The built-in in-memory cache backed by :persistent_term.

Every HGT file is stored under its own key, so adding one neither rewrites the rest of the cache nor triggers a global garbage collection. Erasing a key does, and purge/0 erases one per cached file:

• All processes in the system will be scheduled to run a scan of their heaps for the term that has been erased. While such scan is relatively light-weight, if there are many processes, the system can become less responsive until all processes have scanned their heaps.

• If the erased term is still used by a process, that process will do a major (fullsweep) garbage collection and copy the term into the process. However, at most two processes at a time will be scheduled to do that kind of garbage collection.

See the persistent_term docs for further information.