/*
 * 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.global_comm.map;

import org.apache.giraph.block_app.framework.api.BlockMasterApi;
import org.apache.giraph.block_app.framework.piece.global_comm.ReducerHandle;

/**
 * Handle to array of reducers
 *
 * @param <I> Key type
 * @param <S> Single value type
 * @param <R> Reduced value type
 */
public interface ReducerMapHandle<I, S, R>
    extends MapHandle<I, ReducerHandle<S, R>> {
  /**
   * Number of elements that were reduced.
   */
  int getReducedSize(BlockMasterApi master);

  /**
   * Broadcast whole map of reducers to master
   *
   * @return Handle to the broadcasted map.
   */
  BroadcastMapHandle<I, R> broadcastValue(BlockMasterApi master);
}
