post - 是否可以在使用 Actix-Multipart 完全传输大型 POST 请求之前发送响应？

Question

我正在查看actix-multipart 示例，并且有很多阻塞文件 IO。是否可以在下载文件之前发送响应？多部分不是Send。我想做这样的事情：

async fn save_file(mut payload: Multipart) -> Result<HttpResponse, Error> {
    async_std::task::spawn(async {
        // iterate over multipart stream
        while let Some(item) = payload.next().await {
            let mut field = item?;
            let content_type = field.content_disposition().unwrap();
            let filename = content_type.get_filename().unwrap();
            let filepath = format!("./tmp/{}", filename);
            // File::create is blocking operation, use threadpool
            let mut f = web::block(|| std::fs::File::create(filepath))
                .await
                .unwrap();
            // Field in turn is stream of *Bytes* object
            while let Some(chunk) = field.next().await {
                let data = chunk.unwrap();
                // filesystem operations are blocking, we have to use threadpool
                f = web::block(move || f.write_all(&data).map(|_| f)).await?;
            }
        }
    });
    Ok(HttpResponse::Ok().into())
}