Use modern Java pattern matching in QueryToFilterAdapter (elastic#134628)

Author: romseygeek

server/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/QueryToFilterAdapter.java

@@ -51,14 +51,14 @@ public static QueryToFilterAdapter build(IndexSearcher searcher, String key, Que
         // Wrapping with a ConstantScoreQuery enables a few more rewrite
         // rules as of Lucene 9.2
         query = searcher.rewrite(new ConstantScoreQuery(query));
-        if (query instanceof ConstantScoreQuery) {
+        if (query instanceof ConstantScoreQuery csq) {
             /*
              * Unwrap constant score because it gets in the way of us
              * understanding what the queries are trying to do and we
              * don't use the score at all anyway. Effectively we always
              * run in constant score mode.
              */
-            query = ((ConstantScoreQuery) query).getQuery();
+            query = csq.getQuery();
         }
         return new QueryToFilterAdapter(searcher, key, query);
     }
@@ -132,8 +132,8 @@ QueryToFilterAdapter union(Query extraQuery) throws IOException {
         extraQuery = searcher().rewrite(new ConstantScoreQuery(extraQuery));
         Query unwrappedExtraQuery = unwrap(extraQuery);
         Query unwrappedQuery = unwrap(query);
-        if (unwrappedQuery instanceof PointRangeQuery && unwrappedExtraQuery instanceof PointRangeQuery) {
-            Query merged = MergedPointRangeQuery.merge((PointRangeQuery) unwrappedQuery, (PointRangeQuery) unwrappedExtraQuery);
+        if (unwrappedQuery instanceof PointRangeQuery q1 && unwrappedExtraQuery instanceof PointRangeQuery q2) {
+            Query merged = MergedPointRangeQuery.merge(q1, q2);
             if (merged != null) {
                 // Should we rewrap here?
                 return new QueryToFilterAdapter(searcher(), key(), merged);
@@ -157,19 +157,19 @@ public boolean isInefficientUnion() {
 
     private static Query unwrap(Query query) {
         while (true) {
-            if (query instanceof ConstantScoreQuery) {
-                query = ((ConstantScoreQuery) query).getQuery();
-                continue;
+            switch (query) {
+                case ConstantScoreQuery csq:
+                    query = csq.getQuery();
+                    continue;
+                case IndexSortSortedNumericDocValuesRangeQuery isq:
+                    query = isq.getFallbackQuery();
+                    continue;
+                case IndexOrDocValuesQuery idq:
+                    query = idq.getIndexQuery();
+                    continue;
+                default:
+                    return query;
             }
-            if (query instanceof IndexSortSortedNumericDocValuesRangeQuery) {
-                query = ((IndexSortSortedNumericDocValuesRangeQuery) query).getFallbackQuery();
-                continue;
-            }
-            if (query instanceof IndexOrDocValuesQuery) {
-                query = ((IndexOrDocValuesQuery) query).getIndexQuery();
-                continue;
-            }
-            return query;
         }
     }