/**
* 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;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
/**
* This represents block replicas which are stored in DataNode.
*/
@InterfaceAudience.Private
public interface Replica {
/** Get the block ID */
public long getBlockId();
/** Get the generation stamp */
public long getGenerationStamp();
/**
* Get the replica state
* @return the replica state
*/
public ReplicaState getState();
/**
* Get the number of bytes received
* @return the number of bytes that have been received
*/
public long getNumBytes();
/**
* Get the number of bytes that have written to disk
* @return the number of bytes that have written to disk
*/
public long getBytesOnDisk();
/**
* Get the number of bytes that are visible to readers
* @return the number of bytes that are visible to readers
*/
public long getVisibleLength();
}