Question about additional type safety and performance

[AnthonyLloyd]

I'd like to use single field structs to eliminate primitive obsession. This doesn't lead to a performance hit in .NET. Is it possible for it to not have a performance hit in Orleans for method parameters? I've tried IConverter<Price, double> but it doesn't support primitives.

I'd also like to do the same for grain keys but I can't see how to do this easily without wrapping the IGrainFactory.

[ReubenBond]

@AnthonyLloyd There will be a small perf hit. I'm fairly sure the added complexity in the code generator to avoid that small perf cost is not worthwhile. You can craft your own codecs if you really want to, eg by copying DoubleCodec and modifying it to use Price instead. I don't think this is worthwhile, though, and if you ever add additional fields, you'd need to adjust your codec to handle that by checking the wire type and switching behavior.

As for grain keys, they should be UTF8 encoded strings so that they can be displayed in logs, traces, metrics, error messages, etc. You can create your own using GrainId.Create(type, key) and use the IGrainFactory overload which accepts a GrainId.

Here's an example of how to write your own codec & copier for a custom primitive wrapper:

[Immutable]
public readonly struct MyValueType(double value)
{
    public double Value { get; } = value;
}

[RegisterSerializer]
public sealed class MyValueTypeCodec : IFieldCodec<MyValueType>
{
    public void WriteField<TBufferWriter>(
        ref Writer<TBufferWriter> writer,
        uint fieldIdDelta,
        Type expectedType,
        MyValueType value)
        where TBufferWriter : IBufferWriter<byte>
    {
        ReferenceCodec.MarkValueField(writer.Session);
        writer.WriteFieldHeader(fieldIdDelta, expectedType, typeof(MyValueType), WireType.Fixed64);
        writer.WriteUInt64(BitConverter.DoubleToUInt64Bits(value.Value));
    }

    public MyValueType ReadValue<TInput>(ref Reader<TInput> reader, Field field)
    {
        ReferenceCodec.MarkValueField(reader.Session);
        return new(BitConverter.UInt64BitsToDouble(reader.ReadUInt64()));
    }
}

[RegisterCopier]
public sealed class MyValueTypeCopier : IDeepCopier<MyValueType>
{
    public MyValueType DeepCopy(MyValueType input, CopyContext context) => input;
}

[AnthonyLloyd]

Many thanks. It looks like something I could test at a later stage.