H3: Accept HttpBody in Request<T> and Response<T>

[stammw]

That is, I think we should leverage the http_body crate's Body trait, which already looks quite similar to what we've got going, and use it in our APIs.

Originally posted by @djc in #723 (comment)

[stammw]

I'm afraid http_body is an interface for upon-hyper layers.

From the hyper code, the h2 glue reads from HttpBody here, then writes into a protocol-specific API here. It also check a bunch of state, among which stream reset check.

I guess we'll have to parametize BodyWriter<B> with a bound on bytes::Buf, and offer some "context + poll" methods to do exactly the same.

The problem with implementing From<http_body::Body> for Body is that we'll bypass the Payload abstraction here.

If we want to hold a http::Body into a quinn_h3::Body variant, we'd have to store it as a &dyn HttpBody and it brings other problems with ownership then.

[djc]

The Payload abstraction is very thin, and I think Sean is okay with removing it. I have a PR to do so: hyperium/hyper#2188

[djc]

I was indeed just in the process of writing a PipeToSendStream variant for H3.

[stammw]

Okay, so why not binding BodyWriter<T> to T: http_body::Body directly then ?

[djc]

I think that's what I was suggesting? 😁

[stammw]

Haha, yeah, I understood having a Body::Stream(http_body::Body) variant from previous conversations. Makes things easier I guess :)

[stammw]

closed via #734