From 5f53935c8aa06558d23200f68419fe26eb4c392e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <clement@meilisearch.com>
Date: Wed, 25 Sep 2024 16:01:08 +0200
Subject: [PATCH] Fix a bug in the Lru

---
 milli/src/update/new/extract/lru.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/milli/src/update/new/extract/lru.rs b/milli/src/update/new/extract/lru.rs
index 8a35cc440..7346c38af 100644
--- a/milli/src/update/new/extract/lru.rs
+++ b/milli/src/update/new/extract/lru.rs
@@ -121,7 +121,7 @@ struct FixedSizeListNode<T> {
 #[derive(Debug)]
 struct FixedSizeList<T> {
     nodes: Box<[Option<FixedSizeListNode<T>>]>,
-    /// The next None in the nodes.
+    /// The first `None` in the nodes.
     next_free: usize,
     // TODO Also, we probably do not need one of the front and back cursors.
     front: usize,
@@ -145,7 +145,7 @@ impl<T> FixedSizeList<T> {
 
     #[inline]
     fn len(&self) -> usize {
-        self.nodes.len() - self.next_free
+        self.next_free
     }
 
     #[inline]
@@ -168,8 +168,9 @@ impl<T> FixedSizeList<T> {
         if self.is_full() {
             None
         } else {
+            let current_free = self.next_free;
             self.next_free += 1;
-            Some(self.next_free)
+            Some(current_free)
         }
     }