Added tuplekey partitioner to partition during merge phase

Author: ArnauPrat

src/main/java/ldbc/snb/datagen/hadoop/HadoopMergeFriendshipFiles.java

@@ -81,6 +81,7 @@ public void run( String outputFileName, ArrayList<String> friendshipFileNames )
         job.setNumReduceTasks(numThreads);
         job.setInputFormatClass(SequenceFileInputFormat.class);
         job.setOutputFormatClass(SequenceFileOutputFormat.class);
+        job.setPartitionerClass(HadoopTuplePartitioner.class);
 
         for ( String s : friendshipFileNames ) {
             FileInputFormat.addInputPath(job, new Path(s));

src/main/java/ldbc/snb/datagen/hadoop/HadoopTuplePartitioner.java

@@ -0,0 +1,19 @@
+package ldbc.snb.datagen.hadoop;
+
+import ldbc.snb.datagen.objects.Person;
+import org.apache.hadoop.mapreduce.Partitioner;
+
+/**
+ * Created by aprat on 25/08/15.
+ */
+public class HadoopTuplePartitioner extends Partitioner<TupleKey, Person> {
+
+    public HadoopTuplePartitioner() {
+        super();
+    }
+
+    @Override
+    public int getPartition(TupleKey key, Person person, int numReduceTasks) {
+        return (int)(key.key % numReduceTasks);
+    }
+}