From 8e8b59900bad65876b064ba074a27d0062350cb3 Mon Sep 17 00:00:00 2001
From: Ignacio Vera <ivera@apache.org>
Date: Thu, 25 Jan 2024 14:24:06 +0100
Subject: [PATCH] Stop capturing the BucketAggregator when building internal
 sub-aggregations

---
 .../bucket/BucketsAggregator.java             | 33 ++++++++++++-------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/BucketsAggregator.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/BucketsAggregator.java
index ec8117cf03135..3416986930041 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/BucketsAggregator.java
+++ b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/BucketsAggregator.java
@@ -180,22 +180,31 @@ protected final InternalAggregations[] buildSubAggsForBuckets(long[] bucketOrdsT
         }
         InternalAggregations[] result = new InternalAggregations[bucketOrdsToCollect.length];
         for (int ord = 0; ord < bucketOrdsToCollect.length; ord++) {
-            final int thisOrd = ord;
-            result[ord] = InternalAggregations.from(new AbstractList<>() {
-                @Override
-                public InternalAggregation get(int index) {
-                    return aggregations[index][thisOrd];
-                }
-
-                @Override
-                public int size() {
-                    return aggregations.length;
-                }
-            });
+            result[ord] = InternalAggregations.from(new InternalAggregationList(aggregations, ord));
         }
         return result;
     }
 
+    private static class InternalAggregationList extends AbstractList<InternalAggregation> {
+        private final InternalAggregation[][] aggregations;
+        private final int ord;
+
+        private InternalAggregationList(InternalAggregation[][] aggregations, int ord) {
+            this.aggregations = aggregations;
+            this.ord = ord;
+        }
+
+        @Override
+        public InternalAggregation get(int index) {
+            return aggregations[index][ord];
+        }
+
+        @Override
+        public int size() {
+            return aggregations.length;
+        }
+    }
+
     /**
      * Build the sub aggregation results for a list of buckets and set them on
      * the buckets. This is usually used by aggregations that are selective