addres comments

Signed-off-by: Sandeep Kumawat <skumwt@amazon.com>

Author: Sandeep Kumawat

plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java

@@ -285,12 +285,7 @@ public void readBlobAsync(String blobName, ActionListener<ReadContext> listener)
                             );
                         }
                     }
-                    listener.onResponse(
-                        new ReadContext.Builder().blobSize(blobSize)
-                            .asyncPartStreams(blobPartInputStreamFutures)
-                            .blobChecksum(blobChecksum)
-                            .build()
-                    );
+                    listener.onResponse(new ReadContext.Builder(blobSize, blobPartInputStreamFutures).blobChecksum(blobChecksum).build());
                 } catch (Exception ex) {
                     listener.onFailure(ex);
                 }

server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/mocks/MockFsAsyncBlobContainer.java

@@ -131,7 +131,7 @@ public void readBlobAsync(String blobName, ActionListener<ReadContext> listener)
                     InputStreamContainer blobPartStream = new InputStreamContainer(readBlob(blobName, offset, partSize), partSize, offset);
                     blobPartStreams.add(() -> CompletableFuture.completedFuture(blobPartStream));
                 }
-                ReadContext blobReadContext = new ReadContext.Builder().blobSize(contentLength).asyncPartStreams(blobPartStreams).build();
+                ReadContext blobReadContext = new ReadContext.Builder(contentLength, blobPartStreams).build();
                 listener.onResponse(blobReadContext);
             } catch (Exception e) {
                 listener.onFailure(e);

server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java

@@ -83,7 +83,7 @@ public interface BlobContainer {
      *
      * @param   blobName
      *          The name of the blob to get an {@link InputStream} for.
-     * @return  The {@code InputStream} to read the blob.
+     * @return  The {@link BlobDownloadResponse} of the blob.
      * @throws  NoSuchFileException if the blob does not exist
      * @throws  IOException if the blob can not be read.
      */

server/src/main/java/org/opensearch/common/blobstore/stream/read/ReadContext.java

@@ -72,7 +72,7 @@ public List<StreamPartCreator> getPartStreams() {
     @ExperimentalApi
     public interface StreamPartCreator extends Supplier<CompletableFuture<InputStreamContainer>> {
         /**
-         * Kicks off a async process to start streaming.
+         * Kicks off an async process to start streaming.
          *
          * @return When the returned future is completed, streaming has
          * just begun. Clients must fully consume the resulting stream.
@@ -87,19 +87,14 @@ public interface StreamPartCreator extends Supplier<CompletableFuture<InputStrea
      * @opensearch.experimental
      */
     public static class Builder {
-        private long blobSize;
-        private List<StreamPartCreator> asyncPartStreams;
+        private final long blobSize;
+        private final List<StreamPartCreator> asyncPartStreams;
         private String blobChecksum;
         private Map<String, String> metadata;
 
-        public Builder blobSize(long blobSize) {
+        public Builder(long blobSize, List<StreamPartCreator> asyncPartStreams) {
             this.blobSize = blobSize;
-            return this;
-        }
-
-        public Builder asyncPartStreams(List<StreamPartCreator> asyncPartStreams) {
             this.asyncPartStreams = asyncPartStreams;
-            return this;
         }
 
         public Builder blobChecksum(String blobChecksum) {

server/src/main/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainer.java

@@ -56,7 +56,7 @@ public class RemoteTransferContainer implements Closeable {
     private final OffsetRangeInputStreamSupplier offsetRangeInputStreamSupplier;
     private final boolean isRemoteDataIntegritySupported;
     private final AtomicBoolean readBlock = new AtomicBoolean();
-    private Map<String, String> metadata = null;
+    private final Map<String, String> metadata;
 
     private static final Logger log = LogManager.getLogger(RemoteTransferContainer.class);
 
@@ -90,6 +90,7 @@ public RemoteTransferContainer(
         this.offsetRangeInputStreamSupplier = offsetRangeInputStreamSupplier;
         this.expectedChecksum = expectedChecksum;
         this.isRemoteDataIntegritySupported = isRemoteDataIntegritySupported;
+        this.metadata = null;
     }
 
     /**

server/src/test/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainerTests.java

@@ -57,9 +57,7 @@ public void testReadBlobAsync() throws Exception {
         final ListenerTestUtils.CountingCompletionListener<ReadContext> completionListener =
             new ListenerTestUtils.CountingCompletionListener<>();
         final CompletableFuture<InputStreamContainer> streamContainerFuture = CompletableFuture.completedFuture(inputStreamContainer);
-        final ReadContext readContext = new ReadContext.Builder().blobSize(size)
-            .asyncPartStreams(List.of(() -> streamContainerFuture))
-            .build();
+        final ReadContext readContext = new ReadContext.Builder(size, List.of(() -> streamContainerFuture)).build();
 
         Mockito.doAnswer(invocation -> {
             ActionListener<ReadContext> readContextActionListener = invocation.getArgument(1);
@@ -105,9 +103,7 @@ public void testReadBlobAsyncException() throws Exception {
         final ListenerTestUtils.CountingCompletionListener<ReadContext> completionListener =
             new ListenerTestUtils.CountingCompletionListener<>();
         final CompletableFuture<InputStreamContainer> streamContainerFuture = CompletableFuture.completedFuture(inputStreamContainer);
-        final ReadContext readContext = new ReadContext.Builder().blobSize(size)
-            .asyncPartStreams(List.of(() -> streamContainerFuture))
-            .build();
+        final ReadContext readContext = new ReadContext.Builder(size, List.of(() -> streamContainerFuture)).build();
 
         Mockito.doAnswer(invocation -> {
             ActionListener<ReadContext> readContextActionListener = invocation.getArgument(1);

server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListenerTests.java

@@ -78,9 +78,7 @@ public void testReadContextListener() throws InterruptedException, IOException {
             UnaryOperator.identity(),
             MAX_CONCURRENT_STREAMS
         );
-        ReadContext readContext = new ReadContext.Builder().blobSize((long) PART_SIZE * NUMBER_OF_PARTS)
-            .asyncPartStreams(blobPartStreams)
-            .build();
+        ReadContext readContext = new ReadContext.Builder((long) PART_SIZE * NUMBER_OF_PARTS, blobPartStreams).build();
         readContextListener.onResponse(readContext);
 
         countDownLatch.await();
@@ -127,9 +125,7 @@ public int available() {
                 threadPool.generic()
             )
         );
-        ReadContext readContext = new ReadContext.Builder().blobSize((long) (PART_SIZE + 1) * NUMBER_OF_PARTS)
-            .asyncPartStreams(blobPartStreams)
-            .build();
+        ReadContext readContext = new ReadContext.Builder((long) (PART_SIZE + 1) * NUMBER_OF_PARTS, blobPartStreams).build();
         readContextListener.onResponse(readContext);
 
         countDownLatch.await();
@@ -182,9 +178,7 @@ public int read(byte[] b) throws IOException {
                 threadPool.generic()
             )
         );
-        ReadContext readContext = new ReadContext.Builder().blobSize((long) (PART_SIZE + 1) * NUMBER_OF_PARTS + 1)
-            .asyncPartStreams(blobPartStreams)
-            .build();
+        ReadContext readContext = new ReadContext.Builder((long) (PART_SIZE + 1) * NUMBER_OF_PARTS + 1, blobPartStreams).build();
         readContextListener.onResponse(readContext);
 
         countDownLatch.await();
@@ -209,9 +203,7 @@ public void testWriteToTempFile_alreadyExists_replacesFile() throws Exception {
             UnaryOperator.identity(),
             MAX_CONCURRENT_STREAMS
         );
-        ReadContext readContext = new ReadContext.Builder().blobSize((long) (PART_SIZE + 1) * NUMBER_OF_PARTS)
-            .asyncPartStreams(blobPartStreams)
-            .build();
+        ReadContext readContext = new ReadContext.Builder((long) (PART_SIZE + 1) * NUMBER_OF_PARTS, blobPartStreams).build();
         readContextListener.onResponse(readContext);
 
         countDownLatch.await();