Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 1 | package eu.mulk.jgvariant.core; |
| 2 | |
| 3 | import static java.nio.ByteOrder.LITTLE_ENDIAN; |
| 4 | |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 5 | import java.lang.reflect.InvocationTargetException; |
| 6 | import java.lang.reflect.RecordComponent; |
| 7 | import java.nio.ByteBuffer; |
| 8 | import java.nio.ByteOrder; |
| 9 | import java.nio.charset.Charset; |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 10 | import java.nio.charset.StandardCharsets; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 11 | import java.util.ArrayList; |
| 12 | import java.util.Arrays; |
| 13 | import java.util.List; |
| 14 | import java.util.Optional; |
| 15 | import org.jetbrains.annotations.Nullable; |
| 16 | |
| 17 | /** |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 18 | * Type class for decodable types. |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 19 | * |
| 20 | * <p>Use the {@code of*} family of constructor methods to acquire a suitable {@link Decoder} for |
| 21 | * the type you wish to decode. |
| 22 | * |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 23 | * <p><strong>Example</strong> |
| 24 | * |
| 25 | * <p>To parse a GVariant of type {@code "a(si)"}, which is an array of pairs of {@link String} and |
| 26 | * {@code int}, you can use the following code: |
| 27 | * |
| 28 | * <pre>{@code |
Matthias Andreas Benkard | 35f7a20 | 2021-12-14 19:29:26 +0100 | [diff] [blame] | 29 | * record ExampleRecord(String s, int i) {} |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 30 | * |
| 31 | * var decoder = |
| 32 | * Decoder.ofArray( |
| 33 | * Decoder.ofStructure( |
| 34 | * ExampleRecord.class, |
Matthias Andreas Benkard | 35f7a20 | 2021-12-14 19:29:26 +0100 | [diff] [blame] | 35 | * Decoder.ofString(UTF_8), |
| 36 | * Decoder.ofInt().withByteOrder(LITTLE_ENDIAN))); |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 37 | * |
| 38 | * byte[] bytes = ...; |
Matthias Andreas Benkard | 35f7a20 | 2021-12-14 19:29:26 +0100 | [diff] [blame] | 39 | * List<ExampleRecord> example = decoder.decode(ByteBuffer.wrap(bytes)); |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 40 | * }</pre> |
| 41 | * |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 42 | * @param <T> the type that the {@link Decoder} can decode. |
| 43 | */ |
| 44 | @SuppressWarnings("java:S1610") |
Matthias Andreas Benkard | 35f7a20 | 2021-12-14 19:29:26 +0100 | [diff] [blame] | 45 | public abstract class Decoder<T> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 46 | |
| 47 | private Decoder() {} |
| 48 | |
| 49 | /** |
| 50 | * @throws java.nio.BufferUnderflowException if the byte buffer is shorter than the requested |
| 51 | * data. |
| 52 | */ |
| 53 | public abstract T decode(ByteBuffer byteSlice); |
| 54 | |
| 55 | abstract byte alignment(); |
| 56 | |
| 57 | @Nullable |
| 58 | abstract Integer fixedSize(); |
| 59 | |
| 60 | final boolean hasFixedSize() { |
| 61 | return fixedSize() != null; |
| 62 | } |
| 63 | |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 64 | /** |
| 65 | * Switches the input {@link ByteBuffer} to a given {@link ByteOrder} before reading from it. |
| 66 | * |
| 67 | * @param byteOrder the byte order to use. |
| 68 | * @return a new, decorated {@link Decoder}. |
| 69 | */ |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 70 | public Decoder<T> withByteOrder(ByteOrder byteOrder) { |
| 71 | var delegate = this; |
| 72 | |
| 73 | return new Decoder<>() { |
| 74 | @Override |
| 75 | public byte alignment() { |
| 76 | return delegate.alignment(); |
| 77 | } |
| 78 | |
| 79 | @Override |
| 80 | public @Nullable Integer fixedSize() { |
| 81 | return delegate.fixedSize(); |
| 82 | } |
| 83 | |
| 84 | @Override |
| 85 | public T decode(ByteBuffer byteSlice) { |
| 86 | byteSlice.order(byteOrder); |
| 87 | return delegate.decode(byteSlice); |
| 88 | } |
| 89 | }; |
| 90 | } |
| 91 | |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 92 | /** |
Matthias Andreas Benkard | 35f7a20 | 2021-12-14 19:29:26 +0100 | [diff] [blame] | 93 | * Creates a {@link Decoder} for an {@code Array} type. |
Matthias Andreas Benkard | 4c32c39 | 2021-12-12 21:23:53 +0100 | [diff] [blame] | 94 | * |
| 95 | * @param elementDecoder a {@link Decoder} for the elements of the array. |
| 96 | * @param <U> the element type. |
| 97 | * @return a new {@link Decoder}. |
| 98 | */ |
Matthias Andreas Benkard | 35f7a20 | 2021-12-14 19:29:26 +0100 | [diff] [blame] | 99 | public static <U> Decoder<List<U>> ofArray(Decoder<U> elementDecoder) { |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 100 | return new ArrayDecoder<>(elementDecoder); |
| 101 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 102 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 103 | /** |
| 104 | * Creates a {@link Decoder} for a {@code Maybe} type. |
| 105 | * |
| 106 | * @param elementDecoder a {@link Decoder} for the contained element. |
| 107 | * @param <U> the element type. |
| 108 | * @return a new {@link Decoder}. |
| 109 | */ |
| 110 | public static <U> Decoder<Optional<U>> ofMaybe(Decoder<U> elementDecoder) { |
| 111 | return new MaybeDecoder<>(elementDecoder); |
| 112 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 113 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 114 | /** |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 115 | * Creates a {@link Decoder} for a {@code Structure} type, decoding into a {@link Record}. |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 116 | * |
| 117 | * @param recordType the {@link Record} type that represents the components of the structure. |
| 118 | * @param componentDecoders a {@link Decoder} for each component of the structure. |
| 119 | * @param <U> the {@link Record} type that represents the components of the structure. |
| 120 | * @return a new {@link Decoder}. |
| 121 | */ |
| 122 | public static <U extends Record> Decoder<U> ofStructure( |
| 123 | Class<U> recordType, Decoder<?>... componentDecoders) { |
| 124 | return new StructureDecoder<>(recordType, componentDecoders); |
| 125 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 126 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 127 | /** |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 128 | * Creates a {@link Decoder} for a {@code Structure} type, decoding into a {@link List}. |
| 129 | * |
| 130 | * <p>Prefer {@link #ofStructure(Class, Decoder[])} if possible, which is both more type-safe and |
| 131 | * more convenient. |
| 132 | * |
| 133 | * @param componentDecoders a {@link Decoder} for each component of the structure. |
| 134 | * @return a new {@link Decoder}. |
| 135 | */ |
| 136 | public static Decoder<Object[]> ofStructure(Decoder<?>... componentDecoders) { |
| 137 | return new TupleDecoder(componentDecoders); |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Creates a {@link Decoder} for the {@code Variant} type. |
| 142 | * |
| 143 | * <p>The returned {@link Object} can be of one of the following types: |
| 144 | * |
| 145 | * <ul> |
| 146 | * <li>{@link Boolean} |
| 147 | * <li>{@link Byte} |
| 148 | * <li>{@link Short} |
| 149 | * <li>{@link Integer} |
| 150 | * <li>{@link Long} |
| 151 | * <li>{@link String} |
| 152 | * <li>{@link Optional} (a GVariant {@code Maybe} type) |
| 153 | * <li>{@link List} (a GVariant array) |
| 154 | * <li>{@link Object[]} (a GVariant structure) |
| 155 | * </ul> |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 156 | * |
| 157 | * @return a new {@link Decoder}. |
| 158 | */ |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 159 | public static Decoder<Object> ofVariant() { |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 160 | return new VariantDecoder(); |
| 161 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 162 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 163 | /** |
| 164 | * Creates a {@link Decoder} for the {@code Boolean} type. |
| 165 | * |
| 166 | * @return a new {@link Decoder}. |
| 167 | */ |
| 168 | public static Decoder<Boolean> ofBoolean() { |
| 169 | return new BooleanDecoder(); |
| 170 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 171 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 172 | /** |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 173 | * Creates a {@link Decoder} for the 8-bit {@code byte} type. |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 174 | * |
| 175 | * <p><strong>Note:</strong> It is often useful to apply {@link #withByteOrder(ByteOrder)} to the |
| 176 | * result of this method. |
| 177 | * |
| 178 | * @return a new {@link Decoder}. |
| 179 | */ |
| 180 | public static Decoder<Byte> ofByte() { |
| 181 | return new ByteDecoder(); |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * Creates a {@link Decoder} for the 16-bit {@code short} type. |
| 186 | * |
| 187 | * <p><strong>Note:</strong> It is often useful to apply {@link #withByteOrder(ByteOrder)} to the |
| 188 | * result of this method. |
| 189 | * |
| 190 | * @return a new {@link Decoder}. |
| 191 | */ |
| 192 | public static Decoder<Short> ofShort() { |
| 193 | return new ShortDecoder(); |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * Creates a {@link Decoder} for the 32-bit {@code int} type. |
| 198 | * |
| 199 | * <p><strong>Note:</strong> It is often useful to apply {@link #withByteOrder(ByteOrder)} to the |
| 200 | * result of this method. |
| 201 | * |
| 202 | * @return a new {@link Decoder}. |
| 203 | */ |
| 204 | public static Decoder<Integer> ofInt() { |
| 205 | return new IntegerDecoder(); |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Creates a {@link Decoder} for the 64-bit {@code long} type. |
| 210 | * |
| 211 | * <p><strong>Note:</strong> It is often useful to apply {@link #withByteOrder(ByteOrder)} to the |
| 212 | * result of this method. |
| 213 | * |
| 214 | * @return a new {@link Decoder}. |
| 215 | */ |
| 216 | public static Decoder<Long> ofLong() { |
| 217 | return new LongDecoder(); |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * Creates a {@link Decoder} for the {@code double} type. |
| 222 | * |
| 223 | * @return a new {@link Decoder}. |
| 224 | */ |
| 225 | public static Decoder<Double> ofDouble() { |
| 226 | return new DoubleDecoder(); |
| 227 | } |
| 228 | |
| 229 | /** |
| 230 | * Creates a {@link Decoder} for the {@link String} type. |
| 231 | * |
| 232 | * <p><strong>Note:</strong> While GVariant does not prescribe any particular encoding, {@link |
| 233 | * java.nio.charset.StandardCharsets#UTF_8} is the most common choice. |
| 234 | * |
| 235 | * @return a new {@link Decoder}. |
| 236 | */ |
| 237 | public static Decoder<String> ofString(Charset charset) { |
| 238 | return new StringDecoder(charset); |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 239 | } |
| 240 | |
| 241 | private static int align(int offset, byte alignment) { |
| 242 | return offset % alignment == 0 ? offset : offset + alignment - (offset % alignment); |
| 243 | } |
| 244 | |
| 245 | private static int getIntN(ByteBuffer byteSlice) { |
| 246 | var intBytes = new byte[4]; |
| 247 | byteSlice.get(intBytes, 0, Math.min(4, byteSlice.limit())); |
| 248 | return ByteBuffer.wrap(intBytes).order(LITTLE_ENDIAN).getInt(); |
| 249 | } |
| 250 | |
| 251 | @SuppressWarnings("java:S3358") |
| 252 | private static int byteCount(int n) { |
| 253 | return n < (1 << 8) ? 1 : n < (1 << 16) ? 2 : 4; |
| 254 | } |
| 255 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 256 | private static class ArrayDecoder<U> extends Decoder<List<U>> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 257 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 258 | private final Decoder<U> elementDecoder; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 259 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 260 | ArrayDecoder(Decoder<U> elementDecoder) { |
| 261 | this.elementDecoder = elementDecoder; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 262 | } |
| 263 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 264 | @Override |
| 265 | public byte alignment() { |
| 266 | return elementDecoder.alignment(); |
| 267 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 268 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 269 | @Override |
| 270 | @Nullable |
| 271 | Integer fixedSize() { |
| 272 | return null; |
| 273 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 274 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 275 | @Override |
| 276 | public List<U> decode(ByteBuffer byteSlice) { |
| 277 | List<U> elements; |
| 278 | |
| 279 | var elementSize = elementDecoder.fixedSize(); |
| 280 | if (elementSize != null) { |
| 281 | // A simple C-style array. |
| 282 | elements = new ArrayList<>(byteSlice.limit() / elementSize); |
| 283 | for (int i = 0; i < byteSlice.limit(); i += elementSize) { |
| 284 | var element = elementDecoder.decode(byteSlice.slice(i, elementSize)); |
| 285 | elements.add(element); |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 286 | } |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 287 | } else { |
| 288 | // An array with aligned elements and a vector of framing offsets in the end. |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 289 | int framingOffsetSize = byteCount(byteSlice.limit()); |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 290 | int lastFramingOffset = |
| 291 | getIntN(byteSlice.slice(byteSlice.limit() - framingOffsetSize, framingOffsetSize)); |
| 292 | int elementCount = (byteSlice.limit() - lastFramingOffset) / framingOffsetSize; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 293 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 294 | elements = new ArrayList<>(elementCount); |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 295 | int position = 0; |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 296 | for (int i = 0; i < elementCount; i++) { |
| 297 | int framingOffset = |
| 298 | getIntN( |
| 299 | byteSlice.slice(lastFramingOffset + i * framingOffsetSize, framingOffsetSize)); |
| 300 | elements.add(elementDecoder.decode(byteSlice.slice(position, framingOffset - position))); |
| 301 | position = align(framingOffset, alignment()); |
| 302 | } |
| 303 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 304 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 305 | return elements; |
| 306 | } |
| 307 | } |
| 308 | |
| 309 | private static class MaybeDecoder<U> extends Decoder<Optional<U>> { |
| 310 | |
| 311 | private final Decoder<U> elementDecoder; |
| 312 | |
| 313 | MaybeDecoder(Decoder<U> elementDecoder) { |
| 314 | this.elementDecoder = elementDecoder; |
| 315 | } |
| 316 | |
| 317 | @Override |
| 318 | public byte alignment() { |
| 319 | return elementDecoder.alignment(); |
| 320 | } |
| 321 | |
| 322 | @Override |
| 323 | @Nullable |
| 324 | Integer fixedSize() { |
| 325 | return null; |
| 326 | } |
| 327 | |
| 328 | @Override |
| 329 | public Optional<U> decode(ByteBuffer byteSlice) { |
| 330 | if (!byteSlice.hasRemaining()) { |
| 331 | return Optional.empty(); |
| 332 | } else { |
| 333 | if (!elementDecoder.hasFixedSize()) { |
| 334 | // Remove trailing zero byte. |
| 335 | byteSlice.limit(byteSlice.limit() - 1); |
| 336 | } |
| 337 | |
| 338 | return Optional.of(elementDecoder.decode(byteSlice)); |
| 339 | } |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | private static class StructureDecoder<U extends Record> extends Decoder<U> { |
| 344 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 345 | private final Class<U> recordType; |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 346 | private final TupleDecoder tupleDecoder; |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 347 | |
| 348 | StructureDecoder(Class<U> recordType, Decoder<?>... componentDecoders) { |
| 349 | var recordComponents = recordType.getRecordComponents(); |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 350 | if (componentDecoders.length != recordComponents.length) { |
| 351 | throw new IllegalArgumentException( |
| 352 | "number of decoders (%d) does not match number of structure components (%d)" |
| 353 | .formatted(componentDecoders.length, recordComponents.length)); |
| 354 | } |
| 355 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 356 | this.recordType = recordType; |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 357 | this.tupleDecoder = new TupleDecoder(componentDecoders); |
| 358 | } |
| 359 | |
| 360 | @Override |
| 361 | public byte alignment() { |
| 362 | return tupleDecoder.alignment(); |
| 363 | } |
| 364 | |
| 365 | @Override |
| 366 | public Integer fixedSize() { |
| 367 | return tupleDecoder.fixedSize(); |
| 368 | } |
| 369 | |
| 370 | @Override |
| 371 | public U decode(ByteBuffer byteSlice) { |
| 372 | Object[] recordConstructorArguments = tupleDecoder.decode(byteSlice); |
| 373 | |
| 374 | try { |
| 375 | var recordComponentTypes = |
| 376 | Arrays.stream(recordType.getRecordComponents()) |
| 377 | .map(RecordComponent::getType) |
| 378 | .toArray(Class<?>[]::new); |
| 379 | var recordConstructor = recordType.getDeclaredConstructor(recordComponentTypes); |
| 380 | return recordConstructor.newInstance(recordConstructorArguments); |
| 381 | } catch (NoSuchMethodException |
| 382 | | InstantiationException |
| 383 | | IllegalAccessException |
| 384 | | InvocationTargetException e) { |
| 385 | throw new IllegalStateException(e); |
| 386 | } |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | private static class TupleDecoder extends Decoder<Object[]> { |
| 391 | |
| 392 | private final Decoder<?>[] componentDecoders; |
| 393 | |
| 394 | TupleDecoder(Decoder<?>... componentDecoders) { |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 395 | this.componentDecoders = componentDecoders; |
| 396 | } |
| 397 | |
| 398 | @Override |
| 399 | public byte alignment() { |
| 400 | return (byte) Arrays.stream(componentDecoders).mapToInt(Decoder::alignment).max().orElse(1); |
| 401 | } |
| 402 | |
| 403 | @Override |
| 404 | public Integer fixedSize() { |
| 405 | int position = 0; |
| 406 | for (var componentDecoder : componentDecoders) { |
| 407 | var fixedComponentSize = componentDecoder.fixedSize(); |
| 408 | if (fixedComponentSize == null) { |
| 409 | return null; |
| 410 | } |
| 411 | |
| 412 | position = align(position, componentDecoder.alignment()); |
| 413 | position += fixedComponentSize; |
| 414 | } |
| 415 | |
| 416 | if (position == 0) { |
| 417 | return 1; |
| 418 | } |
| 419 | |
| 420 | return align(position, alignment()); |
| 421 | } |
| 422 | |
| 423 | @Override |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 424 | public Object[] decode(ByteBuffer byteSlice) { |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 425 | int framingOffsetSize = byteCount(byteSlice.limit()); |
| 426 | |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 427 | var objects = new Object[componentDecoders.length]; |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 428 | |
| 429 | int position = 0; |
| 430 | int framingOffsetIndex = 0; |
| 431 | int componentIndex = 0; |
| 432 | for (var componentDecoder : componentDecoders) { |
| 433 | position = align(position, componentDecoder.alignment()); |
| 434 | |
| 435 | var fixedComponentSize = componentDecoder.fixedSize(); |
| 436 | if (fixedComponentSize != null) { |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 437 | objects[componentIndex] = |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 438 | componentDecoder.decode(byteSlice.slice(position, fixedComponentSize)); |
| 439 | position += fixedComponentSize; |
| 440 | } else { |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 441 | if (componentIndex == componentDecoders.length - 1) { |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 442 | // The last component never has a framing offset. |
| 443 | int endPosition = byteSlice.limit() - framingOffsetIndex * framingOffsetSize; |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 444 | objects[componentIndex] = |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 445 | componentDecoder.decode(byteSlice.slice(position, endPosition - position)); |
| 446 | position = endPosition; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 447 | } else { |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 448 | int framingOffset = |
| 449 | getIntN( |
| 450 | byteSlice.slice( |
| 451 | byteSlice.limit() - (1 + framingOffsetIndex) * framingOffsetSize, |
| 452 | framingOffsetSize)); |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 453 | objects[componentIndex] = |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 454 | componentDecoder.decode(byteSlice.slice(position, framingOffset - position)); |
| 455 | position = framingOffset; |
| 456 | ++framingOffsetIndex; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 457 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 458 | } |
| 459 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 460 | ++componentIndex; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 461 | } |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 462 | |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 463 | return objects; |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 464 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 465 | } |
| 466 | |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 467 | private static class VariantDecoder extends Decoder<Object> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 468 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 469 | @Override |
| 470 | public byte alignment() { |
| 471 | return 8; |
| 472 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 473 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 474 | @Override |
| 475 | @Nullable |
| 476 | Integer fixedSize() { |
| 477 | return null; |
| 478 | } |
| 479 | |
| 480 | @Override |
Matthias Andreas Benkard | 55c3481 | 2021-12-14 21:51:10 +0100 | [diff] [blame] | 481 | public Object decode(ByteBuffer byteSlice) { |
| 482 | for (int i = byteSlice.limit() - 1; i >= 0; --i) { |
| 483 | if (byteSlice.get(i) != 0) { |
| 484 | continue; |
| 485 | } |
| 486 | |
| 487 | var data = byteSlice.slice(0, i); |
| 488 | var signature = byteSlice.slice(i + 1, byteSlice.limit() - (i + 1)); |
| 489 | |
| 490 | Decoder<?> decoder = parseSignature(signature); |
| 491 | return decoder.decode(data); |
| 492 | } |
| 493 | |
| 494 | throw new IllegalArgumentException("variant signature not found"); |
| 495 | } |
| 496 | |
| 497 | private static Decoder<?> parseSignature(ByteBuffer signature) { |
| 498 | char c = (char) signature.get(); |
| 499 | return switch (c) { |
| 500 | case 'b' -> Decoder.ofBoolean(); |
| 501 | case 'y' -> Decoder.ofByte(); |
| 502 | case 'n', 'q' -> Decoder.ofShort(); |
| 503 | case 'i', 'u' -> Decoder.ofInt(); |
| 504 | case 'x', 't' -> Decoder.ofLong(); |
| 505 | case 'd' -> Decoder.ofDouble(); |
| 506 | case 's', 'o', 'g' -> Decoder.ofString(StandardCharsets.UTF_8); |
| 507 | case 'v' -> Decoder.ofVariant(); |
| 508 | case 'm' -> Decoder.ofMaybe(parseSignature(signature)); |
| 509 | case 'a' -> Decoder.ofArray(parseSignature(signature)); |
| 510 | case '(', '{' -> Decoder.ofStructure(parseTupleTypes(signature).toArray(new Decoder<?>[0])); |
| 511 | default -> throw new IllegalArgumentException( |
| 512 | String.format("encountered unknown signature byte '%c'", c)); |
| 513 | }; |
| 514 | } |
| 515 | |
| 516 | private static List<Decoder<?>> parseTupleTypes(ByteBuffer signature) { |
| 517 | List<Decoder<?>> decoders = new ArrayList<>(); |
| 518 | |
| 519 | while (true) { |
| 520 | char c = (char) signature.get(signature.position()); |
| 521 | if (c == ')' || c == '}') { |
| 522 | signature.get(); |
| 523 | break; |
| 524 | } |
| 525 | |
| 526 | decoders.add(parseSignature(signature)); |
| 527 | } |
| 528 | |
| 529 | return decoders; |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 530 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 531 | } |
| 532 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 533 | private static class BooleanDecoder extends Decoder<Boolean> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 534 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 535 | @Override |
| 536 | public byte alignment() { |
| 537 | return 1; |
| 538 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 539 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 540 | @Override |
| 541 | public Integer fixedSize() { |
| 542 | return 1; |
| 543 | } |
| 544 | |
| 545 | @Override |
| 546 | public Boolean decode(ByteBuffer byteSlice) { |
| 547 | return byteSlice.get() != 0; |
| 548 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 549 | } |
| 550 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 551 | private static class ByteDecoder extends Decoder<Byte> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 552 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 553 | @Override |
| 554 | public byte alignment() { |
| 555 | return 1; |
| 556 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 557 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 558 | @Override |
| 559 | public Integer fixedSize() { |
| 560 | return 1; |
| 561 | } |
| 562 | |
| 563 | @Override |
| 564 | public Byte decode(ByteBuffer byteSlice) { |
| 565 | return byteSlice.get(); |
| 566 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 567 | } |
| 568 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 569 | private static class ShortDecoder extends Decoder<Short> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 570 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 571 | @Override |
| 572 | public byte alignment() { |
| 573 | return 2; |
| 574 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 575 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 576 | @Override |
| 577 | public Integer fixedSize() { |
| 578 | return 2; |
| 579 | } |
| 580 | |
| 581 | @Override |
| 582 | public Short decode(ByteBuffer byteSlice) { |
| 583 | return byteSlice.getShort(); |
| 584 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 585 | } |
| 586 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 587 | private static class IntegerDecoder extends Decoder<Integer> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 588 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 589 | @Override |
| 590 | public byte alignment() { |
| 591 | return 4; |
| 592 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 593 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 594 | @Override |
| 595 | public Integer fixedSize() { |
| 596 | return 4; |
| 597 | } |
| 598 | |
| 599 | @Override |
| 600 | public Integer decode(ByteBuffer byteSlice) { |
| 601 | return byteSlice.getInt(); |
| 602 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 603 | } |
| 604 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 605 | private static class LongDecoder extends Decoder<Long> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 606 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 607 | @Override |
| 608 | public byte alignment() { |
| 609 | return 8; |
| 610 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 611 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 612 | @Override |
| 613 | public Integer fixedSize() { |
| 614 | return 8; |
| 615 | } |
| 616 | |
| 617 | @Override |
| 618 | public Long decode(ByteBuffer byteSlice) { |
| 619 | return byteSlice.getLong(); |
| 620 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 621 | } |
| 622 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 623 | private static class DoubleDecoder extends Decoder<Double> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 624 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 625 | @Override |
| 626 | public byte alignment() { |
| 627 | return 8; |
| 628 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 629 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 630 | @Override |
| 631 | public Integer fixedSize() { |
| 632 | return 8; |
| 633 | } |
| 634 | |
| 635 | @Override |
| 636 | public Double decode(ByteBuffer byteSlice) { |
| 637 | return byteSlice.getDouble(); |
| 638 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 639 | } |
| 640 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 641 | private static class StringDecoder extends Decoder<String> { |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 642 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 643 | private final Charset charset; |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 644 | |
Matthias Andreas Benkard | 3443018 | 2021-12-14 20:00:36 +0100 | [diff] [blame] | 645 | public StringDecoder(Charset charset) { |
| 646 | this.charset = charset; |
| 647 | } |
| 648 | |
| 649 | @Override |
| 650 | public byte alignment() { |
| 651 | return 1; |
| 652 | } |
| 653 | |
| 654 | @Override |
| 655 | @Nullable |
| 656 | Integer fixedSize() { |
| 657 | return null; |
| 658 | } |
| 659 | |
| 660 | @Override |
| 661 | public String decode(ByteBuffer byteSlice) { |
| 662 | byteSlice.limit(byteSlice.limit() - 1); |
| 663 | return charset.decode(byteSlice).toString(); |
| 664 | } |
Matthias Andreas Benkard | 261532a | 2021-12-12 20:09:27 +0100 | [diff] [blame] | 665 | } |
| 666 | } |