1   /* Copyright 2002-2025 CS GROUP
2    * Licensed to CS GROUP (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 org.orekit.errors.OrekitIllegalArgumentException;
20  import org.orekit.errors.OrekitMessages;
21  
22  /**
23   * Pair of time stamped values being defined at the same date.
24   *
25   * @param <K> first time stamped value
26   * @param <V> second time stamped value
27   *
28   * @author Vincent Cucchietti
29   * @see TimeStamped
30   */
31  public class TimeStampedPair<K extends TimeStamped, V extends TimeStamped> implements TimeStamped {
32  
33      /** Default date equality threshold of 1 ns. */
34      public static final double DEFAULT_DATE_EQUALITY_THRESHOLD = 1e-9;
35  
36      /** First time stamped value. */
37      private final K first;
38  
39      /** Second time stamped value. */
40      private final V second;
41  
42      /**
43       * Constructor.
44       * <p>
45       * First and second value must have the same date.
46       *
47       * @param first first time stamped value
48       * @param second second time stamped value
49       */
50      public TimeStampedPair(final K first, final V second) {
51          this(first, second, DEFAULT_DATE_EQUALITY_THRESHOLD);
52      }
53  
54      /**
55       * Constructor.
56       * <p>
57       * First and second value must have the same date.
58       *
59       * @param first first time stamped value
60       * @param second second time stamped value
61       * @param dateEqualityThreshold threshold below which dates are considered equal
62       */
63      public TimeStampedPair(final K first, final V second, final double dateEqualityThreshold) {
64          checkDatesConsistency(first.getDate(), second.getDate(), dateEqualityThreshold);
65          this.first  = first;
66          this.second = second;
67      }
68  
69      /**
70       * Check date consistency.
71       *
72       * @param firstDate first date
73       * @param secondDate second date
74       * @param dateEqualityThreshold threshold below which dates are considered equal
75       */
76      public static void checkDatesConsistency(final AbsoluteDate firstDate, final AbsoluteDate secondDate,
77                                               final double dateEqualityThreshold) {
78          if (!firstDate.isCloseTo(secondDate, dateEqualityThreshold)) {
79              throw new OrekitIllegalArgumentException(OrekitMessages.DATES_MISMATCH, firstDate, secondDate);
80          }
81      }
82  
83      /** {@inheritDoc} */
84      @Override
85      public AbsoluteDate getDate() {
86          return first.getDate();
87      }
88  
89      /** Get first time stamped value.
90       * @return first time stamped value
91       */
92      public K getFirst() {
93          return first;
94      }
95  
96      /** Get second time stamped value.
97       * @return second time stamped value
98       */
99      public V getSecond() {
100         return second;
101     }
102 
103 }