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.hdfs.server.datanode.fsdataset;
019    
020    import java.io.File;
021    import java.io.IOException;
022    
023    /**
024     * This is an interface for the underlying volume.
025     */
026    public interface FsVolumeSpi {
027      /** @return a list of block pools. */
028      public String[] getBlockPoolList();
029    
030      /** @return the available storage space in bytes. */
031      public long getAvailable() throws IOException;
032    
033      /** @return the base path to the volume */
034      public String getBasePath();
035    
036      /** @return the path to the volume */
037      public String getPath(String bpid) throws IOException;
038    
039      /** @return the directory for the finalized blocks in the block pool. */
040      public File getFinalizedDir(String bpid) throws IOException;
041    }