pub fn sweep(
folder: &Path,
mine: &mut BTreeMap<String, i64>,
used: &BTreeSet<String>,
now_ms: i64,
)Expand description
The sealed files this device wrote that no record points to any more,
removed once that has lasted UNUSED_DAYS. mine holds when a record last
pointed to each (milliseconds), used the names records point to now, or
named lately. One whose file was made fresh lately (sealed again, named
again by another device) stays.