ayushtkn commented on a change in pull request #1819: HDFS-14989. Add a 'swapBlockList' operation to Namenode. URL: https://github.com/apache/hadoop/pull/1819#discussion_r371324385
########## File path: hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/SwapBlockListOp.java ########## @@ -0,0 +1,190 @@ +/** + * 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.namenode; + +import java.io.FileNotFoundException; +import java.io.IOException; + +import org.apache.hadoop.fs.FileAlreadyExistsException; +import org.apache.hadoop.fs.FileStatus; +import org.apache.hadoop.fs.permission.FsAction; +import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo; +import org.apache.hadoop.hdfs.server.namenode.FSDirectory.DirOp; +import org.apache.hadoop.hdfs.server.namenode.INodeFile.HeaderFormat; +import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot; +import org.apache.hadoop.util.Time; + +/** + * Class to carry out the operation of swapping blocks from one file to another. + * Along with swapping blocks, we can also optionally swap the block layout + * of a file header, which is useful for client operations like converting + * replicated to EC file. + */ +public final class SwapBlockListOp { + + private SwapBlockListOp() { + } + + static SwapBlockListResult swapBlocks(FSDirectory fsd, FSPermissionChecker pc, + String src, String dst, long genTimestamp) + throws IOException { + + final INodesInPath srcIIP = fsd.resolvePath(pc, src, DirOp.WRITE); + final INodesInPath dstIIP = fsd.resolvePath(pc, dst, DirOp.WRITE); + if (fsd.isPermissionEnabled()) { + fsd.checkAncestorAccess(pc, srcIIP, FsAction.WRITE); + fsd.checkAncestorAccess(pc, dstIIP, FsAction.WRITE); + } + if (NameNode.stateChangeLog.isDebugEnabled()) { + NameNode.stateChangeLog.debug("DIR* FSDirectory.swapBlockList: " + + srcIIP.getPath() + " and " + dstIIP.getPath()); + } + SwapBlockListResult result = null; Review comment: nit. My IDE complains that the null assignment is redundant. No need to assign null, it is already null. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
