pub async fn watch_events(pool: PgPool, wake: Arc<Sender<u64>>)Expand description
Turn database notifications into wake-ups, until the daemon stops.
The published value is a counter, not a watermark: subscriptions re-read from their own cursors anyway, so all this has to carry is “something changed”. A counter is always different from the last one, which means a receiver can never mistake two appends for one.
A listener that cannot connect or that dies is not fatal, and deliberately
so — it degrades a subscription from milliseconds to
SUBSCRIPTION_POLL_SECS, and a kernel that refused to serve at all
because its notification channel was unavailable would be trading a slower
stream for no stream.