From 4600c7f32de2683c465d3dcfaf4ddac8a7c250c6 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 12 Jul 2024 20:13:55 +0000
Subject: [PATCH] move infallible handling into error

Signed-off-by: Jason Volk <jason@zemos.net>
---
 src/core/error.rs        | 12 +++++++++++-
 src/core/utils/mod.rs    | 13 -------------
 src/router/serve/unix.rs | 12 ++++++++----
 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/src/core/error.rs b/src/core/error.rs
index 77faae3a..01460217 100644
--- a/src/core/error.rs
+++ b/src/core/error.rs
@@ -196,7 +196,11 @@ impl UnwindSafe for Error {}
 impl RefUnwindSafe for Error {}
 
 impl From<Infallible> for Error {
-	fn from(i: Infallible) -> Self { match i {} }
+	#[cold]
+	#[inline(never)]
+	fn from(_i: Infallible) -> Self {
+		panic!("infallible error should never exist");
+	}
 }
 
 impl fmt::Debug for Error {
@@ -273,6 +277,12 @@ pub fn inspect_debug_log<E: fmt::Debug>(error: &E) {
 	debug_error!("{error:?}");
 }
 
+#[cold]
+#[inline(never)]
+pub fn infallible(_e: &Infallible) {
+	panic!("infallible error should never exist");
+}
+
 impl axum::response::IntoResponse for Error {
 	fn into_response(self) -> axum::response::Response {
 		let response: UiaaResponse = self.into();
diff --git a/src/core/utils/mod.rs b/src/core/utils/mod.rs
index 4e5ba480..bbd52829 100644
--- a/src/core/utils/mod.rs
+++ b/src/core/utils/mod.rs
@@ -26,21 +26,8 @@ pub use string::{str_from_bytes, string_from_bytes};
 pub use sys::available_parallelism;
 pub use time::now_millis as millis_since_unix_epoch;
 
-use crate::Result;
-
 pub fn clamp<T: Ord>(val: T, min: T, max: T) -> T { cmp::min(cmp::max(val, min), max) }
 
-/// Boilerplate for wraps which are typed to never error.
-///
-/// * <https://doc.rust-lang.org/std/convert/enum.Infallible.html>
-#[must_use]
-pub fn unwrap_infallible<T>(result: Result<T, std::convert::Infallible>) -> T {
-	match result {
-		Ok(val) => val,
-		Err(err) => match err {},
-	}
-}
-
 #[must_use]
 pub fn generate_keypair() -> Vec<u8> {
 	let mut value = rand::string(8).as_bytes().to_vec();
diff --git a/src/router/serve/unix.rs b/src/router/serve/unix.rs
index 8373b749..e876b2ac 100644
--- a/src/router/serve/unix.rs
+++ b/src/router/serve/unix.rs
@@ -10,7 +10,7 @@ use axum::{
 	extract::{connect_info::IntoMakeServiceWithConnectInfo, Request},
 	Router,
 };
-use conduit::{debug_error, trace, utils, Error, Result, Server};
+use conduit::{debug_error, error::infallible, trace, Error, Result, Server};
 use hyper::{body::Incoming, service::service_fn};
 use hyper_util::{
 	rt::{TokioExecutor, TokioIo},
@@ -24,7 +24,6 @@ use tokio::{
 };
 use tower::{Service, ServiceExt};
 use tracing::{debug, info, warn};
-use utils::unwrap_infallible;
 
 type MakeService = IntoMakeServiceWithConnectInfo<Router, net::SocketAddr>;
 
@@ -62,9 +61,14 @@ async fn accept(
 	let socket = TokioIo::new(socket);
 	trace!(?listener, ?socket, ?remote, "accepted");
 
-	let called = unwrap_infallible(app.call(NULL_ADDR).await);
-	let handler = service_fn(move |req: Request<Incoming>| called.clone().oneshot(req));
+	let called = app
+		.call(NULL_ADDR)
+		.await
+		.inspect_err(infallible)
+		.expect("infallible");
 
+	let service = move |req: Request<Incoming>| called.clone().oneshot(req);
+	let handler = service_fn(service);
 	let task = async move {
 		// bug on darwin causes all results to be errors. do not unwrap this
 		_ = builder.serve_connection(socket, handler).await;