com.google.appengine.tools.mapreduce.StubRecordReader.java Source code

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Here is the source code for com.google.appengine.tools.mapreduce.StubRecordReader.java

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/*
 * Copyright 2010 Google Inc.
 *
 * Licensed 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 com.google.appengine.tools.mapreduce;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;

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

/**
 * Reader that just passes through the values from a {@link StubInputSplit}.
 *
 *
 */
public class StubRecordReader extends RecordReader<IntWritable, IntWritable> implements Writable {
    private StubInputSplit split;
    private int currentOffset;

    public InputSplit getSplit() {
        return split;
    }

    @Override
    public void close() {
    }

    @Override
    public IntWritable getCurrentKey() {
        return split.getKey(currentOffset);
    }

    @Override
    public IntWritable getCurrentValue() {
        // We have no values.
        return null;
    }

    @Override
    public float getProgress() {
        return 0;
    }

    @Override
    public void initialize(InputSplit split, TaskAttemptContext context) {
        this.split = (StubInputSplit) split;
        currentOffset = -1;
    }

    @Override
    public boolean nextKeyValue() {
        return ++currentOffset < split.getKeys().size();
    }

    @Override
    public void readFields(DataInput in) throws IOException {
    }

    @Override
    public void write(DataOutput out) throws IOException {
    }
}