/*

  * 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;

 import org.apache.giraph.aggregators.Aggregator;

 import org.apache.giraph.block_app.framework.piece.global_comm.BroadcastHandle;

 import org.apache.giraph.master.MasterAggregatorUsage;

 import org.apache.giraph.master.MasterGlobalCommUsage;

 import org.apache.hadoop.io.Writable;

 /**

  * Block computation API available for the master methods.

  *

  * Interface to the MasterCompute methods.

  */

 public interface BlockMasterApi extends MasterAggregatorUsage,

     MasterGlobalCommUsage, StatusReporter, BlockApi, BlockOutputApi {

   /**

    * No need to use it, and introduces global dependencies.

    *

    * Store data locally within the piece, or use ObjectHolder.

    */

   @Deprecated

   @Override

   <A extends Writable>

   boolean registerPersistentAggregator(

       String name, Class<? extends Aggregator<A>> aggregatorClass

   ) throws InstantiationException, IllegalAccessException;

   /**

    * Broadcast given value to all workers for next computation.

    * @param value Value to broadcast

    */

   <T extends Writable> BroadcastHandle<T> broadcast(T value);

   /**

    * Call this to log a line to command line of the job. Use in moderation -

    * it's a synchronous call to Job client

    *

    * @param line Line to print

    */

   void logToCommandLine(String line);

 }