Write API for Scala seems to be missing

[ioreskovic]

Write API for Scala seems to be missing. Is that a deliberate choice or an oversight?

I case of former, is it still in development, and if so, what is the Akka-friendly alternative?

[bednar]

Hi @ioreskovic,

We currently don't have implemented the write API in Scala. We want to have a Akka-friendly Write API and I hope so that we will have an enough time to implemented soon.

Could you describe your requirements? It will help us to implement what users want.

Regards

[ioreskovic]

Thank you for your response @bednar!

Well, looking at other use cases within alpakka connectors, I would like to see something along these lines:

• A plain sink, which may or may not do under the hood batching: Sink[Point[T], Future[WriteResult]] where WriteResult would be an indicator of an operation, perhaps Done is a good starting candidate if no other information is to be transmitted

• An explicit batched sink: Sink[Seq[Point[T]], Future[WriteResult]]

• A simple flow: Flow[Point[T], WriteResult, Mat] where this WriteResult could be different from the one in sink, here perhaps carrying more information, such as input + response

• Batched flow Flow[Seq[Point[T]], WriteResult, Mat] with "atomicity" guarantees with a batch, meaning if the input (Seq[Point[T]]) has passed through the flow, then all the elements have been written (or submitted to writing, depending on which delivery guarantees are used)

• Flow with context FlowWithContext[Point[T], C, WriteResult, C, Mat]

• Batched flow with context FlowWithContext[Seq[Point[T]], C, WriteResults, C, Mat]

Edit: Looking at alpakka-kafka, a unifying type such as Envelope a = Single a | Multi [a] | PassThrough (and their corresponding responses) might be more ergonomic, and then simple and batched flow(withContext) and could be replaced with a "flexiFlow(withContext)": Flow[Envelope[T, PT], Results[T, PT], Mat]

[bednar]

@ioreskovic thanks for detail info. It is huge inspiration for us! Thanks again.

[funston]

might consider changing the README to take out that write is supported?

"The reference Scala client that allows query and write for the InfluxDB 2.0 by Akka Streams."