smartcache.cs

public interface IStateHolderGrain<T> : IGrainWithGuidKey
{
    Task<T> GetItem();
    Task<T> SetItem(T obj);
}

public class StateHolder<T>
{
    public StateHolder() : this(default(T))
    {
    }

    public StateHolder(T value)
    {
        Value = value;
    }

    public T Value { get; set; }
}

public abstract class StateHolderGrain<T> : Grain<StateHolder<T>>,
    IStateHolderGrain<T>
{
    public Task<T> GetItem()
    {
        return Task.FromResult(State.Value);
    }

    public async Task<T> SetItem(T item)
    {
        State.Value = item;
        await WriteStateAsync();

        return State.Value;
    }
}