prevent unbounded growth

ampproject · Mar 16, 2021 · 1c5f13a · 1c5f13a
1 parent cb0bde6
commit 1c5f13a
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/service/performance-impl.js b/src/service/performance-impl.js
@@ -358,7 +358,8 @@ export class Performance {
       } else if (entry.entryType === 'layout-shift') {
         // Ignore layout shift that occurs within 500ms of user input, as it is
         // likely in response to the user's action.
-        if (!entry.hadRecentInput) {
+        // 1000 here is a magic number to prevent unbounded growth. We don't expect it to be reached.
+        if (!entry.hadRecentInput && this.layoutShifts_.length < 1000) {
           this.layoutShifts_.push(entry);
         }
       } else if (entry.entryType === 'largest-contentful-paint') {