From 6da810cf6723d1fd689ec6b57c18d5f2d8eddfc1 Mon Sep 17 00:00:00 2001
From: Max Inden <mail@max-inden.de>
Date: Fri, 29 Mar 2024 17:24:13 +0100
Subject: [PATCH] No % operation

---
 neqo-common/benches/timer.rs | 57 ++++++++++++++++++------------------
 neqo-common/src/timer.rs     |  8 +++--
 2 files changed, 34 insertions(+), 31 deletions(-)

diff --git a/neqo-common/benches/timer.rs b/neqo-common/benches/timer.rs
index d6d75ef20b..280f1b8281 100644
--- a/neqo-common/benches/timer.rs
+++ b/neqo-common/benches/timer.rs
@@ -11,41 +11,40 @@ use neqo_common::timer::Timer;
 use test_fixture::now;
 
 fn benchmark_timer(c: &mut Criterion) {
-    c.bench_function("drain a small timer quickly", |b| {
-        b.iter_batched(make_small_timer, drain, criterion::BatchSize::SmallInput);
+    c.bench_function("drain a timer quickly", |b| {
+        b.iter_batched(
+            || {
+                const TIMES: &[u64] = &[1, 2, 3, 5, 8, 13, 21, 34];
+                let now = now();
+                let mut timer = Timer::new(now, Duration::from_millis(777), 100);
+                for &t in TIMES {
+                    timer.add(now + Duration::from_secs(t), ());
+                }
+                timer
+            },
+            |mut timer| {
+                while let Some(t) = timer.next_time() {
+                    assert!(timer.take_next(t).is_some());
+                }
+            },
+            criterion::BatchSize::SmallInput,
+        );
     });
-    c.bench_function("drain a large mostly empty timer quickly", |b| {
+    c.bench_function("drain an empty timer", |b| {
         b.iter_batched(
-            make_large_mostly_empty_timer,
-            drain,
+            || {
+                let now = now();
+                let timer = Timer::<()>::new(now, Duration::from_millis(4), 16384);
+                let lookup_time = now + Duration::from_millis(400);
+                (timer, lookup_time)
+            },
+            |(mut timer, lookup_time)| {
+                assert_eq!(None, timer.take_next(lookup_time));
+            },
             criterion::BatchSize::SmallInput,
         );
     });
 }
 
-fn make_small_timer() -> Timer<()> {
-    const TIMES: &[u64] = &[1, 2, 3, 5, 8, 13, 21, 34];
-
-    let now = now();
-    let mut timer = Timer::new(now, Duration::from_millis(777), 100);
-    for &t in TIMES {
-        timer.add(now + Duration::from_secs(t), ());
-    }
-    timer
-}
-
-fn make_large_mostly_empty_timer() -> Timer<()> {
-    let now = now();
-    let mut timer = Timer::new(now, Duration::from_millis(4), 16384);
-    timer.add(now + Duration::from_millis(400), ());
-    timer
-}
-
-fn drain(mut timer: Timer<()>) {
-    while let Some(t) = timer.next_time() {
-        assert!(timer.take_next(t).is_some());
-    }
-}
-
 criterion_group!(benches, benchmark_timer);
 criterion_main!(benches);
diff --git a/neqo-common/src/timer.rs b/neqo-common/src/timer.rs
index 7f70da1924..41afd2cdab 100644
--- a/neqo-common/src/timer.rs
+++ b/neqo-common/src/timer.rs
@@ -198,12 +198,16 @@ impl<T> Timer<T> {
     ///
     /// Impossible, I think.
     pub fn take_next(&mut self, until: Instant) -> Option<T> {
-        let last_bucket = (self.cursor + self.delta(until)) % self.items.len();
-        let range = if self.cursor < last_bucket {
+        let last_bucket = self.cursor + self.delta(until);
+
+        let range = if last_bucket <= self.items.len() {
+            // Simple case, no wrap around.
             #[allow(clippy::range_plus_one)] // non-inclusive range to match with type below
             (self.cursor..(last_bucket + 1)).chain(0..0) // additional empty range to match with
                                                          // type below
         } else {
+            // Complex case, with wrap around.
+            let last_bucket = last_bucket - self.items.len();
             (self.cursor..self.items.len()).chain(0..last_bucket)
         };