org.apache.hadoop.mapred.LaunchTaskAction.java Source code

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Here is the source code for org.apache.hadoop.mapred.LaunchTaskAction.java

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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.mapred;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Represents a directive from the {@link org.apache.hadoop.mapred.JobTracker} 
 * to the {@link org.apache.hadoop.mapred.TaskTracker} to launch a new task.
 * 
 */
class LaunchTaskAction extends TaskTrackerAction {
    public static final Log LOG = LogFactory.getLog(LaunchTaskAction.class);

    private Task task;

    public LaunchTaskAction() {
        super(ActionType.LAUNCH_TASK);
    }

    public LaunchTaskAction(Task task) {
        super(ActionType.LAUNCH_TASK);
        this.task = task;
    }

    public Task getTask() {
        return task;
    }

    public void write(DataOutput out) throws IOException {
        out.writeBoolean(task.isMapTask());
        task.write(out);

    }

    public void readFields(DataInput in) throws IOException {
        boolean isMapTask = in.readBoolean();
        if (isMapTask) {
            task = new MapTask();
        } else {
            task = new ReduceTask();
        }

        task.readFields(in);
    }
}