Streaming file

[Paul-Vandell]

Hi there,
amazing lib gread job here.

Would like to not used the serve static file but more having a dynamic file serving. But can't figure out with a simple file serving by streaming an opened file into the response.
I mean just a kind of route files/<id>/view where i can just stream the previous saved file from the hard drive.
I saw a ResBody::Stream() which require a futures util stream but can't figure out from an opened tokio::io file into the required stream.
I saw a nice way from axum here tokio-rs/axum#608 (comment).
Should i try with this example https://github.com/hyperium/hyper/blob/master/examples/send_file.rs but seams to be more in one chunk instead of a stream.

Does this example is the correct way or do we have a better way ?

    let mut file = tokio::fs::File::open("image_path.png"))
    .await
    .unwrap();
    let mut contents = vec![];
    file.read_to_end(&mut contents).await.unwrap();
    let t = ResBody::Once(contents.into());
    res.set_body(t);
    res.add_header("Content-Type", "image/png", true).unwrap();

What should be your best way here ? Thx in advance.

[chrislearn]

Try this:

#[handler]
async fn hello(res: &mut Response) {
    let file = tokio::fs::File::open("Cargo.toml").await.unwrap();
    let stream = ReaderStream::new(file);

    res.add_header(header::CONTENT_TYPE, "text/toml; charset=utf-8", true);
    res.add_header(header::CONTENT_DISPOSITION,   "attachment; filename=\"Cargo.toml\"", true);
    res.streaming(stream);
}

Or you can just use NamedFiile.

[Paul-Vandell]

Sorry did'nt see the NamedFiled, Amazing thx a lot. :)

[Paul-Vandell]

@chrislearn after testing both, the NamedFile is 4 time faster than using the ReaderStream & StaticFile solution. Do you know where the diff come from ?

[chrislearn]

I'm not sure, maybe tokio File read file with very small size.