/**
* 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.hadoop.hive.ql.udf.generic;
import static java.math.BigDecimal.ROUND_HALF_UP;
import static java.util.Calendar.DATE;
import static java.util.Calendar.HOUR_OF_DAY;
import static java.util.Calendar.MINUTE;
import static java.util.Calendar.MONTH;
import static java.util.Calendar.SECOND;
import static java.util.Calendar.YEAR;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.DATE_GROUP;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.STRING_GROUP;
import java.math.BigDecimal;
import java.util.Calendar;
import java.util.Date;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
import org.apache.hadoop.hive.serde2.objectinspector.ConstantObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
/**
* UDFMonthsBetween.
*
*/
@Description(name = "months_between", value = "_FUNC_(date1, date2, roundOff) "
+ "- returns number of months between dates date1 and date2",
extended = "If date1 is later than date2, then the result is positive. "
+ "If date1 is earlier than date2, then the result is negative. "
+ "If date1 and date2 are either the same days of the month or both last days of months, "
+ "then the result is always an integer. "
+ "Otherwise the UDF calculates the fractional portion of the result based on a 31-day "
+ "month and considers the difference in time components date1 and date2.\n"
+ "date1 and date2 type can be date, timestamp or string in the format "
+ "'yyyy-MM-dd' or 'yyyy-MM-dd HH:mm:ss'. "
+ "The result is rounded to 8 decimal places by default. Set roundOff=false otherwise.\n"
+ " Example:\n"
+ " > SELECT _FUNC_('1997-02-28 10:30:00', '1996-10-30');\n 3.94959677")
public class GenericUDFMonthsBetween extends GenericUDF {
private transient Converter[] tsConverters = new Converter[2];
private transient PrimitiveCategory[] tsInputTypes = new PrimitiveCategory[2];
private transient Converter[] dtConverters = new Converter[2];
private transient PrimitiveCategory[] dtInputTypes = new PrimitiveCategory[2];
private final Calendar cal1 = Calendar.getInstance();
private final Calendar cal2 = Calendar.getInstance();
private final DoubleWritable output = new DoubleWritable();
private boolean isRoundOffNeeded = true;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
checkArgsSize(arguments, 2, 3);
checkArgPrimitive(arguments, 0);
checkArgPrimitive(arguments, 1);
if (arguments.length == 3) {
if (arguments[2] instanceof ConstantObjectInspector) {
isRoundOffNeeded = getConstantBooleanValue(arguments, 2);
}
}
// the function should support both short date and full timestamp format
// time part of the timestamp should not be skipped
checkArgGroups(arguments, 0, tsInputTypes, STRING_GROUP, DATE_GROUP);
checkArgGroups(arguments, 1, tsInputTypes, STRING_GROUP, DATE_GROUP);
checkArgGroups(arguments, 0, dtInputTypes, STRING_GROUP, DATE_GROUP);
checkArgGroups(arguments, 1, dtInputTypes, STRING_GROUP, DATE_GROUP);
obtainTimestampConverter(arguments, 0, tsInputTypes, tsConverters);
obtainTimestampConverter(arguments, 1, tsInputTypes, tsConverters);
obtainDateConverter(arguments, 0, dtInputTypes, dtConverters);
obtainDateConverter(arguments, 1, dtInputTypes, dtConverters);
ObjectInspector outputOI = PrimitiveObjectInspectorFactory.writableDoubleObjectInspector;
return outputOI;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
// the function should support both short date and full timestamp format
// time part of the timestamp should not be skipped
Date date1 = getTimestampValue(arguments, 0, tsConverters);
if (date1 == null) {
date1 = getDateValue(arguments, 0, dtInputTypes, dtConverters);
if (date1 == null) {
return null;
}
}
Date date2 = getTimestampValue(arguments, 1, tsConverters);
if (date2 == null) {
date2 = getDateValue(arguments, 1, dtInputTypes, dtConverters);
if (date2 == null) {
return null;
}
}
cal1.setTime(date1);
cal2.setTime(date2);
// skip day/time part if both dates are end of the month
// or the same day of the month
int monDiffInt = (cal1.get(YEAR) - cal2.get(YEAR)) * 12 + (cal1.get(MONTH) - cal2.get(MONTH));
if (cal1.get(DATE) == cal2.get(DATE)
|| (cal1.get(DATE) == cal1.getActualMaximum(DATE) && cal2.get(DATE) == cal2
.getActualMaximum(DATE))) {
output.set(monDiffInt);
return output;
}
int sec1 = getDayPartInSec(cal1);
int sec2 = getDayPartInSec(cal2);
// 1 sec is 0.000000373 months (1/2678400). 1 month is 31 days.
// there should be no adjustments for leap seconds
double monBtwDbl = monDiffInt + (sec1 - sec2) / 2678400D;
if (isRoundOffNeeded) {
// Round a double to 8 decimal places.
monBtwDbl = BigDecimal.valueOf(monBtwDbl).setScale(8, ROUND_HALF_UP).doubleValue();
}
output.set(monBtwDbl);
return output;
}
protected int getDayPartInSec(Calendar cal) {
int dd = cal.get(DATE);
int HH = cal.get(HOUR_OF_DAY);
int mm = cal.get(MINUTE);
int ss = cal.get(SECOND);
int dayInSec = dd * 86400 + HH * 3600 + mm * 60 + ss;
return dayInSec;
}
@Override
public String getDisplayString(String[] children) {
return getStandardDisplayString(getFuncName(), children);
}
@Override
protected String getFuncName() {
return "months_between";
}
}