content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.underfs.hdfs;
  
  import alluxio.collections.Pair;
  import alluxio.security.authorization.AccessControlList;
  import alluxio.security.authorization.AclEntry;
  import alluxio.security.authorization.DefaultAccessControlList;
  
  import org.apache.hadoop.fs.FileSystem;
  
  import java.io.IOException;
  import java.util.List;
  import javax.annotation.Nullable;
  
  /**
   * Interface for providing HDFS ACLs.
   */
  public interface HdfsAclProvider {
    /**
     * Returns the {@link AccessControlList} from an hdfs path.
     *
     * @param hdfs the HDFS client
     * @param path the path to retrieve the ACL for
     * @return a Pair object containing the {@link AccessControlList} representation and
     *         the  {@link DefaultAccessControlList} representation or null if ACL is
     *         unsupported/disabled
     * @throws IOException if ACL is supported but cannot be retrieved
     */
    @Nullable
    Pair<AccessControlList, DefaultAccessControlList> getAcl(FileSystem hdfs, String path)
        throws IOException;
  
    /**
     * Sets the ACL and default ACL for an hdfs path using ACL entries.
     *
     * @param hdfs the HDFS client
     * @param path the path to set the ACL entries for
     * @param aclEntries list of AclEntries, could be a representation of {@link AccessControlList}
     *                   or {@link DefaultAccessControlList}
     * @throws IOException if ACL can not be set
     */
    void setAclEntries(FileSystem hdfs, String path, List<AclEntry> aclEntries) throws IOException;
  }
  