org.apache.hadoop.hdfs.RaidDFSUtil.java Source code

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Here is the source code for org.apache.hadoop.hdfs.RaidDFSUtil.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.hdfs;

import java.io.IOException;
import java.io.OutputStream;
import java.util.LinkedList;
import java.util.List;
import java.util.Random;
import java.util.zip.CRC32;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.raid.RaidCodec;

public abstract class RaidDFSUtil {
    public static final String[] codes = new String[] { "xor", "rs" };
    final static Log LOG = LogFactory.getLog(RaidDFSUtil.class);
    final static Random random = new Random();

    /**
     * This function create two mock source and parity files and merge them.
     */
    public static void constructFakeRaidFile(DistributedFileSystem dfs, String filePath, RaidCodec codec)
            throws IOException {
        long blockSize = 512L;
        byte[] buffer = new byte[(int) (codec.numDataBlocks * blockSize)];
        int[] checksum = new int[codec.numDataBlocks];

        OutputStream out = dfs.create(new Path(filePath), true, 1, codec.parityReplication, blockSize);
        random.nextBytes(buffer);
        out.write(buffer);
        out.close();

        Path parityTmp = new Path(filePath + "_parity");
        buffer = new byte[(int) (codec.numParityBlocks * blockSize)];
        out = dfs.create(parityTmp, true, 1, codec.parityReplication, blockSize);
        random.nextBytes(buffer);
        out.write(buffer);
        out.close();

        FileStatus stat = dfs.getFileStatus(new Path(filePath));
        dfs.setTimes(parityTmp, stat.getModificationTime(), stat.getAccessTime());

        dfs.merge(parityTmp, new Path(filePath), codec.id, checksum);

    }

    /**
     * Returns the corrupt blocks in a file.
     */
    public static List<LocatedBlock> corruptBlocksInFile(DistributedFileSystem dfs, String path, long offset,
            long length) throws IOException {
        List<LocatedBlock> corrupt = new LinkedList<LocatedBlock>();
        LocatedBlocks locatedBlocks = getBlockLocations(dfs, path, offset, length);
        for (LocatedBlock b : locatedBlocks.getLocatedBlocks()) {
            if (b.isCorrupt() || (b.getLocations().length == 0 && b.getBlockSize() > 0)) {
                corrupt.add(b);
            }
        }
        return corrupt;
    }

    public static LocatedBlocks getBlockLocations(DistributedFileSystem dfs, String path, long offset, long length)
            throws IOException {
        return dfs.getClient().namenode.getBlockLocations(path, offset, length);
    }

    public static long getCRC(FileSystem fs, Path p) throws IOException {
        CRC32 crc = new CRC32();
        FSDataInputStream stm = fs.open(p);
        int b;
        while ((b = stm.read()) >= 0) {
            crc.update(b);
        }
        stm.close();
        return crc.getValue();
    }

    public static void cleanUp(FileSystem fileSys, Path dir) throws IOException {
        if (fileSys.exists(dir)) {
            fileSys.delete(dir, true);
        }
    }

    public static void reportCorruptBlocks(FileSystem fs, Path file, int[] idxs, long blockSize)
            throws IOException {
        DistributedFileSystem dfs = (DistributedFileSystem) fs;
        LocatedBlocks lbs = dfs.getLocatedBlocks(file, 0L, fs.getFileStatus(file).getLen());
        LocatedBlock[] lbArray = new LocatedBlock[idxs.length];
        for (int i = 0; i < idxs.length; i++) {
            lbArray[i] = lbs.get(idxs[i]);
        }
        reportCorruptBlocksToNN(dfs, lbArray);
    }

    public static void reportCorruptBlocksToNN(DistributedFileSystem dfs, LocatedBlock[] blocks)
            throws IOException {
        dfs.getClient().namenode.reportBadBlocks(blocks);
    }
}