| /** |
| * 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.protocol; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.ArrayList; |
| |
| import org.apache.hadoop.hdfs.protocol.Block; |
| import org.apache.hadoop.hdfs.protocol.DatanodeInfo; |
| import org.apache.hadoop.hdfs.protocol.LocatedBlock; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableFactories; |
| import org.apache.hadoop.io.WritableFactory; |
| |
| /** |
| * BlockRecoveryCommand is an instruction to a data-node to recover |
| * the specified blocks. |
| * |
| * The data-node that receives this command treats itself as a primary |
| * data-node in the recover process. |
| * |
| * Block recovery is identified by a recoveryId, which is also the new |
| * generation stamp, which the block will have after the recovery succeeds. |
| */ |
| public class BlockRecoveryCommand extends DatanodeCommand { |
| Collection<RecoveringBlock> recoveringBlocks; |
| |
| /** |
| * This is a block with locations from which it should be recovered |
| * and the new generation stamp, which the block will have after |
| * successful recovery. |
| * |
| * The new generation stamp of the block, also plays role of the recovery id. |
| */ |
| public static class RecoveringBlock extends LocatedBlock { |
| private long newGenerationStamp; |
| |
| /** |
| * Create empty RecoveringBlock. |
| */ |
| public RecoveringBlock() { |
| super(); |
| newGenerationStamp = -1L; |
| } |
| |
| /** |
| * Create RecoveringBlock. |
| */ |
| public RecoveringBlock(Block b, DatanodeInfo[] locs, long newGS) { |
| super(b, locs, -1, false); // startOffset is unknown |
| this.newGenerationStamp = newGS; |
| } |
| |
| /** |
| * Return the new generation stamp of the block, |
| * which also plays role of the recovery id. |
| */ |
| public long getNewGenerationStamp() { |
| return newGenerationStamp; |
| } |
| |
| /////////////////////////////////////////// |
| // Writable |
| /////////////////////////////////////////// |
| static { // register a ctor |
| WritableFactories.setFactory |
| (RecoveringBlock.class, |
| new WritableFactory() { |
| public Writable newInstance() { return new RecoveringBlock(); } |
| }); |
| } |
| |
| public void write(DataOutput out) throws IOException { |
| super.write(out); |
| out.writeLong(newGenerationStamp); |
| } |
| |
| public void readFields(DataInput in) throws IOException { |
| super.readFields(in); |
| newGenerationStamp = in.readLong(); |
| } |
| } |
| |
| /** |
| * Create empty BlockRecoveryCommand. |
| */ |
| public BlockRecoveryCommand() { |
| this(0); |
| } |
| |
| /** |
| * Create BlockRecoveryCommand with |
| * the specified capacity for recovering blocks. |
| */ |
| public BlockRecoveryCommand(int capacity) { |
| super(DatanodeProtocol.DNA_RECOVERBLOCK); |
| recoveringBlocks = new ArrayList<RecoveringBlock>(capacity); |
| } |
| |
| /** |
| * Return the list of recovering blocks. |
| */ |
| public Collection<RecoveringBlock> getRecoveringBlocks() { |
| return recoveringBlocks; |
| } |
| |
| /** |
| * Add recovering block to the command. |
| */ |
| public void add(RecoveringBlock block) { |
| recoveringBlocks.add(block); |
| } |
| |
| /////////////////////////////////////////// |
| // Writable |
| /////////////////////////////////////////// |
| static { // register a ctor |
| WritableFactories.setFactory |
| (BlockRecoveryCommand.class, |
| new WritableFactory() { |
| public Writable newInstance() { return new BlockRecoveryCommand(); } |
| }); |
| } |
| |
| public void write(DataOutput out) throws IOException { |
| super.write(out); |
| out.writeInt(recoveringBlocks.size()); |
| for(RecoveringBlock block : recoveringBlocks) { |
| block.write(out); |
| } |
| } |
| |
| public void readFields(DataInput in) throws IOException { |
| super.readFields(in); |
| int numBlocks = in.readInt(); |
| recoveringBlocks = new ArrayList<RecoveringBlock>(numBlocks); |
| for(int i = 0; i < numBlocks; i++) { |
| RecoveringBlock b = new RecoveringBlock(); |
| b.readFields(in); |
| add(b); |
| } |
| } |
| } |