Neat. This is very similar to [0], which is _not_ a cache but rather a complete mirror of an Etcd keyspace. It does Key/Value decoding up front, into a user-defined & validated runtime type, and promises to never mutate an existing instance (instead decoding into a new instance upon revision change).
The typical workflow is do do all of your "reads" out of the keyspace, attempt to apply Etcd transactions, and (if needed) block until your keyspace has caught up such that you read your write -- or someone else's conflicting write.
Drat! I went looking for people doing something similar when I sat down to design our client, but did not find your package. That's a real pity, I would love to have collaborated on this.
I guess Go package discovery remains an unsolved problem.
Slightly different trade-offs. This package is emphatically just "for" Etcd, choosing to directly expose MVCC types & concepts from the client.
It also doesn't wrap transactions -- you use the etcd client directly for that.
The Nagel delay it implements helps quite a bit with scaling, though, while keeping the benefits of a tightly packed sorted keyspace. And you can directly access / walk decoded state without copies.
I wish pkg.dev had a signin and option to star/watch a package. I do this with GitHub repos I should revisit. Would have been handy for pkg.dev :) yes, I know - nobody wants yet another login
