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 */
018package org.apache.hadoop.hdfs.server.namenode;
019
020import org.apache.hadoop.classification.InterfaceAudience;
021import org.apache.hadoop.fs.permission.FsPermission;
022import org.apache.hadoop.fs.permission.PermissionStatus;
023import org.apache.hadoop.hdfs.server.namenode.INodeWithAdditionalFields.PermissionStatusFormat;
024
025/**
026 * The attributes of an inode.
027 */
028@InterfaceAudience.Private
029public interface INodeAttributes {
030  /**
031   * @return null if the local name is null;
032   *         otherwise, return the local name byte array.
033   */
034  public byte[] getLocalNameBytes();
035
036  /** @return the user name. */
037  public String getUserName();
038
039  /** @return the group name. */
040  public String getGroupName();
041  
042  /** @return the permission. */
043  public FsPermission getFsPermission();
044
045  /** @return the permission as a short. */
046  public short getFsPermissionShort();
047  
048  /** @return the permission information as a long. */
049  public long getPermissionLong();
050
051  /** @return the modification time. */
052  public long getModificationTime();
053
054  /** @return the access time. */
055  public long getAccessTime();
056
057  /** A read-only copy of the inode attributes. */
058  public static abstract class SnapshotCopy implements INodeAttributes {
059    private final byte[] name;
060    private final long permission;
061    private final long modificationTime;
062    private final long accessTime;
063
064    SnapshotCopy(byte[] name, PermissionStatus permissions,
065        long modificationTime, long accessTime) {
066      this.name = name;
067      this.permission = PermissionStatusFormat.toLong(permissions);
068      this.modificationTime = modificationTime;
069      this.accessTime = accessTime;
070    }
071
072    SnapshotCopy(INode inode) {
073      this.name = inode.getLocalNameBytes();
074      this.permission = inode.getPermissionLong();
075      this.modificationTime = inode.getModificationTime();
076      this.accessTime = inode.getAccessTime();
077    }
078
079    @Override
080    public final byte[] getLocalNameBytes() {
081      return name;
082    }
083
084    @Override
085    public final String getUserName() {
086      final int n = (int)PermissionStatusFormat.USER.retrieve(permission);
087      return SerialNumberManager.INSTANCE.getUser(n);
088    }
089
090    @Override
091    public final String getGroupName() {
092      final int n = (int)PermissionStatusFormat.GROUP.retrieve(permission);
093      return SerialNumberManager.INSTANCE.getGroup(n);
094    }
095
096    @Override
097    public final FsPermission getFsPermission() {
098      return new FsPermission(getFsPermissionShort());
099    }
100
101    @Override
102    public final short getFsPermissionShort() {
103      return (short)PermissionStatusFormat.MODE.retrieve(permission);
104    }
105    
106    @Override
107    public long getPermissionLong() {
108      return permission;
109    }
110
111    @Override
112    public final long getModificationTime() {
113      return modificationTime;
114    }
115
116    @Override
117    public final long getAccessTime() {
118      return accessTime;
119    }
120  }
121}