Struct SlotFetch 

pub struct SlotFetch {
    pub found: bool,
    pub data: Option<Vec<u8>>,
    pub lsn: u64,
    pub slot_index: usize,
    pub bin_arc: Arc<RwLock<TreeNode>>,
}

Combined search result carrying slot data and the BIN arc, returned by Tree::search_with_data.

Avoids the double-descent pattern where Tree::search checked key existence and a second call re-descended to fetch the actual slot bytes. One descent now serves both purposes (Wave-11-I optimisation).

Fields

found: bool

true if an exact key match was found and is not expired.

data: Option<Vec<u8>>

Data bytes for the slot (None when found is false).

lsn: u64

Raw slot LSN as u64; zero when found is false.

slot_index: usize

Slot index within the BIN. Set to the actual BIN slot index when found is true; 0 otherwise.

Used by CursorImpl to set current_index correctly so that retrieve_next advances to the right slot after a search.

bin_arc: Arc<RwLock<TreeNode>>

Arc to the BIN that the descent reached. Always Some when the tree has at least one node, regardless of whether found is true.