From 4d7edd4d15be68146210c3970d2aeddf00570355 Mon Sep 17 00:00:00 2001
From: Marco Gorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Fri, 31 May 2024 10:15:22 +0100
Subject: [PATCH] fixup

---
 crates/polars-time/src/truncate.rs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/crates/polars-time/src/truncate.rs b/crates/polars-time/src/truncate.rs
index 5afda307a108..a095ff0628e4 100644
--- a/crates/polars-time/src/truncate.rs
+++ b/crates/polars-time/src/truncate.rs
@@ -51,6 +51,10 @@ impl PolarsTruncate for DatetimeChunked {
                 }
             }
         }
+        let mut duration_cache = match duration_cache_opt {
+            Some(cache) => cache,
+            None => FastFixedCache::new((every.len() as f64).sqrt() as usize),
+        };
 
         let func = match self.time_unit() {
             TimeUnit::Nanoseconds => Window::truncate_ns,
@@ -71,10 +75,8 @@ impl PolarsTruncate for DatetimeChunked {
             opt_every,
         ) {
             (Some(timestamp), Some(every)) => {
-                let every = duration_cache_opt
-                    .as_mut()
-                    .map(|cache| *cache.get_or_insert_with(every, |every| Duration::parse(every)))
-                    .unwrap();
+                let every =
+                    *duration_cache.get_or_insert_with(every, |every| Duration::parse(every));
 
                 if every.negative {
                     polars_bail!(ComputeError: "cannot truncate a Datetime to a negative duration")