[Go] no zero-copy?

[asido]

I generated Go code and see there is no Wrap() method. Instead, there is Encode(io.Reader), which fetches and assigns all values to public fields in the model. Is there no zero-copy alternative in Go, that allows to read the data in-place?

[neomantra]

This is correct. The current Go implementation takes raw SBE message and creates a fully-formed Golang struct from it and thus every field is marshaled.

The reasoning behind this is described here:
https://github.com/real-logic/simple-binary-encoding/wiki/Golang-User-Guide#golang-idioms

This design prioritizes easy-to-use and hard-to-misuse over performance. It should be possible to make a zero-copy / flyweight generator if someone were up to the task.

[matthewdowney]

@ethanf curious if your impl ended up looking promising?

[ethanf]

@ethanf curious if your impl ended up looking promising?

I've updated https://github.com/ethanf/simple-binary-encoding/tree/go-flyweight with the latest code. It's code complete and mostly works, but there's still work to do updating the tests unfortunately.

[ethanf]

https://github.com/ethanf/simple-binary-encoding/tree/go-flyweight has passing tests now, does anyone have a preference for how to switch between the flyweight and struct versions of the generated code? Is a system property that switches between the generators acceptable?

[neomantra]

Thanks for your contribution! I only started looking at it and will take it for a spin in a few weeks.

I do think that using system properties like that is consistent with other SBE / Aeron tool options.