real-logic
[Go] no zero-copy?
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?
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.
@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.
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?
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.