refactor(router/atc): remove unnecessary tb_nkeys()

[chronolaw]

Summary

KAG-4138

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

Fix #[issue number]

[chronolaw]

I checked the code in runloop/handler, the item in route_and_service array should always has two elements,
do we really need this assert? I think that removing this check will get some speed improvement.

@hanshuebner , I think that you introduced this check before, do you have some opnions?

[bungle]

I checked the code in runloop/handler, the item in route_and_service array should always has two elements, do we really need this assert? I think that removing this check will get some speed improvement.

@hanshuebner , I think that you introduced this check before, do you have some opnions?

Yes, I was wondering the same. We have a lot of other places in code too where we have asserts like we don’t trust the input (here it happens in a loop). If we error here it leads most probably to issue where router is never build, but we have cleaner error message. But this probably never happens.

I would say that if you have 10000 routes and one of then errors in this, it is still better to have new router. Thus logging this rare/imposdible case would be softer, but I am fine removing it altogether.

[hanshuebner]

The assert is there for robustness. It fulfills no functional purpose and my expectation was that the performance impact was negligible.

[chronolaw]

Though table.nkey() is fast and JITable, but it will be run many times in the loop, I think removing it should be acceptable.

[ADD-SP]

The function split_routes_and_services_by_path was called when rebuilding router, this is not the hot path when proxying.

Doing this kind of assertion for robustness when rebuilding router is acceptable for me.

[chronolaw]

�Close due to ADD-SP's comment