Create a LRU cache for resolved DidDocuments

[paullatzelsperger]

Feature Request

In the context of IATP, many things are based on DID documents, such as resolving key material, resolving service URLs (e.g. for the CredentialService), and possibly others.

In order to decrease the amount of network calls to resolve the DID document, we will implement a LRU cache, that the DidResolverRegistry uses.

Which Areas Would Be Affected?

identity-did-core

Why Is the Feature Desired?

Not all of the operations that require information extracted from a DID are done in the same place, and tunneling the did document through everywhere would introduce weird and incorrect dependencies in SPI modules.

Solution Proposal

Create a LRU cache based on a LinkedHashmap, cache DID documents, as it is safe to assume, that a DID document will be used multiple times in close temporal vicinity.