private TReturnType ReadAllCache <TReturnType>(Func <IDictionary <string, T>, TReturnType> func)
{
_cacheLock.EnterReadLock();
try
{
var cache = MemoryCache.Default;
var lastChange = _cacheProvider.LastChanged;
var savedLastChange = cache[_cacheUpdateNumberKey] as long?;
if (cache[_cacheKey] is IDictionary <string, T> result && savedLastChange == lastChange)
{
return(func(result));
}
var data = cache[_cacheKey] as IDictionary <string, T>;
if (_cacheProvider is IPersistentCacheProviderEx <T> _cacheProviderWithDelta &&
savedLastChange != null && data != null)
{
var(replacedItemsIdentifiers, updatedItems, lastUpdate) =
_cacheProviderWithDelta.GetDelta(savedLastChange);
ApplyDelta(data, replacedItemsIdentifiers, updatedItems);
SetCache(cache, lastUpdate);
}
else
{
data = _cacheProvider.GetAllCachedItems();
lastChange = _cacheProvider.LastChanged;
SetCache(cache, data, lastChange);
}
return(func(data));
}
finally
{
_cacheLock.ExitReadLock();
}
}
