验证URL中GUID值是否重复的类库，防止用户之截刷URL(代码存在问题，一直没找到来。看有没有高人能看出来。)

验证URL中GUID值是否重复的类库，防止用户直截刷URL，设计思路如下：
定义了两个队列：
当前写入队列 Hashtable writeTb
备份队列 Hashtable readTb
已经使用过的GUID值记录在writeTb,readTb列表中。
当新的GUID值上来的时候，判断writeTb,readTb队列中是否存在GUID值，如果存在，就判断为非法。
两个队列根据一定的间隔时间来轮换切读写。当readTb切换成写队列的时候。readTb中记录的GUID值全部清除。
直接上代码：(代码是存在问题的，没跑多久的时候CPU就100%了，一直找不到问题，看看有没有高人能看出问题所在)
public class RequestValidate { private Thread clearTbWorker = null; private Hashtable tb1 = new Hashtable(100000); private Hashtable tb2 = new Hashtable(100000);
///

/// 上次转换TB时间 ///

private DateTime lastSwitchTbTime { get; set; }
///

/// 写TB索引 ///

private int writeTbIndex{get;set;}
///

/// 当前写入队列 ///

private Hashtable writeTb { get { if (writeTbIndex == 1) return tb1; else return tb2; } }
///

/// 备份队列 ///

private Hashtable readTb { get { if (writeTbIndex == 1) return tb2; else return tb1; } }
private HttpRequest request { get { return HttpContext.Current.Request; } }
///

/// GUID受限使用时间 ///

private TimeSpan GuidExpiredMinute = TimeSpan.FromMinutes(2);
private RequestValidate() { lastSwitchTbTime = System.DateTime.Now; clearTbWorker = new Thread(new ThreadStart(ClearTbWork)); clearTbWorker.Start(); }
private static RequestValidate instance = null; public static RequestValidate Instance { get { if (instance == null) { lock (typeof(RequestValidate)) { if (instance == null) { instance = new RequestValidate(); } } } return instance; } }
///

/// 验证客户端GUID值是否合法 ///

/// public bool Validate() { string guid = request["guid"]; if (string.IsNullOrEmpty(guid)) { #if DEBUG return false; #else return true; #endif }
if (!string.IsNullOrEmpty(request["t"])) { HttpContext.Current.Response.ContentType = "text/html"; HttpContext.Current.Response.Write("readTb:"+readTb.Count); HttpContext.Current.Response.Write("writeTb:" + this.writeTb.Count); HttpContext.Current.Response.End(); }
bool isTrue = true;
try { string htKey = guid.ToLower(); if (readTb.ContainsKey(htKey)) { isTrue = false; } else if (writeTb.ContainsKey(htKey)) { isTrue = false; } else { writeTb[htKey] = System.DateTime.Now; } } catch (Exception ex) { Log.LogComplement.Error(ex); }
return isTrue;
}
///

/// 清除过期队列 ///

private void ClearTbWork() { while (true) { try {
TimeSpan ts = System.DateTime.Now - lastSwitchTbTime; if (ts < GuidExpiredMinute) { System.Threading.Thread.Sleep(ts); }
//清除GuidExpiredMinute分钟之前备份队列 readTb.Clear();
if (writeTbIndex == 1) writeTbIndex = 2; else writeTbIndex = 1;
lastSwitchTbTime = System.DateTime.Now;
} catch (Exception ex) { Log.LogComplement.Error(ex); } finally { System.Threading.Thread.Sleep(GuidExpiredMinute); } }
} }

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