/// <summary>
/// Gets an item from cache, and if not found, executes the itemFactory to create item and add to cache with an expiration timespan.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="itemFactory">The item factory.</param>
/// <param name="expiration">The expiration.</param>
/// <returns></returns>
internal protected static T GetOrAddExisting(string key, Func <T> itemFactory, TimeSpan expiration)
{
string qualifiedKey = QualifiedKey(key);
var value = RockCacheManager <T> .Instance.Cache.Get(qualifiedKey);
RockCache.UpdateCacheHitMiss(key, value != null);
if (value != null)
{
return(value);
}
if (itemFactory == null)
{
return(default(T));
}
value = itemFactory();
if (value != null)
{
UpdateCacheItem(key, value, expiration);
}
return(value);
}
static RockCacheManager()
{
RockCache.AddManager(Instance);
}