arrow 3.0.0

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// to you under the Apache License, Version 2.0 (the
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// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#[macro_use]
extern crate criterion;
use criterion::Criterion;

use rand::distributions::Alphanumeric;
use rand::Rng;

use std::sync::Arc;

extern crate arrow;

use arrow::array::*;
use arrow::util::test_util::seedable_rng;

fn create_strings(size: usize, null_density: f32) -> ArrayRef {
    let rng = &mut seedable_rng();

    let mut builder = StringBuilder::new(size);
    for _ in 0..size {
        let x = rng.gen::<f32>();
        if x < null_density {
            let value = rng.sample_iter(&Alphanumeric).take(4).collect::<String>();
            builder.append_value(&value).unwrap();
        } else {
            builder.append_null().unwrap()
        }
    }
    Arc::new(builder.finish())
}

fn create_slices(size: usize) -> Vec<(usize, usize)> {
    let rng = &mut seedable_rng();

    (0..size)
        .map(|_| {
            let start = rng.gen_range(0, size / 2);
            let end = rng.gen_range(start + 1, size);
            (start, end)
        })
        .collect()
}

fn bench(v1: &ArrayRef, slices: &[(usize, usize)]) {
    let mut mutable = MutableArrayData::new(vec![v1.data_ref()], false, 5);
    for (start, end) in slices {
        mutable.extend(0, *start, *end)
    }
    mutable.freeze();
}

fn add_benchmark(c: &mut Criterion) {
    let v1 = create_strings(1024, 0.0);
    let v2 = create_slices(1024);
    c.bench_function("mutable str 1024", |b| b.iter(|| bench(&v1, &v2)));

    let v1 = create_strings(1024, 0.5);
    let v2 = create_slices(1024);
    c.bench_function("mutable str nulls 1024", |b| b.iter(|| bench(&v1, &v2)));
}

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