public interface IDetector
{
double ActiveTime
{ get; set; }
LinkedListNode<IDetector> DetectorNode
{
get;
set;
}
}
接口定义了两个属性，一个是最近活越时间，另一个就是LinkedListNode<IDetector>这个属性比交关键，通过LinkedListNode<IDetector>可以让LinkedList在Remove时复杂度为O(1).接下来就要针对基于LRU算法处理超时制定一个应用规则
public interface ILRUDetector
{
void Update(IDetector item);
void Detection(int timeout);
double GetTime();
Action<IList<IDetector>> Timeout { get; set; }
}
规则也是比较简单，Update用于更新跟踪对象，一般在处理接受ping或pong包后进行调用；Detection方法是探测超出指定时间的对象，时间当位是毫秒，如果存在有超时的对象则触发Timeout事件；GetTime是获取探测器已经运行的时间单位毫秒！规则定好了那接着要做的事实就是要实现它:
class LRUDetector : ILRUDetector, IDisposable
{
public LRUDetector()
{
mTimeWatch = new System.Diagnostics.Stopwatch();
mTimeWatch.Restart();
}
private Buffers.XSpinLock xSpinLock = new Buffers.XSpinLock();
private System.Diagnostics.Stopwatch mTimeWatch;
private LinkedList<IDetector> mItems = new LinkedList<IDetector>();
public Action<IList<IDetector>> Timeout
{
get; set;
}
public void Detection(int timeout)
{
double time = GetTime();
List<IDetector> result = new List<IDetector>();
using (xSpinLock.Enter())
{
LinkedListNode<IDetector> last = mItems.Last;
while (last != null && (time - last.Value.ActiveTime) > timeout)
{
mItems.Remove(last);
result.Add(last.Value);
last.Value.DetectorNode = null;
last = mItems.Last;
}
}
if (Timeout != null && result.Count > 0)
Timeout(result);
}
public void Update(IDetector item)
{
using (xSpinLock.Enter())
{
if (item.DetectorNode == null)
item.DetectorNode = new LinkedListNode<IDetector>(item);
item.ActiveTime = GetTime();
if (item.DetectorNode.List == mItems)
mItems.Remove(item.DetectorNode);
mItems.AddFirst(item);
}
}
public void Dispose()
{
mItems.Clear();
}
public double GetTime()
{
return mTimeWatch.Elapsed.TotalMilliseconds;
}
}
