Function batch_build_binary_rows

crates/paimon/src/spec/binary_row.rs:1106–1124

Build BinaryRows for all rows in the batch for the given field indices. Downcasts columns once, then iterates rows — O(F) downcasts instead of O(N*F).

(
    batch: &RecordBatch,
    field_indices: &[usize],
    fields: &[crate::spec::DataField],
)

/// Build BinaryRows for all rows in the batch for the given field indices.
/// Downcasts columns once, then iterates rows — O(F) downcasts instead of O(N*F).
fn batch_build_binary_rows(
    batch: &RecordBatch,
    field_indices: &[usize],
    fields: &[crate::spec::DataField],
) -> crate::Result<Vec<BinaryRow>> {
    let typed_columns = downcast_columns(batch, field_indices, fields)?;
    let arity = field_indices.len() as i32;
    let num_rows = batch.num_rows();
    let mut rows = Vec::with_capacity(num_rows);

    for row_idx in 0..num_rows {
        let mut builder = BinaryRowBuilder::new(arity);
        for (pos, (typed_col, field)) in typed_columns.iter().enumerate() {
            write_typed_value(&mut builder, pos, row_idx, typed_col, field.data_type());
        }
        rows.push(builder.build());
    }
    Ok(rows)
}

/// Batch-compute serialized partition bytes for all rows.
/// Returns one `Vec<u8>` per row, identical to calling