Get when absent
Cache when gotten (with arrival time)
Track last accessed time.
Size limited cache (configuration param)
Stale time i.e. when to throw it out and get new regardless of popularity (configuration param)
Purge function - Dump the 20% of nodes that have been accessed the least recently.
I said this was complete on the 3.11-3.17.19 status report even though it was not closed since the plan is to merge today or tomorrow (Sun or Mon). But I don’t want to close the ticket since that’s kinds of a distraction.