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
019 package org.apache.hadoop.fs;
020
021 import java.io.IOException;
022 import java.util.EnumSet;
023
024 import org.apache.hadoop.HadoopIllegalArgumentException;
025 import org.apache.hadoop.classification.InterfaceAudience;
026 import org.apache.hadoop.classification.InterfaceStability;
027
028 @InterfaceAudience.Public
029 @InterfaceStability.Stable
030 public 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 }