org.apache.tinkerpop.shaded.kryo.io.Input Java Examples

@Override
public Registration readClass(final Input input) {
    final int classID = input.readVarInt(true);
    switch (classID) {
        case Kryo.NULL:
            return null;
        case NAME + 2: // Offset for NAME and NULL.
            return readName(input);
    }

    if (classID == memoizedClassId) return memoizedClassIdValue;
    final Registration registration = idToRegistration.get(classID - 2);
    if (registration == null) throw new KryoException("Encountered unregistered class ID: " + (classID - 2));
    memoizedClassId = classID;
    memoizedClassIdValue = registration;
    return registration;
}
 

@Override
public void read(Kryo kryo, Input input) {
    this.schemaTable = SchemaTable.of(input.readString(), input.readString());
    String s = input.readString();
    if (s.equals("s")) {
        //sequence
        this.id = ID.from(input.readLong());
    } else {
        int size = input.readInt();
        List<Comparable> identifiers = new ArrayList<>();
        for (int i = 0; i < size; i++) {
            String identifier = input.readString();
            identifiers.add(identifier);
        }
        this.id = ID.from(identifiers);
    }
}
 

@Override
public RequestMessage deserializeRequest(final ByteBuf msg) throws SerializationException {
    try {
        final Kryo kryo = kryoThreadLocal.get();
        final byte[] payload = new byte[msg.readableBytes()];
        msg.readBytes(payload);
        try (final Input input = new Input(payload)) {
            // by the time the message gets here, the mime length/type have been already read, so this part just
            // needs to process the payload.
            final UUID id = kryo.readObject(input, UUID.class);
            final String processor = input.readString();
            final String op = input.readString();

            final RequestMessage.Builder builder = RequestMessage.build(op)
                    .overrideRequestId(id)
                    .processor(processor);

            final Map<String, Object> args = kryo.readObject(input, HashMap.class);
            args.forEach(builder::addArg);
            return builder.create();
        }
    } catch (Exception ex) {
        logger.warn(String.format("Request [%s] could not be deserialized by %s.", msg, AbstractGryoMessageSerializerV1d0.class.getName()), ex);
        throw new SerializationException(ex);
    }
}
 

@Override
public RequestMessage deserializeRequest(final ByteBuf msg) throws SerializationException {
    try {
        final Kryo kryo = kryoThreadLocal.get();
        final byte[] payload = new byte[msg.readableBytes()];
        msg.readBytes(payload);
        try (final Input input = new Input(payload)) {
            // by the time the message gets here, the mime length/type have been already read, so this part just
            // needs to process the payload.
            return kryo.readObject(input, RequestMessage.class);
        }
    } catch (Exception ex) {
        logger.warn(String.format("Request [%s] could not be deserialized by %s.", msg, AbstractGryoMessageSerializerV3d0.class.getName()), ex);
        throw new SerializationException(ex);
    }
}
 

@Test
public void shouldRegisterMultipleIoRegistryToSerialize() throws Exception {
    final GryoMapper mapper = builder.get().addRegistry(IoXIoRegistry.InstanceBased.instance())
            .addRegistry(IoYIoRegistry.InstanceBased.instance()).create();
    final Kryo kryo = mapper.createMapper();
    try (final OutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);
        final IoX x = new IoX("x");
        final IoY y = new IoY(100, 200);
        kryo.writeClassAndObject(out, x);
        kryo.writeClassAndObject(out, y);

        try (final InputStream inputStream = new ByteArrayInputStream(out.toBytes())) {
            final Input input = new Input(inputStream);
            final IoX readX = (IoX) kryo.readClassAndObject(input);
            final IoY readY = (IoY) kryo.readClassAndObject(input);
            assertEquals(x, readX);
            assertEquals(y, readY);
        }
    }
}
 

@Test
public void shouldSerializeWithoutRegistration() throws Exception {
    final GryoMapper mapper = builder.get().registrationRequired(false).create();
    final Kryo kryo = mapper.createMapper();
    try (final OutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);
        final IoX x = new IoX("x");
        final IoY y = new IoY(100, 200);
        kryo.writeClassAndObject(out, x);
        kryo.writeClassAndObject(out, y);

        try (final InputStream inputStream = new ByteArrayInputStream(out.toBytes())) {
            final Input input = new Input(inputStream);
            final IoX readX = (IoX) kryo.readClassAndObject(input);
            final IoY readY = (IoY) kryo.readClassAndObject(input);
            assertEquals(x, readX);
            assertEquals(y, readY);
        }
    }
}
 

@Test
public void shouldSerializeWithCustomClassResolverToHashMap() throws Exception {
    final Supplier<ClassResolver> classResolver = new CustomClassResolverSupplier();
    final GryoMapper mapper = builder.get().classResolver(classResolver).create();
    final Kryo kryo = mapper.createMapper();
    try (final OutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);
        final IoY y = new IoY(100, 200);

        kryo.writeClassAndObject(out, y);

        final GryoMapper mapperWithoutKnowledgeOfIoy = builder.get().create();
        final Kryo kryoWithoutKnowledgeOfIox = mapperWithoutKnowledgeOfIoy.createMapper();
        try (final InputStream inputStream = new ByteArrayInputStream(out.toBytes())) {
            final Input input = new Input(inputStream);
            final Map readY = (HashMap) kryoWithoutKnowledgeOfIox.readClassAndObject(input);
            assertEquals("100-200", readY.get("y"));
        }
    }
}
 

@Test
public void shouldSerializeWithCustomClassResolverToDetachedVertex() throws Exception {
    final Supplier<ClassResolver> classResolver = new CustomClassResolverSupplier();
    final GryoMapper mapper = builder.get().classResolver(classResolver).create();
    final Kryo kryo = mapper.createMapper();
    try (final OutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);
        final IoX x = new IoX("no-way-this-will-ever-work");

        kryo.writeClassAndObject(out, x);

        final GryoMapper mapperWithoutKnowledgeOfIox = builder.get().create();
        final Kryo kryoWithoutKnowledgeOfIox = mapperWithoutKnowledgeOfIox.createMapper();
        try (final InputStream inputStream = new ByteArrayInputStream(out.toBytes())) {
            final Input input = new Input(inputStream);
            final DetachedVertex readX = (DetachedVertex) kryoWithoutKnowledgeOfIox.readClassAndObject(input);
            assertEquals("no-way-this-will-ever-work", readX.value("x"));
        }
    }
}
 

@Test
public void shouldSerializeDeserialize() throws Exception {
    final GryoMapper mapper = builder.get().create();
    final Kryo kryo = mapper.createMapper();
    try (final OutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);

        final Map<String,Object> props = new HashMap<>();
        final List<Map<String, Object>> propertyNames = new ArrayList<>(1);
        final Map<String,Object> propertyName = new HashMap<>();
        propertyName.put(GraphSONTokens.ID, "x");
        propertyName.put(GraphSONTokens.KEY, "x");
        propertyName.put(GraphSONTokens.VALUE, "no-way-this-will-ever-work");
        propertyNames.add(propertyName);
        props.put("x", propertyNames);
        final DetachedVertex v = new DetachedVertex(100, Vertex.DEFAULT_LABEL, props);

        kryo.writeClassAndObject(out, v);

        try (final InputStream inputStream = new ByteArrayInputStream(out.toBytes())) {
            final Input input = new Input(inputStream);
            final DetachedVertex readX = (DetachedVertex) kryo.readClassAndObject(input);
            assertEquals("no-way-this-will-ever-work", readX.value("x"));
        }
    }
}
 

protected Registration readName(final Input input) {
    final int nameId = input.readVarInt(true);
    if (nameIdToClass == null) nameIdToClass = new IntMap<>();
    Class type = nameIdToClass.get(nameId);
    if (type == null) {
        // Only read the class name the first time encountered in object graph.
        final String className = input.readString();
        type = getTypeByName(className);
        if (type == null) {
            try {
                type = Class.forName(className, false, kryo.getClassLoader());
            } catch (ClassNotFoundException ex) {
                throw new KryoException("Unable to find class: " + className, ex);
            }
            if (nameToClass == null) nameToClass = new ObjectMap<>();
            nameToClass.put(className, type);
        }
        nameIdToClass.put(nameId, type);
    }
    return kryo.getRegistration(type);
}
 

@Override
public TinkerGraph read(final Kryo kryo, final Input input, final Class<TinkerGraph> tinkerGraphClass) {
    final Configuration conf = new BaseConfiguration();
    conf.setProperty("gremlin.tinkergraph.defaultVertexPropertyCardinality", "list");
    final TinkerGraph graph = TinkerGraph.open(conf);
    final int len = input.readInt();
    final byte[] bytes = input.readBytes(len);
    try (final ByteArrayInputStream stream = new ByteArrayInputStream(bytes)) {
        GryoReader.build().mapper(() -> kryo).create().readGraph(stream, graph);
    } catch (Exception io) {
        throw new RuntimeException(io);
    }

    return graph;
}
 

@Test
public void shouldSerializeWithColorClassResolverToTinkerGraph() throws Exception {
    final Map<String,Color> colors = new HashMap<>();
    colors.put("red", Color.RED);
    colors.put("green", Color.GREEN);

    final ArrayList<Color> colorList = new ArrayList<>(Arrays.asList(Color.RED, Color.GREEN));

    final Supplier<ClassResolver> classResolver = new CustomClassResolverSupplier();
    final GryoMapper mapper = GryoMapper.build().version(GryoVersion.V3_0).addRegistry(TinkerIoRegistryV3d0.instance()).classResolver(classResolver).create();
    final Kryo kryo = mapper.createMapper();
    try (final ByteArrayOutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);

        kryo.writeObject(out, colorList);
        out.flush();
        final byte[] b = stream.toByteArray();

        try (final InputStream inputStream = new ByteArrayInputStream(b)) {
            final Input input = new Input(inputStream);
            final List m = kryo.readObject(input, ArrayList.class);
            final TinkerGraph readX = (TinkerGraph) m.get(0);
            assertEquals(104, IteratorUtils.count(readX.vertices()));
            assertEquals(102, IteratorUtils.count(readX.edges()));
        }
    }
}
 

@Test
public void shouldSerializeWithColorClassResolverToTinkerGraphUsingDeprecatedTinkerIoRegistry() throws Exception {
    final Map<String,Color> colors = new HashMap<>();
    colors.put("red", Color.RED);
    colors.put("green", Color.GREEN);

    final ArrayList<Color> colorList = new ArrayList<>(Arrays.asList(Color.RED, Color.GREEN));

    final Supplier<ClassResolver> classResolver = new CustomClassResolverSupplier();
    final GryoMapper mapper = GryoMapper.build().version(GryoVersion.V3_0).addRegistry(TinkerIoRegistryV3d0.instance()).classResolver(classResolver).create();
    final Kryo kryo = mapper.createMapper();
    try (final ByteArrayOutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);

        kryo.writeObject(out, colorList);
        out.flush();
        final byte[] b = stream.toByteArray();

        try (final InputStream inputStream = new ByteArrayInputStream(b)) {
            final Input input = new Input(inputStream);
            final List m = kryo.readObject(input, ArrayList.class);
            final TinkerGraph readX = (TinkerGraph) m.get(0);
            assertEquals(104, IteratorUtils.count(readX.vertices()));
            assertEquals(102, IteratorUtils.count(readX.edges()));
        }
    }
}
 

@Test
public void shouldSerializeWithColorClassResolverToTinkerGraphUsingDeprecatedTinkerIoRegistry() throws Exception {
    final Map<String,Color> colors = new HashMap<>();
    colors.put("red", Color.RED);
    colors.put("green", Color.GREEN);

    final ArrayList<Color> colorList = new ArrayList<>(Arrays.asList(Color.RED, Color.GREEN));

    final Supplier<ClassResolver> classResolver = new CustomClassResolverSupplier();
    final GryoMapper mapper = GryoMapper.build().version(GryoVersion.V3_0).addRegistry(TinkerIoRegistryV3d0.instance()).classResolver(classResolver).create();
    final Kryo kryo = mapper.createMapper();
    try (final ByteArrayOutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);

        kryo.writeObject(out, colorList);
        out.flush();
        final byte[] b = stream.toByteArray();

        try (final InputStream inputStream = new ByteArrayInputStream(b)) {
            final Input input = new Input(inputStream);
            final List m = kryo.readObject(input, ArrayList.class);
            final TinkerGraph readX = (TinkerGraph) m.get(0);
            assertEquals(104, IteratorUtils.count(readX.vertices()));
            assertEquals(102, IteratorUtils.count(readX.edges()));
        }
    }
}
 

@Test
public void shouldSerializeWithColorClassResolverToTinkerGraph() throws Exception {
    final Map<String,Color> colors = new HashMap<>();
    colors.put("red", Color.RED);
    colors.put("green", Color.GREEN);

    final ArrayList<Color> colorList = new ArrayList<>(Arrays.asList(Color.RED, Color.GREEN));

    final Supplier<ClassResolver> classResolver = new CustomClassResolverSupplier();
    final GryoMapper mapper = GryoMapper.build().version(GryoVersion.V3_0).addRegistry(TinkerIoRegistryV3d0.instance()).classResolver(classResolver).create();
    final Kryo kryo = mapper.createMapper();
    try (final ByteArrayOutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);

        kryo.writeObject(out, colorList);
        out.flush();
        final byte[] b = stream.toByteArray();

        try (final InputStream inputStream = new ByteArrayInputStream(b)) {
            final Input input = new Input(inputStream);
            final List m = kryo.readObject(input, ArrayList.class);
            final TinkerGraph readX = (TinkerGraph) m.get(0);
            assertEquals(104, IteratorUtils.count(readX.vertices()));
            assertEquals(102, IteratorUtils.count(readX.edges()));
        }
    }
}
 

@Override
public TinkerGraph read(final Kryo kryo, final Input input, final Class<TinkerGraph> tinkerGraphClass) {
    final Configuration conf = new BaseConfiguration();
    conf.setProperty("gremlin.tinkergraph.defaultVertexPropertyCardinality", "list");
    final TinkerGraph graph = TinkerGraph.open(conf);
    final int len = input.readInt();
    final byte[] bytes = input.readBytes(len);
    try (final ByteArrayInputStream stream = new ByteArrayInputStream(bytes)) {
        GryoReader.build().mapper(() -> kryo).create().readGraph(stream, graph);
    } catch (Exception io) {
        throw new RuntimeException(io);
    }

    return graph;
}
 

@Override
public TinkerGraph read(final Kryo kryo, final Input input, final Class<TinkerGraph> tinkerGraphClass) {
    final Configuration conf = new BaseConfiguration();
    conf.setProperty("gremlin.tinkergraph.defaultVertexPropertyCardinality", "list");
    final TinkerGraph graph = TinkerGraph.open(conf);
    final int len = input.readInt();
    final byte[] bytes = input.readBytes(len);
    try (final ByteArrayInputStream stream = new ByteArrayInputStream(bytes)) {
        GryoReader.build().mapper(() -> kryo).create().readGraph(stream, graph);
    } catch (Exception io) {
        throw new RuntimeException(io);
    }

    return graph;
}
 

@Override
public TinkerGraph read(final Kryo kryo, final Input input, final Class<TinkerGraph> tinkerGraphClass) {
    final Configuration conf = new BaseConfiguration();
    conf.setProperty("gremlin.tinkergraph.defaultVertexPropertyCardinality", "list");
    final TinkerGraph graph = TinkerGraph.open(conf);
    final int len = input.readInt();
    final byte[] bytes = input.readBytes(len);
    try (final ByteArrayInputStream stream = new ByteArrayInputStream(bytes)) {
        GryoReader.build().mapper(() -> kryo).create().readGraph(stream, graph);
    } catch (Exception io) {
        throw new RuntimeException(io);
    }

    return graph;
}
 

private Vertex readVertexInternal(final Function<Attachable<Vertex>, Vertex> vertexMaker,
                                  final Function<Attachable<Edge>, Edge> edgeMaker,
                                  final Direction d,
                                  final Input input) throws IOException {
    readHeader(input);
    final StarGraph starGraph = kryo.readObject(input, StarGraph.class);

    // read the terminator
    kryo.readClassAndObject(input);

    final Vertex v = vertexMaker.apply(starGraph.getStarVertex());
    if (edgeMaker != null)
        starGraph.getStarVertex().edges(d).forEachRemaining(e -> edgeMaker.apply((Attachable<Edge>) e));
    return v;
}
 

public <T> T serializeDeserialize(final Object o, final Class<T> clazz) throws Exception {
    final Kryo kryo = builder.get().create().createMapper();
    try (final ByteArrayOutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);
        kryo.writeObject(out, o);
        out.flush();

        try (final InputStream inputStream = new ByteArrayInputStream(stream.toByteArray())) {
            final Input input = new Input(inputStream);
            return kryo.readObject(input, clazz);
        }
    }
}
 

@Override
public ResponseMessage deserializeResponse(final ByteBuf msg) throws SerializationException {
    try {
        final Kryo kryo = kryoThreadLocal.get();
        final byte[] payload = new byte[msg.capacity()];
        msg.readBytes(payload);
        try (final Input input = new Input(payload)) {
            return kryo.readObject(input, ResponseMessage.class);
        }
    } catch (Exception ex) {
        logger.warn(String.format("Response [%s] could not be deserialized by %s.", msg, AbstractGryoMessageSerializerV3d0.class.getName()), ex);
        throw new SerializationException(ex);
    }
}
 

@Test
public void shouldExpectReadFailureAsIoRegistryOrderIsNotRespected() throws Exception {
    final GryoMapper mapperWrite = builder.get().addRegistry(IoXIoRegistry.InstanceBased.instance())
            .addRegistry(IoYIoRegistry.InstanceBased.instance()).create();

    final GryoMapper mapperRead = GryoMapper.build()
            .addRegistry(IoYIoRegistry.InstanceBased.instance())
            .addRegistry(IoXIoRegistry.InstanceBased.instance()).create();

    final Kryo kryoWriter = mapperWrite.createMapper();
    final Kryo kryoReader = mapperRead.createMapper();
    try (final OutputStream stream = new ByteArrayOutputStream()) {
        final Output out = new Output(stream);
        final IoX x = new IoX("x");
        final IoY y = new IoY(100, 200);
        kryoWriter.writeClassAndObject(out, x);
        kryoWriter.writeClassAndObject(out, y);

        try (final InputStream inputStream = new ByteArrayInputStream(out.toBytes())) {
            final Input input = new Input(inputStream);

            // kryo will read a IoY instance as we've reversed the registries.  it is neither an X or a Y
            // so assert that both are incorrect
            final IoY readY = (IoY) kryoReader.readClassAndObject(input);
            assertNotEquals(y, readY);
            assertNotEquals(x, readY);
        }
    }
}
 

@Override
public T read(final Kryo kryo, final Input input, final Class<T> aClass) {
    // Same caching opportunity as in write(...)
    final ShadedKryoAdapter shadedKryoAdapter = new ShadedKryoAdapter(kryo);
    final ShadedInputAdapter shadedInputAdapter = new ShadedInputAdapter(input);
    return serializer.read(shadedKryoAdapter, shadedInputAdapter, aClass);
}
 

/**
 * Read a {@link Property} from output generated by  {@link GryoWriter#writeProperty(OutputStream, Property)} or
 * via an {@link Property} passed to {@link GryoWriter#writeObject(OutputStream, Object)}.
 *
 * @param inputStream          a stream containing at least one {@link Property} as written by the accompanying
 *                             {@link GraphWriter#writeProperty(OutputStream, Property)} method.
 * @param propertyAttachMethod a function that creates re-attaches a {@link Property} to a {@link Host} object.
 */
@Override
public Property readProperty(final InputStream inputStream,
                             final Function<Attachable<Property>, Property> propertyAttachMethod) throws IOException {
    final Input input = new Input(inputStream);
    readHeader(input);
    final Attachable<Property> attachable = kryo.readObject(input, DetachedProperty.class);
    return propertyAttachMethod.apply(attachable);
}
 

/**
 * Read data into a {@link Graph} from output generated by any of the {@link GryoWriter} {@code writeVertex} or
 * {@code writeVertices} methods or by {@link GryoWriter#writeGraph(OutputStream, Graph)}.
 *
 * @param inputStream    a stream containing an entire graph of vertices and edges as defined by the accompanying
 *                       {@link GraphWriter#writeGraph(OutputStream, Graph)}.
 * @param graphToWriteTo the graph to write to when reading from the stream.
 * @throws IOException
 */
@Override
public void readGraph(final InputStream inputStream, final Graph graphToWriteTo) throws IOException {
    // dual pass - create all vertices and store to cache the ids.  then create edges.  as long as we don't
    // have vertex labels in the output we can't do this single pass
    final Map<StarGraph.StarVertex, Vertex> cache = new HashMap<>();
    final AtomicLong counter = new AtomicLong(0);

    final Graph.Features.EdgeFeatures edgeFeatures = graphToWriteTo.features().edge();
    final boolean supportsTx = graphToWriteTo.features().graph().supportsTransactions();

    IteratorUtils.iterate(new VertexInputIterator(new Input(inputStream), attachable -> {
        final Vertex v = cache.put((StarGraph.StarVertex) attachable.get(), attachable.attach(Attachable.Method.create(graphToWriteTo)));
        if (supportsTx && counter.incrementAndGet() % batchSize == 0)
            graphToWriteTo.tx().commit();
        return v;
    }, null, null));
    cache.entrySet().forEach(kv -> kv.getKey().edges(Direction.IN).forEachRemaining(e -> {
        // can't use a standard Attachable attach method here because we have to use the cache for those
        // graphs that don't support userSuppliedIds on edges. note that outVertex/inVertex methods return
        // StarAdjacentVertex whose equality should match StarVertex.
        final Vertex cachedOutV = cache.get(e.outVertex());
        final Vertex cachedInV = cache.get(e.inVertex());

        if (null == cachedOutV) throw new IllegalStateException(String.format("Could not find outV with id [%s] to create edge with id [%s]", e.outVertex().id(), e.id()));
        if (null == cachedInV) throw new IllegalStateException(String.format("Could not find inV with id [%s] to create edge with id [%s]", e.inVertex().id(), e.id()));

        final Edge newEdge = edgeFeatures.willAllowId(e.id()) ? cachedOutV.addEdge(e.label(), cachedInV, T.id, e.id()) : cachedOutV.addEdge(e.label(), cachedInV);
        e.properties().forEachRemaining(p -> newEdge.property(p.key(), p.value()));
        if (supportsTx && counter.incrementAndGet() % batchSize == 0)
            graphToWriteTo.tx().commit();
    }));

    if (supportsTx) graphToWriteTo.tx().commit();
}
 

@Override
public Optional<Vertex> readVertex(final InputStream inputStream, final GraphFilter graphFilter) throws IOException {
    StarGraphGryoSerializer serializer = this.graphFilterCache.get(graphFilter);
    if (null == serializer) {
        serializer = StarGraphGryoSerializer.withGraphFilter(graphFilter);
        this.graphFilterCache.put(graphFilter, serializer);
    }
    final Input input = new Input(inputStream);
    this.readHeader(input);
    final StarGraph starGraph = this.kryo.readObject(input, StarGraph.class, serializer);
    // read the terminator
    this.kryo.readClassAndObject(input);
    return Optional.ofNullable(starGraph == null ? null : starGraph.getStarVertex());
}
 

@SuppressWarnings("unused")
private static Map<HugeKeys, Object> readEntry(Kryo kryo, Input input) {
    int columnSize = input.readInt();
    Map<HugeKeys, Object> map = new LinkedHashMap<>();
    for (int i = 0; i < columnSize; i++) {
        HugeKeys key = kryo.readObject(input, HugeKeys.class);
        Object val = kryo.readClassAndObject(input);
        map.put(key, val);
    }
    return map;
}
 

@Override
public WrappedArray<T> read(final Kryo kryo, final Input input, final Class<WrappedArray<T>> aClass) {
    final int size = input.readVarInt(true);
    final Object[] array = new Object[size];
    for (int i = 0; i < size; i++) {
        array[i] = kryo.readClassAndObject(input);
    }
    return new WrappedArray.ofRef<>((T[]) array);
}
 

@Override
public Id read(Kryo kryo, Input input, Class<Id> clazz) {
    int type = input.readByteUnsigned();
    int length = input.read();
    byte[] idBytes = input.readBytes(length);
    return IdGenerator.of(idBytes, IdType.values()[type]);
}
 

private void readHeader(final Input input) throws IOException {
    if (!Arrays.equals(GryoMapper.GIO, input.readBytes(3)))
        throw new IOException("Invalid format - first three bytes of header do not match expected value");

    // skip the next 13 bytes - for future use
    input.readBytes(13);
}