Add path prefix support to hashed prefix snapshots

Signed-off-by: Ashish Singh <ssashish@amazon.com>

server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java

@@ -338,6 +338,16 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
  Setting.Property.NodeScope
  );
 
+ /**
+ * Controls the fixed prefix for the snapshot shard blob path.
+ */
+ public static final Setting<String> SNAPSHOT_SHARD_PATH_PREFIX = Setting.simpleString(
+ "cluster.snapshot.shard.path.prefix",
+ "",
+ Setting.Property.NodeScope,
+ Setting.Property.Final
+ );
+
  protected volatile boolean supportURLRepo;
 
  private volatile int maxShardBlobDeleteBatch;
@@ -429,6 +439,8 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
 
  private final NamedXContentRegistry namedXContentRegistry;
 
+ private final String snapshotShardPathPrefix;
+
  /**
  * Flag that is set to {@code true} if this instance is started with {@link #metadata} that has a higher value for
  * {@link RepositoryMetadata#pendingGeneration()} than for {@link RepositoryMetadata#generation()} indicating a full cluster restart
@@ -480,6 +492,7 @@ protected BlobStoreRepository(
  this.clusterService = clusterService;
  this.recoverySettings = recoverySettings;
  this.remoteStoreSettings = new RemoteStoreSettings(clusterService.getSettings(), clusterService.getClusterSettings());
+ this.snapshotShardPathPrefix = SNAPSHOT_SHARD_PATH_PREFIX.get(clusterService.getSettings());
  }
 
  @Override
@@ -2687,6 +2700,7 @@ private BlobPath shardPath(IndexId indexId, int shardId) {
  SnapshotShardPathInput shardPathInput = new SnapshotShardPathInput.Builder().basePath(basePath())
  .indexUUID(indexId.getId())
  .shardId(String.valueOf(shardId))
+ .fixedPrefix(snapshotShardPathPrefix)
  .build();
  PathHashAlgorithm pathHashAlgorithm = pathType != PathType.FIXED ? FNV_1A_COMPOSITE_1 : null;
  return pathType.path(shardPathInput, pathHashAlgorithm);

test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java

@@ -403,6 +403,8 @@ public abstract class OpenSearchIntegTestCase extends OpenSearchTestCase {
 
  private static Boolean segmentsPathFixedPrefix;
 
+ private static Boolean snapshotShardPathFixedPrefix;
+
  private Path remoteStoreRepositoryPath;
 
  private ReplicationType randomReplicationType;
@@ -414,6 +416,7 @@ public static void beforeClass() throws Exception {
  prefixModeVerificationEnable = randomBoolean();
  translogPathFixedPrefix = randomBoolean();
  segmentsPathFixedPrefix = randomBoolean();
+ snapshotShardPathFixedPrefix = randomBoolean();
  testClusterRule.beforeClass();
  }
 
@@ -2901,6 +2904,7 @@ private static Settings buildRemoteStoreNodeAttributes(
  settings.put(RemoteStoreSettings.CLUSTER_REMOTE_STORE_PINNED_TIMESTAMP_ENABLED.getKey(), randomBoolean());
  settings.put(RemoteStoreSettings.CLUSTER_REMOTE_STORE_SEGMENTS_PATH_PREFIX.getKey(), translogPathFixedPrefix ? "a" : "");
  settings.put(RemoteStoreSettings.CLUSTER_REMOTE_STORE_TRANSLOG_PATH_PREFIX.getKey(), segmentsPathFixedPrefix ? "b" : "");
+ settings.put(BlobStoreRepository.SNAPSHOT_SHARD_PATH_PREFIX.getKey(), segmentsPathFixedPrefix ? "c" : "");
  return settings.build();
  }