pub fn effective_ceiling(
recorded: Option<f64>,
sent: Option<f64>,
) -> Option<f64>Expand description
The ceiling a call works under, and the batch’s recorded ceiling from
then on: the lower of the ceiling recorded so far and the one this call
carries. None when neither names one.
The recorded ceiling is not fixed at first admission. A runner records
this value durably before the call sends anything, so after any call the
recorded ceiling is effective_ceiling(recorded, sent). That is what
makes a tightening stick: a later re-send carrying the original, higher
value works under the lower one, and a caller can tighten a batch’s
ceiling but never loosen it.