From 52d7f3ed1ce0f85f3e927460f64356e9910bc2ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <clement@meilisearch.com>
Date: Wed, 25 Sep 2024 15:37:13 +0200
Subject: [PATCH] Reduce the lru key size from 20 to 8 bytes

---
 milli/src/update/new/extract/cache.rs | 2 +-
 milli/src/update/new/extract/lru.rs   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/milli/src/update/new/extract/cache.rs b/milli/src/update/new/extract/cache.rs
index 4f6f30e70..1c7db0473 100644
--- a/milli/src/update/new/extract/cache.rs
+++ b/milli/src/update/new/extract/cache.rs
@@ -11,7 +11,7 @@ use crate::CboRoaringBitmapCodec;
 
 #[derive(Debug)]
 pub struct CboCachedSorter<MF> {
-    cache: Lru<SmallVec<[u8; 20]>, DelAddRoaringBitmap>,
+    cache: Lru<SmallVec<[u8; 8]>, DelAddRoaringBitmap>,
     sorter: Sorter<MF>,
     deladd_buffer: Vec<u8>,
     cbo_buffer: Vec<u8>,
diff --git a/milli/src/update/new/extract/lru.rs b/milli/src/update/new/extract/lru.rs
index 7c13d9350..cfec6e157 100644
--- a/milli/src/update/new/extract/lru.rs
+++ b/milli/src/update/new/extract/lru.rs
@@ -59,10 +59,10 @@ impl<K: Clone + Eq + Hash, V, S: BuildHasher> Lru<K, V, S> {
             Entry::Vacant(vac) => {
                 let key = vac.key().clone();
                 if self.storage.is_full() {
-                    let idx = self.storage.back_idx();
                     // It's fine to unwrap here because:
                     // * the cache capacity is non zero
                     // * the cache is full
+                    let idx = self.storage.back_idx();
                     let node = self.storage.move_front(idx).unwrap();
                     let LruNode { key, value } = mem::replace(node, LruNode { key, value });
                     vac.insert(idx);
@@ -128,8 +128,8 @@ struct FixedSizeList<T> {
     // to find a free place.
     // TODO remove the free list as it is always growing:
     //      we cannot remove entries from the map.
-    //      Also, we probably do not need one of the front and back cursors.
     free: Vec<usize>,
+    // TODO Also, we probably do not need one of the front and back cursors.
     front: usize,
     back: usize,
 }