
|
||
|
|
T right = RightOf(node);
|
||
|
|
node.Right = LeftOf(right);
|
||
|
|
if (node.Right != null)
|
||
|
|
{
|
||
|
|
node.Right.Parent = node;
|
||
|
|
}
|
||
|
|
T nodeParent = ParentOf(node);
|
||
|
|
right.Parent = nodeParent;
|
||
|
|
if (nodeParent == null)
|
||
|
|
{
|
||
|
|
Root = right;
|
||
|
|
}
|
||
|
|
else if (node == LeftOf(nodeParent))
|
||
|
|
{
|
||
|
|
nodeParent.Left = right;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
nodeParent.Right = right;
|
||
|
|
}
|
||
|
|
right.Left = node;
|
||
|
|
node.Parent = right;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
protected virtual void RotateRight(T node)
|
||
|
|
{
|
||
|
|
if (node != null)
|
||
|
|
{
|
||
|
|
T left = LeftOf(node);
|
||
|
|
node.Left = RightOf(left);
|
||
|
|
if (node.Left != null)
|
||
|
|
{
|
||
|
|
node.Left.Parent = node;
|
||
|
|
}
|
||
|
|
T nodeParent = ParentOf(node);
|
||
|
|
left.Parent = nodeParent;
|
||
|
|
if (nodeParent == null)
|
||
|
|
{
|
||
|
|
Root = left;
|
||
|
|
}
|
||
|
|
else if (node == RightOf(nodeParent))
|
||
|
|
{
|
||
|
|
nodeParent.Right = left;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
nodeParent.Left = left;
|
||
|
|
}
|
||
|
|
left.Right = node;
|
||
|
|
node.Parent = left;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#region Safety-Methods
|
||
|
|
|
||
|
|
// These methods save memory by allowing us to forego sentinel nil nodes, as well as serve as protection against NullReferenceExceptions.
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Returns the color of <paramref name="node"/>, or Black if it is null.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node</param>
|
||
|
|
/// <returns>The boolean color of <paramref name="node"/>, or black if null</returns>
|
||
|
|
protected static bool ColorOf(T node)
|
||
|
|
{
|
||
|
|
return node == null || node.Color;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Sets the color of <paramref name="node"/> node to <paramref name="color"/>.
|
||
|
|
/// <br></br>
|
||
|
|
/// This method does nothing if <paramref name="node"/> is null.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node to set the color of</param>
|
||
|
|
/// <param name="color">Color (Boolean)</param>
|
||
|
|
protected static void SetColor(T node, bool color)
|
||
|
|
{
|
||
|
|
if (node != null)
|
||
|
|
{
|
||
|
|
node.Color = color;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// This method returns the left node of <paramref name="node"/>, or null if <paramref name="node"/> is null.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node to retrieve the left child from</param>
|
||
|
|
/// <returns>Left child of <paramref name="node"/></returns>
|
||
|
|
protected static T LeftOf(T node)
|
||
|
|
{
|
||
|
|
return node?.Left;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// This method returns the right node of <paramref name="node"/>, or null if <paramref name="node"/> is null.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node to retrieve the right child from</param>
|
||
|
|
/// <returns>Right child of <paramref name="node"/></returns>
|
||
|
|
protected static T RightOf(T node)
|
||
|
|
{
|
||
|
|
return node?.Right;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Returns the parent node of <paramref name="node"/>, or null if <paramref name="node"/> is null.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="node">Node to retrieve the parent from</param>
|
||
|
|
/// <returns>Parent of <paramref name="node"/></returns>
|
||
|
|
protected static T ParentOf(T node)
|
||
|
|
{
|
||
|
|
return node?.Parent;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endregion
|
||
|
|
}
|
||
|
|
}
|