hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/resolver/order/OrderedResolver.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hdfs.server.federation.resolver.order;

import org.apache.hadoop.hdfs.server.federation.resolver.PathLocation;


/**
 * Policy that decides which should be the first location accessed given
 * multiple destinations.
 */
public interface OrderedResolver {

  /**
   * Get the first namespace based on this resolver approach.
   *
   * @param path Path to check.
   * @param loc Federated location with multiple destinations.
   * @return First namespace out of the locations.
   */
  String getFirstNamespace(String path, PathLocation loc);
}