/*

  * 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.comm.messages.primitives.long_id;

 import com.google.common.collect.Lists;

 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;

 import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;

 import it.unimi.dsi.fastutil.longs.LongIterator;

 import java.util.List;

 import org.apache.giraph.comm.messages.MessageStore;

 import org.apache.giraph.comm.messages.PartitionSplitInfo;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;

 import org.apache.giraph.factories.MessageValueFactory;

 import org.apache.hadoop.io.LongWritable;

 import org.apache.hadoop.io.Writable;

 /**

  * Special message store to be used when ids are LongWritable and no combiner

  * is used.

  * Uses fastutil primitive maps in order to decrease number of objects and

  * get better performance.

  *

  * @param <M> message type

  * @param <T> datastructure used to hold messages

  */

 public abstract class LongAbstractStore<M extends Writable, T>

   implements MessageStore<LongWritable, M> {

   /** Message value factory */

   protected final MessageValueFactory<M> messageValueFactory;

   /** Map from partition id to map from vertex id to message */

   protected final

   Int2ObjectOpenHashMap<Long2ObjectOpenHashMap<T>> map;

   /** Service worker */

   protected final PartitionSplitInfo<LongWritable> partitionInfo;

   /** Giraph configuration */

   protected final ImmutableClassesGiraphConfiguration<LongWritable, ?, ?>

   config;

   /**

    * Constructor

    *

    * @param messageValueFactory Factory for creating message values

    * @param partitionInfo       Partition split info

    * @param config              Hadoop configuration

    */

   public LongAbstractStore(

       MessageValueFactory<M> messageValueFactory,

       PartitionSplitInfo<LongWritable> partitionInfo,

       ImmutableClassesGiraphConfiguration<LongWritable, Writable, Writable>

           config) {

     this.messageValueFactory = messageValueFactory;

     this.partitionInfo = partitionInfo;

     this.config = config;

     map = new Int2ObjectOpenHashMap<>();

     for (int partitionId : partitionInfo.getPartitionIds()) {

       Long2ObjectOpenHashMap<T> partitionMap = new Long2ObjectOpenHashMap<T>(

           (int) partitionInfo.getPartitionVertexCount(partitionId));

       map.put(partitionId, partitionMap);

     }

   }

   /**

    * Get map which holds messages for partition which vertex belongs to.

    *

    * @param vertexId Id of the vertex

    * @return Map which holds messages for partition which vertex belongs to.

    */

   protected Long2ObjectOpenHashMap<T> getPartitionMap(

       LongWritable vertexId) {

     return map.get(partitionInfo.getPartitionId(vertexId));

   }

   @Override

   public void clearPartition(int partitionId) {

     map.get(partitionId).clear();

   }

   @Override

   public boolean hasMessagesForVertex(LongWritable vertexId) {

     return getPartitionMap(vertexId).containsKey(vertexId.get());

   }

   @Override

   public boolean hasMessagesForPartition(int partitionId) {

     Long2ObjectOpenHashMap<T> partitionMessages = map.get(partitionId);

     return partitionMessages != null && !partitionMessages.isEmpty();

   }

   @Override

   public void clearVertexMessages(LongWritable vertexId) {

     getPartitionMap(vertexId).remove(vertexId.get());

   }

   @Override

   public void clearAll() {

     map.clear();

   }

   @Override

   public Iterable<LongWritable> getPartitionDestinationVertices(

       int partitionId) {

     Long2ObjectOpenHashMap<T> partitionMap =

         map.get(partitionId);

     List<LongWritable> vertices =

         Lists.newArrayListWithCapacity(partitionMap.size());

     LongIterator iterator = partitionMap.keySet().iterator();

     while (iterator.hasNext()) {

       vertices.add(new LongWritable(iterator.nextLong()));

     }

     return vertices;

   }

 }