/*
* Hivemall: Hive scalable Machine Learning Library
*
* Copyright (C) 2013-2014
* National Institute of Advanced Industrial Science and Technology (AIST)
* Registration Number: H25PRO-1520
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package hivemall.knn.distance;
import static hivemall.utils.hadoop.WritableUtils.val;
import java.math.BigInteger;
import java.util.List;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.udf.UDFType;
import org.apache.hadoop.io.IntWritable;
@UDFType(deterministic = true, stateful = false)
public final class PopcountUDF extends UDF {
public IntWritable evaluate(long a) {
return val(Long.bitCount(a));
}
public IntWritable evaluate(String a) {
BigInteger ai = new BigInteger(a);
return val(ai.bitCount());
}
public IntWritable evaluate(List<Long> a) {
int result = 0;
for(int i = 0; i < a.size(); i++) {
long x = a.get(i).longValue();
result += Long.bitCount(x);
}
return val(result);
}
/**
* Count bits that both bits are 1.
*/
public IntWritable evaluate(long a, long b) {
long innerProduct = a & b;
return val(Long.bitCount(innerProduct));
}
/**
* Count bits that both bits are 1.
*/
public IntWritable evaluate(String a, String b) {
BigInteger ai = new BigInteger(a);
BigInteger bi = new BigInteger(b);
BigInteger innerProduct = ai.and(bi);
return val(innerProduct.bitCount());
}
/**
* Count bits that both bits are 1.
*/
public IntWritable evaluate(List<Long> a, List<Long> b) {
final int min = Math.min(a.size(), b.size());
int result = 0;
for(int i = 0; i < min; i++) {
long innerProduct = a.get(i).longValue() & b.get(i).longValue();
result += Long.bitCount(innerProduct);
}
return val(result);
}
}