org.apache.hadoop.mapreduce.task.MapContextImpl.java Source code

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Here is the source code for org.apache.hadoop.mapreduce.task.MapContextImpl.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.mapreduce.task;

import java.io.IOException;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.MapContext;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.OutputCommitter;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.StatusReporter;
import org.apache.hadoop.mapreduce.TaskAttemptID;

/**
 * The context that is given to the {@link Mapper}.
 * @param <KEYIN> the key input type to the Mapper
 * @param <VALUEIN> the value input type to the Mapper
 * @param <KEYOUT> the key output type from the Mapper
 * @param <VALUEOUT> the value output type from the Mapper
 */
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class MapContextImpl<KEYIN, VALUEIN, KEYOUT, VALUEOUT>
        extends TaskInputOutputContextImpl<KEYIN, VALUEIN, KEYOUT, VALUEOUT>
        implements MapContext<KEYIN, VALUEIN, KEYOUT, VALUEOUT> {
    private RecordReader<KEYIN, VALUEIN> reader;
    private InputSplit split;

    public MapContextImpl(Configuration conf, TaskAttemptID taskid, RecordReader<KEYIN, VALUEIN> reader,
            RecordWriter<KEYOUT, VALUEOUT> writer, OutputCommitter committer, StatusReporter reporter,
            InputSplit split) {
        super(conf, taskid, writer, committer, reporter);
        this.reader = reader;
        this.split = split;
    }

    /**
     * Get the input split for this map.
     */
    public InputSplit getInputSplit() {
        return split;
    }

    @Override
    public KEYIN getCurrentKey() throws IOException, InterruptedException {
        return reader.getCurrentKey();
    }

    @Override
    public VALUEIN getCurrentValue() throws IOException, InterruptedException {
        return reader.getCurrentValue();
    }

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
        return reader.nextKeyValue();
    }

}