001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.fs;
020
021import java.io.IOException;
022import java.util.EnumSet;
023
024import org.apache.hadoop.HadoopIllegalArgumentException;
025import org.apache.hadoop.classification.InterfaceAudience;
026import org.apache.hadoop.classification.InterfaceStability;
027
028@InterfaceAudience.Public
029@InterfaceStability.Stable
030public enum XAttrSetFlag {
031  /**
032   * Create a new xattr.
033   * If the xattr exists already, exception will be thrown.
034   */
035  CREATE((short) 0x01),
036
037  /**
038   * Replace a existing xattr.
039   * If the xattr does not exist, exception will be thrown.
040   */
041  REPLACE((short) 0x02);
042
043  private final short flag;
044
045  private XAttrSetFlag(short flag) {
046    this.flag = flag;
047  }
048
049  short getFlag() {
050    return flag;
051  }
052
053  public static void validate(String xAttrName, boolean xAttrExists,
054      EnumSet<XAttrSetFlag> flag) throws IOException {
055    if (flag == null || flag.isEmpty()) {
056      throw new HadoopIllegalArgumentException("A flag must be specified.");
057    }
058
059    if (xAttrExists) {
060      if (!flag.contains(REPLACE)) {
061        throw new IOException("XAttr: " + xAttrName +
062            " already exists. The REPLACE flag must be specified.");
063      }
064    } else {
065      if (!flag.contains(CREATE)) {
066        throw new IOException("XAttr: " + xAttrName +
067            " does not exist. The CREATE flag must be specified.");
068      }
069    }
070  }
071}