Matthias Andreas Benkard | b5d657a | 2022-02-03 21:14:30 +0100 | [diff] [blame^] | 1 | // SPDX-FileCopyrightText: © 2021 Matthias Andreas Benkard <code@mail.matthias.benkard.de> |
| 2 | // |
| 3 | // SPDX-License-Identifier: LGPL-3.0-or-later |
| 4 | |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 5 | package eu.mulk.jgvariant.ostree; |
| 6 | |
| 7 | import static org.apiguardian.api.API.Status.STABLE; |
| 8 | |
| 9 | import org.apiguardian.api.API; |
| 10 | |
| 11 | /** |
| 12 | * An object type as found in an OSTree repository. |
| 13 | * |
| 14 | * <p>Each object type has its own file extension. |
| 15 | * |
| 16 | * <p>In an OSTree repository, objects are located in a subfolder of the {@code /objects} folder |
| 17 | * based on their {@link Checksum}. The schema for looking up objects is {@code |
| 18 | * /objects/{checksumHead}/{checksumRest}.{fileExtension}} where: |
| 19 | * |
| 20 | * <dl> |
| 21 | * <dt>{@code {checksumHead}} |
| 22 | * <dd>the first two characters of {@link Checksum#hex()} |
| 23 | * <dt>{@code {checksumRest}} |
| 24 | * <dd>the substring of {@link Checksum#hex()} starting from the 3rd character |
| 25 | * <dt>{@code {fileExtension}} |
| 26 | * <dd>the {@link #fileExtension()} of the object type |
| 27 | * </dl> |
| 28 | */ |
| 29 | @API(status = STABLE) |
| 30 | public enum ObjectType { |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 31 | |
| 32 | /** |
| 33 | * A regular file. |
| 34 | * |
| 35 | * <p>File ending: {@code .file} |
| 36 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 37 | FILE((byte) 1, "file"), |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 38 | |
| 39 | /** |
| 40 | * A serialized {@link DirTree} object. |
| 41 | * |
| 42 | * <p>File ending: {@code .dirtree} |
| 43 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 44 | DIR_TREE((byte) 2, "dirtree"), |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 45 | |
| 46 | /** |
| 47 | * A serialized {@link DirMeta} object. |
| 48 | * |
| 49 | * <p>File ending: {@code .dirmeta} |
| 50 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 51 | DIR_META((byte) 3, "dirmeta"), |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 52 | |
| 53 | /** |
| 54 | * A serialized {@link Commit} object. |
| 55 | * |
| 56 | * <p>File ending: {@code .commit} |
| 57 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 58 | COMMIT((byte) 4, "commit"), |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 59 | |
| 60 | /** |
| 61 | * A tombstone file standing in for a commit that was deleted. |
| 62 | * |
| 63 | * <p>File ending: {@code .commit-tombstone} |
| 64 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 65 | TOMBSTONE_COMMIT((byte) 5, "commit-tombstone"), |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 66 | |
| 67 | /** |
| 68 | * Detached metadata for a {@link Commit}. |
| 69 | * |
| 70 | * <p>Often goes together with a {@link #TOMBSTONE_COMMIT}. |
| 71 | * |
| 72 | * <p>File ending: {@code .commitmeta} |
| 73 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 74 | COMMIT_META((byte) 6, "commitmeta"), |
Matthias Andreas Benkard | c7aa2b6 | 2022-01-23 18:10:03 +0100 | [diff] [blame] | 75 | |
| 76 | /** |
| 77 | * A symlink to a {@link #FILE} that lives somewhere else. |
| 78 | * |
| 79 | * <p>File ending: {@code .payload-link} |
| 80 | */ |
Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame] | 81 | PAYLOAD_LINK((byte) 7, "payload-link"); |
| 82 | |
| 83 | private final byte byteValue; |
| 84 | private final String fileExtension; |
| 85 | |
| 86 | /** |
| 87 | * The serialized byte value. |
| 88 | * |
| 89 | * @return a byte representing this value in serialized GVariant structures. |
| 90 | */ |
| 91 | public byte byteValue() { |
| 92 | return byteValue; |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * The file extension carried by files of this type. |
| 97 | * |
| 98 | * @return a file extension. |
| 99 | */ |
| 100 | public String fileExtension() { |
| 101 | return fileExtension; |
| 102 | } |
| 103 | |
| 104 | ObjectType(byte byteValue, String fileExtension) { |
| 105 | this.byteValue = byteValue; |
| 106 | this.fileExtension = fileExtension; |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * Returns the {@link ObjectType} corresponding to a serialized GVariant value. |
| 111 | * |
| 112 | * @param byteValue a serialized value as used in GVariant. |
| 113 | * @return the {@link ObjectType} corresponding to the serialized value. |
| 114 | * @throws IllegalArgumentException if the byte value is invalid. |
| 115 | */ |
| 116 | public static ObjectType valueOf(byte byteValue) { |
| 117 | return switch (byteValue) { |
| 118 | case 1 -> FILE; |
| 119 | case 2 -> DIR_TREE; |
| 120 | case 3 -> DIR_META; |
| 121 | case 4 -> COMMIT; |
| 122 | case 5 -> TOMBSTONE_COMMIT; |
| 123 | case 6 -> COMMIT_META; |
| 124 | case 7 -> PAYLOAD_LINK; |
| 125 | default -> throw new IllegalArgumentException("invalid ObjectType: %d".formatted(byteValue)); |
| 126 | }; |
| 127 | } |
| 128 | } |