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 ACL feature. */
052  public AclFeature getAclFeature();
053
054  /** @return the modification time. */
055  public long getModificationTime();
056
057  /** @return the access time. */
058  public long getAccessTime();
059
060  /** A read-only copy of the inode attributes. */
061  public static abstract class SnapshotCopy implements INodeAttributes {
062    private final byte[] name;
063    private final long permission;
064    private final AclFeature aclFeature;
065    private final long modificationTime;
066    private final long accessTime;
067
068    SnapshotCopy(byte[] name, PermissionStatus permissions,
069        AclFeature aclFeature, long modificationTime, long accessTime) {
070      this.name = name;
071      this.permission = PermissionStatusFormat.toLong(permissions);
072      this.aclFeature = aclFeature;
073      this.modificationTime = modificationTime;
074      this.accessTime = accessTime;
075    }
076
077    SnapshotCopy(INode inode) {
078      this.name = inode.getLocalNameBytes();
079      this.permission = inode.getPermissionLong();
080      this.aclFeature = inode.getAclFeature();
081      this.modificationTime = inode.getModificationTime();
082      this.accessTime = inode.getAccessTime();
083    }
084
085    @Override
086    public final byte[] getLocalNameBytes() {
087      return name;
088    }
089
090    @Override
091    public final String getUserName() {
092      final int n = (int)PermissionStatusFormat.USER.retrieve(permission);
093      return SerialNumberManager.INSTANCE.getUser(n);
094    }
095
096    @Override
097    public final String getGroupName() {
098      final int n = (int)PermissionStatusFormat.GROUP.retrieve(permission);
099      return SerialNumberManager.INSTANCE.getGroup(n);
100    }
101
102    @Override
103    public final FsPermission getFsPermission() {
104      return new FsPermission(getFsPermissionShort());
105    }
106
107    @Override
108    public final short getFsPermissionShort() {
109      return (short)PermissionStatusFormat.MODE.retrieve(permission);
110    }
111    
112    @Override
113    public long getPermissionLong() {
114      return permission;
115    }
116
117    @Override
118    public AclFeature getAclFeature() {
119      return aclFeature;
120    }
121
122    @Override
123    public final long getModificationTime() {
124      return modificationTime;
125    }
126
127    @Override
128    public final long getAccessTime() {
129      return accessTime;
130    }
131  }
132}