Call getLastUnsafeSegmentGenerationForGets directly on Engine

Author: arteam

server/src/main/java/org/elasticsearch/action/get/TransportGetFromTranslogAction.java

@@ -27,7 +27,6 @@
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.engine.Engine;
 import org.elasticsearch.index.engine.InternalEngine;
-import org.elasticsearch.index.engine.ReadOnlyEngine;
 import org.elasticsearch.index.get.GetResult;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.shard.ShardId;
@@ -82,11 +81,7 @@ protected void doExecute(Task task, Request request, ActionListener<Response> li
                 if (engine == null) {
                     throw new AlreadyClosedException("engine closed");
                 }
-                if (engine instanceof InternalEngine internalEngine) {
-                    segmentGeneration = internalEngine.getLastUnsafeSegmentGenerationForGets();
-                } else if (engine instanceof ReadOnlyEngine readOnlyEngine) {
-                    segmentGeneration = readOnlyEngine.getLastUnsafeSegmentGenerationForGets();
-                }
+                segmentGeneration = engine.getLastUnsafeSegmentGenerationForGets();
             }
             return new Response(result, indexShard.getOperationPrimaryTerm(), segmentGeneration);
         });

server/src/main/java/org/elasticsearch/action/get/TransportShardMultiGetFomTranslogAction.java

@@ -23,8 +23,6 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.engine.Engine;
-import org.elasticsearch.index.engine.InternalEngine;
-import org.elasticsearch.index.engine.ReadOnlyEngine;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.indices.IndicesService;
@@ -103,11 +101,7 @@ protected void doExecute(Task task, Request request, ActionListener<Response> li
                 if (engine == null) {
                     throw new AlreadyClosedException("engine closed");
                 }
-                if (engine instanceof InternalEngine internalEngine) {
-                    segmentGeneration = internalEngine.getLastUnsafeSegmentGenerationForGets();
-                } else if (engine instanceof ReadOnlyEngine readOnlyEngine) {
-                    segmentGeneration = readOnlyEngine.getLastUnsafeSegmentGenerationForGets();
-                }
+                segmentGeneration = engine.getLastUnsafeSegmentGenerationForGets();
             }
             return new Response(multiGetShardResponse, indexShard.getOperationPrimaryTerm(), segmentGeneration);
         });