Function synth_rows

src/clusterd-test-driver/src/data.rs:122–130

Generate `n` synthetic rows for `desc`, with row indices running `start..start + n`. Successive batches over disjoint index ranges produce distinct rows that never consolidate, so a downstream count equals the total rows written (provided the schema carries a wide-enough column; see [`synth_cell`]).

(desc: &RelationDesc, start: u64, n: u64, pad: usize)

/// consolidate, so a downstream count equals the total rows written (provided the
/// schema carries a wide-enough column; see [`synth_cell`]).
pub fn synth_rows(desc: &RelationDesc, start: u64, n: u64, pad: usize) -> Vec<Row> {
    let types: Vec<SqlScalarType> = desc.iter_types().map(|c| c.scalar_type.clone()).collect();
    (start..start + n)
        .map(|i| {
            let cells: Vec<Cell> = types.iter().map(|t| synth_cell(t, i, pad)).collect();
            pack_cells(&cells)
        })
        .collect()
}

/// Builds `n` rows of the [`sample_desc`] schema; `payload` is `pad` bytes wide so
/// callers can target a byte budget (≈ `n * (pad + overhead)`).