/*
* 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.mapred;
import static hivemall.utils.hadoop.WritableUtils.val;
import hivemall.utils.hadoop.HadoopUtils;
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.Text;
@Description(name = "rowid",
value = "_FUNC_() - Returns a generated row id of a form {TASK_ID}-{SEQUENCE_NUMBER}")
@UDFType(deterministic = false, stateful = true)
public class RowIdUDF extends UDF {
private long sequence;
private int taskId;
public RowIdUDF() {
this.sequence = 0L;
this.taskId = -1;
}
public Text evaluate() {
if (taskId == -1) {
this.taskId = HadoopUtils.getTaskId() + 1;
}
sequence++;
String rowid = taskId + "-" + sequence;
return val(rowid);
}
}