MessageStoreUse.cs

public class Global : System.Web.HttpApplication {
    protected void Application_Start(object sender, EventArgs e) {
        var store = new SmartMessageStore();
        DependencyResolver.Register(typeof(IMessageStore), () => store);
    }
}

SmartMessageStore.cs

public class SmartMessageStore : IMessageStore {
    private readonly IMessageStore _store = new InProcessMessageStore();

    public Task<IEnumerable<Message>> GetAll(string key) {
        return _store.GetAll(key);
    }

    public Task<IEnumerable<Message>> GetAllSince(string key, long id) {
        return GetLastId().ContinueWith(t => {
            if (t.Result.HasValue) {
                id = Math.Min(id, t.Result.Value - 1);
            }
            return _store.GetAllSince(key, id);
        }).Unwrap();
    }

    public Task<long?> GetLastId() {
        return _store.GetLastId();
    }

    public Task Save(string key, object value) {
        return _store.Save(key, value);
    }
}