/*
* 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 hivemall.tools.bits;
import hivemall.utils.hadoop.HiveUtils;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.List;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.UDFType;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.LongObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.LongWritable;
@Description(name = "unbits",
value = "_FUNC_(long[] bitset) - Returns an long array of the give bitset representation")
@UDFType(deterministic = true, stateful = false)
public final class UnBitsUDF extends GenericUDF {
private ListObjectInspector listOI;
private LongObjectInspector listElemLongOI;
public UnBitsUDF() {}
@Override
public ObjectInspector initialize(ObjectInspector[] argOIs) throws UDFArgumentException {
if (argOIs.length != 1) {
throw new UDFArgumentLengthException(
"Expected 1 argument for _FUNC_(long[] bitset) but got " + argOIs.length
+ " arguments");
}
this.listOI = HiveUtils.asListOI(argOIs[0]);
this.listElemLongOI = HiveUtils.asLongOI(listOI.getListElementObjectInspector());
return ObjectInspectorFactory.getStandardListObjectInspector(PrimitiveObjectInspectorFactory.writableLongObjectInspector);
}
@Override
public List<LongWritable> evaluate(DeferredObject[] args) throws HiveException {
assert (args.length == 1);
Object arg0 = args[0].get();
if (arg0 == null) {
return null;
}
long[] longs = HiveUtils.asLongArray(arg0, listOI, listElemLongOI);
BitSet bitset = BitSet.valueOf(longs);
int size = bitset.cardinality();
final List<LongWritable> list = new ArrayList<LongWritable>(size);
for (int i = bitset.nextSetBit(0); i >= 0; i = bitset.nextSetBit(i + 1)) {
list.add(new LongWritable(i));
}
return list;
}
@Override
public String getDisplayString(String[] args) {
return "unbits(" + Arrays.toString(args) + ")";
}
}