package com.ontology2.bakemono.pse3;
import java.io.IOException;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.mapreduce.Counter;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.Reducer.Context;
import com.hp.hpl.jena.graph.Triple;
import com.ontology2.bakemono.jena.WritableTriple;
public class Uniq extends Reducer<WritableTriple, LongWritable, Triple, LongWritable> {
private static org.apache.commons.logging.Log logger = LogFactory.getLog(Uniq.class);
@Override
protected void reduce(WritableTriple key, Iterable<LongWritable> value,
Context context)
throws IOException, InterruptedException {
context.write(key.getTriple(), new LongWritable(1));
incrementCounter(context,UniqCounters.DISTINCT_KEYS,1);
for(LongWritable v:value) {
incrementCounter(context,UniqCounters.TOTAL_VALUES,1);
};
}
//
// this code prevents failing test because the mock object Context we are passing back
// always returns null from getCounter... With a more sophisticated mock object perhaps
// the system will produce individual mocks for each counter so we can watch what
// happens with counters
//
private void incrementCounter(Context context,Enum <?> counterId,long amount) {
Counter counter=context.getCounter(counterId);
if(counter!=null) {
counter.increment(amount);
};
};
}