Convert Bytes to Buf with bytes library

Question

I'm trying to convert the result of a reqwest file download in to a type which implements the Read trait. Reqwest has given back a Bytes type. Bytes does not seem to implement Read trait but in the same library there is Buf which does implement Read.

I have been trying to find a way to convert Bytes to Buf but I have not found a way. Am I going about this the right way if I want to get something which implements Read and is there a way to do it by converting Bytes to Buf?

Bytes is a struct that implement the trait Buf, what you ask don't make sense. Bytes implement AsRef and Deref that return a slice if you want. — Stargateur, Jan 01 '22 at 08:33
@Stargateur well I'm facing the error "the trait `std::io::Read` is not implemented for `bytes::Bytes`". Is this something I can get working with Bytes? — Qwertie, Jan 01 '22 at 09:44

score 2 · Accepted Answer · answered Jan 01 '22 at 10:23

Notice that Bytes already implements Buf. But you need to have the trait in scope for using it:

fn main() {
    use bytes::Bytes;
    use bytes::Buf;

    let mut buf = Bytes::from("Hello world");
    assert_eq!(b'H', buf.get_u8());
}

Playground

With that in mind, if you need a Read object, you can call the method reader to get such type:

fn main() {
    use bytes::Bytes;
    use bytes::Buf;
    use std::io::Read;
    
    let mut buf = Bytes::from("Hello world");
    let mut reader: Box<dyn Read> = Box::new(buf.reader()) as Box<dyn Read>;
}

Playground

Convert Bytes to Buf with bytes library

1 Answers1