/*

  * 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.ooc.command;

 import org.apache.giraph.ooc.OutOfCoreEngine;

 import org.apache.giraph.ooc.data.DiskBackedEdgeStore;

 import org.apache.giraph.ooc.data.DiskBackedMessageStore;

 import org.apache.giraph.ooc.data.DiskBackedPartitionStore;

 import java.io.IOException;

 /**

  * IOCommand to store raw data buffers on disk.

  */

 public class StoreDataBufferIOCommand extends IOCommand {

   /**

    * Types of raw data buffer to offload to disk (either vertices/edges buffer

    * in INPUT_SUPERSTEP or incoming message buffer).

    */

   public enum DataBufferType { PARTITION, MESSAGE };

   /**

    * Type of the buffer to store on disk.

    */

   private final DataBufferType type;

   /**

    * Constructor

    *

    * @param oocEngine out-of-core engine

    * @param partitionId id of the partition to offload its buffers

    * @param type type of the buffer to store on disk

    */

   public StoreDataBufferIOCommand(OutOfCoreEngine oocEngine,

                                   int partitionId,

                                   DataBufferType type) {

     super(oocEngine, partitionId);

     this.type = type;

   }

   @Override

   public boolean execute() throws IOException {

     boolean executed = false;

     if (oocEngine.getMetaPartitionManager()

         .startOffloadingBuffer(partitionId)) {

       switch (type) {

       case PARTITION:

         DiskBackedPartitionStore partitionStore =

             (DiskBackedPartitionStore)

                 oocEngine.getServerData().getPartitionStore();

         numBytesTransferred +=

             partitionStore.offloadBuffers(partitionId);

         DiskBackedEdgeStore edgeStore =

             (DiskBackedEdgeStore) oocEngine.getServerData().getEdgeStore();

         numBytesTransferred += edgeStore.offloadBuffers(partitionId);

         break;

       case MESSAGE:

         DiskBackedMessageStore messageStore =

             (DiskBackedMessageStore)

                 oocEngine.getServerData().getIncomingMessageStore();

         numBytesTransferred +=

             messageStore.offloadBuffers(partitionId);

         break;

       default:

         throw new IllegalStateException("execute: requested data buffer type " +

             "does not exist!");

       }

       oocEngine.getMetaPartitionManager().doneOffloadingBuffer(partitionId);

       executed = true;

     }

     return executed;

   }

   @Override

   public IOCommandType getType() {

     return IOCommandType.STORE_BUFFER;

   }

   @Override

   public String toString() {

     return "StoreDataBufferIOCommand: (partitionId = " + partitionId + ", " +

         "type = " + type.name() + ")";

   }

 }