From 903a87c815c9930a00e1066c391778c831a43a2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Teo=20Klestrup=20R=C3=B6ijezon?= <teo@nullable.se>
Date: Mon, 14 Feb 2022 09:15:13 +0100
Subject: [PATCH] Update `Scheduler` for infallible `DelayQueue`
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Signed-off-by: Teo Klestrup Röijezon <teo@nullable.se>
---
 kube-runtime/src/scheduler.rs | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/kube-runtime/src/scheduler.rs b/kube-runtime/src/scheduler.rs
index f63193c54..369717a40 100644
--- a/kube-runtime/src/scheduler.rs
+++ b/kube-runtime/src/scheduler.rs
@@ -9,14 +9,11 @@ use std::{
     task::{Context, Poll},
 };
 use thiserror::Error;
-use tokio::time::{self, Instant};
+use tokio::time::Instant;
 use tokio_util::time::delay_queue::{self, DelayQueue};
 
 #[derive(Debug, Error)]
-pub enum Error {
-    #[error("timer failure: {0}")]
-    TimerError(#[source] time::error::Error),
-}
+pub enum Error {}
 pub type Result<T, E = Error> = std::result::Result<T, E>;
 
 /// A request to re-emit `message` at a given `Instant` (`run_at`).
@@ -95,24 +92,23 @@ impl<'a, T: Hash + Eq + Clone, R> SchedulerProj<'a, T, R> {
         &mut self,
         cx: &mut Context<'_>,
         can_take_message: impl Fn(&T) -> bool,
-    ) -> Poll<Result<T, time::error::Error>> {
+    ) -> Poll<T> {
         if let Some(msg) = self.pending.iter().find(|msg| can_take_message(*msg)).cloned() {
-            return Poll::Ready(Ok(self.pending.take(&msg).unwrap()));
+            return Poll::Ready(self.pending.take(&msg).unwrap());
         }
 
         loop {
             match self.queue.poll_expired(cx) {
-                Poll::Ready(Some(Ok(msg))) => {
+                Poll::Ready(Some(msg)) => {
                     let msg = msg.into_inner();
                     self.scheduled.remove(&msg).expect(
-                    "Expired message was popped from the Scheduler queue, but was not in the metadata map",
-                );
+                        "Expired message was popped from the Scheduler queue, but was not in the metadata map",
+                    );
                     if can_take_message(&msg) {
-                        break Poll::Ready(Ok(msg));
+                        break Poll::Ready(msg);
                     }
                     self.pending.insert(msg);
                 }
-                Poll::Ready(Some(Err(err))) => break Poll::Ready(Err(err)),
                 Poll::Ready(None) | Poll::Pending => break Poll::Pending,
             }
         }
@@ -147,7 +143,7 @@ where
         }
 
         match scheduler.poll_pop_queue_message(cx, &can_take_message) {
-            Poll::Ready(expired) => Poll::Ready(Some(expired.map_err(Error::TimerError))),
+            Poll::Ready(expired) => Poll::Ready(Some(Ok(expired))),
             Poll::Pending => Poll::Pending,
         }
     }