uk.ac.rdg.resc.edal.time.FixedYearLengthChronology Maven / Gradle / Ivy
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/*
* Copyright (c) 2010 The University of Reading
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University of Reading, nor the names of the
* authors or contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package uk.ac.rdg.resc.edal.time;
import org.joda.time.Chronology;
import org.joda.time.DateTimeConstants;
import org.joda.time.DateTimeField;
import org.joda.time.DateTimeFieldType;
import org.joda.time.DateTimeZone;
import org.joda.time.DurationField;
import org.joda.time.DurationFieldType;
import org.joda.time.chrono.BaseChronology;
import org.joda.time.field.MillisDurationField;
import org.joda.time.field.PreciseDateTimeField;
import org.joda.time.field.PreciseDurationDateTimeField;
import org.joda.time.field.PreciseDurationField;
import org.joda.time.field.ZeroIsMaxDateTimeField;
/**
* A Chronology in which every year has the same number of days. Such calendar
* systems are used in many climate simulations.
* In these Chronologies, a millisecond instant of zero corresponds with
* 1970-01-01T00:00:00.000Z and a year has a fixed number of milliseconds.
* There is no concept of an era in these Chronologies, so all durations and fields
* relating to this concept are not supported. Additionally, the concept of a
* "weekyear" (the year that "owns" a given week) is not implemented.
* Instances of this class can only be created in {@link DateTimeZone#UTC}.
* (Support for time zones makes little sense in this chronology).
* Instances of this class are immutable.
* Note: Much of this code was copied from the package-private
* BasicChronology.
* @author Jon Blower
* @see "http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#calendar"
*/
abstract class FixedYearLengthChronology extends BaseChronology {
///// DURATIONS /////
private static final DurationField millisecondDuration = MillisDurationField.INSTANCE;
private static final DurationField secondDuration =
new PreciseDurationField(DurationFieldType.seconds(), DateTimeConstants.MILLIS_PER_SECOND);
private static final DurationField minuteDuration =
new PreciseDurationField(DurationFieldType.minutes(), DateTimeConstants.MILLIS_PER_MINUTE);
private static final DurationField hourDuration =
new PreciseDurationField(DurationFieldType.hours(), DateTimeConstants.MILLIS_PER_HOUR);
private static final DurationField halfdayDuration =
new PreciseDurationField(DurationFieldType.halfdays(), 12 * DateTimeConstants.MILLIS_PER_HOUR);
private static final DurationField dayDuration =
new PreciseDurationField(DurationFieldType.days(), 2 * halfdayDuration.getUnitMillis());
private static final DurationField weekDuration =
new PreciseDurationField(DurationFieldType.weeks(), 7 * dayDuration.getUnitMillis());
// We don't know the length of the year or century until we know how many
// days there are in a year
private final DurationField yearDuration;
private final DurationField centuryDuration;
///// DATE-TIME FIELDS /////
private static final DateTimeField millisOfSecond =
new PreciseDateTimeField(DateTimeFieldType.millisOfSecond(), millisecondDuration, secondDuration);
private static final DateTimeField millisOfDay =
new PreciseDateTimeField(DateTimeFieldType.millisOfDay(), millisecondDuration, dayDuration);
private static final DateTimeField secondOfMinute =
new PreciseDateTimeField(DateTimeFieldType.secondOfMinute(), secondDuration, minuteDuration);
private static final DateTimeField secondOfDay =
new PreciseDateTimeField(DateTimeFieldType.secondOfDay(), secondDuration, dayDuration);
private static final DateTimeField minuteOfHour =
new PreciseDateTimeField(DateTimeFieldType.minuteOfHour(), minuteDuration, hourDuration);
private static final DateTimeField minuteOfDay =
new PreciseDateTimeField(DateTimeFieldType.minuteOfDay(), minuteDuration, dayDuration);
private static final DateTimeField hourOfDay =
new PreciseDateTimeField(DateTimeFieldType.hourOfDay(), hourDuration, dayDuration);
private static final DateTimeField hourOfHalfday =
new PreciseDateTimeField(DateTimeFieldType.hourOfHalfday(), hourDuration, halfdayDuration);
private static final DateTimeField halfdayOfDay =
new PreciseDateTimeField(DateTimeFieldType.halfdayOfDay(), halfdayDuration, dayDuration);
private static final DateTimeField clockhourOfDay =
new ZeroIsMaxDateTimeField(hourOfDay, DateTimeFieldType.clockhourOfDay());
private static final DateTimeField clockhourOfHalfday =
new ZeroIsMaxDateTimeField(hourOfHalfday, DateTimeFieldType.clockhourOfHalfday());
private static final DateTimeField dayOfWeek =
new PreciseDateTimeField(DateTimeFieldType.dayOfWeek(), dayDuration, weekDuration);
// We don't know the length of the year or century until we know how many
// days there are in a year
private final DateTimeField dayOfYear;
private final DateTimeField yearOfCentury;
private final DateTimeField year;
private final int daysInYear;
private static final class YearField extends PreciseDurationDateTimeField {
public YearField(DurationField yearDuration) {
super(DateTimeFieldType.year(), yearDuration);
}
@Override
public int get(long instant) {
// We need to use Math.floor() to deal with negative instants
long millis = this.getDurationField().getUnitMillis();
double imillis = millis == 0 ? 0 : 1.0 / millis;
return (int) Math.floor(instant * imillis) + 1970;
}
/** Returns null: the field has no range */
@Override
public DurationField getRangeDurationField() { return null; }
@Override
public int getMinimumValue() { return this.get(Long.MIN_VALUE); }
@Override
// We subtract one to ensure that the whole of this year can be
// encoded
public int getMaximumValue() { return this.get(Long.MAX_VALUE) - 1; }
};
///// CONSTRUCTORS AND FACTORIES /////
/**
* @param daysInYear The number of days in each year
*/
protected FixedYearLengthChronology(int daysInYear) {
this.daysInYear = daysInYear;
this.yearDuration = new PreciseDurationField(DurationFieldType.years(),
daysInYear * dayDuration.getUnitMillis());
this.centuryDuration = new PreciseDurationField(DurationFieldType.centuries(),
100 * yearDuration.getUnitMillis());
this.dayOfYear = new OneBasedPreciseDateTimeField(DateTimeFieldType.dayOfYear(),
dayDuration, this.yearDuration);
this.yearOfCentury = new PreciseDateTimeField(DateTimeFieldType.yearOfCentury(),
this.yearDuration, this.centuryDuration);
this.year = new YearField(this.yearDuration);
}
///// DURATION ACCESSORS /////
@Override
public final DurationField millis() { return millisecondDuration; }
@Override
public final DurationField seconds() { return secondDuration; }
@Override
public final DurationField minutes() { return minuteDuration; }
@Override
public final DurationField hours() { return hourDuration; }
@Override
public final DurationField halfdays() { return halfdayDuration; }
/** Each day has exactly the same length: there is no daylight saving */
@Override
public final DurationField days() { return dayDuration; }
/** Each week has 7 days */
@Override
public final DurationField weeks() { return weekDuration; }
@Override
public abstract DurationField months();
@Override
public final DurationField years() { return this.yearDuration; }
@Override
public final DurationField centuries() { return this.centuryDuration; }
///// DATE-TIME FIELD ACCESSORS /////
@Override
public final DateTimeField millisOfSecond() { return millisOfSecond; }
@Override
public final DateTimeField millisOfDay() { return millisOfDay; }
@Override
public final DateTimeField secondOfMinute() { return secondOfMinute; }
@Override
public final DateTimeField secondOfDay() { return secondOfDay; }
@Override
public final DateTimeField minuteOfHour() { return minuteOfHour; }
@Override
public final DateTimeField minuteOfDay() { return minuteOfDay; }
@Override
public final DateTimeField hourOfDay() { return hourOfDay; }
@Override
public final DateTimeField hourOfHalfday() { return hourOfHalfday; }
@Override
public final DateTimeField halfdayOfDay() { return halfdayOfDay; }
@Override
public final DateTimeField clockhourOfDay() { return clockhourOfDay; }
@Override
public final DateTimeField clockhourOfHalfday() { return clockhourOfHalfday; }
@Override
public final DateTimeField dayOfWeek() { return dayOfWeek; }
@Override
public abstract DateTimeField dayOfMonth();
@Override
public final DateTimeField dayOfYear() { return dayOfYear;}
@Override
public abstract DateTimeField monthOfYear();
@Override
public final DateTimeField year() { return year; }
@Override
public final DateTimeField yearOfCentury() { return yearOfCentury; }
/** Returns the number of days in the year */
final int getDaysInYear() { return this.daysInYear; }
/** Always returns UTC */
@Override
public final DateTimeZone getZone() { return DateTimeZone.UTC; }
/** Throws UnsupportedOperationException unless the time zone is UTC */
@Override
public final Chronology withZone(DateTimeZone zone) {
if (zone.equals(DateTimeZone.UTC)) return this.withUTC();
throw new UnsupportedOperationException("Not supported yet.");
}
/** Returns this object */
@Override
public final Chronology withUTC() { return this; }
}