| /** |
| * 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.server.datanode; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.fs.FileUtil; |
| import org.apache.hadoop.fs.HardLink; |
| import org.apache.hadoop.hdfs.protocol.Block; |
| import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi; |
| import org.apache.hadoop.io.IOUtils; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| |
| /** |
| * This class is used by datanodes to maintain meta data of its replicas. |
| * It provides a general interface for meta information of a replica. |
| */ |
| @InterfaceAudience.Private |
| abstract public class ReplicaInfo extends Block implements Replica { |
| |
| /** volume where the replica belongs */ |
| private FsVolumeSpi volume; |
| |
| /** directory where block & meta files belong */ |
| |
| /** |
| * Base directory containing numerically-identified sub directories and |
| * possibly blocks. |
| */ |
| private File baseDir; |
| |
| /** |
| * Whether or not this replica's parent directory includes subdirs, in which |
| * case we can generate them based on the replica's block ID |
| */ |
| private boolean hasSubdirs; |
| |
| private static final Map<String, File> internedBaseDirs = new HashMap<String, File>(); |
| |
| /** |
| * Constructor for a zero length replica |
| * @param blockId block id |
| * @param genStamp replica generation stamp |
| * @param vol volume where replica is located |
| * @param dir directory path where block and meta files are located |
| */ |
| ReplicaInfo(long blockId, long genStamp, FsVolumeSpi vol, File dir) { |
| this( blockId, 0L, genStamp, vol, dir); |
| } |
| |
| /** |
| * Constructor |
| * @param block a block |
| * @param vol volume where replica is located |
| * @param dir directory path where block and meta files are located |
| */ |
| ReplicaInfo(Block block, FsVolumeSpi vol, File dir) { |
| this(block.getBlockId(), block.getNumBytes(), |
| block.getGenerationStamp(), vol, dir); |
| } |
| |
| /** |
| * Constructor |
| * @param blockId block id |
| * @param len replica length |
| * @param genStamp replica generation stamp |
| * @param vol volume where replica is located |
| * @param dir directory path where block and meta files are located |
| */ |
| ReplicaInfo(long blockId, long len, long genStamp, |
| FsVolumeSpi vol, File dir) { |
| super(blockId, len, genStamp); |
| this.volume = vol; |
| setDirInternal(dir); |
| } |
| |
| /** |
| * Copy constructor. |
| * @param from where to copy from |
| */ |
| ReplicaInfo(ReplicaInfo from) { |
| this(from, from.getVolume(), from.getDir()); |
| } |
| |
| /** |
| * Get the full path of this replica's data file |
| * @return the full path of this replica's data file |
| */ |
| public File getBlockFile() { |
| return new File(getDir(), getBlockName()); |
| } |
| |
| /** |
| * Get the full path of this replica's meta file |
| * @return the full path of this replica's meta file |
| */ |
| public File getMetaFile() { |
| return new File(getDir(), |
| DatanodeUtil.getMetaName(getBlockName(), getGenerationStamp())); |
| } |
| |
| /** |
| * Get the volume where this replica is located on disk |
| * @return the volume where this replica is located on disk |
| */ |
| public FsVolumeSpi getVolume() { |
| return volume; |
| } |
| |
| /** |
| * Set the volume where this replica is located on disk |
| */ |
| void setVolume(FsVolumeSpi vol) { |
| this.volume = vol; |
| } |
| |
| /** |
| * Get the storageUuid of the volume that stores this replica. |
| */ |
| @Override |
| public String getStorageUuid() { |
| return volume.getStorageID(); |
| } |
| |
| /** |
| * Return the parent directory path where this replica is located |
| * @return the parent directory path where this replica is located |
| */ |
| File getDir() { |
| return hasSubdirs ? DatanodeUtil.idToBlockDir(baseDir, |
| getBlockId()) : baseDir; |
| } |
| |
| /** |
| * Set the parent directory where this replica is located |
| * @param dir the parent directory where the replica is located |
| */ |
| public void setDir(File dir) { |
| setDirInternal(dir); |
| } |
| |
| private void setDirInternal(File dir) { |
| if (dir == null) { |
| baseDir = null; |
| return; |
| } |
| |
| ReplicaDirInfo dirInfo = parseBaseDir(dir); |
| this.hasSubdirs = dirInfo.hasSubidrs; |
| |
| synchronized (internedBaseDirs) { |
| if (!internedBaseDirs.containsKey(dirInfo.baseDirPath)) { |
| // Create a new String path of this file and make a brand new File object |
| // to guarantee we drop the reference to the underlying char[] storage. |
| File baseDir = new File(dirInfo.baseDirPath); |
| internedBaseDirs.put(dirInfo.baseDirPath, baseDir); |
| } |
| this.baseDir = internedBaseDirs.get(dirInfo.baseDirPath); |
| } |
| } |
| |
| @VisibleForTesting |
| public static class ReplicaDirInfo { |
| public String baseDirPath; |
| public boolean hasSubidrs; |
| |
| public ReplicaDirInfo (String baseDirPath, boolean hasSubidrs) { |
| this.baseDirPath = baseDirPath; |
| this.hasSubidrs = hasSubidrs; |
| } |
| } |
| |
| @VisibleForTesting |
| public static ReplicaDirInfo parseBaseDir(File dir) { |
| |
| File currentDir = dir; |
| boolean hasSubdirs = false; |
| while (currentDir.getName().startsWith(DataStorage.BLOCK_SUBDIR_PREFIX)) { |
| hasSubdirs = true; |
| currentDir = currentDir.getParentFile(); |
| } |
| |
| return new ReplicaDirInfo(currentDir.getAbsolutePath(), hasSubdirs); |
| } |
| |
| /** |
| * check if this replica has already been unlinked. |
| * @return true if the replica has already been unlinked |
| * or no need to be detached; false otherwise |
| */ |
| public boolean isUnlinked() { |
| return true; // no need to be unlinked |
| } |
| |
| /** |
| * set that this replica is unlinked |
| */ |
| public void setUnlinked() { |
| // no need to be unlinked |
| } |
| |
| /** |
| * Copy specified file into a temporary file. Then rename the |
| * temporary file to the original name. This will cause any |
| * hardlinks to the original file to be removed. The temporary |
| * files are created in the same directory. The temporary files will |
| * be recovered (especially on Windows) on datanode restart. |
| */ |
| private void unlinkFile(File file, Block b) throws IOException { |
| File tmpFile = DatanodeUtil.createTmpFile(b, DatanodeUtil.getUnlinkTmpFile(file)); |
| try { |
| FileInputStream in = new FileInputStream(file); |
| try { |
| FileOutputStream out = new FileOutputStream(tmpFile); |
| try { |
| IOUtils.copyBytes(in, out, 16*1024); |
| } finally { |
| out.close(); |
| } |
| } finally { |
| in.close(); |
| } |
| if (file.length() != tmpFile.length()) { |
| throw new IOException("Copy of file " + file + " size " + file.length()+ |
| " into file " + tmpFile + |
| " resulted in a size of " + tmpFile.length()); |
| } |
| FileUtil.replaceFile(tmpFile, file); |
| } catch (IOException e) { |
| boolean done = tmpFile.delete(); |
| if (!done) { |
| DataNode.LOG.info("detachFile failed to delete temporary file " + |
| tmpFile); |
| } |
| throw e; |
| } |
| } |
| |
| /** |
| * Remove a hard link by copying the block to a temporary place and |
| * then moving it back |
| * @param numLinks number of hard links |
| * @return true if copy is successful; |
| * false if it is already detached or no need to be detached |
| * @throws IOException if there is any copy error |
| */ |
| public boolean unlinkBlock(int numLinks) throws IOException { |
| if (isUnlinked()) { |
| return false; |
| } |
| File file = getBlockFile(); |
| if (file == null || getVolume() == null) { |
| throw new IOException("detachBlock:Block not found. " + this); |
| } |
| File meta = getMetaFile(); |
| |
| if (HardLink.getLinkCount(file) > numLinks) { |
| DataNode.LOG.info("CopyOnWrite for block " + this); |
| unlinkFile(file, this); |
| } |
| if (HardLink.getLinkCount(meta) > numLinks) { |
| unlinkFile(meta, this); |
| } |
| setUnlinked(); |
| return true; |
| } |
| |
| /** |
| * Set this replica's generation stamp to be a newer one |
| * @param newGS new generation stamp |
| * @throws IOException is the new generation stamp is not greater than the current one |
| */ |
| void setNewerGenerationStamp(long newGS) throws IOException { |
| long curGS = getGenerationStamp(); |
| if (newGS <= curGS) { |
| throw new IOException("New generation stamp (" + newGS |
| + ") must be greater than current one (" + curGS + ")"); |
| } |
| setGenerationStamp(newGS); |
| } |
| |
| @Override //Object |
| public String toString() { |
| return getClass().getSimpleName() |
| + ", " + super.toString() |
| + ", " + getState() |
| + "\n getNumBytes() = " + getNumBytes() |
| + "\n getBytesOnDisk() = " + getBytesOnDisk() |
| + "\n getVisibleLength()= " + getVisibleLength() |
| + "\n getVolume() = " + getVolume() |
| + "\n getBlockFile() = " + getBlockFile(); |
| } |
| } |