fix panic of concurrent map writes, when using in memory mode

[kom0055]

#1306 fix panic of concurrent map writes, when using in memory mode

[paralin]

Doesn't this generic map type exists somewhere else already that we can import from?

[zachmu]

Doesn't this generic map type exists somewhere else already that we can import from?

Unfortunately not, this is a gap in the standard golang libraries at the moment. Various third party packages implement one but it's easy to enough to write your own like this.

[zachmu]

Thanks for the contribution. This PR looks fine, but please understand that this by itself doesn't make the in-memory implementation thread-safe. There's still no transaction support or row locking, which is necessary for true concurrency. This may work for some limited use cases but it's not a general solution to concurrency.

[zachmu]

I had to merge main to correct a testing issue on our end. New PR is here:

#2185