internal void RollbackState()
{
if (previousState != null)
{
TotalItemCount = previousState.TotalItemCount;
IsLoaded = previousState.IsLoaded;
var fetchedKeys = FetchedKeys;
InitializeFetchedKeys();
InitializeDifferenceCollections();
foreach (var fetchedKey in fetchedKeys)
{
FetchedKeys.Add(fetchedKey);
}
foreach (var addedKey in previousState.AddedKeys)
{
if (fetchedKeys.ContainsKey(addedKey))
{
FetchedKeys.Remove(addedKey);
}
addedKeys.Add(addedKey, addedKey);
}
foreach (var removedKey in previousState.RemovedKeys)
{
if (!FetchedKeys.ContainsKey(removedKey))
{
FetchedKeys.Add(removedKey);
}
removedKeys.Add(removedKey, removedKey);
}
}
}
/// <summary>
/// Determines whether cached state contains specified item.
/// </summary>
/// <param name="key">The key.</param>
/// <returns>Check result.</returns>
public bool Contains(Key key)
{
if (removedKeys.ContainsKey(key))
{
return(false);
}
if (addedKeys.ContainsKey(key))
{
return(true);
}
if (FetchedKeys.ContainsKey(key))
{
return(true);
}
return(false);
}