/**
* 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hdfs.qjournal.protocol.JournalRequestInfo;
import org.apache.hadoop.io.FastWritableCore;
/**
* This class enumerates all FastWritable classes for hdfs, and forces their
* registration. This must be used on server side at startup time, before any
* client requests are served.
*/
public class FastWritableHDFS extends FastWritableCore {
public static final Log LOG = LogFactory.getLog(FastWritableHDFS.class
.getName());
private static boolean initialized = false;
public synchronized static void init() {
if (initialized) {
LOG.info("FastWritable already initialized");
return;
}
// initialize core classes
FastWritableCore.init();
// enumerate all FastWritable classes for hdfs, and force
// initialization
JournalRequestInfo.init();
// initialization is only done once
initialized = true;
LOG.info("FastWritable initialization complete.");
}
}