use bytes::Buf;
use futures_util::{ready, stream::Stream};
use http_body::{Body, Frame};
use pin_project_lite::pin_project;
use std::{
pin::Pin,
task::{Context, Poll},
};
pin_project! {
#[derive(Clone, Copy, Debug)]
pub struct StreamBody<S> {
#[pin]
stream: S,
}
}
impl<S> StreamBody<S> {
pub fn new(stream: S) -> Self {
Self { stream }
}
}
impl<S, D, E> Body for StreamBody<S>
where
S: Stream<Item = Result<Frame<D>, E>>,
D: Buf,
{
type Data = D;
type Error = E;
fn poll_frame(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Option<Result<Frame<Self::Data>, Self::Error>>> {
match self.project().stream.poll_next(cx) {
Poll::Ready(Some(result)) => Poll::Ready(Some(result)),
Poll::Ready(None) => Poll::Ready(None),
Poll::Pending => Poll::Pending,
}
}
}
impl<S: Stream> Stream for StreamBody<S> {
type Item = S::Item;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
self.project().stream.poll_next(cx)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.stream.size_hint()
}
}
pin_project! {
#[derive(Clone, Copy, Debug)]
pub struct BodyStream<B> {
#[pin]
body: B,
}
}
impl<B> BodyStream<B> {
pub fn new(body: B) -> Self {
Self { body }
}
}
impl<B> Body for BodyStream<B>
where
B: Body,
{
type Data = B::Data;
type Error = B::Error;
fn poll_frame(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Option<Result<Frame<Self::Data>, Self::Error>>> {
self.project().body.poll_frame(cx)
}
}
impl<B> Stream for BodyStream<B>
where
B: Body,
{
type Item = Result<Frame<B::Data>, B::Error>;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
match self.project().body.poll_frame(cx) {
Poll::Ready(Some(frame)) => Poll::Ready(Some(frame)),
Poll::Ready(None) => Poll::Ready(None),
Poll::Pending => Poll::Pending,
}
}
}
pin_project! {
#[derive(Clone, Copy, Debug)]
pub struct BodyDataStream<B> {
#[pin]
body: B,
}
}
impl<B> BodyDataStream<B> {
pub fn new(body: B) -> Self {
Self { body }
}
}
impl<B> Stream for BodyDataStream<B>
where
B: Body,
{
type Item = Result<B::Data, B::Error>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
loop {
return match ready!(self.as_mut().project().body.poll_frame(cx)) {
Some(Ok(frame)) => match frame.into_data() {
Ok(bytes) => Poll::Ready(Some(Ok(bytes))),
Err(_) => continue,
},
Some(Err(err)) => Poll::Ready(Some(Err(err))),
None => Poll::Ready(None),
};
}
}
}
#[cfg(test)]
mod tests {
use crate::{BodyExt, BodyStream, StreamBody};
use bytes::Bytes;
use futures_util::StreamExt;
use http_body::Frame;
use std::convert::Infallible;
#[tokio::test]
async fn body_from_stream() {
let chunks: Vec<Result<_, Infallible>> = vec![
Ok(Frame::data(Bytes::from(vec![1]))),
Ok(Frame::data(Bytes::from(vec![2]))),
Ok(Frame::data(Bytes::from(vec![3]))),
];
let stream = futures_util::stream::iter(chunks);
let mut body = StreamBody::new(stream);
assert_eq!(
body.frame()
.await
.unwrap()
.unwrap()
.into_data()
.unwrap()
.as_ref(),
[1]
);
assert_eq!(
body.frame()
.await
.unwrap()
.unwrap()
.into_data()
.unwrap()
.as_ref(),
[2]
);
assert_eq!(
body.frame()
.await
.unwrap()
.unwrap()
.into_data()
.unwrap()
.as_ref(),
[3]
);
assert!(body.frame().await.is_none());
}
#[tokio::test]
async fn stream_from_body() {
let chunks: Vec<Result<_, Infallible>> = vec![
Ok(Frame::data(Bytes::from(vec![1]))),
Ok(Frame::data(Bytes::from(vec![2]))),
Ok(Frame::data(Bytes::from(vec![3]))),
];
let stream = futures_util::stream::iter(chunks);
let body = StreamBody::new(stream);
let mut stream = BodyStream::new(body);
assert_eq!(
stream
.next()
.await
.unwrap()
.unwrap()
.into_data()
.unwrap()
.as_ref(),
[1]
);
assert_eq!(
stream
.next()
.await
.unwrap()
.unwrap()
.into_data()
.unwrap()
.as_ref(),
[2]
);
assert_eq!(
stream
.next()
.await
.unwrap()
.unwrap()
.into_data()
.unwrap()
.as_ref(),
[3]
);
assert!(stream.next().await.is_none());
}
}