lams-github

Till now we had "are-learners-answers-updated" polling on controller

level.

It was rewritten to following scenario:

- method which stores learner answers is aware whether answers have

changed, i.e. it knows if charts need to be updated

- it flushes latest data to DB and puts tool content ID to Sink

- Sink notifies all interested Fluxes (currently only charts updating

one, but in the future other ones like updating table with answer % too)

- FluxMap holds a map of tool content ID -> interested hot publisher

Flux

- the Flux checks if it is interested in the tool content ID from the

Sink

- if so, it fetches data from DB and emits it to all subscribers, i.e.

opened monitoring windows with charts displayed

- data is cached so it is immediately available on for the next

subscriber

- data is throttled so calls to DB are not made too often

- if all subscribers are gone, the hot publisher Flux is still active; a

timeout is added which removes it from FluxMap when there were not emits

for the given time Show less