Cache

A module to help with creating an in-memory cache for ActivityPub objects. It stores objects under the IRI key of their ID.

It is used in various places where caching the objects makes sense, like the slower storage modules, or just as a memoisation mechanism.

Cache invalidation

One of the benefits of using this module as opposed to a generic LRU cache, is that it provides invalidation mechanisms specific for Objects and Activities.

As an example, if activity was updated, the cache can aggregate all the objects relevant to that activity (its Object, its Actor, etc) and do a cascade invalidation for all of them