/**
* 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.fsdataset.impl;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.server.common.GenerationStamp;
import org.apache.hadoop.hdfs.server.datanode.DatanodeUtil;
import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.util.Arrays;
/**
* Utility methods.
*/
@InterfaceAudience.Private
public class FsDatasetUtil {
static boolean isUnlinkTmpFile(File f) {
return f.getName().endsWith(DatanodeUtil.UNLINK_BLOCK_SUFFIX);
}
static File getOrigFile(File unlinkTmpFile) {
final String name = unlinkTmpFile.getName();
if (!name.endsWith(DatanodeUtil.UNLINK_BLOCK_SUFFIX)) {
throw new IllegalArgumentException(
"unlinkTmpFile=" + unlinkTmpFile + " does not end with " +
DatanodeUtil.UNLINK_BLOCK_SUFFIX);
}
final int n = name.length() - DatanodeUtil.UNLINK_BLOCK_SUFFIX.length();
return new File(unlinkTmpFile.getParentFile(), name.substring(0, n));
}
static File getMetaFile(File f, long gs) {
return new File(f.getParent(), DatanodeUtil.getMetaName(f.getName(), gs));
}
/**
* Find the corresponding meta data file from a given block file
*/
static File findMetaFile(final File blockFile) throws IOException {
final String prefix = blockFile.getName() + "_";
final File parent = blockFile.getParentFile();
final File[] matches = parent.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return dir.equals(parent) && name.startsWith(prefix) &&
name.endsWith(Block.METADATA_EXTENSION);
}
});
if (matches == null || matches.length == 0) {
throw new IOException("Meta file not found, blockFile=" + blockFile);
}
if (matches.length > 1) {
throw new IOException(
"Found more than one meta files: " + Arrays.asList(matches));
}
return matches[0];
}
/**
* Find the meta-file for the specified block file
* and then return the generation stamp from the name of the meta-file.
*/
static long getGenerationStampFromFile(File[] listdir, File blockFile) {
String blockName = blockFile.getName();
for (int j = 0; j < listdir.length; j++) {
String fileName = listdir[j].getName();
if (!fileName.startsWith(blockName)) {
continue;
}
if (blockFile == listdir[j]) {
continue;
}
String blkName = blockFile.getName();
if (fileName.startsWith(blkName + "_")) {
return Block.getGenerationStamp(listdir[j].getName());
}
}
FsDatasetImpl.LOG.warn("Block " + blockFile + " does not have a metafile!");
return GenerationStamp.GRANDFATHER_GENERATION_STAMP;
}
/**
* Find the corresponding meta data file from a given block file
*/
static long parseGenerationStamp(File blockFile, File metaFile)
throws IOException {
final String metaname = metaFile.getName();
final String gs = metaname.substring(blockFile.getName().length() + 1,
metaname.length() - Block.METADATA_EXTENSION.length());
try {
return Long.parseLong(gs);
} catch (NumberFormatException nfe) {
throw new IOException(
"Failed to parse generation stamp: blockFile=" + blockFile +
", metaFile=" + metaFile, nfe);
}
}
}