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- /**
- * 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.*;
- import java.util.List;
- import org.apache.hadoop.hdfs.protocol.Block;
- import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
- import org.apache.hadoop.hdfs.server.namenode.DatanodeDescriptor.BlockTargetPair;
- import org.apache.hadoop.io.*;
- /****************************************************
- * A BlockCommand is an instruction to a datanode
- * regarding some blocks under its control. It tells
- * the DataNode to either invalidate a set of indicated
- * blocks, or to copy a set of indicated blocks to
- * another DataNode.
- *
- ****************************************************/
- public class BlockCommand extends DatanodeCommand {
- Block blocks[];
- DatanodeInfo targets[][];
- public BlockCommand() {}
- /**
- * Create BlockCommand for transferring blocks to another datanode
- * @param blocktargetlist blocks to be transferred
- */
- public BlockCommand(int action, List<BlockTargetPair> blocktargetlist) {
- super(action);
- blocks = new Block[blocktargetlist.size()];
- targets = new DatanodeInfo[blocks.length][];
- for(int i = 0; i < blocks.length; i++) {
- BlockTargetPair p = blocktargetlist.get(i);
- blocks[i] = p.block;
- targets[i] = p.targets;
- }
- }
- private static final DatanodeInfo[][] EMPTY_TARGET = {};
- /**
- * Create BlockCommand for the given action
- * @param blocks blocks related to the action
- */
- public BlockCommand(int action, Block blocks[]) {
- super(action);
- this.blocks = blocks;
- this.targets = EMPTY_TARGET;
- }
- public Block[] getBlocks() {
- return blocks;
- }
- public DatanodeInfo[][] getTargets() {
- return targets;
- }
- ///////////////////////////////////////////
- // Writable
- ///////////////////////////////////////////
- static { // register a ctor
- WritableFactories.setFactory
- (BlockCommand.class,
- new WritableFactory() {
- public Writable newInstance() { return new BlockCommand(); }
- });
- }
- public void write(DataOutput out) throws IOException {
- super.write(out);
- out.writeInt(blocks.length);
- for (int i = 0; i < blocks.length; i++) {
- blocks[i].write(out);
- }
- out.writeInt(targets.length);
- for (int i = 0; i < targets.length; i++) {
- out.writeInt(targets[i].length);
- for (int j = 0; j < targets[i].length; j++) {
- targets[i][j].write(out);
- }
- }
- }
- public void readFields(DataInput in) throws IOException {
- super.readFields(in);
- this.blocks = new Block[in.readInt()];
- for (int i = 0; i < blocks.length; i++) {
- blocks[i] = new Block();
- blocks[i].readFields(in);
- }
- this.targets = new DatanodeInfo[in.readInt()][];
- for (int i = 0; i < targets.length; i++) {
- this.targets[i] = new DatanodeInfo[in.readInt()];
- for (int j = 0; j < targets[i].length; j++) {
- targets[i][j] = new DatanodeInfo();
- targets[i][j].readFields(in);
- }
- }
- }
- }
