org.apache.hama.bsp.Task.java Source code

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Here is the source code for org.apache.hama.bsp.Task.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.hama.bsp;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hama.ipc.BSPPeerProtocol;

/**
 * Base class for tasks.
 */
public abstract class Task implements Writable {
    public static final Log LOG = LogFactory.getLog(Task.class);
    // //////////////////////////////////////////
    // Fields
    // //////////////////////////////////////////

    protected BSPJobID jobId;
    protected String jobFile;
    protected TaskAttemptID taskId;
    protected int partition;

    protected LocalDirAllocator lDirAlloc;

    // Current counters
    private transient Counters counters = new Counters();

    public Task() {
        jobId = new BSPJobID();
        taskId = new TaskAttemptID();
    }

    public Task(BSPJobID jobId, String jobFile, TaskAttemptID taskId, int partition) {
        this.jobId = jobId;
        this.jobFile = jobFile;
        this.taskId = taskId;
        this.partition = partition;
    }

    // //////////////////////////////////////////
    // Accessors
    // //////////////////////////////////////////
    public void setJobFile(String jobFile) {
        this.jobFile = jobFile;
    }

    public String getJobFile() {
        return jobFile;
    }

    public TaskAttemptID getTaskAttemptId() {
        return this.taskId;
    }

    public TaskAttemptID getTaskID() {
        return taskId;
    }

    /**
     * Get the job name for this task.
     * 
     * @return the job name
     */
    public BSPJobID getJobID() {
        return jobId;
    }

    /**
     * Get the index of this task within the job.
     * 
     * @return the integer part of the task id
     */
    public int getPartition() {
        return partition;
    }

    /**
     * Construct output file names so that, when an output directory listing is
     * sorted lexicographically, positions correspond to output partitions.
     */
    private static final NumberFormat NUMBER_FORMAT = NumberFormat.getInstance();
    static {
        NUMBER_FORMAT.setMinimumIntegerDigits(5);
        NUMBER_FORMAT.setGroupingUsed(false);
    }

    static synchronized String getOutputName(int partition) {
        return "part-" + NUMBER_FORMAT.format(partition);
    }

    @Override
    public String toString() {
        return taskId.toString();
    }

    // //////////////////////////////////////////
    // Writable
    // //////////////////////////////////////////
    @Override
    public void write(DataOutput out) throws IOException {
        jobId.write(out);
        Text.writeString(out, jobFile);
        taskId.write(out);
        out.writeInt(partition);
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        jobId.readFields(in);
        jobFile = Text.readString(in);
        taskId.readFields(in);
        partition = in.readInt();
    }

    /**
     * Run this task as a part of the named job. This method is executed in the
     * child process.
     * 
     * @param bspPeer for communications
     * @param umbilical for communications with GroomServer
     */
    public abstract void run(BSPJob job, BSPPeerImpl<?, ?, ?, ?, ?> bspPeer, BSPPeerProtocol umbilical)
            throws Exception;

    public abstract BSPTaskRunner createRunner(GroomServer groom);

    public void done(BSPPeerProtocol umbilical) throws IOException {
        umbilical.done(getTaskID());
    }

    public abstract BSPJob getConf();

    public abstract void setConf(BSPJob localJobConf);

    Counters getCounters() {
        return counters;
    }

}