1 /* Copyright 2002-2019 CS Systèmes d'Information 2 * Licensed to CS Systèmes d'Information (CS) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * CS licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.orekit.time; 18 19 import java.io.Serializable; 20 21 import org.hipparchus.RealFieldElement; 22 23 /** Interface for time scales. 24 * <p>This is the interface representing all time scales. Time scales are related 25 * to each other by some offsets that may be discontinuous (for example 26 * the {@link UTCScale UTC scale} with respect to the {@link TAIScale 27 * TAI scale}).</p> 28 * @author Luc Maisonobe 29 * @see AbsoluteDate 30 */ 31 public interface TimeScale extends Serializable { 32 33 /** Get the offset to convert locations from {@link TAIScale} to instance. 34 * @param date conversion date 35 * @return offset in seconds to add to a location in <em>{@link TAIScale} 36 * time scale</em> to get a location in <em>instance time scale</em> 37 * @see #offsetToTAI(DateComponents, TimeComponents) 38 */ 39 double offsetFromTAI(AbsoluteDate date); 40 41 /** Get the offset to convert locations from {@link TAIScale} to instance. 42 * @param date conversion date 43 * @param <T> type of the filed elements 44 * @return offset in seconds to add to a location in <em>{@link TAIScale} 45 * time scale</em> to get a location in <em>instance time scale</em> 46 * @see #offsetToTAI(DateComponents, TimeComponents) 47 * @since 9.0 48 */ 49 <T extends RealFieldElement<T>> T offsetFromTAI(FieldAbsoluteDate<T> date); 50 51 /** Get the offset to convert locations from instance to {@link TAIScale}. 52 * @param date date location in the time scale 53 * @param time time location in the time scale 54 * @return offset in seconds to add to a location in <em>instance time scale</em> 55 * to get a location in <em>{@link TAIScale} time scale</em> 56 * @see #offsetFromTAI(AbsoluteDate) 57 */ 58 default double offsetToTAI(final DateComponents date, final TimeComponents time) { 59 final AbsoluteDateteDate">AbsoluteDate reference = new AbsoluteDate(date, time, TimeScalesFactory.getTAI()); 60 double offset = 0; 61 for (int i = 0; i < 8; i++) { 62 offset = -offsetFromTAI(reference.shiftedBy(offset)); 63 } 64 return offset; 65 } 66 67 /** Check if date is within a leap second introduction <em>in this time scale</em>. 68 * <p> 69 * This method will return false for all time scales that do <em>not</em> 70 * implement leap seconds, even if the date corresponds to a leap second 71 * in {@link UTCScale UTC scale}. 72 * </p> 73 * @param date date to check 74 * @return true if time is within a leap second introduction 75 */ 76 default boolean insideLeap(final AbsoluteDate date) { 77 return false; 78 } 79 80 /** Check if date is within a leap second introduction <em>in this time scale</em>. 81 * <p> 82 * This method will return false for all time scales that do <em>not</em> 83 * implement leap seconds, even if the date corresponds to a leap second 84 * in {@link UTCScale UTC scale}. 85 * </p> 86 * @param date date to check 87 * @param <T> type of the filed elements 88 * @return true if time is within a leap second introduction 89 * @since 9.0 90 */ 91 default <T extends RealFieldElement<T>> boolean insideLeap(final FieldAbsoluteDate<T> date) { 92 return false; 93 } 94 95 /** Check length of the current minute <em>in this time scale</em>. 96 * <p> 97 * This method will return 60 for all time scales that do <em>not</em> 98 * implement leap seconds, even if the date corresponds to a leap second 99 * in {@link UTCScale UTC scale}, and 61 for time scales that do implement 100 * leap second when the current date is within the last minute before the 101 * leap, or during the leap itself. 102 * </p> 103 * @param date date to check 104 * @return 60 or 61 depending on leap seconds introduction 105 */ 106 default int minuteDuration(final AbsoluteDate date) { 107 return 60; 108 } 109 110 /** Check length of the current minute <em>in this time scale</em>. 111 * <p> 112 * This method will return 60 for all time scales that do <em>not</em> 113 * implement leap seconds, even if the date corresponds to a leap second 114 * in {@link UTCScale UTC scale}, and 61 for time scales that do implement 115 * leap second when the current date is within the last minute before the 116 * leap, or during the leap itself. 117 * </p> 118 * @param date date to check 119 * @param <T> type of the filed elements 120 * @return 60 or 61 depending on leap seconds introduction 121 * @since 9.0 122 */ 123 default <T extends RealFieldElement<T>> int minuteDuration(final FieldAbsoluteDate<T> date) { 124 return 60; 125 } 126 127 /** Get the value of the previous leap. 128 * <p> 129 * This method will return 0.0 for all time scales that do <em>not</em> 130 * implement leap seconds. 131 * </p> 132 * @param date date to check 133 * @return value of the previous leap 134 */ 135 default double getLeap(final AbsoluteDate date) { 136 return 0; 137 } 138 139 /** Get the value of the previous leap. 140 * <p> 141 * This method will return 0.0 for all time scales that do <em>not</em> 142 * implement leap seconds. 143 * </p> 144 * @param date date to check 145 * @param <T> type of the filed elements 146 * @return value of the previous leap 147 * @since 9.0 148 */ 149 default <T extends RealFieldElement<T>> T getLeap(final FieldAbsoluteDate<T> date) { 150 return date.getField().getZero(); 151 } 152 153 /** Get the name time scale. 154 * @return name of the time scale 155 */ 156 String getName(); 157 158 }