From eaf35c9bf5c4cc9ee9d98b39a2e63cfcd47625fa Mon Sep 17 00:00:00 2001
From: Welly Shen <hivoid19@gmail.com>
Date: Mon, 31 May 2021 01:35:15 +0800
Subject: [PATCH] perf: limit the cache number of resize observer with the
 length of items

---
 .changeset/twelve-roses-notice.md | 5 +++++
 src/useVirtual.ts                 | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/twelve-roses-notice.md

diff --git a/.changeset/twelve-roses-notice.md b/.changeset/twelve-roses-notice.md
new file mode 100644
index 00000000..3077527e
--- /dev/null
+++ b/.changeset/twelve-roses-notice.md
@@ -0,0 +1,5 @@
+---
+"react-cool-virtual": patch
+---
+
+perf: limit the cache number of resize observers with the length of items
diff --git a/src/useVirtual.ts b/src/useVirtual.ts
index 10c2605f..f40bfe1b 100644
--- a/src/useVirtual.ts
+++ b/src/useVirtual.ts
@@ -302,7 +302,7 @@ export default <
     isScrollToItemRef.current = false;
     userScrollRef.current = true;
 
-    const len = rosRef.current.size - msDataRef.current.length;
+    const len = rosRef.current.size - items.length;
     const iter = rosRef.current[Symbol.iterator]();
     for (let i = 0; i < len; i += 1)
       rosRef.current.delete(iter.next().value[0]);