fn criterion_benchmark()

in native/spark-expr/benches/conditional.rs [44:136]
84 lines of code
10 McCabe index (conditional complexity)

fn criterion_benchmark(c: &mut Criterion) {
    // create input data
    let mut c1 = Int32Builder::new();
    let mut c2 = StringBuilder::new();
    let mut c3 = StringBuilder::new();
    for i in 0..1000 {
        c1.append_value(i);
        if i % 7 == 0 {
            c2.append_null();
        } else {
            c2.append_value(format!("string {i}"));
        }
        if i % 9 == 0 {
            c3.append_null();
        } else {
            c3.append_value(format!("other string {i}"));
        }
    }
    let c1 = Arc::new(c1.finish());
    let c2 = Arc::new(c2.finish());
    let c3 = Arc::new(c3.finish());
    let schema = Schema::new(vec![
        Field::new("c1", DataType::Int32, true),
        Field::new("c2", DataType::Utf8, true),
        Field::new("c3", DataType::Utf8, true),
    ]);
    let batch = RecordBatch::try_new(Arc::new(schema), vec![c1, c2, c3]).unwrap();

    // use same predicate for all benchmarks
    let predicate = Arc::new(BinaryExpr::new(
        make_col("c1", 0),
        Operator::LtEq,
        make_lit_i32(500),
    ));

    // CASE WHEN c1 <= 500 THEN 1 ELSE 0 END
    c.bench_function("case_when: scalar or scalar", |b| {
        let expr = Arc::new(
            CaseExpr::try_new(
                None,
                vec![(predicate.clone(), make_lit_i32(1))],
                Some(make_lit_i32(0)),
            )
            .unwrap(),
        );
        b.iter(|| black_box(expr.evaluate(black_box(&batch)).unwrap()))
    });
    c.bench_function("if: scalar or scalar", |b| {
        let expr = Arc::new(IfExpr::new(
            predicate.clone(),
            make_lit_i32(1),
            make_lit_i32(0),
        ));
        b.iter(|| black_box(expr.evaluate(black_box(&batch)).unwrap()))
    });

    // CASE WHEN c1 <= 500 THEN c2 [ELSE NULL] END
    c.bench_function("case_when: column or null", |b| {
        let expr = Arc::new(
            CaseExpr::try_new(None, vec![(predicate.clone(), make_col("c2", 1))], None).unwrap(),
        );
        b.iter(|| black_box(expr.evaluate(black_box(&batch)).unwrap()))
    });
    c.bench_function("if: column or null", |b| {
        let expr = Arc::new(IfExpr::new(
            predicate.clone(),
            make_col("c2", 1),
            make_null_lit(),
        ));
        b.iter(|| black_box(expr.evaluate(black_box(&batch)).unwrap()))
    });

    // CASE WHEN c1 <= 500 THEN c2 ELSE c3 END
    c.bench_function("case_when: expr or expr", |b| {
        let expr = Arc::new(
            CaseExpr::try_new(
                None,
                vec![(predicate.clone(), make_col("c2", 1))],
                Some(make_col("c3", 2)),
            )
            .unwrap(),
        );
        b.iter(|| black_box(expr.evaluate(black_box(&batch)).unwrap()))
    });
    c.bench_function("if: expr or expr", |b| {
        let expr = Arc::new(IfExpr::new(
            predicate.clone(),
            make_col("c2", 1),
            make_col("c3", 2),
        ));
        b.iter(|| black_box(expr.evaluate(black_box(&batch)).unwrap()))
    });
}