/// <summary>
/// 移动一个节点到顶端
/// </summary>
/// <param name="inputNode"></param>
private void MoveToHead(LRULindNode <X, Y> inputNode)
{
//移除节点
RemoveNodeInLink(inputNode);
//新增节点
AddNode(inputNode);
}
/// <summary>
/// 设置储存值(重复键值则复写）
/// </summary>
/// <param name="inputKey">输入的Key</param>
/// <param name="inputValue">输入的Value</param>
public void Set(X inputKey, Y inputValue)
{
//若存在则复写
if (IfContainsKey(inputKey))
{
LRULindNode <X, Y> useNode = m_useCache[inputKey];
MoveToHead(useNode);
useNode.ThisValue = inputValue;
}
//不存在则添加
else
{
LRULindNode <X, Y> addedNode = new LRULindNode <X, Y>();
addedNode.ThisKey = inputKey;
addedNode.ThisValue = inputValue;
AddNode(addedNode);
//添加到字典
m_useCache.Add(inputKey, addedNode);
//增加数量
m_count++;
if (m_count > m_capacity)
{
var nodeNeedRemove = Poptail();
RemoveNodeInManger(nodeNeedRemove);
}
}
//清空迭代缓存
m_useBackDic = null;
}
/// <summary>
/// 新添一个节点到顶端
/// </summary>
/// <param name="inputNode"></param>
private void AddNode(LRULindNode <X, Y> inputNode)
{
var nowHeadNode = m_headNode.PostNode;
m_headNode.PostNode = inputNode;
inputNode.PreNode = m_headNode;
nowHeadNode.PreNode = inputNode;
inputNode.PostNode = nowHeadNode;
}
/// <summary>
/// 从链表中移除节点
/// </summary>
/// <param name="inputNode"></param>
private void RemoveNodeInLink(LRULindNode <X, Y> inputNode)
{
var nowPreNode = inputNode.PreNode;
var nowPostNode = inputNode.PostNode;
inputNode.PreNode = null;
inputNode.PostNode = null;
nowPreNode.PostNode = nowPostNode;
nowPostNode.PreNode = nowPreNode;
}
/// <summary>
/// 获取值
/// </summary>
/// <param name="inputKey">输入的键值</param>
/// <returns>对应值</returns>
public Y Get(X inputKey)
{
if (!IfContainsKey(inputKey))
{
throw new ArgumentException();
}
LRULindNode <X, Y> useNode = m_useCache[inputKey];
MoveToHead(useNode);
return(useNode.ThisValue);
}
/// <summary>
/// 构造LRU缓存
/// </summary>
/// <param name="inputCapacity">容量</param>
/// <exception cref="ArgumentException">容量小于等于1</exception>
public LRUCacheManger(int inputCapacity)
{
if (inputCapacity <= 1)
{
throw new ArgumentException();
}
m_useCache = new Dictionary <X, LRULindNode <X, Y> >();
m_count = 0;
m_capacity = inputCapacity;
m_headNode = new EndNode <X, Y>();
m_tailNode = new EndNode <X, Y>();
m_headNode.PostNode = m_tailNode;
m_headNode.PreNode = null;
m_tailNode.PostNode = null;
m_tailNode.PreNode = m_headNode;
}
/// <summary>
/// 弹出尾节点
/// </summary>
/// <returns>尾节点</returns>
private LRULindNode <X, Y> Poptail()
{
LRULindNode <X, Y> useNode = m_tailNode.PreNode;
return(useNode);
}
/// <summary>
/// 从缓存系统中移除节点
/// </summary>
/// <param name="nodeNeedRemove"></param>
private void RemoveNodeInManger(LRULindNode <X, Y> nodeNeedRemove)
{
RemoveNodeInLink(nodeNeedRemove);
m_useCache.Remove(nodeNeedRemove.ThisKey);
m_count--;
}