blake3_benchmark.rs

use blake3;
use sha2;
use rand;
use sha2::Digest;
use rand::RngCore;
use std::time::Duration;

const RUN_COUNT: usize = 10;
const HASH_DATA_SIZE: usize = 1024 * 1024 * 1024; // 1 GB

fn main() {
  let rand_data = {
    let mut rand_data: Vec<u8> = vec![0; HASH_DATA_SIZE];
    rand::thread_rng().fill_bytes(&mut rand_data);
    rand_data
  };

  let sha256_time = {
    let mut total = Duration::new(0, 0);
    for _ in 0..RUN_COUNT {
      let mut hasher = sha2::Sha256::new();
      let start = std::time::Instant::now();
      hasher.update(&rand_data);
      let hash = hasher.finalize();
      if hash.as_ptr() == 0 as *const u8 {
        panic!("This prevents `hash` from being optimized away.")
      }
      total += start.elapsed();
    }
    total
  };
  println!("sha256: {:?}", sha256_time);

  let blake3_time = {
    let mut total = Duration::new(0, 0);
    for _ in 0..RUN_COUNT{
      let mut hasher = blake3::Hasher::new();
      let start = std::time::Instant::now();
      hasher.update(&rand_data);
      let hash = hasher.finalize();
      if hash.as_bytes().as_ptr() == 0 as *const u8 {
        panic!("This prevents `hash` from being optimized away.")
      }
      total += start.elapsed();
    }
    total
  };
  println!("blake3: {:?}", blake3_time);

  println!("");
  println!("abs difference: {:?}", sha256_time - blake3_time);
  println!("% difference r: {:.2}%", (sha256_time.as_nanos() as f64 / blake3_time.as_nanos() as f64) * 100.0);
  println!("% difference i: {:.2}%", (blake3_time.as_nanos() as f64 / sha256_time.as_nanos() as f64) * 100.0);
}