/*

  * 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.graph.partition;

 import java.io.DataInput;

 import java.io.DataOutput;

 import java.io.IOException;

 import org.apache.giraph.graph.WorkerInfo;

 import org.apache.hadoop.conf.Configurable;

 import org.apache.hadoop.conf.Configuration;

 /**

  * Basic partition owner, can be subclassed for more complicated partition

  * owner implementations.

  */

 public class BasicPartitionOwner implements PartitionOwner, Configurable {

   /** Configuration */

   private Configuration conf;

   /** Partition id */

   private int partitionId = -1;

   /** Owning worker information */

   private WorkerInfo workerInfo;

   /** Previous (if any) worker info */

   private WorkerInfo previousWorkerInfo;

   /** Checkpoint files prefix for this partition */

   private String checkpointFilesPrefix;

   /**

    * Default constructor.

    */

   public BasicPartitionOwner() { }

   /**

    * Constructor with partition id and worker info.

    *

    * @param partitionId Partition id of this partition.

    * @param workerInfo Owner of the partition.

    */

   public BasicPartitionOwner(int partitionId, WorkerInfo workerInfo) {

     this(partitionId, workerInfo, null, null);

   }

   /**

    * Constructor with partition id and worker info.

    *

    * @param partitionId Partition id of this partition.

    * @param workerInfo Owner of the partition.

    * @param previousWorkerInfo Previous owner of this partition.

    * @param checkpointFilesPrefix Prefix of the checkpoint files.

    */

   public BasicPartitionOwner(int partitionId,

                              WorkerInfo workerInfo,

                              WorkerInfo previousWorkerInfo,

                              String checkpointFilesPrefix) {

     this.partitionId = partitionId;

     this.workerInfo = workerInfo;

     this.previousWorkerInfo = previousWorkerInfo;

     this.checkpointFilesPrefix = checkpointFilesPrefix;

   }

   @Override

   public int getPartitionId() {

     return partitionId;

   }

   @Override

   public WorkerInfo getWorkerInfo() {

     return workerInfo;

   }

   @Override

   public void setWorkerInfo(WorkerInfo workerInfo) {

     this.workerInfo = workerInfo;

   }

   @Override

   public WorkerInfo getPreviousWorkerInfo() {

     return previousWorkerInfo;

   }

   @Override

   public void setPreviousWorkerInfo(WorkerInfo workerInfo) {

     this.previousWorkerInfo = workerInfo;

   }

   @Override

   public String getCheckpointFilesPrefix() {

     return checkpointFilesPrefix;

   }

   @Override

   public void setCheckpointFilesPrefix(String checkpointFilesPrefix) {

     this.checkpointFilesPrefix = checkpointFilesPrefix;

   }

   @Override

   public void readFields(DataInput input) throws IOException {

     partitionId = input.readInt();

     workerInfo = new WorkerInfo();

     workerInfo.readFields(input);

     boolean hasPreviousWorkerInfo = input.readBoolean();

     if (hasPreviousWorkerInfo) {

       previousWorkerInfo = new WorkerInfo();

       previousWorkerInfo.readFields(input);

     }

     boolean hasCheckpointFilePrefix = input.readBoolean();

     if (hasCheckpointFilePrefix) {

       checkpointFilesPrefix = input.readUTF();

     }

   }

   @Override

   public void write(DataOutput output) throws IOException {

     output.writeInt(partitionId);

     workerInfo.write(output);

     if (previousWorkerInfo != null) {

       output.writeBoolean(true);

       previousWorkerInfo.write(output);

     } else {

       output.writeBoolean(false);

     }

     if (checkpointFilesPrefix != null) {

       output.writeBoolean(true);

       output.writeUTF(checkpointFilesPrefix);

     } else {

       output.writeBoolean(false);

     }

   }

   @Override

   public Configuration getConf() {

     return conf;

   }

   @Override

   public void setConf(Configuration conf) {

     this.conf = conf;

   }

   @Override

   public String toString() {

     return "(id=" + partitionId + ",cur=" + workerInfo + ",prev=" +

         previousWorkerInfo + ",ckpt_file=" + checkpointFilesPrefix + ")";

   }

 }