/**
* 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 org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableFactories;
import org.apache.hadoop.io.WritableFactory;
/**
* A RaidTaskCommand is an instruction to a datanode
* regarding some raid tasks. It tells the Datanode to
* construct some blocks and send them to given datanodes.
*
* RaidTaskCommand format:
* # of tasks
* For each RaidTask:
* RaidTask
*
* When datanode receives the command, it will iterate all RaidTask
* one by one. For each RaidTask, it reads *good* blocks from the machines,
* and generates the target blocks. Then it sends the constructed blocks
* to the machines provided.
*
*/
public class RaidTaskCommand extends DatanodeCommand {
public RaidTask[] tasks;
public RaidTaskCommand() {}
public RaidTaskCommand(int action, RaidTask[] tasks) {
super(action);
this.tasks = tasks;
}
/////////////////////////////////////////////////
// Writable
/////////////////////////////////////////////////
static {
WritableFactories.setFactory(RaidTaskCommand.class,
new WritableFactory() {
@Override
public Writable newInstance() {
return new RaidTaskCommand();
}});
}
@Override
public void write(DataOutput out) throws IOException {
super.write(out);
out.writeInt(tasks.length);
for (int i = 0; i < tasks.length; i++) {
tasks[i].write(out);
}
}
@Override
public void readFields(DataInput in) throws IOException {
super.readFields(in);
this.tasks = new RaidTask[in.readInt()];
for (int i = 0; i < this.tasks.length; i++) {
this.tasks[i] = new RaidTask();
this.tasks[i].readFields(in);
}
}
}