Make Producer.Send method also accept Message[] in addition to List<Message>

[plewam]

Hi All,

In my streaming system I internally work with arrays for faster access. However when I push to rmq streams I always have to convert my already existing array into a list by calling ToList().

await Producer.Send(streamMessage.ToList(), CompressionType.Gzip).ConfigureAwait(false);

As far as I understand it, it would only make sense for the batch feature.

Not a big deal, but more a smaller performance improvement.

[Gsantomaggio]

Hi @plewam thank you for reporting the question.

We can add it, but we would do the same ToList() conversion unless we add another publish command:

rabbitmq-stream-dotnet-client/RabbitMQ.Stream.Client/Publish.cs

Lines 33 to 54 in cf8c927

	public Publish(byte publisherId, List<(ulong, Message)> messages)
	{
	this.publisherId = publisherId;
	this.messages = messages;
	MessageCount = messages.Count;
	}
	public int Write(Span<byte> span)
	{
	var offset = WireFormatting.WriteUInt16(span, Key);
	offset += WireFormatting.WriteUInt16(span[offset..], Version);
	offset += WireFormatting.WriteByte(span[offset..], publisherId);
	// this assumes we never write an empty publish frame
	offset += WireFormatting.WriteInt32(span[offset..], MessageCount);
	foreach (var (publishingId, msg) in messages)
	{
	offset += WireFormatting.WriteUInt64(span[offset..], publishingId);
	// this only write "simple" messages, we assume msg is just the binary body
	// not stream encoded data
	offset += WireFormatting.WriteUInt32(span[offset..], (uint)msg.Size);
	offset += msg.Write(span[offset..]);
	}

I don't know the percentage of gain in terms of performance using an array instead of a List.

[plewam]

Ah I see, as you are not altering the list you could potentially use an array instead. This article provides a nice overview why the array is faster, https://www.bytehide.com/blog/array-vs-list-csharp

The main reason simply is the way faster access speed of an array vs. a list.

[Gsantomaggio]

I agree that an array can be faster than a List. I was wondering if this change has a real impact on stream the system.

• We currently have other issues to follow, but it would be helpful if you could make the change and report some benchmark results.

• Do you have performance problems?