/*

  * 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.block_app.framework.api.giraph;

 import java.io.DataInput;

 import java.io.DataOutput;

 import java.io.IOException;

 import org.apache.giraph.block_app.framework.internal.BlockMasterLogic;

 import org.apache.giraph.block_app.framework.internal.BlockWorkerPieces;

 import org.apache.giraph.block_app.framework.output.BlockOutputHandle;

 import org.apache.giraph.master.MasterCompute;

 import org.apache.giraph.writable.kryo.KryoWritableWrapper;

 /**

  * MasterCompute class which executes block computation.

  *

  * @param <S> Execution stage type

  */

 public final class BlockMasterCompute<S> extends MasterCompute {

   private BlockMasterLogic<S> blockMasterLogic = new BlockMasterLogic<>();

   @Override

   public void initialize() throws InstantiationException,

       IllegalAccessException {

     blockMasterLogic.initialize(getConf(), new BlockMasterApiWrapper(this,

         new BlockOutputHandle(getContext().getJobID().toString(),

         getConf(), getContext())));

   }

   @Override

   public void compute() {

     BlockWorkerPieces<S> workerPieces =

         blockMasterLogic.computeNext(getSuperstep());

     if (workerPieces == null) {

       haltComputation();

     } else {

       BlockWorkerPieces.setNextWorkerPieces(this, workerPieces);

     }

   }

   @Override

   public void write(DataOutput out) throws IOException {

     new KryoWritableWrapper<>(blockMasterLogic).write(out);

   }

   @Override

   public void readFields(DataInput in) throws IOException {

     KryoWritableWrapper<BlockMasterLogic<S>> object =

         new KryoWritableWrapper<>();

     object.readFields(in);

     blockMasterLogic = object.get();

     blockMasterLogic.initializeAfterRead(new BlockMasterApiWrapper(this,

         new BlockOutputHandle()));

   }

 }