/*

  * 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.migration;

 import java.io.DataInput;

 import java.io.DataOutput;

 import java.io.IOException;

 import java.util.List;

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

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

 import org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 /**

  * Replacement for WorkerContext when migrating to Blocks Framework,

  * disallowing functions that are tied to execution order.

  */

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

 public class MigrationWorkerContext

     extends DefaultImmutableClassesGiraphConfigurable

     implements Writable {

   private BlockWorkerContextApi api;

   private List<Writable> receivedMessages;

   public void setApi(BlockWorkerContextApi api) {

     this.api = api;

     this.setConf(api.getConf());

   }

   public void setReceivedMessages(List<Writable> receivedMessages) {

     this.receivedMessages = receivedMessages;

   }

   public void preSuperstep() { }

   public void postSuperstep() { }

   @SuppressWarnings("deprecation")

   public long getTotalNumVertices() {

     return api.getTotalNumVertices();

   }

   @SuppressWarnings("deprecation")

   public long getTotalNumEdges() {

     return api.getTotalNumEdges();

   }

   @Override

   public void readFields(DataInput in) throws IOException {

   }

   @Override

   public void write(DataOutput out) throws IOException {

   }

   public final int getWorkerCount() {

     return api.getWorkerCount();

   }

   public final int getMyWorkerIndex() {

     return api.getMyWorkerIndex();

   }

   public final List<Writable> getAndClearMessagesFromOtherWorkers() {

     List<Writable> ret = receivedMessages;

     receivedMessages = null;

     return ret;

   }

   public final void sendMessageToWorker(Writable message, int workerIndex) {

     ((BlockWorkerContextSendApi<WritableComparable, Writable>) api)

       .sendMessageToWorker(message, workerIndex);

   }

   /**

    * Drop-in replacement for WorkerContext when migrating to

    * Blocks Framework.

    */

   public static class MigrationFullWorkerContext

       extends MigrationWorkerContext {

     public void preApplication()

         throws InstantiationException, IllegalAccessException {

     }

     public void postApplication() { }

   }

 }