Matthias Andreas Benkard | 0511464 | 2021-12-29 21:51:29 +0100 | [diff] [blame^] | 1 | package eu.mulk.jgvariant.ostree; |
| 2 | |
| 3 | import static org.apiguardian.api.API.Status.STABLE; |
| 4 | |
| 5 | import org.apiguardian.api.API; |
| 6 | |
| 7 | /** |
| 8 | * An object type as found in an OSTree repository. |
| 9 | * |
| 10 | * <p>Each object type has its own file extension. |
| 11 | * |
| 12 | * <p>In an OSTree repository, objects are located in a subfolder of the {@code /objects} folder |
| 13 | * based on their {@link Checksum}. The schema for looking up objects is {@code |
| 14 | * /objects/{checksumHead}/{checksumRest}.{fileExtension}} where: |
| 15 | * |
| 16 | * <dl> |
| 17 | * <dt>{@code {checksumHead}} |
| 18 | * <dd>the first two characters of {@link Checksum#hex()} |
| 19 | * <dt>{@code {checksumRest}} |
| 20 | * <dd>the substring of {@link Checksum#hex()} starting from the 3rd character |
| 21 | * <dt>{@code {fileExtension}} |
| 22 | * <dd>the {@link #fileExtension()} of the object type |
| 23 | * </dl> |
| 24 | */ |
| 25 | @API(status = STABLE) |
| 26 | public enum ObjectType { |
| 27 | FILE((byte) 1, "file"), |
| 28 | DIR_TREE((byte) 2, "dirtree"), |
| 29 | DIR_META((byte) 3, "dirmeta"), |
| 30 | COMMIT((byte) 4, "commit"), |
| 31 | TOMBSTONE_COMMIT((byte) 5, "commit-tombstone"), |
| 32 | COMMIT_META((byte) 6, "commitmeta"), |
| 33 | PAYLOAD_LINK((byte) 7, "payload-link"); |
| 34 | |
| 35 | private final byte byteValue; |
| 36 | private final String fileExtension; |
| 37 | |
| 38 | /** |
| 39 | * The serialized byte value. |
| 40 | * |
| 41 | * @return a byte representing this value in serialized GVariant structures. |
| 42 | */ |
| 43 | public byte byteValue() { |
| 44 | return byteValue; |
| 45 | } |
| 46 | |
| 47 | /** |
| 48 | * The file extension carried by files of this type. |
| 49 | * |
| 50 | * @return a file extension. |
| 51 | */ |
| 52 | public String fileExtension() { |
| 53 | return fileExtension; |
| 54 | } |
| 55 | |
| 56 | ObjectType(byte byteValue, String fileExtension) { |
| 57 | this.byteValue = byteValue; |
| 58 | this.fileExtension = fileExtension; |
| 59 | } |
| 60 | |
| 61 | /** |
| 62 | * Returns the {@link ObjectType} corresponding to a serialized GVariant value. |
| 63 | * |
| 64 | * @param byteValue a serialized value as used in GVariant. |
| 65 | * @return the {@link ObjectType} corresponding to the serialized value. |
| 66 | * @throws IllegalArgumentException if the byte value is invalid. |
| 67 | */ |
| 68 | public static ObjectType valueOf(byte byteValue) { |
| 69 | return switch (byteValue) { |
| 70 | case 1 -> FILE; |
| 71 | case 2 -> DIR_TREE; |
| 72 | case 3 -> DIR_META; |
| 73 | case 4 -> COMMIT; |
| 74 | case 5 -> TOMBSTONE_COMMIT; |
| 75 | case 6 -> COMMIT_META; |
| 76 | case 7 -> PAYLOAD_LINK; |
| 77 | default -> throw new IllegalArgumentException("invalid ObjectType: %d".formatted(byteValue)); |
| 78 | }; |
| 79 | } |
| 80 | } |