commonware-storage 2026.4.0

use commonware_cryptography::{sha256, Sha256};
use commonware_math::algebra::Random as _;
use commonware_storage::merkle::{self, mem::Mem, Family, Location};
use criterion::{criterion_group, Criterion};
use futures::executor::block_on;
use rand::{rngs::StdRng, seq::SliceRandom, SeedableRng};

type StandardHasher<H> = merkle::hasher::Standard<H>;

const SAMPLE_SIZE: usize = 100;

#[cfg(not(full_bench))]
const N_LEAVES: [usize; 2] = [10_000, 100_000];
#[cfg(full_bench)]
const N_LEAVES: [usize; 5] = [10_000, 100_000, 1_000_000, 5_000_000, 10_000_000];

fn bench_prove_single_element_family<F: Family>(c: &mut Criterion, family: &str) {
    for n in N_LEAVES {
        let hasher = StandardHasher::<Sha256>::new();
        let mut mem = Mem::<F, _>::new(&hasher);
        let mut elements = Vec::with_capacity(n);
        let mut sampler = StdRng::seed_from_u64(0);
        block_on(async {
            let batch = {
                let mut batch = mem.new_batch();
                for i in 0..n {
                    let element = sha256::Digest::random(&mut sampler);
                    batch = batch.add(&hasher, &element);
                    elements.push((i, element));
                }
                batch.merkleize(&mem, &hasher)
            };
            mem.apply_batch(&batch).unwrap();
        });
        let root = *mem.root();

        // Select SAMPLE_SIZE random elements without replacement and create/verify proofs
        c.bench_function(
            &format!(
                "{}/n={n} samples={SAMPLE_SIZE} family={family}",
                module_path!(),
            ),
            |b| {
                b.iter_batched(
                    || {
                        elements
                            .choose_multiple(&mut sampler, SAMPLE_SIZE)
                            .cloned()
                            .map(|(loc, element)| (Location::<F>::new(loc as u64), element))
                            .collect::<Vec<_>>()
                    },
                    |samples| {
                        block_on(async {
                            let hasher = StandardHasher::<Sha256>::new();
                            for (loc, element) in samples {
                                let proof = mem.proof(&hasher, loc).unwrap();
                                assert!(
                                    proof.verify_element_inclusion(&hasher, &element, loc, &root)
                                );
                            }
                        });
                    },
                    criterion::BatchSize::SmallInput,
                )
            },
        );
    }
}

fn bench_prove_single_element(c: &mut Criterion) {
    bench_prove_single_element_family::<commonware_storage::mmr::Family>(c, "mmr");
    bench_prove_single_element_family::<commonware_storage::mmb::Family>(c, "mmb");
}

criterion_group! {
    name = benches;
    config = Criterion::default().sample_size(10);
    targets = bench_prove_single_element
}