kevy-bytes 1.17.0

24-byte small-byte-string with inline SSO. Pure Rust.
Documentation 
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//! SmallBytes hot-path micro-bench. Pairs each operation against the closest
//! `Vec<u8>` baseline so the ratio is the headline number.
//!
//! `cargo run -p kevy-bytes --example bench_sso --release`

use kevy_bench::{bench, black_box, report};
use kevy_bytes::SmallBytes;

const SAMPLES: usize = 60;
const INNER: usize = 200_000;

fn main() {
    println!("kevy-bytes SmallBytes micro-bench — vs Vec<u8> baseline");
    println!("(ratios are the signal; absolutes drift on a loaded host)\n");

    // 12-byte payload: inline path (< 22 B threshold).
    let short = b"hello world!".to_vec();
    // 64-byte payload: heap path.
    let long: Vec<u8> = (0u8..64).collect();

    println!("== from_slice (construct from &[u8]) ==");
    let sb_short = bench(SAMPLES, INNER, || {
        black_box(SmallBytes::from_slice(black_box(&short)));
    });
    report("SmallBytes::from_slice (12B, inline)", sb_short);
    let vec_short = bench(SAMPLES, INNER, || {
        black_box(Vec::<u8>::from(black_box(short.as_slice())));
    });
    report("Vec::from           (12B)         ", vec_short);
    println!(
        "  ratio (Vec / SmallBytes inline) = {:.2}×\n",
        vec_short.median_ns as f64 / sb_short.median_ns as f64
    );

    let sb_long = bench(SAMPLES, INNER, || {
        black_box(SmallBytes::from_slice(black_box(&long)));
    });
    report("SmallBytes::from_slice (64B, heap) ", sb_long);
    let vec_long = bench(SAMPLES, INNER, || {
        black_box(Vec::<u8>::from(black_box(long.as_slice())));
    });
    report("Vec::from           (64B)         ", vec_long);

    println!("\n== clone (deep copy) ==");
    let sb12 = SmallBytes::from_slice(&short);
    let vec12 = short.clone();
    let cl_sb = bench(SAMPLES, INNER, || {
        black_box(black_box(&sb12).clone());
    });
    report("SmallBytes clone (12B, inline)    ", cl_sb);
    let cl_vec = bench(SAMPLES, INNER, || {
        black_box(black_box(&vec12).clone());
    });
    report("Vec clone        (12B)            ", cl_vec);
    println!(
        "  ratio (Vec / SmallBytes inline) = {:.2}×\n",
        cl_vec.median_ns as f64 / cl_sb.median_ns as f64
    );

    println!("== as_slice (read borrow; no alloc) ==");
    let sb_as = bench(SAMPLES, INNER, || {
        black_box(black_box(&sb12).as_slice());
    });
    report("SmallBytes as_slice (inline)      ", sb_as);
    let v_as = bench(SAMPLES, INNER, || {
        black_box(black_box(&vec12).as_slice());
    });
    report("Vec as_slice                      ", v_as);

    println!("\n== len ==");
    let sb_len = bench(SAMPLES, INNER, || {
        black_box(black_box(&sb12).len());
    });
    report("SmallBytes len   (inline)         ", sb_len);
    let v_len = bench(SAMPLES, INNER, || {
        black_box(black_box(&vec12).len());
    });
    report("Vec len                           ", v_len);
}