Code cleanup from PR review.

Signed-off-by: Marc Handalian <handalm@amazon.com>

server/src/main/java/org/opensearch/indices/replication/GetCheckpointInfoRequest.java → server/src/main/java/org/opensearch/indices/replication/CheckpointInfoRequest.java

@@ -15,20 +15,20 @@
 import java.io.IOException;
 
 /**
- * Request object for fetching Segment Metadata from a {@link ReplicationCheckpoint}
+ * Request object for fetching Segment Metadata for a {@link ReplicationCheckpoint} from a {@link SegmentReplicationSource}.
  *
  * @opensearch.internal
  */
-public class GetCheckpointInfoRequest extends SegmentReplicationTransportRequest {
+public class CheckpointInfoRequest extends SegmentReplicationTransportRequest {
 
     private final ReplicationCheckpoint checkpoint;
 
-    public GetCheckpointInfoRequest(StreamInput in) throws IOException {
+    public CheckpointInfoRequest(StreamInput in) throws IOException {
         super(in);
         checkpoint = new ReplicationCheckpoint(in);
     }
 
-    public GetCheckpointInfoRequest(
+    public CheckpointInfoRequest(
         long replicationId,
         String targetAllocationId,
         DiscoveryNode targetNode,

server/src/main/java/org/opensearch/indices/replication/CheckpointInfoResponse.java

@@ -19,7 +19,8 @@
 
 /**
  * Response returned from a {@link SegmentReplicationSource} that includes the file metadata, and SegmentInfos
- * associated with a particular {@link ReplicationCheckpoint}.
+ * associated with a particular {@link ReplicationCheckpoint}. The {@link SegmentReplicationSource} may determine that
+ * the requested {@link ReplicationCheckpoint} is behind and return a different {@link ReplicationCheckpoint} in this response.
  *
  * @opensearch.internal
  */

server/src/main/java/org/opensearch/indices/replication/GetFilesRequest.java → server/src/main/java/org/opensearch/indices/replication/GetSegmentFilesRequest.java

@@ -18,15 +18,17 @@
 
 /**
  * TransportRequest to fetch segments from another Node.
+ * Request includes a list of {@link StoreFileMetadata} of the files to copy and
+ * the related {@link ReplicationCheckpoint}.
  *
  * @opensearch.internal
  */
-public class GetFilesRequest extends SegmentReplicationTransportRequest {
+public class GetSegmentFilesRequest extends SegmentReplicationTransportRequest {
 
     private final List<StoreFileMetadata> filesToFetch;
     private final ReplicationCheckpoint checkpoint;
 
-    public GetFilesRequest(
+    public GetSegmentFilesRequest(
         long replicationId,
         String targetAllocationId,
         DiscoveryNode targetNode,
@@ -38,7 +40,7 @@ public GetFilesRequest(
         this.checkpoint = checkpoint;
     }
 
-    public GetFilesRequest(StreamInput in) throws IOException {
+    public GetSegmentFilesRequest(StreamInput in) throws IOException {
         super(in);
         this.filesToFetch = in.readList(StoreFileMetadata::new);
         this.checkpoint = new ReplicationCheckpoint(in);

server/src/main/java/org/opensearch/indices/replication/GetFilesResponse.java → server/src/main/java/org/opensearch/indices/replication/GetSegmentFilesResponse.java

@@ -19,11 +19,11 @@
  *
  * @opensearch.internal
  */
-public class GetFilesResponse extends TransportResponse {
+public class GetSegmentFilesResponse extends TransportResponse {
 
-    public GetFilesResponse() {}
+    public GetSegmentFilesResponse() {}
 
-    public GetFilesResponse(StreamInput streamInput) {
+    public GetSegmentFilesResponse(StreamInput streamInput) {
 
     }
 

server/src/main/java/org/opensearch/indices/replication/PeerReplicationSource.java

@@ -50,7 +50,7 @@ public PeerReplicationSource(
     public void getCheckpointMetadata(long replicationId, ReplicationCheckpoint checkpoint, StepListener<CheckpointInfoResponse> listener) {
         final Writeable.Reader<CheckpointInfoResponse> reader = CheckpointInfoResponse::new;
         final ActionListener<CheckpointInfoResponse> responseListener = ActionListener.map(listener, r -> r);
-        GetCheckpointInfoRequest request = new GetCheckpointInfoRequest(replicationId, allocationId, localNode, checkpoint);
+        CheckpointInfoRequest request = new CheckpointInfoRequest(replicationId, allocationId, localNode, checkpoint);
         transportClient.executeRetryableAction(GET_CHECKPOINT_INFO, request, responseListener, reader);
     }
 
@@ -60,12 +60,12 @@ public void getFiles(
         ReplicationCheckpoint checkpoint,
         Store store,
         List<StoreFileMetadata> filesToFetch,
-        StepListener<GetFilesResponse> listener
+        StepListener<GetSegmentFilesResponse> listener
     ) {
-        final Writeable.Reader<GetFilesResponse> reader = GetFilesResponse::new;
-        final ActionListener<GetFilesResponse> responseListener = ActionListener.map(listener, r -> r);
+        final Writeable.Reader<GetSegmentFilesResponse> reader = GetSegmentFilesResponse::new;
+        final ActionListener<GetSegmentFilesResponse> responseListener = ActionListener.map(listener, r -> r);
 
-        GetFilesRequest request = new GetFilesRequest(replicationId, allocationId, localNode, filesToFetch, checkpoint);
+        GetSegmentFilesRequest request = new GetSegmentFilesRequest(replicationId, allocationId, localNode, filesToFetch, checkpoint);
         transportClient.executeRetryableAction(GET_FILES, request, responseListener, reader);
     }
 }

server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSource.java

@@ -28,6 +28,6 @@ void getFiles(
         ReplicationCheckpoint checkpoint,
         Store store,
         List<StoreFileMetadata> filesToFetch,
-        StepListener<GetFilesResponse> listener
+        StepListener<GetSegmentFilesResponse> listener
     );
 }

server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTransportRequest.java

@@ -33,10 +33,10 @@ protected SegmentReplicationTransportRequest(StreamInput in) throws IOException
         targetNode = new DiscoveryNode(in);
     }
 
-    protected SegmentReplicationTransportRequest(long replicationId, String targetAllocationId, DiscoveryNode discoveryNode) {
+    protected SegmentReplicationTransportRequest(long replicationId, String targetAllocationId, DiscoveryNode targetNode) {
         this.replicationId = replicationId;
         this.targetAllocationId = targetAllocationId;
-        this.targetNode = discoveryNode;
+        this.targetNode = targetNode;
     }
 
     @Override