Struct and aggregate actors

Struct messages

Use the struct interfaces and SpawnStruct when request or response messages are value types:

public readonly record struct Add(int Left, int Right);
public readonly record struct Sum(int Value);

public sealed class CalculatorActor : IActorStruct<Add, Sum>
{
    public Task<Sum> Receive(Add message) =>
        Task.FromResult(new Sum(message.Left + message.Right));
}

IActorRefStruct<CalculatorActor, Add, Sum> calculator =
    system.SpawnStruct<CalculatorActor, Add, Sum>();

Sum sum = await calculator.Ask(new Add(2, 3));

Aggregate actors

Aggregate actors receive queued requests in batches. They are useful when processing many items together is cheaper than paying the per-item cost:

public sealed class BatchWriter : IActorAggregate<WriteItem>
{
    public Task Receive(List<WriteItem> messages) => storage.WriteBatch(messages);
}

IActorRefAggregate<BatchWriter, WriteItem> writer =
    system.SpawnAggregate<BatchWriter, WriteItem>();

Aggregate request/response actors implement IActorAggregate<TRequest, TResponse> and receive a List<ActorMessageReply<TRequest, TResponse>>, allowing each request to complete its own reply.