com.antbrains.crf.hadoop.FeatureCounter.java Source code

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Here is the source code for com.antbrains.crf.hadoop.FeatureCounter.java

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/**
 *  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.antbrains.crf.hadoop;

import gnu.trove.map.hash.TObjectIntHashMap;
import gnu.trove.procedure.TObjectIntProcedure;

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

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

import com.antbrains.crf.SgdCrf;
import com.antbrains.crf.Template;

public class FeatureCounter {

    public static class CounterMapper extends Mapper<Object, Text, Text, LongWritable> {
        private Template template;

        private TObjectIntHashMap<String> counter;
        private int batchSize = 100000;

        @Override
        protected void setup(Context context) throws IOException, InterruptedException {
            Configuration conf = context.getConfiguration();
            String s = conf.get("templates");
            if (s == null)
                throw new IllegalArgumentException("templates is null");
            template = new Template(str2StrArr(s));
            counter = new TObjectIntHashMap<String>((int) (this.batchSize * 1.25), 0.8f, 0);
        }

        @Override
        protected void cleanup(final Context context) throws IOException, InterruptedException {
            counter.forEachEntry(new TObjectIntProcedure<String>() {
                @Override
                public boolean execute(String text, int index) {
                    try {
                        context.write(new Text(text), new LongWritable(index));
                    } catch (Exception e) {
                        throw new RuntimeException(e);
                    }
                    return true;
                }
            });
            counter.clear();
        }

        @Override
        public void map(Object key, Text value, final Context context) throws IOException, InterruptedException {
            String sen = value.toString().replaceAll("\t", "");
            sen = StringTools.normalizeQuery(sen);
            List<String> attributes = new ArrayList<String>(sen.length());
            for (int i = 0; i < sen.length(); i++) {
                attributes.add(sen.charAt(i) + "");
            }
            List<String> features = template.expandTemplate(attributes, attributes.size());
            for (String feature : features) {
                if (feature.contains("_B-") || feature.contains("_B+")) {
                    continue;
                }
                int count = counter.get(feature);
                counter.put(feature, count + 1);
            }

            if (counter.size() >= batchSize) {
                counter.forEachEntry(new TObjectIntProcedure<String>() {
                    @Override
                    public boolean execute(String text, int index) {
                        try {
                            context.write(new Text(text), new LongWritable(index));
                        } catch (Exception e) {
                            throw new RuntimeException(e);
                        }
                        return true;
                    }
                });
                counter.clear();
            }
        }
    }

    public static class SumReducer extends Reducer<Text, LongWritable, Text, LongWritable> {
        private LongWritable result = new LongWritable();

        @Override
        public void reduce(Text key, Iterable<LongWritable> values, Context context)
                throws IOException, InterruptedException {
            long sum = 0;
            for (LongWritable val : values) {
                sum += val.get();
            }
            result.set(sum);
            context.write(key, result);
        }
    }

    private static String[] str2StrArr(String s) {
        return s.split("\n");
    }

    private static String strArr2Str(String[] arr) {
        StringBuilder sb = new StringBuilder("");
        for (String s : arr) {
            s = s.replaceAll("\n", "");
            sb.append(s).append("\n");
        }
        return sb.toString();
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length != 3) {
            System.err.println("Usage: wordcount <in> <out> <templatefile>");
            System.exit(2);
        }

        String[] templates = SgdCrf.readTemplates(otherArgs[2]).toArray(new String[0]);
        conf.set("templates", strArr2Str(templates));

        Job job = new Job(conf, FeatureCounter.class.getSimpleName());

        job.setJarByClass(FeatureCounter.class);
        job.setMapperClass(CounterMapper.class);
        job.setCombinerClass(SumReducer.class);
        job.setReducerClass(SumReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(LongWritable.class);
        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}