#[macro_use]
extern crate criterion;
use criterion::{black_box, BenchmarkId, Criterion};

use pprof2::criterion::{Output, PProfProfiler};

// Thanks to the example provided by @jebbow in his article
// https://www.jibbow.com/posts/criterion-flamegraphs/

fn fibonacci(n: u64) -> u64 {
    match n {
        0 | 1 => 1,
        n => fibonacci(n - 1) + fibonacci(n - 2),
    }
}

fn bench(c: &mut Criterion) {
    c.bench_function("Fibonacci", |b| b.iter(|| fibonacci(black_box(20))));
}

fn bench_group(c: &mut Criterion) {
    let mut group = c.benchmark_group("Fibonacci Sizes");

    for s in &[1, 10, 100, 1000] {
        group.bench_with_input(BenchmarkId::from_parameter(s), s, |b, s| {
            b.iter(|| fibonacci(black_box(*s)))
        });
    }
}

criterion_group! {
    name = benches;
    config = Criterion::default().with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
    targets = bench, bench_group
}
criterion_main!(benches);