Removing the SegmentInfosRef class

As with the now-deleted IndexCommitRef class, this wrapper class is not needed. It has been replaced with a GatedCloseable instance wrapping a SegmentInfos

Signed-off-by: Kartik Ganesh <[email protected]>

server/src/main/java/org/opensearch/index/engine/Engine.java

@@ -1122,9 +1122,10 @@ public abstract void forceMerge(
     /**
      * Fetch a snapshot of the latest SegmentInfos from the engine and ensure that segment files are retained in the directory
      * until closed.
-     * @return {@link SegmentInfosRef} - A ref to segmentInfos that must be closed for segment files to be deleted.
+     * @return {@link GatedCloseable} - A wrapper around a {@link SegmentInfos} instance that must be closed for segment files
+     * to be deleted.
      */
-    public SegmentInfosRef getLatestSegmentInfosSafe() {
+    public GatedCloseable<SegmentInfos> getLatestSegmentInfosSafe() {
         return null;
     };
 

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

@@ -2269,15 +2269,15 @@ public GatedCloseable<IndexCommit> acquireLastIndexCommit(final boolean flushFir
     }
 
     @Override
-    public SegmentInfosRef getLatestSegmentInfosSafe() {
+    public GatedCloseable<SegmentInfos> getLatestSegmentInfosSafe() {
         assert (engineConfig.isReadOnly() == false);
         final SegmentInfos segmentInfos = getLatestSegmentInfos();
         try {
             indexWriter.incRefDeleter(segmentInfos);
         } catch (IOException e) {
             throw new EngineException(shardId, e.getMessage(), e);
         }
-        return new Engine.SegmentInfosRef(segmentInfos, () -> indexWriter.decRefDeleter(segmentInfos));
+        return new GatedCloseable<>(segmentInfos, () -> indexWriter.decRefDeleter(segmentInfos));
     }
 
     @Override

server/src/main/java/org/opensearch/index/shard/IndexShard.java

@@ -1498,10 +1498,10 @@ public GatedCloseable<IndexCommit> acquireLastIndexCommit(boolean flushFirst) th
     /**
      * Fetch a ref to the latest SegmentInfos held by the engine.  This ensures the files will not be deleted until
      * the ref is closed.
-     * @return {@link Engine.SegmentInfosRef}
+     * @return a {@link GatedCloseable} wrapper around a {@link SegmentInfos} instance
      * @throws EngineException - When infos cannot be retrieved from the Engine.
      */
-    public Engine.SegmentInfosRef getLatestSegmentInfosSafe() throws EngineException {
+    public GatedCloseable<SegmentInfos> getLatestSegmentInfosSafe() throws EngineException {
         return getEngine().getLatestSegmentInfosSafe();
     }
 

server/src/main/java/org/opensearch/indices/replication/copy/CopyState.java

@@ -11,8 +11,8 @@
 import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.store.ByteBuffersDataOutput;
 import org.apache.lucene.store.ByteBuffersIndexOutput;
+import org.opensearch.common.concurrent.GatedCloseable;
 import org.opensearch.common.util.concurrent.AbstractRefCounted;
-import org.opensearch.index.engine.Engine;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.store.Store;
 
@@ -21,15 +21,15 @@
 
 public class CopyState extends AbstractRefCounted {
 
-    private final Engine.SegmentInfosRef segmentInfosRef;
+    private final GatedCloseable<SegmentInfos> segmentInfosRef;
     private final ReplicationCheckpoint checkpoint;
     private final Store.MetadataSnapshot metadataSnapshot;
     private final byte[] infosBytes;
 
     CopyState(IndexShard shard) throws IOException {
         super("replication-nrt-state");
         this.segmentInfosRef = shard.getLatestSegmentInfosSafe();
-        final SegmentInfos segmentInfos = segmentInfosRef.getSegmentInfos();
+        final SegmentInfos segmentInfos = segmentInfosRef.get();
         this.checkpoint = new ReplicationCheckpoint(
             shard.shardId(),
             shard.getOperationPrimaryTerm(),