Session Registry

[IslandUsurper]

eipmi:get_session/2 used a list comprehension to find the right PID associated with an IPMI session. This got unacceptably slow when we tried to maintain connections to even a dozen different servers. (We hope to be able to scale to hundreds.) This PR associates the PID to the session in an ETS table, which has constant-time lookup instead of the linear-time of lists.

Note: the ETS table definition uses {write_concurrency, auto} which didn't appear until OTP 25. I know this is an important option for our use-case, but I don't know about generally. I updated the CI parameters accordingly, but if this isn't something you want to support, we can figure that out.

[schlagert]

Thanks again for the contribution. Looks good to me at first glance (as always 😉). I'll have a closer look today.

[schlagert]

I really would like to keep OTP-24 compatibility. I think a good compromise would be to try to create the ETS table with the new option and if that fails falling back to creation without the new option. I will merge the PR and make the necessary change in a separate commit.

[schlagert]

Do you need a release of this feature on hex.pm in the near future?

[IslandUsurper]

I believe {write_concurrency, true} works on OTP 24 if you want to fallback to that when auto doesn't work.

A hex.pm release would be appreciated, but we can use my GitHub branch until then. It's just nicer not to have git: deps in mix.exs.

[IslandUsurper]

Hi, @schlagert. What would be the timeframe for getting a new version on hex.pm? My manager doesn't like having git deps anywhere.

[schlagert]

Hi, I'll try to get this done this week.

[schlagert]

I have made the new version available on hex.pm.