Refactor remote writeable entity and store to make it more reusable

Signed-off-by: Bukhtawar Khan <bukhtawa@amazon.com>

server/src/main/java/org/opensearch/cluster/routing/remote/InternalRemoteRoutingTableService.java

@@ -20,14 +20,15 @@
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.common.remote.RemoteWritableEntityStore;
+import org.opensearch.common.remote.RemoteWriteableEntityBlobStore;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.compress.Compressor;
 import org.opensearch.gateway.remote.ClusterMetadataManifest;
+import org.opensearch.gateway.remote.RemoteClusterStateUtils;
 import org.opensearch.gateway.remote.RemoteStateTransferException;
-import org.opensearch.gateway.remote.model.RemoteClusterStateBlobStore;
 import org.opensearch.gateway.remote.model.RemoteRoutingTableBlobStore;
 import org.opensearch.gateway.remote.routingtable.RemoteIndexRoutingTable;
 import org.opensearch.gateway.remote.routingtable.RemoteRoutingTableDiff;
@@ -262,12 +263,13 @@ protected void doStart() {
             clusterSettings
         );
 
-        this.remoteRoutingTableDiffStore = new RemoteClusterStateBlobStore<>(
+        this.remoteRoutingTableDiffStore = new RemoteWriteableEntityBlobStore<>(
             new BlobStoreTransferService(blobStoreRepository.blobStore(), threadPool),
             blobStoreRepository,
             clusterName,
             threadPool,
-            ThreadPool.Names.REMOTE_STATE_READ
+            ThreadPool.Names.REMOTE_STATE_READ,
+            RemoteClusterStateUtils.CLUSTER_STATE_PATH_TOKEN
         );
     }
 

server/src/main/java/org/opensearch/common/remote/AbstractClusterMetadataWriteableBlobEntity.java

@@ -0,0 +1,43 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.remote;
+
+import org.opensearch.core.compress.Compressor;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.gateway.remote.ClusterMetadataManifest.UploadedMetadata;
+
+/**
+ * An extension of {@link RemoteWriteableEntity} class which caters to the use case of writing to and reading from a blob storage
+ *
+ * @param <T> The class type which can be uploaded to or downloaded from a blob storage.
+ */
+public abstract class AbstractClusterMetadataWriteableBlobEntity<T> extends RemoteWriteableBlobEntity<T> {
+
+    protected final NamedXContentRegistry namedXContentRegistry;
+
+    public AbstractClusterMetadataWriteableBlobEntity(
+        final String clusterUUID,
+        final Compressor compressor,
+        final NamedXContentRegistry namedXContentRegistry
+    ) {
+        super(clusterUUID, compressor);
+        this.namedXContentRegistry = namedXContentRegistry;
+    }
+
+    public AbstractClusterMetadataWriteableBlobEntity(final String clusterUUID, final Compressor compressor) {
+        super(clusterUUID, compressor);
+        this.namedXContentRegistry = null;
+    }
+
+    public abstract UploadedMetadata getUploadedMetadata();
+
+    public NamedXContentRegistry getNamedXContentRegistry() {
+        return namedXContentRegistry;
+    }
+}

server/src/main/java/org/opensearch/common/remote/AbstractRemoteWritableEntityManager.java

@@ -31,7 +31,7 @@ public abstract class AbstractRemoteWritableEntityManager implements RemoteWrita
      * @return the remote writable entity store for the given entity
      * @throws IllegalArgumentException if the entity type is unknown
      */
-    protected RemoteWritableEntityStore getStore(AbstractRemoteWritableBlobEntity entity) {
+    protected RemoteWritableEntityStore getStore(AbstractClusterMetadataWriteableBlobEntity entity) {
         RemoteWritableEntityStore remoteStore = remoteWritableEntityStores.get(entity.getType());
         if (remoteStore == null) {
             throw new IllegalArgumentException("Unknown entity type [" + entity.getType() + "]");
@@ -49,7 +49,7 @@ protected RemoteWritableEntityStore getStore(AbstractRemoteWritableBlobEntity en
      */
     protected abstract ActionListener<Void> getWrappedWriteListener(
         String component,
-        AbstractRemoteWritableBlobEntity remoteEntity,
+        AbstractClusterMetadataWriteableBlobEntity remoteEntity,
         ActionListener<ClusterMetadataManifest.UploadedMetadata> listener
     );
 
@@ -64,21 +64,21 @@ protected abstract ActionListener<Void> getWrappedWriteListener(
      */
     protected abstract ActionListener<Object> getWrappedReadListener(
         String component,
-        AbstractRemoteWritableBlobEntity remoteEntity,
+        AbstractClusterMetadataWriteableBlobEntity remoteEntity,
         ActionListener<RemoteReadResult> listener
     );
 
     @Override
     public void writeAsync(
         String component,
-        AbstractRemoteWritableBlobEntity entity,
+        AbstractClusterMetadataWriteableBlobEntity entity,
         ActionListener<ClusterMetadataManifest.UploadedMetadata> listener
     ) {
         getStore(entity).writeAsync(entity, getWrappedWriteListener(component, entity, listener));
     }
 
     @Override
-    public void readAsync(String component, AbstractRemoteWritableBlobEntity entity, ActionListener<RemoteReadResult> listener) {
+    public void readAsync(String component, AbstractClusterMetadataWriteableBlobEntity entity, ActionListener<RemoteReadResult> listener) {
         getStore(entity).readAsync(entity, getWrappedReadListener(component, entity, listener));
     }
 }

server/src/main/java/org/opensearch/common/remote/RemoteWritableEntityManager.java

@@ -29,7 +29,7 @@ public interface RemoteWritableEntityManager {
      *                 {@link ActionListener#onFailure(Exception)} method is called with
      *                 an exception if the read operation fails.
      */
-    void readAsync(String component, AbstractRemoteWritableBlobEntity entity, ActionListener<RemoteReadResult> listener);
+    void readAsync(String component, AbstractClusterMetadataWriteableBlobEntity entity, ActionListener<RemoteReadResult> listener);
 
     /**
      * Performs an asynchronous write operation for the specified component and entity.
@@ -43,5 +43,5 @@ public interface RemoteWritableEntityManager {
      *                 {@link ActionListener#onFailure(Exception)} method is called with
      *                 an exception if the write operation fails.
      */
-    void writeAsync(String component, AbstractRemoteWritableBlobEntity entity, ActionListener<UploadedMetadata> listener);
+    void writeAsync(String component, AbstractClusterMetadataWriteableBlobEntity entity, ActionListener<UploadedMetadata> listener);
 }

server/src/main/java/org/opensearch/common/remote/AbstractRemoteWritableBlobEntity.java → server/src/main/java/org/opensearch/common/remote/RemoteWriteableBlobEntity.java

@@ -10,38 +10,25 @@
 
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.core.compress.Compressor;
-import org.opensearch.core.xcontent.NamedXContentRegistry;
-import org.opensearch.gateway.remote.ClusterMetadataManifest.UploadedMetadata;
 
 import static org.opensearch.gateway.remote.RemoteClusterStateUtils.PATH_DELIMITER;
 
 /**
- * An extension of {@link RemoteWriteableEntity} class which caters to the use case of writing to and reading from a blob storage
- *
- * @param <T> The class type which can be uploaded to or downloaded from a blob storage.
+ * The abstract class which represents a {@link RemoteWriteableEntity} that can be written to a store
+ * @param <T>
  */
-public abstract class AbstractRemoteWritableBlobEntity<T> implements RemoteWriteableEntity<T> {
+public abstract class RemoteWriteableBlobEntity<T> implements RemoteWriteableEntity<T> {
 
     protected String blobFileName;
 
     protected String blobName;
     private final String clusterUUID;
     private final Compressor compressor;
-    private final NamedXContentRegistry namedXContentRegistry;
     private String[] pathTokens;
 
-    public AbstractRemoteWritableBlobEntity(
-        final String clusterUUID,
-        final Compressor compressor,
-        final NamedXContentRegistry namedXContentRegistry
-    ) {
+    public RemoteWriteableBlobEntity(final String clusterUUID, final Compressor compressor) {
         this.clusterUUID = clusterUUID;
         this.compressor = compressor;
-        this.namedXContentRegistry = namedXContentRegistry;
-    }
-
-    public AbstractRemoteWritableBlobEntity(final String clusterUUID, final Compressor compressor) {
-        this(clusterUUID, compressor, null);
     }
 
     public abstract BlobPathParameters getBlobPathParameters();
@@ -80,16 +67,10 @@ public String clusterUUID() {
         return clusterUUID;
     }
 
-    public abstract UploadedMetadata getUploadedMetadata();
-
     public void setFullBlobName(BlobPath blobPath) {
         this.blobName = blobPath.buildAsString() + blobFileName;
     }
 
-    public NamedXContentRegistry getNamedXContentRegistry() {
-        return namedXContentRegistry;
-    }
-
     protected Compressor getCompressor() {
         return compressor;
     }

server/src/main/java/org/opensearch/gateway/remote/model/RemoteClusterStateBlobStore.java → server/src/main/java/org/opensearch/common/remote/RemoteWriteableEntityBlobStore.java

@@ -6,49 +6,48 @@
  * compatible open source license.
  */
 
-package org.opensearch.gateway.remote.model;
+package org.opensearch.common.remote;
 
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.blobstore.stream.write.WritePriority;
-import org.opensearch.common.remote.AbstractRemoteWritableBlobEntity;
-import org.opensearch.common.remote.RemoteWritableEntityStore;
-import org.opensearch.common.remote.RemoteWriteableEntity;
 import org.opensearch.core.action.ActionListener;
-import org.opensearch.gateway.remote.RemoteClusterStateUtils;
 import org.opensearch.index.translog.transfer.BlobStoreTransferService;
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 import java.util.concurrent.ExecutorService;
 
-import static org.opensearch.gateway.remote.RemoteClusterStateUtils.CLUSTER_STATE_PATH_TOKEN;
-
 /**
  * Abstract class for a blob type storage
  *
  * @param <T> The entity which can be uploaded to / downloaded from blob store
  * @param <U> The concrete class implementing {@link RemoteWriteableEntity} which is used as a wrapper for T entity.
  */
-public class RemoteClusterStateBlobStore<T, U extends AbstractRemoteWritableBlobEntity<T>> implements RemoteWritableEntityStore<T, U> {
+public class RemoteWriteableEntityBlobStore<T, U extends RemoteWriteableBlobEntity<T>> implements RemoteWritableEntityStore<T, U> {
 
     private final BlobStoreTransferService transferService;
     private final BlobStoreRepository blobStoreRepository;
     private final String clusterName;
     private final ExecutorService executorService;
+    private final String pathToken;
 
-    public RemoteClusterStateBlobStore(
+    public RemoteWriteableEntityBlobStore(
         final BlobStoreTransferService blobStoreTransferService,
         final BlobStoreRepository blobStoreRepository,
         final String clusterName,
         final ThreadPool threadPool,
-        final String executor
+        final String executor,
+        final String pathToken
     ) {
         this.transferService = blobStoreTransferService;
         this.blobStoreRepository = blobStoreRepository;
         this.clusterName = clusterName;
         this.executorService = threadPool.executor(executor);
+        this.pathToken = pathToken;
     }
 
     @Override
@@ -95,21 +94,18 @@ public String getClusterName() {
     }
 
     public BlobPath getBlobPathPrefix(String clusterUUID) {
-        return blobStoreRepository.basePath()
-            .add(RemoteClusterStateUtils.encodeString(getClusterName()))
-            .add(CLUSTER_STATE_PATH_TOKEN)
-            .add(clusterUUID);
+        return blobStoreRepository.basePath().add(encodeString(getClusterName())).add(pathToken).add(clusterUUID);
     }
 
-    public BlobPath getBlobPathForUpload(final AbstractRemoteWritableBlobEntity<T> obj) {
+    public BlobPath getBlobPathForUpload(final RemoteWriteableBlobEntity<T> obj) {
         BlobPath blobPath = getBlobPathPrefix(obj.clusterUUID());
         for (String token : obj.getBlobPathParameters().getPathTokens()) {
             blobPath = blobPath.add(token);
         }
         return blobPath;
     }
 
-    public BlobPath getBlobPathForDownload(final AbstractRemoteWritableBlobEntity<T> obj) {
+    public BlobPath getBlobPathForDownload(final RemoteWriteableBlobEntity<T> obj) {
         String[] pathTokens = obj.getBlobPathTokens();
         BlobPath blobPath = new BlobPath();
         if (pathTokens == null || pathTokens.length < 1) {
@@ -122,4 +118,8 @@ public BlobPath getBlobPathForDownload(final AbstractRemoteWritableBlobEntity<T>
         return blobPath;
     }
 
+    private static String encodeString(String content) {
+        return Base64.getUrlEncoder().withoutPadding().encodeToString(content.getBytes(StandardCharsets.UTF_8));
+    }
+
 }

server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateAttributesManager.java

@@ -11,12 +11,12 @@
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.DiffableUtils;
 import org.opensearch.cluster.DiffableUtils.NonDiffableValueSerializer;
-import org.opensearch.common.remote.AbstractRemoteWritableBlobEntity;
+import org.opensearch.common.remote.AbstractClusterMetadataWriteableBlobEntity;
 import org.opensearch.common.remote.AbstractRemoteWritableEntityManager;
+import org.opensearch.common.remote.RemoteWriteableEntityBlobStore;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.gateway.remote.model.RemoteClusterBlocks;
-import org.opensearch.gateway.remote.model.RemoteClusterStateBlobStore;
 import org.opensearch.gateway.remote.model.RemoteClusterStateCustoms;
 import org.opensearch.gateway.remote.model.RemoteDiscoveryNodes;
 import org.opensearch.gateway.remote.model.RemoteReadResult;
@@ -28,7 +28,7 @@
 import java.util.Map;
 
 /**
- * A Manager which provides APIs to upload and download attributes of ClusterState to the {@link RemoteClusterStateBlobStore}
+ * A Manager which provides APIs to upload and download attributes of ClusterState to the {@link RemoteWriteableEntityBlobStore}
  *
  * @opensearch.internal
  */
@@ -47,40 +47,43 @@ public class RemoteClusterStateAttributesManager extends AbstractRemoteWritableE
     ) {
         this.remoteWritableEntityStores.put(
             RemoteDiscoveryNodes.DISCOVERY_NODES,
-            new RemoteClusterStateBlobStore<>(
+            new RemoteWriteableEntityBlobStore<>(
                 blobStoreTransferService,
                 blobStoreRepository,
                 clusterName,
                 threadpool,
-                ThreadPool.Names.REMOTE_STATE_READ
+                ThreadPool.Names.REMOTE_STATE_READ,
+                RemoteClusterStateUtils.CLUSTER_STATE_PATH_TOKEN
             )
         );
         this.remoteWritableEntityStores.put(
             RemoteClusterBlocks.CLUSTER_BLOCKS,
-            new RemoteClusterStateBlobStore<>(
+            new RemoteWriteableEntityBlobStore<>(
                 blobStoreTransferService,
                 blobStoreRepository,
                 clusterName,
                 threadpool,
-                ThreadPool.Names.REMOTE_STATE_READ
+                ThreadPool.Names.REMOTE_STATE_READ,
+                RemoteClusterStateUtils.CLUSTER_STATE_PATH_TOKEN
             )
         );
         this.remoteWritableEntityStores.put(
             RemoteClusterStateCustoms.CLUSTER_STATE_CUSTOM,
-            new RemoteClusterStateBlobStore<>(
+            new RemoteWriteableEntityBlobStore<>(
                 blobStoreTransferService,
                 blobStoreRepository,
                 clusterName,
                 threadpool,
-                ThreadPool.Names.REMOTE_STATE_READ
+                ThreadPool.Names.REMOTE_STATE_READ,
+                RemoteClusterStateUtils.CLUSTER_STATE_PATH_TOKEN
             )
         );
     }
 
     @Override
     protected ActionListener<Void> getWrappedWriteListener(
         String component,
-        AbstractRemoteWritableBlobEntity remoteEntity,
+        AbstractClusterMetadataWriteableBlobEntity remoteEntity,
         ActionListener<ClusterMetadataManifest.UploadedMetadata> listener
     ) {
         return ActionListener.wrap(
@@ -92,7 +95,7 @@ protected ActionListener<Void> getWrappedWriteListener(
     @Override
     protected ActionListener<Object> getWrappedReadListener(
         String component,
-        AbstractRemoteWritableBlobEntity remoteEntity,
+        AbstractClusterMetadataWriteableBlobEntity remoteEntity,
         ActionListener<RemoteReadResult> listener
     ) {
         return ActionListener.wrap(