com.mozilla.grouperfish.transforms.coclustering.pig.storage.KMeansOutputLoader.java Source code

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Here is the source code for com.mozilla.grouperfish.transforms.coclustering.pig.storage.KMeansOutputLoader.java

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/*
 * Copyright 2011 Mozilla Foundation
 *
 * 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.mozilla.grouperfish.transforms.coclustering.pig.storage;

import java.io.IOException;
import java.util.Iterator;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.mahout.clustering.WeightedVectorWritable;
import org.apache.mahout.math.NamedVector;
import org.apache.mahout.math.Vector;
import org.apache.pig.LoadFunc;
import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigSplit;
import org.apache.pig.data.BagFactory;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;

/**
 * KMeansOutputLoader loads Mahout WeightedWeightedVectorWritables and stores
 * cluster IDs and named vectors as bag.
 */
public class KMeansOutputLoader extends LoadFunc {

    protected RecordReader<IntWritable, WeightedVectorWritable> reader = null;
    protected BagFactory bagFactory = BagFactory.getInstance();
    protected TupleFactory tupleFactory = TupleFactory.getInstance();

    private static final Logger LOG = LoggerFactory.getLogger(KMeansOutputLoader.class);

    public KMeansOutputLoader() {
    }

    @Override
    public InputFormat<IntWritable, WeightedVectorWritable> getInputFormat() throws IOException {
        return new SequenceFileInputFormat<IntWritable, WeightedVectorWritable>();
    }

    @Override
    public void setLocation(String location, Job job) throws IOException {
        FileInputFormat.setInputPaths(job, location);
    }

    @SuppressWarnings({ "unchecked", "rawtypes" })
    @Override
    public void prepareToRead(RecordReader reader, PigSplit split) {
        this.reader = (RecordReader<IntWritable, WeightedVectorWritable>) reader;
    }

    @Override
    public Tuple getNext() throws IOException {
        try {
            if (!this.reader.nextKeyValue()) {
                return null;
            }
            Tuple currRow = tupleFactory.newTuple(3);
            DataBag rowInfoBag = bagFactory.newDefaultBag();
            IntWritable key = (IntWritable) reader.getCurrentKey();
            int clusterID = key.get();
            WeightedVectorWritable value = (WeightedVectorWritable) reader.getCurrentValue();
            Vector rowInfo = value.getVector();
            NamedVector nrowInfo = (NamedVector) rowInfo;
            int vectorID = Integer.parseInt(nrowInfo.getName());
            for (Iterator<Vector.Element> itr = rowInfo.iterateNonZero(); itr.hasNext();) {
                Vector.Element elemInfo = itr.next();
                Tuple currElement = tupleFactory.newTuple(2);
                currElement.set(0, elemInfo.index());
                currElement.set(1, elemInfo.get());
                rowInfoBag.add(currElement);
            }
            currRow.set(0, clusterID);
            currRow.set(1, vectorID);
            currRow.set(2, rowInfoBag);
            return currRow;
        } catch (InterruptedException ie) {
            LOG.error("Interrupted while reading", ie);
            throw new IOException(ie);
        } catch (NumberFormatException ne) {
            LOG.error("Possible use of non int values for NamedVector keys", ne);
            throw new IOException(ne);
        } catch (ClassCastException e) {
            LOG.error("Possible cast of normal Vector to NamedVector", e);
            throw new IOException(e);
        }
    }
}