ArrayOverlapsUDF.java

ArrayOverlapsUDF.java

/*
 * Hivemall: Hive scalable Machine Learning Library
 *
 * Copyright (C) 2015 Makoto YUI
 * Copyright (C) 2013-2015 National Institute of Advanced Industrial Science and Technology (AIST)
 *
 * Licensed 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.array;

import java.util.Collections;
import java.util.List;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.udf.UDFType;
import org.apache.hadoop.io.BooleanWritable;

@Description(name = "array_overlaps", value = "_FUNC_(ary1, ary2) - Returns true if have elements in common")
@UDFType(deterministic = true, stateful = false)
public final class ArrayOverlapsUDF extends UDF {

    @Nonnull
    public BooleanWritable evaluate(@Nullable final List<String> ary1, @Nullable final List<String> ary2) {
        return evaluate(ary1, ary2, false);
    }

    @Nonnull
    public BooleanWritable evaluate(@Nullable List<String> ary1, @Nullable List<String> ary2, final boolean sorted) {
        if(ary1 == null) {
            return ary2 == null ? new BooleanWritable(true) : new BooleanWritable(false);
        } else if(ary2 == null) {
            return new BooleanWritable(false);
        }

        if(sorted == false) {
            Collections.sort(ary1);
        }

        for(String k : ary2) {
            if(Collections.binarySearch(ary2, k) >= 0) {
                return new BooleanWritable(true);
            }
        }
        return new BooleanWritable(false);
    }

}