Add deleteByQuery to InternalEngine (elastic#129679)

Author: bcully

server/src/main/java/org/elasticsearch/index/engine/InternalEngine.java

@@ -94,6 +94,7 @@
 import org.elasticsearch.index.seqno.SequenceNumbers;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.index.shard.ShardLongFieldRange;
+import org.elasticsearch.index.shard.ShardSplittingQuery;
 import org.elasticsearch.index.store.Store;
 import org.elasticsearch.index.translog.Translog;
 import org.elasticsearch.index.translog.TranslogConfig;
@@ -3610,4 +3611,9 @@ protected long estimateMergeBytes(MergePolicy.OneMerge merge) {
             return 0L;
         }
     }
+
+    // Used to clean up unowned documents. Client-visible deletes should always be soft deletes.
+    protected void deleteByQuery(ShardSplittingQuery query) throws Exception {
+        indexWriter.deleteDocuments(query);
+    }
 }

server/src/main/java/org/elasticsearch/index/shard/ShardSplittingQuery.java

@@ -52,13 +52,13 @@
  * It can be used to split a shard into N shards marking every document that doesn't belong into the shard
  * as deleted. See {@link org.apache.lucene.index.IndexWriter#deleteDocuments(Query...)}
  */
-final class ShardSplittingQuery extends Query {
+public final class ShardSplittingQuery extends Query {
     private final IndexMetadata indexMetadata;
     private final IndexRouting indexRouting;
     private final int shardId;
     private final BitSetProducer nestedParentBitSetProducer;
 
-    ShardSplittingQuery(IndexMetadata indexMetadata, int shardId, boolean hasNested) {
+    public ShardSplittingQuery(IndexMetadata indexMetadata, int shardId, boolean hasNested) {
         this.indexMetadata = indexMetadata;
         this.indexRouting = IndexRouting.fromIndexMetadata(indexMetadata);
         this.shardId = shardId;