Concurrent access from multiple instances

[pardeike]

Concurrent access from multiple instances

[nevir]

I don't know if hermes will really solve this for you (no more than any other pure-JS cache implementation would, at least). Hermes (and Apollo's default implementation) load the entire cache into the memory; there's no back and forth with the disk beyond that point.

Since, AFAIK, you can't perform RPC between iOS apps: you would need to serialize the cache to disk (in a shared location, like one managed via an app group) when switching between apps.

I'm also assuming you're in a react native world? The other unfortunate reality is that shuffling data along RN's bridge is pretty expensive, so you want to minimize the amount of time spent hydrating/dehydrating cache data.

Due to all that, I don't think concurrent access is really feasible with hermes :(

That said, it might be feasible to refactor hermes to track diffs between past "save points", so that you can minimize the time spent saving/restoring state between app switches. Synchronizing those deltas across multiple apps might get tricky, though.