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    package org.apache.hadoop.fs.viewfs;
019    
020    import org.apache.hadoop.fs.permission.FsPermission;
021    
022    /**
023     * Config variable prefixes for ViewFs -
024     *     see {@link org.apache.hadoop.fs.viewfs.ViewFs} for examples.
025     * The mount table is specified in the config using these prefixes.
026     * See {@link org.apache.hadoop.fs.viewfs.ConfigUtil} for convenience lib.
027     */
028    public interface Constants {
029      /**
030       * Prefix for the config variable prefix for the ViewFs mount-table
031       */
032      public static final String CONFIG_VIEWFS_PREFIX = "fs.viewfs.mounttable";
033     
034      /**
035       * Prefix for the home dir for the mount table - if not specified
036       * then the hadoop default value (/user) is used.
037       */
038      public static final String CONFIG_VIEWFS_HOMEDIR = "homedir";
039      
040      /**
041       * Config variable name for the default mount table.
042       */
043      public static final String CONFIG_VIEWFS_DEFAULT_MOUNT_TABLE = "default";
044      
045      /**
046       * Config variable full prefix for the default mount table.
047       */
048      public static final String CONFIG_VIEWFS_PREFIX_DEFAULT_MOUNT_TABLE = 
049              CONFIG_VIEWFS_PREFIX + "." + CONFIG_VIEWFS_DEFAULT_MOUNT_TABLE;
050      
051      /**
052       * Config variable for specifying a simple link
053       */
054      public static final String CONFIG_VIEWFS_LINK = "link";
055      
056      /**
057       * Config variable for specifying a merge link
058       */
059      public static final String CONFIG_VIEWFS_LINK_MERGE = "linkMerge";
060      
061      /**
062       * Config variable for specifying a merge of the root of the mount-table
063       *  with the root of another file system. 
064       */
065      public static final String CONFIG_VIEWFS_LINK_MERGE_SLASH = "linkMergeSlash";
066    
067      static public final FsPermission PERMISSION_RRR = 
068        new FsPermission((short) 0444);
069    }