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.s3a;
  
  import com.amazonaws.services.s3.model.AccessControlList;
  import com.amazonaws.services.s3.model.Grant;
  import com.amazonaws.services.s3.model.Grantee;
  import com.amazonaws.services.s3.model.GroupGrantee;
  import com.amazonaws.services.s3.model.Permission;
  
  /**
   * Util functions for S3A under file system.
   */
  public final class S3AUtils {
    /**
     * Translates S3 bucket ACL to Alluxio owner mode.
     *
     * @param acl the acl of S3 bucket
     * @param userId the S3 user id of the Alluxio owner
     * @return the translated posix mode in short format
     */
    public static short translateBucketAcl(AccessControlList acl, String userId) {
      short mode = (short) 0;
      for (Grant grant : acl.getGrantsAsList()) {
        Permission perm = grant.getPermission();
        Grantee grantee = grant.getGrantee();
        if (perm.equals(Permission.Read)) {
          if (isUserIdInGrantee(grantee, userId)) {
            // If the bucket is readable by the user, add r and x to the owner mode.
            mode |= (short) 0500;
          }
        } else if (perm.equals(Permission.Write)) {
          if (isUserIdInGrantee(grantee, userId)) {
            // If the bucket is writable by the user, +w to the owner mode.
            mode |= (short) 0200;
          }
        } else if (perm.equals(Permission.FullControl)) {
          if (isUserIdInGrantee(grantee, userId)) {
            // If the user has full control to the bucket, +rwx to the owner mode.
            mode |= (short) 0700;
          }
        }
      }
      return mode;
    }
  
    private static boolean isUserIdInGrantee(Grantee grantee, String userId) {
      return grantee.getIdentifier() != null && grantee.getIdentifier().equals(userId)
          || grantee.equals(GroupGrantee.AllUsers)
          || grantee.equals(GroupGrantee.AuthenticatedUsers);
    }
  
    private S3AUtils() {} // prevent instantiation
  }
  