org.apache.pig.builtin.SubtractDuration Maven / Gradle / Ivy
/**
* 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 org.apache.pig.builtin;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.pig.EvalFunc;
import org.apache.pig.FuncSpec;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.joda.time.DateTime;
import org.joda.time.Period;
/**
* SubtractDuration returns the result of a DateTime object plus a Duration object
*
*
* - Jodatime: http://joda-time.sourceforge.net/
* - ISO8601 Duration Format: http://en.wikipedia.org/wiki/ISO_8601#Durations
*
*
*
* Example usage:
*
* ISOin = LOAD 'test.tsv' USING PigStorage('\t') AS (dt:datetime, dr:chararray);
*
* DESCRIBE ISOin;
* ISOin: {dt: datetime,dr: chararray}
*
* DUMP ISOin;
*
* (2009-01-07T01:07:01.000Z,PT1S)
* (2008-02-06T02:06:02.000Z,PT1M)
* (2007-03-05T03:05:03.000Z,P1D)
* ...
*
* dtsubtract = FOREACH ISOin GENERATE SubtractDuration(dt, dr) AS dt1;
*
* DESCRIBE dtsubtract;
* dtsubtract: {dt1: datetime}
*
* DUMP dtsubtract;
*
* (2009-01-07T01:07:00.000Z)
* (2008-02-06T02:05:02.000Z)
* (2007-03-04T03:05:03.000Z)
*
*
*/
public class SubtractDuration extends EvalFunc {
@Override
public DateTime exec(Tuple input) throws IOException {
if (input == null || input.size() < 2) {
return null;
}
return ((DateTime) input.get(0)).minus(new Period((String) input.get(1)));
}
@Override
public Schema outputSchema(Schema input) {
return new Schema(new Schema.FieldSchema(getSchemaName(this.getClass().getName().toLowerCase(), input), DataType.DATETIME));
}
@Override
public List getArgToFuncMapping() throws FrontendException {
List funcList = new ArrayList();
Schema s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.DATETIME));
s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
funcList.add(new FuncSpec(this.getClass().getName(), s));
return funcList;
}
}