/*

  * 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.block;

 import java.util.Iterator;

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

 import org.apache.giraph.block_app.framework.piece.delegate.FilteringPiece;

 import org.apache.giraph.function.Consumer;

 import org.apache.giraph.function.vertex.SupplierFromVertex;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 import com.google.common.base.Function;

 import com.google.common.collect.Iterators;

 /**

  * Block which filters out calls to vertexSend/vertexReceive functions

  * of all pieces in a given block.

  * Filtering happens based on toCallSend and toCallReceive suppliers

  * that are passed in, as every piece is just wrapped with FilteringPiece.

  *

  * @param <I> Vertex id type

  * @param <V> Vertex value type

  * @param <E> Edge value type

  */

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

 public final class FilteringBlock<I extends WritableComparable,

         V extends Writable, E extends Writable>

     implements Block {

   private final SupplierFromVertex<I, V, E, Boolean> toCallSend;

   private final SupplierFromVertex<I, V, E, Boolean> toCallReceive;

   private final Block block;

   /**

    * Creates filtering block which uses passed {@code toCallSend} to filter

    * calls to {@code vertexSend}, and passed {@code toCallReceive} to filter

    * calls to {@code vertexReceive}, on all pieces within passed {@code block}.

    */

   public FilteringBlock(

       SupplierFromVertex<I, V, E, Boolean> toCallSend,

       SupplierFromVertex<I, V, E, Boolean> toCallReceive,

       Block block) {

     this.toCallSend = toCallSend;

     this.toCallReceive = toCallReceive;

     this.block = block;

   }

   /**

    * Creates filtering block, where both vertexSend and vertexReceive is

    * filtered based on same supplier.

    */

   public FilteringBlock(

       SupplierFromVertex<I, V, E, Boolean> toCallSendAndReceive, Block block) {

     this(toCallSendAndReceive, toCallSendAndReceive, block);

   }

   /**

    * Creates filtering block, that filters only vertexReceive function,

    * and always calls vertexSend function.

    */

   public static

   <I extends WritableComparable, V extends Writable, E extends Writable>

   Block createReceiveFiltering(

       SupplierFromVertex<I, V, E, Boolean> toCallReceive,

       Block innerBlock) {

     return new FilteringBlock<>(null, toCallReceive, innerBlock);

   }

   /**

    * Creates filtering block, that filters only vertexSend function,

    * and always calls vertexReceive function.

    */

   public static

   <I extends WritableComparable, V extends Writable, E extends Writable>

   Block createSendFiltering(

       SupplierFromVertex<I, V, E, Boolean> toCallSend,

       Block innerBlock) {

     return new FilteringBlock<>(toCallSend, null, innerBlock);

   }

   @Override

   public Iterator<AbstractPiece> iterator() {

     return Iterators.transform(

         block.iterator(),

         new Function<AbstractPiece, AbstractPiece>() {

           @Override

           public AbstractPiece apply(AbstractPiece input) {

             return new FilteringPiece<>(toCallSend, toCallReceive, input);

           }

         });

   }

   @Override

   public void forAllPossiblePieces(Consumer<AbstractPiece> consumer) {

     block.forAllPossiblePieces(consumer);

   }

   @Override

   public PieceCount getPieceCount() {

     return block.getPieceCount();

   }

 }