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use http::Uri;
use aws_smithy_async::future::never::Never;
use std::marker::PhantomData;
use std::task::{Context, Poll};
use tokio::net::TcpStream;
use crate::erase::boxclone::BoxFuture;
use tower::BoxError;
#[non_exhaustive]
#[derive(Debug)]
pub struct NeverService<Req, Resp, Err> {
_resp: PhantomData<(Req, Resp, Err)>,
}
impl<Req, Resp, Err> Clone for NeverService<Req, Resp, Err> {
fn clone(&self) -> Self {
Self {
_resp: Default::default(),
}
}
}
impl<Req, Resp, Err> Default for NeverService<Req, Resp, Err> {
fn default() -> Self {
Self::new()
}
}
impl<Req, Resp, Err> NeverService<Req, Resp, Err> {
pub fn new() -> Self {
NeverService {
_resp: Default::default(),
}
}
}
mod stream {
use hyper::client::connect::{Connected, Connection};
use std::io::Error;
use std::pin::Pin;
use std::task::{Context, Poll};
use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
#[non_exhaustive]
#[derive(Debug, Default)]
pub struct EmptyStream;
impl EmptyStream {
pub fn new() -> Self {
Self
}
}
impl AsyncRead for EmptyStream {
fn poll_read(
self: Pin<&mut Self>,
_cx: &mut Context<'_>,
_buf: &mut ReadBuf<'_>,
) -> Poll<std::io::Result<()>> {
Poll::Pending
}
}
impl AsyncWrite for EmptyStream {
fn poll_write(
self: Pin<&mut Self>,
_cx: &mut Context<'_>,
_buf: &[u8],
) -> Poll<Result<usize, Error>> {
Poll::Pending
}
fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
Poll::Pending
}
fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
Poll::Pending
}
}
impl Connection for EmptyStream {
fn connected(&self) -> Connected {
Connected::new()
}
}
}
pub type NeverConnected = NeverService<Uri, TcpStream, BoxError>;
#[derive(Clone, Debug, Default)]
pub struct NeverReplies;
impl NeverReplies {
pub fn new() -> Self {
Self
}
}
impl tower::Service<Uri> for NeverReplies {
type Response = stream::EmptyStream;
type Error = BoxError;
type Future = std::future::Ready<Result<Self::Response, Self::Error>>;
fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
fn call(&mut self, _req: Uri) -> Self::Future {
std::future::ready(Ok(stream::EmptyStream::new()))
}
}
impl<Req, Resp, Err> tower::Service<Req> for NeverService<Req, Resp, Err> {
type Response = Resp;
type Error = Err;
type Future = BoxFuture<Self::Response, Self::Error>;
fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
fn call(&mut self, _req: Req) -> Self::Future {
Box::pin(async move {
Never::new().await;
unreachable!()
})
}
}