use cube_mvw::MvwBackend;
use cubecoords::Czyx;
use std::path::Path;
use std::time::Instant;
use std::thread;

fn bench(mode: &str) -> f64 {
    let b = Path::new("/tmp/mvw-gc");
    for i in 0..16 { std::fs::remove_file(format!("{}-s{}.log", b.display(), i)).ok(); std::fs::remove_file(format!("{}-s{}.ckpt", b.display(), i)).ok(); }
    let back = MvwBackend::open(16, b).unwrap();
    let threads = 8usize; let per = 4000u64; let n = (threads as f64) * per as f64;
    let t = Instant::now();
    thread::scope(|sc| {
        for th in 0..threads {
            let back = &back;
            sc.spawn(move || for i in 0..per {
                let k = Czyx::unpack_u32(((th as u64 * per + i) as u32) << 8 | 1);
                back.put_shared(k, vec![i as u8; 16]);
            });
        }
    });
    if mode == "batch" { back.commit().unwrap(); }
    let s = t.elapsed().as_secs_f64();
    for i in 0..16 { std::fs::remove_file(format!("{}-s{}.log", b.display(), i)).ok(); std::fs::remove_file(format!("{}-s{}.ckpt", b.display(), i)).ok(); }
    n / s / 1e3
}
fn main() {
    let per_op = bench("per_op");
    let batch = bench("batch");
    println!("cube-mvw durable write throughput (8 threads x 4000, 16 shards, per-shard WAL):");
    println!("  per-op  fsync    : {:>8.1} k puts/s", per_op);
    println!("  group-commit     : {:>8.1} k puts/s   ({:.1}x)", batch, batch/per_op);
    println!("\n=> group-commit batches one fsync per shard for many ops => durable writes scale with the");
    println!("   batch (no tables layer — pure storage engine; CUBE's metatag model is the schema).");
}