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hyperledger / anoncreds-rs

anoncreds-rs
https://wiki.hyperledger.org/display/anoncreds
Apache License 2.0
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FFI_OBJECTS can become an issue for the JavaScript wrapper. #73

Open berendsliedrecht opened 1 year ago

berendsliedrecht commented 1 year ago

Right now, the anoncreds library has a static hash map to keep all the anoncreds objects, and their associated handle, in memory for access later on. This works fine for languages with a deconstructor, but can be very tedious in languages without a deconstructor, like JavaScript.

We (@TimoGlastra and I) were wondering if it makes sense to just pass a stringified JSON into the library which would remove this issue entirely. It does make referencing a previous anoncreds object a bit more annoying, but it would prevent any unwanted memory leaks.

Timo also mentioned that this is how the indy-sdk has done it. Was there a specific reason why anoncreds derived from that?

cc: @andrewwhitehead @TimoGlastra

andrewwhitehead commented 1 year ago

Wouldn't you have the same issue passing in a string, in that the buffer needs to be freed afterward?

berendsliedrecht commented 1 year ago

Wouldn't you have the same issue passing in a string, in that the buffer needs to be freed afterward?

That would be handled by the GC of the JavaScript runtime. So with the string, once it's out-of-scope (or however the GCs in V8 work) it will be freed but we cannot give a method that should be called when the anoncreds object class, which contains the handle, gets garbage collected. I believe there are some RFCs open for this issue, but it won't be added anytime soon.