arrow2 0.9.1

use std::sync::Arc;

use criterion::{criterion_group, criterion_main, Criterion};

use arrow2::array::*;
use arrow2::chunk::Chunk;
use arrow2::error::Result;
use arrow2::io::json::write;
use arrow2::util::bench_util::*;

fn write_batch(columns: &Chunk<Arc<dyn Array>>) -> Result<()> {
    let mut writer = vec![];
    let format = write::JsonArray::default();

    let batches = vec![Ok(columns.clone())].into_iter();

    // Advancing this iterator serializes the next batch to its internal buffer (i.e. CPU-bounded)
    let blocks = write::Serializer::new(batches, vec!["c1".to_string()], vec![], format);

    // the operation of writing is IO-bounded.
    write::write(&mut writer, format, blocks)?;

    Ok(())
}

fn make_chunk(array: impl Array + 'static) -> Chunk<Arc<dyn Array>> {
    Chunk::new(vec![Arc::new(array) as Arc<dyn Array>])
}

fn add_benchmark(c: &mut Criterion) {
    (10..=18).step_by(2).for_each(|log2_size| {
        let size = 2usize.pow(log2_size);

        let array = create_primitive_array::<i32>(size, 0.1);
        let columns = make_chunk(array);

        c.bench_function(&format!("json write i32 2^{}", log2_size), |b| {
            b.iter(|| write_batch(&columns))
        });

        let array = create_string_array::<i32>(size, 100, 0.1, 42);
        let columns = make_chunk(array);

        c.bench_function(&format!("json write utf8 2^{}", log2_size), |b| {
            b.iter(|| write_batch(&columns))
        });

        let array = create_primitive_array::<f64>(size, 0.1);
        let columns = make_chunk(array);

        c.bench_function(&format!("json write f64 2^{}", log2_size), |b| {
            b.iter(|| write_batch(&columns))
        });
    });
}

criterion_group!(benches, add_benchmark);
criterion_main!(benches);