garage/src/util/async_hash.rs
2022-07-29 12:24:48 +02:00

64 lines
1.6 KiB
Rust

use bytes::Bytes;
use digest::Digest;
use tokio::sync::{mpsc, oneshot};
use tokio::task::JoinHandle;
use crate::data::*;
/// Compute the sha256 of a slice,
/// spawning on a tokio thread for CPU-intensive processing
/// The argument has to be an owned Bytes, as it is moved out to a new thread.
pub async fn async_sha256sum(data: Bytes) -> Hash {
tokio::task::spawn_blocking(move || sha256sum(&data))
.await
.unwrap()
}
/// Compute the blake2sum of a slice,
/// spawning on a tokio thread for CPU-intensive processing.
/// The argument has to be an owned Bytes, as it is moved out to a new thread.
pub async fn async_blake2sum(data: Bytes) -> Hash {
tokio::task::spawn_blocking(move || blake2sum(&data))
.await
.unwrap()
}
// ----
pub struct AsyncHasher<D: Digest> {
sendblk: mpsc::UnboundedSender<(Bytes, oneshot::Sender<()>)>,
task: JoinHandle<digest::Output<D>>,
}
impl<D: Digest> AsyncHasher<D> {
pub fn new() -> Self {
let (sendblk, mut recvblk) = mpsc::unbounded_channel::<(Bytes, oneshot::Sender<()>)>();
let task = tokio::task::spawn_blocking(move || {
let mut digest = D::new();
while let Some((blk, ch)) = recvblk.blocking_recv() {
digest.update(&blk[..]);
let _ = ch.send(());
}
digest.finalize()
});
Self { sendblk, task }
}
pub async fn update(&self, b: Bytes) {
let (tx, rx) = oneshot::channel();
self.sendblk.send((b, tx)).unwrap();
let _ = rx.await;
}
pub async fn finalize(self) -> digest::Output<D> {
drop(self.sendblk);
self.task.await.unwrap()
}
}
impl<D: Digest> Default for AsyncHasher<D> {
fn default() -> Self {
Self::new()
}
}