| package eu.mulk.jgvariant.ostree; |
| |
| import eu.mulk.jgvariant.core.Decoder; |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| import java.util.List; |
| |
| /** |
| * A payload file from a static delta. |
| * |
| * <p>The first byte is a compression byte: {@code 0} for none, {@code 'x'} for LZMA. The actual |
| * GVariant data begins right after. |
| * |
| * <p>Reference: {@code |
| * ostree-repo-static-delta-private.h#OSTREE_STATIC_DELTA_PART_PAYLOAD_FORMAT_V0} |
| * |
| * @param fileModes the {@link FileMode}s of the files generated by this delta payload. |
| * @param xattrs the {@link Xattr}s of the files generated by this delta payload. |
| * @param rawDataSource the data bytes used in the delta operations. |
| * @param operations the operations to apply during delta patching. |
| * @see DeltaSuperblock |
| */ |
| public record DeltaPartPayload( |
| List<FileMode> fileModes, |
| List<List<Xattr>> xattrs, |
| ByteString rawDataSource, |
| List<DeltaOperation> operations) { |
| |
| private static final Decoder<DeltaPartPayload> DECODER = |
| Decoder.ofStructure( |
| DeltaPartPayload.class, |
| Decoder.ofArray(FileMode.decoder()), |
| Decoder.ofArray(Decoder.ofArray(Xattr.decoder())), |
| ByteString.decoder(), |
| ByteString.decoder().map(DeltaPartPayload::parseDeltaOperationList)) |
| .contramap(DeltaPartPayload::preparse); |
| |
| private static ByteBuffer preparse(ByteBuffer byteBuffer) { |
| byte compressionByte = byteBuffer.get(0); |
| return switch (compressionByte) { |
| case 0 -> byteBuffer.slice(1, byteBuffer.limit()); |
| case (byte) 'x' -> throw new UnsupportedOperationException( |
| "LZMA compression of static deltas is unsupported"); |
| default -> throw new IllegalArgumentException( |
| "unrecognized compression byte '%d'".formatted(compressionByte)); |
| }; |
| } |
| |
| private static List<DeltaOperation> parseDeltaOperationList(ByteString byteString) { |
| return byteString.stream().map(DeltaOperation::valueOf).toList(); |
| } |
| |
| /** |
| * A file mode triple (UID, GID, and permission bits). |
| * |
| * @param uid |
| * @param gid |
| * @param mode |
| */ |
| public record FileMode(int uid, int gid, int mode) { |
| |
| private static final Decoder<FileMode> DECODER = |
| Decoder.ofStructure( |
| FileMode.class, |
| Decoder.ofInt().withByteOrder(ByteOrder.LITTLE_ENDIAN), |
| Decoder.ofInt().withByteOrder(ByteOrder.LITTLE_ENDIAN), |
| Decoder.ofInt().withByteOrder(ByteOrder.LITTLE_ENDIAN)); |
| |
| /** |
| * Acquires a {@link Decoder} for the enclosing type. |
| * |
| * @return a possibly shared {@link Decoder}. |
| */ |
| public static Decoder<FileMode> decoder() { |
| return DECODER; |
| } |
| } |
| |
| /** |
| * Acquires a {@link Decoder} for the enclosing type. |
| * |
| * <p>FIXME: The first byte is actually a compression byte: {@code 0} for none, {@code 'x'} for |
| * LZMA. |
| * |
| * @return a possibly shared {@link Decoder}. |
| */ |
| public static Decoder<DeltaPartPayload> decoder() { |
| return DECODER; |
| } |
| } |