com.cloudera.crunch.impl.mr.run.CrunchInputFormat.java Source code

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Here is the source code for com.cloudera.crunch.impl.mr.run.CrunchInputFormat.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 com.cloudera.crunch.impl.mr.run;

import java.io.IOException;
import java.util.List;
import java.util.Map;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.util.ReflectionUtils;

import com.google.common.collect.Lists;

public class CrunchInputFormat<K, V> extends InputFormat<K, V> {

    @Override
    public List<InputSplit> getSplits(JobContext job) throws IOException, InterruptedException {
        List<InputSplit> splits = Lists.newArrayList();
        Configuration conf = job.getConfiguration();
        Job jobCopy = new Job(conf);
        Map<Class<? extends InputFormat>, Map<Integer, List<Path>>> formatNodeMap = CrunchInputs
                .getFormatNodeMap(jobCopy);

        // First, build a map of InputFormats to Paths
        for (Map.Entry<Class<? extends InputFormat>, Map<Integer, List<Path>>> entry : formatNodeMap.entrySet()) {
            Class<? extends InputFormat> formatClass = entry.getKey();
            InputFormat format = (InputFormat) ReflectionUtils.newInstance(formatClass, conf);
            for (Map.Entry<Integer, List<Path>> nodeEntry : entry.getValue().entrySet()) {
                Integer nodeIndex = nodeEntry.getKey();
                List<Path> paths = nodeEntry.getValue();
                FileInputFormat.setInputPaths(jobCopy, paths.toArray(new Path[paths.size()]));

                // Get splits for each input path and tag with InputFormat
                // and Mapper types by wrapping in a TaggedInputSplit.
                List<InputSplit> pathSplits = format.getSplits(jobCopy);
                for (InputSplit pathSplit : pathSplits) {
                    splits.add(new CrunchInputSplit(pathSplit, formatClass, nodeIndex, conf));
                }
            }
        }
        return splits;
    }

    @Override
    public RecordReader<K, V> createRecordReader(InputSplit inputSplit, TaskAttemptContext context)
            throws IOException, InterruptedException {
        return new CrunchRecordReader(inputSplit, context);
    }

}