org.apache.hadoop.hdfs.tools.offlineEditsViewer.BinaryEditsVisitor Maven / Gradle / Ivy
/**
* 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.tools.offlineEditsViewer;
import java.io.File;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp;
import org.apache.hadoop.hdfs.server.namenode.EditLogFileOutputStream;
import org.apache.hadoop.hdfs.server.namenode.NameNodeLayoutVersion;
/**
* BinaryEditsVisitor implements a binary EditsVisitor
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class BinaryEditsVisitor implements OfflineEditsVisitor {
final private EditLogFileOutputStream elfos;
/**
* Create a processor that writes to a given file
* @param outputName Name of file to write output to
*/
public BinaryEditsVisitor(String outputName) throws IOException {
this.elfos = new EditLogFileOutputStream(new Configuration(),
new File(outputName), 0);
elfos.create(NameNodeLayoutVersion.CURRENT_LAYOUT_VERSION);
}
/**
* Start the visitor (initialization)
*/
@Override
public void start(int version) throws IOException {
}
/**
* Finish the visitor
*/
@Override
public void close(Throwable error) throws IOException {
elfos.setReadyToFlush();
elfos.flushAndSync(true);
elfos.close();
}
@Override
public void visitOp(FSEditLogOp op) throws IOException {
elfos.write(op);
}
}