/// <summary>
    /// 数据库缓存通知模式
    /// 1.SELECT  DATABASEPROPERTYEX('DATABASENAME','IsBrokerEnabled') 1 表示启用，0表示未启用
    /// 2.启用IsBrokerEnabled
    /// ALTER DATABASE [DATABASENAME] SET NEW_BROKER WITH ROLLBACK IMMEDIATE;
    /// ALTER DATABASE [DATABASENAME] SET ENABLE_BROKER;/ALTER DATABASE [DATABASENAME] SET DISABLE_BROKER;
    /// 
    /// 3.GRANT SUBSCRIBE QUERY NOTIFICATIONS TO [当前数据库登录用户名，如果是sa可以跳过]
    ///  
    /// 4.exec sp_changedbowner @loginame = '[当前数据库登录用户名，如果是sa,则使用sa账号]'
    /// 
    /// </summary>
    public class DMSLinqSqlWebCacheNotifyProvider : IDMSLinqCacheProvider
    {

        System.Web.Caching.Cache webCache = System.Web.HttpRuntime.Cache;
        private static object syncObj = new object();
        public DMSLinqSqlWebCacheNotifyProvider()
        {
            lock (syncObj)
            {
                System.Web.HttpContext context = System.Web.HttpContext.Current;
                if (context != null)
                    webCache = context.Cache;
                else
                    webCache = System.Web.HttpRuntime.Cache;
            }
        }

        public string GetDependencyKey(System.Data.IDbCommand command, string[] tableNames)
        {
            string dependencyKey = command.CommandText;
            foreach (System.Data.IDbDataParameter item in command.Parameters)
            {
                dependencyKey += string.Format("-{0}-{1}", item.ParameterName, item.Value);
            }
#if DEBUG
            System.Diagnostics.Debug.WriteLine(string.Format("{0},use dependency key successfully", dependencyKey));
#endif
            return dependencyKey;
        }

        public object GetCache(string dependencyKey)
        {
            object resultValue = webCache[dependencyKey];
#if DEBUG
            System.Diagnostics.Debug.WriteLine(string.Format("this cache is empty?：{0}", resultValue == null ? "true" : "false"));
#endif
            return resultValue;
        }
        public System.Web.Caching.CacheDependency GetCacheDependency(string connectionString, System.Data.IDbCommand command, string[] tableNames, ref string dependencyKey)
        {
            System.Web.Caching.SqlCacheDependency dependency = null;
            try
            {
                dependency = new System.Web.Caching.SqlCacheDependency((System.Data.SqlClient.SqlCommand)command);
            }
            catch (Exception ex)
            {
                DMSFrame.Loggers.LoggerManager.Logger.Log(ex, ReflectionUtils.GetMethodBaseInfo(System.Reflection.MethodBase.GetCurrentMethod()), DMSFrame.Loggers.ErrorLevel.Fatal);
            }
#if DEBUG
            System.Diagnostics.Debug.WriteLine(string.Format("Get the sqlcachedependency successfully.{0}", dependency == null ? "false" : "true"));
#endif
            return dependency;
        }
        public void SetCache(System.Web.Caching.CacheDependency dependency, string dependencyKey, object Value)
        {
            if (dependency != null)
            {
#if DEBUG
                System.Diagnostics.Debug.WriteLine(string.Format("Add cache is successfully,{0}", dependencyKey));
#endif
                webCache.Insert(dependencyKey, Value, dependency);
            }
        }
    }