use std::{
io,
ops::{Deref, DerefMut},
pin::Pin,
task::{Context, Poll},
};
use futures::Stream;
use pin_project_lite::pin_project;
use tokio::io::{AsyncRead, AsyncWrite};
use tokio_listener::{Listener, ListenerAddress};
use tonic::transport::server::{Connected, TcpConnectInfo, UdsConnectInfo};
/// A wrapper around a [Listener] which implements the [Stream] trait.
/// Mainly used to bridge [tokio_listener] with [tonic].
pub struct ListenerStream {
inner: Listener,
}
impl ListenerStream {
/// Convert a [Listener] into a [Stream].
pub fn new(inner: Listener) -> Self {
Self { inner }
}
/// Binds to the specified address and returns a [Stream] of connections.
pub async fn bind(addr: &ListenerAddress) -> io::Result<Self> {
let listener = Listener::bind(addr, &Default::default(), &Default::default()).await?;
Ok(Self::new(listener))
}
}
impl Stream for ListenerStream {
type Item = io::Result<Connection>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
match self.inner.poll_accept(cx) {
Poll::Ready(Ok((connection, _))) => Poll::Ready(Some(Ok(Connection::new(connection)))),
Poll::Ready(Err(err)) => Poll::Ready(Some(Err(err))),
Poll::Pending => Poll::Pending,
}
}
}
pin_project! {
/// A wrapper around a [tokio_listener::Connection] that implements the [Connected] trait
/// so it is compatible with [tonic].
pub struct Connection {
#[pin]
inner: tokio_listener::Connection,
}
}
impl Connection {
fn new(inner: tokio_listener::Connection) -> Self {
Self { inner }
}
}
impl Deref for Connection {
type Target = tokio_listener::Connection;
fn deref(&self) -> &Self::Target {
&self.inner
}
}
impl DerefMut for Connection {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.inner
}
}
#[derive(Clone)]
pub enum ListenerConnectInfo {
TCP(TcpConnectInfo),
Unix(UdsConnectInfo),
Stdio,
Other,
}
impl Connected for Connection {
type ConnectInfo = ListenerConnectInfo;
fn connect_info(&self) -> Self::ConnectInfo {
if let Some(tcp_stream) = self.try_borrow_tcp() {
ListenerConnectInfo::TCP(tcp_stream.connect_info())
} else if let Some(unix_stream) = self.try_borrow_unix() {
ListenerConnectInfo::Unix(unix_stream.connect_info())
} else if let Some(_) = self.try_borrow_stdio() {
ListenerConnectInfo::Stdio
} else {
ListenerConnectInfo::Other
}
}
}
impl AsyncRead for Connection {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut std::task::Context<'_>,
buf: &mut tokio::io::ReadBuf<'_>,
) -> Poll<io::Result<()>> {
self.project().inner.poll_read(cx, buf)
}
}
impl AsyncWrite for Connection {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut std::task::Context<'_>,
buf: &[u8],
) -> Poll<std::result::Result<usize, io::Error>> {
self.project().inner.poll_write(cx, buf)
}
fn poll_flush(
self: Pin<&mut Self>,
cx: &mut std::task::Context<'_>,
) -> Poll<std::result::Result<(), io::Error>> {
self.project().inner.poll_flush(cx)
}
fn poll_shutdown(
self: Pin<&mut Self>,
cx: &mut std::task::Context<'_>,
) -> Poll<std::result::Result<(), io::Error>> {
self.project().inner.poll_shutdown(cx)
}
}