1 /* Copyright 2002-2024 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
18 package org.orekit.frames;
19
20 import java.io.Serializable;
21 import java.util.HashMap;
22 import java.util.Map;
23
24 import org.hipparchus.Field;
25 import org.hipparchus.CalculusFieldElement;
26 import org.orekit.time.AbsoluteDate;
27 import org.orekit.time.FieldAbsoluteDate;
28
29 /**
30 ** Transform provider using fixed transform.
31 * @author Luc Maisonobe
32 */
33 public class FixedTransformProvider implements TransformProvider {
34
35 /** Serializable UID. */
36 private static final long serialVersionUID = 20170106L;
37
38 /** Fixed transform. */
39 private final Transform transform;
40
41 /** Cached field-based transforms. */
42 private final transient Map<Field<? extends CalculusFieldElement<?>>, FieldTransform<? extends CalculusFieldElement<?>>> cached;
43
44 /** Simple constructor.
45 * @param transform fixed transform
46 */
47 public FixedTransformProvider(final Transform transform) {
48 this.transform = transform;
49 this.cached = new HashMap<>();
50 }
51
52 /** {@inheritDoc} */
53 public Transform getTransform(final AbsoluteDate date) {
54 return transform;
55 }
56
57 /** {@inheritDoc} */
58 @Override
59 public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
60
61 @SuppressWarnings("unchecked")
62 final FieldTransform<T> ft =
63 (FieldTransform<T>) cached.computeIfAbsent(date.getField(),
64 f -> new FieldTransform<>((Field<T>) f, transform));
65
66 return ft;
67
68 }
69
70 /** Replace the instance with a data transfer object for serialization.
71 * <p>
72 * This intermediate class serializes nothing.
73 * </p>
74 * @return data transfer object that will be serialized
75 */
76 private Object writeReplace() {
77 return new DataTransferObject(transform);
78 }
79
80 /** Internal class used only for serialization. */
81 private static class DataTransferObject implements Serializable {
82
83 /** Serializable UID. */
84 private static final long serialVersionUID = 20170106L;
85
86 /** Fixed transform. */
87 private final Transform transform;
88
89 /** Simple constructor.
90 * @param transform fixed transform
91 */
92 private DataTransferObject(final Transform transform) {
93 this.transform = transform;
94 }
95
96 /** Replace the deserialized data transfer object with a {@link FixedTransformProvider}.
97 * @return replacement {@link FixedTransformProvider}
98 */
99 private Object readResolve() {
100 return new FixedTransformProvider(transform);
101 }
102
103 }
104
105 }