//! Streaming file digests used by downloads, transfers and backups.

use sha2::{Digest, Sha256, Sha512};
use std::io::Read;
use std::path::Path;

fn digest_file<D: Digest>(path: &Path) -> std::io::Result<String> {
    let mut file = std::fs::File::open(path)?;
    let mut hasher = D::new();
    let mut buffer = vec![0u8; 256 * 1024];
    loop {
        let n = file.read(&mut buffer)?;
        if n == 0 {
            break;
        }
        hasher.update(&buffer[..n]);
    }
    Ok(hex::encode(hasher.finalize()))
}

pub fn sha256_file(path: &Path) -> std::io::Result<String> {
    digest_file::<Sha256>(path)
}

pub fn sha512_file(path: &Path) -> std::io::Result<String> {
    digest_file::<Sha512>(path)
}