1   /* Contributed in the public domain.
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.files.spice.binary.daf.generic;
18  
19  import java.util.Collections;
20  import java.util.List;
21  
22  /**
23   * Class representing a generic DAF file, containing file-wide metadata,
24   * optional comments, and multiple {@link DAFArray}.
25   *
26   * DAF (Double Precision Array File) is a binary file architecture designed to
27   * store arrays of double precision arrays used by SPICE, NAIF toolkit software library.
28   * The architecture forms the basis of multiple file formats used to store different
29   * data related to astrodynamics, such as SPK, PCK and CK files
30   * (https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/daf.html).
31   *
32   * DAF files provide a generic architecture onto which more specific file
33   * formats are implemented. They are organized in records of fixed length (1024 bytes)
34   * containing different information. The first record is called the file record,
35   * and contains global metadata for the file. This is followed by an optional block
36   * comprising any number of comment records. After this, the file consits of sets of
37   * summary records, name records and element records. These are structured as blocks
38   * of 1 summary record (which contains multiple array summaries, providing metadata
39   * about each array), followed by 1 name record (comprising names for the corresponding
40   * arrays whose summaries were in the previous summary record) and finally by as many
41   * element records as required to store the arrays described in the corresponding summary
42   * records. For a detailed description of the DAF architecture, see NAIF documentation
43   * (https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/daf.html).
44   *
45   * @author Rafael Ayala
46   * @since XX.XX
47   */
48  public class DAF {
49  
50      /**
51       * Global file-wide metadata found in the file record (the first record of the file).
52       */
53      private final DAFFileRecord metadata;
54  
55      /**
56       * Comments from the DAF file. Not always present.
57       */
58      private final String comments;
59  
60      /**
61       * DAF arrays contained in the DAF file.
62       */
63      private final List<DAFArray> arrays;
64  
65      /**
66       * Simple constructor.
67       *
68       * @param metadata global file-wide metadata for the DAF file contained in
69       * the file record
70       * @param comments comments from the DAF file. Not always present
71       * @param arrays list of {@link DAFArray} (each comprising an array summary,
72       * an array name and array elements)
73       */
74      public DAF(final DAFFileRecord metadata,
75              final String comments,
76              final List<DAFArray> arrays) {
77          this.metadata = metadata;
78          this.comments = comments;
79          this.arrays = arrays;
80      }
81  
82      /**
83       * Get thefile record, storing global file-wide metadata.
84       *
85       * @return the {@link DAFFileRecord}
86       */
87      public DAFFileRecord getMetadata() {
88          return metadata;
89      }
90  
91      /**
92       * Get the comments from the DAF file.
93       *
94       * @return comments from the DAF file
95       */
96      public String getComments() {
97          return comments;
98      }
99  
100     /**
101      * Get the arrays contained in the DAF file.
102      *
103      * @return list of {@link DAFArray}
104      */
105     public List<DAFArray> getArrays() {
106         return Collections.unmodifiableList(arrays);
107     }
108 }