/// <summary>
/// Determines whether [is up to date] [the specified key].
/// </summary>
/// <param name="key">The key.</param>
/// <param name="synchTicks">The synch ticks.</param>
/// <returns></returns>
public static ClusteredCachingSynchronizationStatus IsUpToDate(string key, out long synchTicks)
{
#region check whether we can delay the synchronization check
if (ClusteredCacheController.CheckAtRequestIsUpToDateDelayInMilliseconds > 0 &&
CheckAtRequestDependencies.ContainsKey(key) &&
CheckAtRequestDependencies[key].LastChecked.HasValue &&
CheckAtRequestDependencies[key].LastChecked.Value.AddMilliseconds(ClusteredCacheController.CheckAtRequestIsUpToDateDelayInMilliseconds) > DateTime.UtcNow)
{
synchTicks = CheckAtRequestDependencies[key].Ticks;
return(ClusteredCachingSynchronizationStatus.UpToDate);
}
#endregion
DataAccessManager dam = new DataAccessManager(ConnectionString);
dam.AddInputParameter("@CacheKey", key);
dam.AddInputParameter("@ApplicationId", ClusteredCacheController.ApplicationId);
synchTicks = dam.ExecuteScalar <long>(GetFormattedStoredProcedureName(SP_SELECT));
if (synchTicks <= 0)
{
return(ClusteredCachingSynchronizationStatus.RemovedFromCollection);
}
else
{
if (CheckAtRequestDependencies.ContainsKey(key))
{
if (CheckAtRequestDependencies[key].Ticks.Equals(synchTicks))
{
if (ClusteredCacheController.CheckAtRequestIsUpToDateDelayInMilliseconds > 0)
{
CheckAtRequestDependencies[key] = GetCheckAtRequestInfo(synchTicks);
}
return(ClusteredCachingSynchronizationStatus.UpToDate);
}
else
{
return(ClusteredCachingSynchronizationStatus.OutOfDate);
}
}
else
{
return(ClusteredCachingSynchronizationStatus.NotFound);
}
}
}
/// <summary>
/// Adds an object to the HttpRuntime.Cache collection and sets an SQL Dependency on it's
/// key.
/// </summary>
/// <param name="key">The cache key.</param>
/// <param name="item">The item to add to the cache.</param>
/// <param name="priority">The priority.</param>
public static void AddCacheItem(string key, object item, CacheItemPriority priority)
{
if (ClusteredCacheController.ClusteredCachingMode == ClusteredCachingMode.ServiceBroker)
{
if (_ServiceBrokerDependencies.ContainsKey(key))
{
_ServiceBrokerDependencies.Remove(key);
}
}
#region insert/update at database
long utcNow = DateTime.UtcNow.Ticks;
DataAccessManager dam = new DataAccessManager(ConnectionString);
dam.AddInputParameter("@CacheKey", key);
dam.AddInputParameter("@LastUpdate", utcNow);
dam.AddInputParameter("@ApplicationId", ClusteredCacheController.ApplicationId);
dam.ExecuteNonQuery(GetFormattedStoredProcedureName(SP_INSERT_UPDATE));
#endregion
#region add to cache collection
HttpRuntime.Cache.Remove(key);
HttpRuntime.Cache.Insert(key, item, null, Cache.NoAbsoluteExpiration, Cache.NoSlidingExpiration, priority, null);
#endregion
#region add dependency
switch (ClusteredCacheController.ClusteredCachingMode)
{
case ClusteredCachingMode.ServiceBroker:
#region service broker
SqlConnection con = new SqlConnection(_ConnectionString);
SqlCommand cmd = new SqlCommand(GetFormattedStoredProcedureName(SP_SELECT), con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("@CacheKey", SqlDbType.NVarChar, 256);
cmd.Parameters[0].Value = key;
// Clear any existing notifications
cmd.Notification = null;
// Create the dependency for this command
SqlDependency dependency = new SqlDependency(cmd);
// Add the event handler
dependency.OnChange += new OnChangeEventHandler(OnChange);
#region execute reader
try
{
con.Open();
// Execute the command.
cmd.ExecuteReader();
// Process the DataReader
}
catch (SqlException err)
{
DataAccessManager.ThrowDataAccessManagerException(err, GetFormattedStoredProcedureName(SP_SELECT));
}
finally
{
con.Close();
}
#endregion
_ServiceBrokerDependencies.Add(dependency.Id, new CacheKeySqlDependency()
{
CacheKey = key, SqlDependency = dependency
});
#endregion
break;
case ClusteredCachingMode.CheckAtRequest:
if (CheckAtRequestDependencies.ContainsKey(key))
{
CheckAtRequestDependencies[key] = GetCheckAtRequestInfo(utcNow);
}
else
{
CheckAtRequestDependencies.Add(key, GetCheckAtRequestInfo(utcNow));
}
break;
}
#endregion
}
