Function route_checkpointed_batch 

pub fn route_checkpointed_batch(
    batch: &RecordBatch,
    row_vnodes: &[u32],
    assignment: &VnodeAssignmentSnapshot,
    self_id: NodeId,
) -> Result<CheckpointRoutePlan, ShuffleRoutingError>

Build a complete local/remote plan from one caller-pinned assignment.

Every input row is assigned exactly once or the whole call fails. Remote batches carry vnode ownership out-of-band; user schemas, including a user field named __laminar_vnode, are never rewritten.

Errors

Returns before producing a plan for malformed metadata, unassigned/out-of-range vnodes, Arrow slicing failures, or a single row above the receiver’s hard decoded-memory bound.