org.apache.accumulo.examples.wikisearch.ingest.WikipediaPartitioner.java Source code

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Here is the source code for org.apache.accumulo.examples.wikisearch.ingest.WikipediaPartitioner.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.accumulo.examples.wikisearch.ingest;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.accumulo.examples.wikisearch.ingest.ArticleExtractor.Article;
import org.apache.accumulo.examples.wikisearch.ingest.WikipediaInputFormat.WikipediaInputSplit;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;

public class WikipediaPartitioner extends Mapper<LongWritable, Text, Text, Article> {

    // private static final Logger log = Logger.getLogger(WikipediaPartitioner.class);

    public final static Charset UTF8 = Charset.forName("UTF-8");
    public static final String DOCUMENT_COLUMN_FAMILY = "d";
    public static final String METADATA_EVENT_COLUMN_FAMILY = "e";
    public static final String METADATA_INDEX_COLUMN_FAMILY = "i";
    public static final String TOKENS_FIELD_NAME = "TEXT";

    private final static Pattern languagePattern = Pattern.compile("([a-z_]+).*.xml(.bz2)?");

    private ArticleExtractor extractor;
    private String language;

    private int myGroup = -1;
    private int numGroups = -1;

    @Override
    public void setup(Context context) {
        Configuration conf = context.getConfiguration();

        WikipediaInputSplit wiSplit = (WikipediaInputSplit) context.getInputSplit();
        myGroup = wiSplit.getPartition();
        numGroups = WikipediaConfiguration.getNumGroups(conf);

        FileSplit split = wiSplit.getFileSplit();
        String fileName = split.getPath().getName();
        Matcher matcher = languagePattern.matcher(fileName);
        if (matcher.matches()) {
            language = matcher.group(1).replace('_', '-').toLowerCase();
        } else {
            throw new RuntimeException("Unknown ingest language! " + fileName);
        }
        extractor = new ArticleExtractor();
    }

    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        Article article = extractor
                .extract(new InputStreamReader(new ByteArrayInputStream(value.getBytes()), UTF8));
        if (article != null) {
            int groupId = WikipediaMapper.getPartitionId(article, numGroups);
            if (groupId != myGroup)
                return;
            context.write(new Text(language), article);
        } else {
            context.getCounter("wikipedia", "invalid articles").increment(1);
            context.progress();
        }
    }

}