large multi-chunk GRPC responses get stuck

[rnbguy]

Version: Deno 1.45.1

If a response has more than u16::MAX many bytes, these polls get stuck.

deno/ext/node/ops/http2.rs

Lines 455 to 477 in 8cbf81c

	fn poll_data_or_trailers(
	cx: &mut std::task::Context,
	body: &mut RecvStream,
	) -> Poll<Result<DataOrTrailers, h2::Error>> {
	loop {
	if let Poll::Ready(trailers) = body.poll_trailers(cx) {
	if let Some(trailers) = trailers? {
	return Poll::Ready(Ok(DataOrTrailers::Trailers(trailers)));
	} else {
	return Poll::Ready(Ok(DataOrTrailers::Eof));
	}
	}
	if let Poll::Ready(data) = body.poll_data(cx) {
	if let Some(data) = data {
	return Poll::Ready(Ok(DataOrTrailers::Data(data?)));
	}
	// If data is None, loop one more time to check for trailers
	continue;
	}
	// Return pending here as poll_data will keep the waker
	return Poll::Pending;
	}
	}

I created a simple pingpong project to reproduce this using a python grpc server: https://github.com/rnbguy/deno-grpc-multi-chunk

Using this example, I realized, Deno parses u16::MAX many bytes in four chunks - 16_384, 16_384, 16_384 and 16_383 - then the poll gets stuck if there are more bytes pending.

Ref: #24147 (comment)