Fix leaking blocks in TopN (#102715) (#102718)

Closes #102646

Author: dnhatn

docs/changelog/102715.yaml

@@ -0,0 +1,6 @@
+pr: 102715
+summary: Fix leaking blocks in TopN
+area: ES|QL
+type: bug
+issues:
+ - 102646

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/topn/ResultBuilderForDoc.java

@@ -11,6 +11,8 @@
 import org.elasticsearch.compute.data.Block;
 import org.elasticsearch.compute.data.BlockFactory;
 import org.elasticsearch.compute.data.DocVector;
+import org.elasticsearch.compute.data.IntVector;
+import org.elasticsearch.core.Releasables;
 
 class ResultBuilderForDoc implements ResultBuilder {
     private final BlockFactory blockFactory;
@@ -42,12 +44,21 @@ public void decodeValue(BytesRef values) {
 
     @Override
     public Block build() {
-        return new DocVector(
-            blockFactory.newIntArrayVector(shards, position),
-            blockFactory.newIntArrayVector(segments, position),
-            blockFactory.newIntArrayVector(docs, position),
-            null
-        ).asBlock();
+        boolean success = false;
+        IntVector shardsVector = null;
+        IntVector segmentsVector = null;
+        try {
+            shardsVector = blockFactory.newIntArrayVector(shards, position);
+            segmentsVector = blockFactory.newIntArrayVector(segments, position);
+            var docsVector = blockFactory.newIntArrayVector(docs, position);
+            var docsBlock = new DocVector(shardsVector, segmentsVector, docsVector, null).asBlock();
+            success = true;
+            return docsBlock;
+        } finally {
+            if (success == false) {
+                Releasables.closeExpectNoException(shardsVector, segmentsVector);
+            }
+        }
     }
 
     @Override