org.apache.hadoop.hdfs.server.blockmanagement.BlockCollection 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.blockmanagement;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.ContentSummary;
import org.apache.hadoop.security.AccessControlException;
/**
* This interface is used by the block manager to expose a
* few characteristics of a collection of Block/BlockUnderConstruction.
*/
@InterfaceAudience.Private
public interface BlockCollection {
/**
* Get the last block of the collection.
*/
BlockInfo getLastBlock();
/**
* Get content summary.
*/
ContentSummary computeContentSummary(BlockStoragePolicySuite bsps)
throws AccessControlException;
/**
* @return the number of blocks or block groups
*/
int numBlocks();
/**
* Get the blocks (striped or contiguous).
*/
BlockInfo[] getBlocks();
/**
* Get preferred block size for the collection
* @return preferred block size in bytes
*/
long getPreferredBlockSize();
/**
* Get block replication for the collection.
* @return block replication value. Return 0 if the file is erasure coded.
*/
short getPreferredBlockReplication();
/**
* @return the storage policy ID.
*/
byte getStoragePolicyID();
/**
* Get the name of the collection.
*/
String getName();
/**
* Set the block (contiguous or striped) at the given index.
*/
void setBlock(int index, BlockInfo blk);
/**
* Convert the last block of the collection to an under-construction block
* and set the locations.
*/
void convertLastBlockToUC(BlockInfo lastBlock,
DatanodeStorageInfo[] targets) throws IOException;
/**
* @return whether the block collection is under construction.
*/
boolean isUnderConstruction();
/**
* @return whether the block collection is in striping format
*/
boolean isStriped();
/**
* @return the id for the block collection
*/
long getId();
}