Two related fixes so the main map reliably picks up new binary
propagation score files as soon as PropagationGridWorker writes them.
1. Propagation.available_valid_times/1 previously preferred ScoreCache
over ScoresFile, using the cache as an index of what was available.
The cache is a lazy ETS of whatever hours have been fetched or
broadcast, which is a strict subset of what's on disk. A new
forecast hour landing on disk while the cache was warm with older
entries was invisible to the timeline until the cache happened to
catch up. Read directly from ScoresFile so the disk store is the
source of truth.
2. Add Propagation.scores_at_fresh/3 that always reads the .ntms file
and overwrites the cache entry, and use it from MapLive's
propagation_updated handler. PropagationGridWorker publishes the
cache_refresh on `propagation:cache` and the timeline ping on
`propagation:updated` as separate PubSub broadcasts, so by the time
MapLive runs through scores_at the ScoreCache GenServer may not
have processed the refresh yet — fetch_bounds then returns the
previous chain's bytes. scores_at_fresh takes disk as the source
of truth for the refresh path and warms the cache as a side effect
so subsequent readers see the new data.
Graham McIntire
2d9e5a2d1f