1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.giraph.reducers.impl; 19 20 import java.io.DataInput; 21 import java.io.DataOutput; 22 import java.io.IOException; 23 24 import org.apache.giraph.reducers.ReduceSameTypeOperation; 25 import org.apache.hadoop.io.BooleanWritable; 26 27 /** 28 * 29 * ReduceOperation for calculating the AND function over boolean values. 30 * The default value when nothing is aggregated is true. 31 * 32 */ 33 public class AndReduce extends ReduceSameTypeOperation<BooleanWritable> { 34 /** Instance */ 35 public static final AndReduce INSTANCE = new AndReduce(); 36 37 @Override 38 public BooleanWritable createInitialValue() { 39 return new BooleanWritable(true); 40 } 41 42 @Override 43 public BooleanWritable reduce( 44 BooleanWritable curValue, BooleanWritable valueToReduce) { 45 curValue.set(curValue.get() && valueToReduce.get()); 46 return curValue; 47 } 48 49 @Override 50 public void write(DataOutput out) throws IOException { 51 } 52 53 @Override 54 public void readFields(DataInput in) throws IOException { 55 } 56 }