fn adopted_measurement(
passed: Option<BaseMeasurement>,
latest: Option<BaseMeasurement>,
scan_started: Instant,
) -> Option<BaseMeasurement>Expand description
The base measurement a scan adopts: the one its caller passed, else the checkout’s latest when that was established before the scan began.
A measurement that lands while the tree is being read is not this scan’s own: it describes a ref the row’s count and files may predate, so the next pass carries it, read against it. A caller’s own answer is never filtered - a drawing read’s refresh is the check that read exists to make.