001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package hivemall.xgboost;
020
021import hivemall.xgboost.utils.XGBoostUtils;
022
023import javax.annotation.Nonnull;
024import javax.annotation.Nullable;
025
026import org.apache.hadoop.hive.ql.exec.Description;
027import org.apache.hadoop.hive.ql.exec.UDF;
028import org.apache.hadoop.hive.ql.metadata.HiveException;
029import org.apache.hadoop.hive.ql.udf.UDFType;
030
031@Description(name = "xgboost_version", value = "_FUNC_() - Returns the version of xgboost",
032        extended = "SELECT xgboost_version();")
033@UDFType(deterministic = true, stateful = false)
034public final class XGBoostVersionUDF extends UDF {
035
036    @Nullable
037    private String version;
038
039    @Nonnull
040    public String evaluate() throws HiveException {
041        if (version == null) {
042            this.version = XGBoostUtils.getVersion();
043        }
044        return version;
045    }
046
047}