/*

  * 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.piece;

 import java.util.List;

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

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

 import org.apache.giraph.types.NoMessage;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 /**

  * Piece that should be extended in common usecases, when we want to be:

  * - sending and then receiving messages from vertices

  * - sending data to be aggregated from workers to master

  * - sending values from master, via aggregators, to workers

  *

  * (basically - we don't want to use WorkerContext)

  *

  * @param <I> Vertex id type

  * @param <V> Vertex value type

  * @param <E> Edge value type

  * @param <M> Message type

  * @param <S> Execution stage type

  */

 @SuppressWarnings("rawtypes")

 public class Piece<I extends WritableComparable, V extends Writable,

     E extends Writable, M extends Writable, S>

     extends DefaultParentPiece<I, V, E, M, Object, NoMessage, S> {

   // Disallowing use of Worker Context functions:

   @Override

   public final void workerContextSend(

       BlockWorkerContextSendApi<I, NoMessage> workerContextApi,

       S executionStage, Object workerValue) {

   }

   @Override

   public final void workerContextReceive(

       BlockWorkerContextReceiveApi workerContextApi,

       S executionStage, Object workerValue, List<NoMessage> workerMessages) {

   }

 }