Struct Export 

pub struct Export {
    pub keys: u64,
    pub skipped: BTreeMap<Vec<u8>, u64>,
}

Run export — walk the keyspace (optionally under prefix) and write rebuild frames to out_path. Returns exported key count. What an export did — including what it did NOT do. The skipped map is the half that used to be invisible: a type with no rebuild verb produced no frames, no error and no mention, so a migration could report success while leaving a whole type behind.

Fields

keys: u64

Keys whose frames are in the file.

skipped: BTreeMap<Vec<u8>, u64>

Type name -> keys left out because nothing here rebuilds them.