/*

  * 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.giraph.partition;

 import org.apache.giraph.worker.LocalData;

 import org.apache.hadoop.io.LongWritable;

 import org.apache.hadoop.io.Writable;

 import org.apache.log4j.Logger;

 /**

  * Factory for long-byte mapping based partitioners.

  *

  * @param <V> vertexValue type

  * @param <E> edgeValue type

  */

 @SuppressWarnings("unchecked")

 public class LongMappingStorePartitionerFactory<V extends Writable,

     E extends Writable> extends GraphPartitionerFactory<LongWritable, V, E> {

   /** Logger Instance */

   private static final Logger LOG = Logger.getLogger(

       LongMappingStorePartitionerFactory.class);

   /** Local Data that supplies the mapping store */

   protected LocalData<LongWritable, V, E, ? extends Writable> localData = null;

   @Override

   public void initialize(LocalData<LongWritable, V, E,

     ? extends Writable> localData) {

     this.localData = localData;

     LOG.info("Initializing LongMappingStorePartitionerFactory with localData");

   }

   @Override

   public int getPartition(LongWritable id, int partitionCount,

     int workerCount) {

     return localData.getMappingStoreOps().getPartition(id,

         partitionCount, workerCount);

   }

   @Override

   public int getWorker(int partition, int partitionCount, int workerCount) {

     int numRows = partitionCount / workerCount;

     numRows = (numRows * workerCount == partitionCount) ? numRows : numRows + 1;

     return partition / numRows;

   }

 }