/*

  * 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.internal;

 import java.util.List;

 import org.apache.giraph.block_app.framework.api.BlockMasterApi;

 import org.apache.giraph.block_app.framework.api.BlockWorkerContextReceiveApi;

 import org.apache.giraph.block_app.framework.api.BlockWorkerContextSendApi;

 import org.apache.giraph.block_app.framework.api.BlockWorkerReceiveApi;

 import org.apache.giraph.block_app.framework.api.BlockWorkerSendApi;

 import org.apache.giraph.block_app.framework.piece.AbstractPiece;

 import org.apache.giraph.block_app.framework.piece.AbstractPiece.InnerVertexSender;

 import org.apache.giraph.block_app.framework.piece.interfaces.VertexReceiver;

 import org.apache.hadoop.io.Writable;

 /**

  * Object holding piece with it's corresponding execution stage.

  *

  * @param <S> Execution stage type

  */

 @SuppressWarnings({ "rawtypes", "unchecked" })

 public class PairedPieceAndStage<S> {

   private final AbstractPiece piece;

   private final S executionStage;

   public PairedPieceAndStage(AbstractPiece piece, S executionStage) {

     this.piece = piece;

     this.executionStage = executionStage;

   }

   public S nextExecutionStage() {

     // if piece is null, then it cannot change the execution stage

     return piece != null ?

       (S) piece.nextExecutionStage(executionStage) : executionStage;

   }

   public S getExecutionStage() {

     return executionStage;

   }

   public void registerReducers(BlockMasterApi masterApi) {

     if (piece != null) {

       piece.wrappedRegisterReducers(masterApi, executionStage);

     }

   }

   public InnerVertexSender getVertexSender(BlockWorkerSendApi sendApi) {

     if (piece != null) {

       return piece.getWrappedVertexSender(sendApi, executionStage);

     }

     return null;

   }

   public void masterCompute(BlockMasterApi masterApi) {

     if (piece != null) {

       piece.masterCompute(masterApi, executionStage);

     }

   }

   public VertexReceiver getVertexReceiver(

       BlockWorkerReceiveApi receiveApi) {

     if (piece != null) {

       return piece.getVertexReceiver(receiveApi, executionStage);

     }

     return null;

   }

   public void workerContextSend(

       BlockWorkerContextSendApi workerContextApi, Object workerValue) {

     if (piece != null) {

       piece.workerContextSend(workerContextApi, executionStage, workerValue);

     }

   }

   public void workerContextReceive(

       BlockWorkerContextReceiveApi workerContextApi,

       Object workerValue, List<Writable> workerMessages) {

     if (piece != null) {

       piece.workerContextReceive(

           workerContextApi, executionStage, workerValue, workerMessages);

     }

   }

   /**

    * @return the piece

    */

   public AbstractPiece getPiece() {

     return piece;

   }

   @Override

   public String toString() {

     return "Piece " + piece + " in stage " + executionStage;

   }

 }