From 028b5a4f0dff037a2bf2838427e3f2b370d60bf4 Mon Sep 17 00:00:00 2001
From: Viktor Lofgren <vlofgren@marginalia.nu>
Date: Sun, 24 Sep 2023 12:12:08 +0200
Subject: [PATCH] (minor performance) Reduce GC churn in index

---
 .../main/java/nu/marginalia/index/svc/IndexQueryService.java | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/code/services-core/index-service/src/main/java/nu/marginalia/index/svc/IndexQueryService.java b/code/services-core/index-service/src/main/java/nu/marginalia/index/svc/IndexQueryService.java
index fee480bc..8b42bbd2 100644
--- a/code/services-core/index-service/src/main/java/nu/marginalia/index/svc/IndexQueryService.java
+++ b/code/services-core/index-service/src/main/java/nu/marginalia/index/svc/IndexQueryService.java
@@ -159,8 +159,11 @@ public class IndexQueryService {
      * <br>
      * Then the results are combined.
      * */
+    private final ThreadLocal<TLongArrayList> resultsArrayListPool = ThreadLocal.withInitial(TLongArrayList::new);
     private TLongList evaluateSubqueries(SearchParameters params) {
-        final TLongArrayList results = new TLongArrayList(params.fetchSize);
+        final TLongArrayList results = resultsArrayListPool.get();
+        results.resetQuick();
+        results.ensureCapacity(params.fetchSize);
 
         // These queries are various term combinations
         for (var subquery : params.subqueries) {