org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.MappableBlockLoaderFactory 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.server.datanode.fsdataset.impl;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.hdfs.server.datanode.DNConf;
import org.apache.hadoop.io.nativeio.NativeIO;
/**
* Creates MappableBlockLoader.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public final class MappableBlockLoaderFactory {
private MappableBlockLoaderFactory() {
// Prevent instantiation
}
/**
* Create a specific cache loader according to the configuration.
* If persistent memory volume is not configured, return a cache loader
* for DRAM cache. Otherwise, return a cache loader for pmem cache.
*/
public static MappableBlockLoader createCacheLoader(DNConf conf) {
if (conf.getPmemVolumes() == null || conf.getPmemVolumes().length == 0) {
return new MemoryMappableBlockLoader();
}
if (NativeIO.isAvailable() && NativeIO.POSIX.isPmdkAvailable()) {
return new NativePmemMappableBlockLoader();
}
return new PmemMappableBlockLoader();
}
}