org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.MappableBlock 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.ExtendedBlockId;
import java.io.Closeable;
/**
* Represents an HDFS block that is mapped by the DataNode.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public interface MappableBlock extends Closeable {
/**
* Get the number of bytes that have been cached.
* @return the number of bytes that have been cached.
*/
long getLength();
/**
* Get cache address if applicable.
* Return -1 if not applicable.
*/
long getAddress();
/**
* Get cached block's ExtendedBlockId.
* @return cached block's ExtendedBlockId..
*/
ExtendedBlockId getKey();
}