分享通用基类库-C#通用缓存类

/*************************************************************************************
* 代码:吴蒋
* 时间:2012.03.30
* 说明:缓存公共基类
* 其他:
* 修改人：
* 修改时间：
* 修改说明：
************************************************************************************/
using System;
using System.Web.Caching;

namespace Common
{
public class DacheHelp
{
protected static volatile System.Web.Caching.Cache webCache = System.Web.HttpRuntime.Cache;

/// <summary>
/// 默认缓存存活期为3600秒(1小时)
/// </summary>
protected int _timeOut = 3600;

private static object syncObj = new object();

/// <summary>
/// 构造函数
/// </summary>
static DacheHelp()
{
}

/// <summary>
/// 设置到期相对时间[单位: 秒]
/// </summary>
public virtual int TimeOut
{
set { _timeOut = value > 0 ? value : 3600; }
get { return _timeOut > 0 ? _timeOut : 3600; }
}

/// <summary>
/// 静态构造函数
/// </summary>
public static System.Web.Caching.Cache GetWebCacheObj
{
get { return webCache; }
}

/// <summary>
/// 加入当前对象到缓存中
/// </summary>
/// <param name="objId">对象的键值</param>
/// <param name="o">缓存的对象</param>
public virtual void AddObject(string objId, object o)
{
if (objId == null || objId.Length == 0 || o == null)
{
return;
}

CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(onRemove);

if (TimeOut == 7200)
{
webCache.Insert(objId, o, null, DateTime.MaxValue, TimeSpan.Zero, System.Web.Caching.CacheItemPriority.High, callBack);
}
else
{
webCache.Insert(objId, o, null, DateTime.Now.AddSeconds(TimeOut), System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.High, callBack);
}
}

/// <summary>
/// 加入当前对象到缓存中
/// </summary>
/// <param name="objId">对象的键值</param>
/// <param name="o">缓存的对象</param>
public virtual void AddObjectWith(string objId, object o)
{
if (objId == null || objId.Length == 0 || o == null)
{
return;
}

CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(onRemove);

webCache.Insert(objId, o, null, System.DateTime.Now.AddSeconds(TimeOut), System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.High, callBack);
}

/// <summary>
/// 加入当前对象到缓存中,并对相关文件建立依赖
/// </summary>
/// <param name="objId">对象的键值</param>
/// <param name="o">缓存的对象</param>
/// <param name="files">监视的路径文件</param>
public virtual void AddObjectWithFileChange(string objId, object o, string[] files)
{
if (objId == null || objId.Length == 0 || o == null)
{
return;
}

CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(onRemove);

CacheDependency dep = new CacheDependency(files, DateTime.Now);

webCache.Insert(objId, o, dep, System.DateTime.Now.AddSeconds(TimeOut), System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.High, callBack);
}

/// <summary>
/// 加入当前对象到缓存中,并使用依赖键
/// </summary>
/// <param name="objId">对象的键值</param>
/// <param name="o">缓存的对象</param>
/// <param name="dependKey">依赖关联的键值</param>
public virtual void AddObjectWithDepend(string objId, object o, string[] dependKey)
{
if (objId == null || objId.Length == 0 || o == null)
{
return;
}

CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(onRemove);

CacheDependency dep = new CacheDependency(null, dependKey, DateTime.Now);

webCache.Insert(objId, o, dep, System.DateTime.Now.AddSeconds(TimeOut), System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.High, callBack);
}

/// <summary>
/// 建立回调委托的一个实例
/// </summary>
/// <param name="key"></param>
/// <param name="val"></param>
/// <param name="reason"></param>
public void onRemove(string key, object val, CacheItemRemovedReason reason)
{
switch (reason)
{
case CacheItemRemovedReason.DependencyChanged:
break;
case CacheItemRemovedReason.Expired:
{
//CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(this.onRemove);

//webCache.Insert(key, val, null, System.DateTime.Now.AddMinutes(TimeOut),
//    System.Web.Caching.Cache.NoSlidingExpiration,
//    System.Web.Caching.CacheItemPriority.High,
//    callBack);
break;
}
case CacheItemRemovedReason.Removed:
{
break;
}
case CacheItemRemovedReason.Underused:
{
break;
}
default: break;
}
//如需要使用缓存日志,则需要使用下面代码
//myLogVisitor.WriteLog(this,key,val,reason);
}

/// <summary>
/// 删除缓存对象
/// </summary>
/// <param name="objId">对象的关键字</param>
public virtual void RemoveObject(string objId)
{
if (objId == null || objId.Length == 0)
{
return;
}
webCache.Remove(objId);
}

/// <summary>
/// 返回一个指定的对象
/// </summary>
/// <param name="objId">对象的关键字</param>
/// <returns>对象</returns>
public virtual object RetrieveObject(string objId)
{
if (objId == null || objId.Length == 0)
{
return null;
}
return webCache.Get(objId);
}
}
}