Renamed "user-defined types" as "structs" in the serialisation format.

components/net/sf/briar/protocol/AckReader.java

@@ -30,7 +30,7 @@ class AckReader implements ObjectReader<Ack> {
 			new CountingConsumer(ProtocolConstants.MAX_PACKET_LENGTH);
 		// Read and digest the data
 		r.addConsumer(counting);
-		r.readUserDefinedId(Types.ACK);
+		r.readStructId(Types.ACK);
 		r.addObjectReader(Types.BATCH_ID, batchIdReader);
 		Collection<BatchId> batches = r.readList(BatchId.class);
 		r.removeObjectReader(Types.BATCH_ID);
@@ -42,7 +42,7 @@ class AckReader implements ObjectReader<Ack> {
 	private static class BatchIdReader implements ObjectReader<BatchId> {
 
 		public BatchId readObject(Reader r) throws IOException {
-			r.readUserDefinedId(Types.BATCH_ID);
+			r.readStructId(Types.BATCH_ID);
 			byte[] b = r.readBytes(UniqueId.LENGTH);
 			if(b.length != UniqueId.LENGTH) throw new FormatException();
 			return new BatchId(b);

components/net/sf/briar/protocol/AuthorFactoryImpl.java

@@ -29,7 +29,7 @@ class AuthorFactoryImpl implements AuthorFactory {
 	throws IOException {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		Writer w = writerFactory.createWriter(out);
-		w.writeUserDefinedId(Types.AUTHOR);
+		w.writeStructId(Types.AUTHOR);
 		w.writeString(name);
 		w.writeBytes(publicKey);
 		MessageDigest messageDigest = crypto.getMessageDigest();

components/net/sf/briar/protocol/AuthorReader.java

@@ -29,7 +29,7 @@ class AuthorReader implements ObjectReader<Author> {
 		messageDigest.reset();
 		// Read and digest the data
 		r.addConsumer(digesting);
-		r.readUserDefinedId(Types.AUTHOR);
+		r.readStructId(Types.AUTHOR);
 		String name = r.readString(ProtocolConstants.MAX_AUTHOR_NAME_LENGTH);
 		byte[] publicKey = r.readBytes(ProtocolConstants.MAX_PUBLIC_KEY_LENGTH);
 		r.removeConsumer(digesting);

components/net/sf/briar/protocol/BatchReader.java

@@ -38,7 +38,7 @@ class BatchReader implements ObjectReader<Batch> {
 		// Read and digest the data
 		r.addConsumer(counting);
 		r.addConsumer(digesting);
-		r.readUserDefinedId(Types.BATCH);
+		r.readStructId(Types.BATCH);
 		r.addObjectReader(Types.MESSAGE, messageReader);
 		List<Message> messages = r.readList(Message.class);
 		r.removeObjectReader(Types.MESSAGE);

components/net/sf/briar/protocol/GroupFactoryImpl.java

@@ -28,7 +28,7 @@ class GroupFactoryImpl implements GroupFactory {
 	public Group createGroup(String name, byte[] publicKey) throws IOException {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		Writer w = writerFactory.createWriter(out);
-		w.writeUserDefinedId(Types.GROUP);
+		w.writeStructId(Types.GROUP);
 		w.writeString(name);
 		if(publicKey == null) w.writeNull();
 		else w.writeBytes(publicKey);

components/net/sf/briar/protocol/GroupReader.java

@@ -29,7 +29,7 @@ class GroupReader implements ObjectReader<Group> {
 		messageDigest.reset();
 		// Read and digest the data
 		r.addConsumer(digesting);
-		r.readUserDefinedId(Types.GROUP);
+		r.readStructId(Types.GROUP);
 		String name = r.readString(ProtocolConstants.MAX_GROUP_NAME_LENGTH);
 		byte[] publicKey = null;
 		if(r.hasNull()) r.readNull();

components/net/sf/briar/protocol/MessageFactoryImpl.java

@@ -107,7 +107,7 @@ class MessageFactoryImpl implements MessageFactory {
 			w.addConsumer(groupConsumer);
 		}
 		// Write the message
-		w.writeUserDefinedId(Types.MESSAGE);
+		w.writeStructId(Types.MESSAGE);
 		if(parent == null) w.writeNull();
 		else w.writeBytes(parent.getBytes());
 		if(group == null) w.writeNull();
@@ -153,7 +153,7 @@ class MessageFactoryImpl implements MessageFactory {
 	}
 
 	private void writeGroup(Writer w, Group g) throws IOException {
-		w.writeUserDefinedId(Types.GROUP);
+		w.writeStructId(Types.GROUP);
 		w.writeString(g.getName());
 		byte[] publicKey = g.getPublicKey();
 		if(publicKey == null) w.writeNull();
@@ -161,7 +161,7 @@ class MessageFactoryImpl implements MessageFactory {
 	}
 
 	private void writeAuthor(Writer w, Author a) throws IOException {
-		w.writeUserDefinedId(Types.AUTHOR);
+		w.writeStructId(Types.AUTHOR);
 		w.writeString(a.getName());
 		w.writeBytes(a.getPublicKey());
 	}

components/net/sf/briar/protocol/MessageIdReader.java

@@ -12,7 +12,7 @@ import net.sf.briar.api.serial.Reader;
 class MessageIdReader implements ObjectReader<MessageId> {
 
 	public MessageId readObject(Reader r) throws IOException {
-		r.readUserDefinedId(Types.MESSAGE_ID);
+		r.readStructId(Types.MESSAGE_ID);
 		byte[] b = r.readBytes(UniqueId.LENGTH);
 		if(b.length != UniqueId.LENGTH) throw new FormatException();
 		return new MessageId(b);

components/net/sf/briar/protocol/MessageReader.java

@@ -50,14 +50,14 @@ class MessageReader implements ObjectReader<Message> {
 		r.addConsumer(copying);
 		r.addConsumer(counting);
 		// Read the initial tag
-		r.readUserDefinedId(Types.MESSAGE);
+		r.readStructId(Types.MESSAGE);
 		// Read the parent's message ID, if there is one
 		MessageId parent = null;
 		if(r.hasNull()) {
 			r.readNull();
 		} else {
 			r.addObjectReader(Types.MESSAGE_ID, messageIdReader);
-			parent = r.readUserDefined(Types.MESSAGE_ID, MessageId.class);
+			parent = r.readStruct(Types.MESSAGE_ID, MessageId.class);
 			r.removeObjectReader(Types.MESSAGE_ID);
 		}
 		// Read the group, if there is one
@@ -66,7 +66,7 @@ class MessageReader implements ObjectReader<Message> {
 			r.readNull();
 		} else {
 			r.addObjectReader(Types.GROUP, groupReader);
-			group = r.readUserDefined(Types.GROUP, Group.class);
+			group = r.readStruct(Types.GROUP, Group.class);
 			r.removeObjectReader(Types.GROUP);
 		}
 		// Read the author, if there is one
@@ -75,7 +75,7 @@ class MessageReader implements ObjectReader<Message> {
 			r.readNull();
 		} else {
 			r.addObjectReader(Types.AUTHOR, authorReader);
-			author = r.readUserDefined(Types.AUTHOR, Author.class);
+			author = r.readStruct(Types.AUTHOR, Author.class);
 			r.removeObjectReader(Types.AUTHOR);
 		}
 		// Read the subject

components/net/sf/briar/protocol/OfferReader.java

@@ -29,7 +29,7 @@ class OfferReader implements ObjectReader<Offer> {
 			new CountingConsumer(ProtocolConstants.MAX_PACKET_LENGTH);
 		// Read the data
 		r.addConsumer(counting);
-		r.readUserDefinedId(Types.OFFER);
+		r.readStructId(Types.OFFER);
 		r.addObjectReader(Types.MESSAGE_ID, messageIdReader);
 		Collection<MessageId> messages = r.readList(MessageId.class);
 		r.removeObjectReader(Types.MESSAGE_ID);

components/net/sf/briar/protocol/ProtocolReaderImpl.java

@@ -39,51 +39,51 @@ class ProtocolReaderImpl implements ProtocolReader {
 	}
 
 	public boolean hasAck() throws IOException {
-		return reader.hasUserDefined(Types.ACK);
+		return reader.hasStruct(Types.ACK);
 	}
 
 	public Ack readAck() throws IOException {
-		return reader.readUserDefined(Types.ACK, Ack.class);
+		return reader.readStruct(Types.ACK, Ack.class);
 	}
 
 	public boolean hasBatch() throws IOException {
-		return reader.hasUserDefined(Types.BATCH);
+		return reader.hasStruct(Types.BATCH);
 	}
 
 	public Batch readBatch() throws IOException {
-		return reader.readUserDefined(Types.BATCH, Batch.class);
+		return reader.readStruct(Types.BATCH, Batch.class);
 	}
 
 	public boolean hasOffer() throws IOException {
-		return reader.hasUserDefined(Types.OFFER);
+		return reader.hasStruct(Types.OFFER);
 	}
 
 	public Offer readOffer() throws IOException {
-		return reader.readUserDefined(Types.OFFER, Offer.class);
+		return reader.readStruct(Types.OFFER, Offer.class);
 	}
 
 	public boolean hasRequest() throws IOException {
-		return reader.hasUserDefined(Types.REQUEST);
+		return reader.hasStruct(Types.REQUEST);
 	}
 
 	public Request readRequest() throws IOException {
-		return reader.readUserDefined(Types.REQUEST, Request.class);
+		return reader.readStruct(Types.REQUEST, Request.class);
 	}
 
 	public boolean hasSubscriptionUpdate() throws IOException {
-		return reader.hasUserDefined(Types.SUBSCRIPTION_UPDATE);
+		return reader.hasStruct(Types.SUBSCRIPTION_UPDATE);
 	}
 
 	public SubscriptionUpdate readSubscriptionUpdate() throws IOException {
-		return reader.readUserDefined(Types.SUBSCRIPTION_UPDATE,
+		return reader.readStruct(Types.SUBSCRIPTION_UPDATE,
 				SubscriptionUpdate.class);
 	}
 
 	public boolean hasTransportUpdate() throws IOException {
-		return reader.hasUserDefined(Types.TRANSPORT_UPDATE);
+		return reader.hasStruct(Types.TRANSPORT_UPDATE);
 	}
 
 	public TransportUpdate readTransportUpdate() throws IOException {
-		return reader.readUserDefined(Types.TRANSPORT_UPDATE, TransportUpdate.class);
+		return reader.readStruct(Types.TRANSPORT_UPDATE, TransportUpdate.class);
 	}
 }

components/net/sf/briar/protocol/RequestReader.java

@@ -25,7 +25,7 @@ class RequestReader implements ObjectReader<Request> {
 			new CountingConsumer(ProtocolConstants.MAX_PACKET_LENGTH);
 		// Read the data
 		r.addConsumer(counting);
-		r.readUserDefinedId(Types.REQUEST);
+		r.readStructId(Types.REQUEST);
 		byte[] bitmap = r.readBytes(ProtocolConstants.MAX_PACKET_LENGTH);
 		r.removeConsumer(counting);
 		// Convert the bitmap into a BitSet

components/net/sf/briar/protocol/SubscriptionUpdateReader.java

@@ -30,7 +30,7 @@ class SubscriptionUpdateReader implements ObjectReader<SubscriptionUpdate> {
 			new CountingConsumer(ProtocolConstants.MAX_PACKET_LENGTH);
 		// Read the data
 		r.addConsumer(counting);
-		r.readUserDefinedId(Types.SUBSCRIPTION_UPDATE);
+		r.readStructId(Types.SUBSCRIPTION_UPDATE);
 		r.addObjectReader(Types.GROUP, groupReader);
 		Map<Group, Long> subs = r.readMap(Group.class, Long.class);
 		r.removeObjectReader(Types.GROUP);

components/net/sf/briar/protocol/TransportUpdateReader.java

@@ -35,7 +35,7 @@ class TransportUpdateReader implements ObjectReader<TransportUpdate> {
 			new CountingConsumer(ProtocolConstants.MAX_PACKET_LENGTH);
 		// Read the data
 		r.addConsumer(counting);
-		r.readUserDefinedId(Types.TRANSPORT_UPDATE);
+		r.readStructId(Types.TRANSPORT_UPDATE);
 		r.addObjectReader(Types.TRANSPORT, transportReader);
 		Collection<Transport> transports = r.readList(Transport.class);
 		r.removeObjectReader(Types.TRANSPORT);
@@ -58,7 +58,7 @@ class TransportUpdateReader implements ObjectReader<TransportUpdate> {
 	private static class TransportReader implements ObjectReader<Transport> {
 
 		public Transport readObject(Reader r) throws IOException {
-			r.readUserDefinedId(Types.TRANSPORT);
+			r.readStructId(Types.TRANSPORT);
 			// Read the ID
 			byte[] b = r.readBytes(UniqueId.LENGTH);
 			if(b.length != UniqueId.LENGTH) throw new FormatException();

components/net/sf/briar/protocol/writers/AckWriterImpl.java

@@ -23,7 +23,7 @@ class AckWriterImpl implements AckWriter {
 	AckWriterImpl(OutputStream out, SerialComponent serial,
 			WriterFactory writerFactory) {
 		this.out = out;
-		headerLength = serial.getSerialisedUserDefinedIdLength(Types.ACK)
+		headerLength = serial.getSerialisedStructIdLength(Types.ACK)
 		+ serial.getSerialisedListStartLength();
 		idLength = serial.getSerialisedUniqueIdLength(Types.BATCH_ID);
 		footerLength = serial.getSerialisedListEndLength();
@@ -41,7 +41,7 @@ class AckWriterImpl implements AckWriter {
 		int overhead = started ? footerLength : headerLength + footerLength;
 		if(capacity < idLength + overhead) return false;
 		if(!started) start();
-		w.writeUserDefinedId(Types.BATCH_ID);
+		w.writeStructId(Types.BATCH_ID);
 		w.writeBytes(b.getBytes());
 		capacity -= idLength;
 		return true;
@@ -56,7 +56,7 @@ class AckWriterImpl implements AckWriter {
 	}
 
 	private void start() throws IOException {
-		w.writeUserDefinedId(Types.ACK);
+		w.writeStructId(Types.ACK);
 		w.writeListStart();
 		capacity -= headerLength;
 		started = true;

components/net/sf/briar/protocol/writers/BatchWriterImpl.java

@@ -28,7 +28,7 @@ class BatchWriterImpl implements BatchWriter {
 	BatchWriterImpl(OutputStream out, SerialComponent serial,
 			WriterFactory writerFactory, MessageDigest messageDigest) {
 		this.out = out;
-		headerLength = serial.getSerialisedUserDefinedIdLength(Types.BATCH)
+		headerLength = serial.getSerialisedStructIdLength(Types.BATCH)
 		+ serial.getSerialisedListStartLength();
 		footerLength = serial.getSerialisedListEndLength();
 		w = writerFactory.createWriter(this.out);
@@ -70,7 +70,7 @@ class BatchWriterImpl implements BatchWriter {
 	private void start() throws IOException {
 		messageDigest.reset();
 		w.addConsumer(digestingConsumer);
-		w.writeUserDefinedId(Types.BATCH);
+		w.writeStructId(Types.BATCH);
 		w.writeListStart();
 		remaining -= headerLength;
 		started = true;

components/net/sf/briar/protocol/writers/OfferWriterImpl.java

@@ -23,7 +23,7 @@ class OfferWriterImpl implements OfferWriter {
 	OfferWriterImpl(OutputStream out, SerialComponent serial,
 			WriterFactory writerFactory) {
 		this.out = out;
-		headerLength = serial.getSerialisedUserDefinedIdLength(Types.OFFER)
+		headerLength = serial.getSerialisedStructIdLength(Types.OFFER)
 		+ serial.getSerialisedListStartLength();
 		idLength = serial.getSerialisedUniqueIdLength(Types.MESSAGE_ID);
 		footerLength = serial.getSerialisedListEndLength();
@@ -41,7 +41,7 @@ class OfferWriterImpl implements OfferWriter {
 		int overhead = started ? footerLength : headerLength + footerLength;
 		if(capacity < idLength + overhead) return false;
 		if(!started) start();
-		w.writeUserDefinedId(Types.MESSAGE_ID);
+		w.writeStructId(Types.MESSAGE_ID);
 		w.writeBytes(m.getBytes());
 		capacity -= idLength;
 		return true;
@@ -56,7 +56,7 @@ class OfferWriterImpl implements OfferWriter {
 	}
 
 	private void start() throws IOException {
-		w.writeUserDefinedId(Types.OFFER);
+		w.writeStructId(Types.OFFER);
 		w.writeListStart();
 		capacity -= headerLength;
 		started = true;

components/net/sf/briar/protocol/writers/RequestWriterImpl.java

@@ -21,7 +21,7 @@ class RequestWriterImpl implements RequestWriter {
 
 	public void writeRequest(BitSet b, int length)
 	throws IOException {
-		w.writeUserDefinedId(Types.REQUEST);
+		w.writeStructId(Types.REQUEST);
 		// If the number of bits isn't a multiple of 8, round up to a byte
 		int bytes = length % 8 == 0 ? length / 8 : length / 8 + 1;
 		byte[] bitmap = new byte[bytes];

components/net/sf/briar/protocol/writers/SubscriptionUpdateWriterImpl.java

@@ -24,7 +24,7 @@ class SubscriptionUpdateWriterImpl implements SubscriptionUpdateWriter {
 
 	public void writeSubscriptions(Map<Group, Long> subs, long timestamp)
 	throws IOException {
-		w.writeUserDefinedId(Types.SUBSCRIPTION_UPDATE);
+		w.writeStructId(Types.SUBSCRIPTION_UPDATE);
 		w.writeMapStart();
 		for(Entry<Group, Long> e : subs.entrySet()) {
 			writeGroup(w, e.getKey());
@@ -36,7 +36,7 @@ class SubscriptionUpdateWriterImpl implements SubscriptionUpdateWriter {
 	}
 
 	private void writeGroup(Writer w, Group g) throws IOException {
-		w.writeUserDefinedId(Types.GROUP);
+		w.writeStructId(Types.GROUP);
 		w.writeString(g.getName());
 		byte[] publicKey = g.getPublicKey();
 		if(publicKey == null) w.writeNull();

components/net/sf/briar/protocol/writers/TransportUpdateWriterImpl.java

@@ -22,10 +22,10 @@ class TransportUpdateWriterImpl implements TransportUpdateWriter {
 
 	public void writeTransports(Collection<Transport> transports,
 			long timestamp) throws IOException {
-		w.writeUserDefinedId(Types.TRANSPORT_UPDATE);
+		w.writeStructId(Types.TRANSPORT_UPDATE);
 		w.writeListStart();
 		for(Transport p : transports) {
-			w.writeUserDefinedId(Types.TRANSPORT);
+			w.writeStructId(Types.TRANSPORT);
 			w.writeBytes(p.getId().getBytes());
 			w.writeInt32(p.getIndex().getInt());
 			w.writeMap(p);

components/net/sf/briar/serial/ReaderImpl.java

@@ -51,7 +51,7 @@ class ReaderImpl implements Reader {
 		}
 		next = (byte) i;
 		// If necessary, read another lookahead byte
-		if(next == Tag.USER) {
+		if(next == Tag.STRUCT) {
 			i = in.read();
 			if(i == -1) throw new FormatException();
 			nextNext = (byte) i;
@@ -64,7 +64,7 @@ class ReaderImpl implements Reader {
 		assert hasLookahead;
 		for(Consumer c : consumers) {
 			c.write(next);
-			if(next == Tag.USER) c.write(nextNext);
+			if(next == Tag.STRUCT) c.write(nextNext);
 		}
 		hasLookahead = false;
 	}
@@ -376,7 +376,7 @@ class ReaderImpl implements Reader {
 	}
 
 	private Object readObject() throws IOException {
-		if(hasUserDefined()) return readUserDefined();
+		if(hasStruct()) return readStruct();
 		if(hasBoolean()) return Boolean.valueOf(readBoolean());
 		if(hasUint7()) return Byte.valueOf(readUint7());
 		if(hasInt8()) return Byte.valueOf(readInt8());
@@ -396,19 +396,19 @@ class ReaderImpl implements Reader {
 		throw new FormatException();
 	}
 
-	private boolean hasUserDefined() throws IOException {
+	private boolean hasStruct() throws IOException {
 		if(!hasLookahead) readLookahead(true);
 		if(eof) return false;
-		return next == Tag.USER
-		|| (next & Tag.SHORT_USER_MASK) == Tag.SHORT_USER;
+		return next == Tag.STRUCT
+		|| (next & Tag.SHORT_STRUCT_MASK) == Tag.SHORT_STRUCT;
 	}
 
-	private Object readUserDefined() throws IOException {
-		if(!hasUserDefined()) throw new FormatException();
-		int tag;
-		if(next == Tag.USER) tag = 0xFF & nextNext;
-		else tag = 0xFF & next ^ Tag.SHORT_USER;
-		return readUserDefined(tag, Object.class);
+	private Object readStruct() throws IOException {
+		if(!hasStruct()) throw new FormatException();
+		int id;
+		if(next == Tag.STRUCT) id = 0xFF & nextNext;
+		else id = 0xFF & next ^ Tag.SHORT_STRUCT;
+		return readStruct(id, Object.class);
 	}
 
 	private <T> T readObject(Class<T> t) throws IOException {
@@ -529,19 +529,19 @@ class ReaderImpl implements Reader {
 		consumeLookahead();
 	}
 
-	public boolean hasUserDefined(int id) throws IOException {
+	public boolean hasStruct(int id) throws IOException {
 		if(id < 0 || id > 255) throw new IllegalArgumentException();
 		if(!hasLookahead) readLookahead(true);
 		if(eof) return false;
-		if(next == Tag.USER)
+		if(next == Tag.STRUCT)
 			return id == (0xFF & nextNext);
-		else if((next & Tag.SHORT_USER_MASK) == Tag.SHORT_USER)
-			return id == (0xFF & next ^ Tag.SHORT_USER);
+		else if((next & Tag.SHORT_STRUCT_MASK) == Tag.SHORT_STRUCT)
+			return id == (0xFF & next ^ Tag.SHORT_STRUCT);
 		else return false;
 	}
 
-	public <T> T readUserDefined(int id, Class<T> t) throws IOException {
-		if(!hasUserDefined(id)) throw new FormatException();
+	public <T> T readStruct(int id, Class<T> t) throws IOException {
+		if(!hasStruct(id)) throw new FormatException();
 		if(id >= objectReaders.length) throw new FormatException();
 		ObjectReader<?> o = objectReaders[id];
 		if(o == null) throw new FormatException();
@@ -552,8 +552,8 @@ class ReaderImpl implements Reader {
 		}
 	}
 
-	public void readUserDefinedId(int id) throws IOException {
-		if(!hasUserDefined(id)) throw new FormatException();
+	public void readStructId(int id) throws IOException {
+		if(!hasStruct(id)) throw new FormatException();
 		consumeLookahead();
 	}
 }

components/net/sf/briar/serial/SerialComponentImpl.java

@@ -6,16 +6,18 @@ import net.sf.briar.api.serial.SerialComponent;
 class SerialComponentImpl implements SerialComponent {
 
 	public int getSerialisedListEndLength() {
+		// END tag
 		return 1;
 	}
 
 	public int getSerialisedListStartLength() {
+		// LIST_START tag
 		return 1;
 	}
 
 	public int getSerialisedUniqueIdLength(int id) {
-		// User-defined ID, BYTES tag, length spec, bytes
-		return getSerialisedUserDefinedIdLength(id) + 1
+		// Struct ID, BYTES tag, length spec, bytes
+		return getSerialisedStructIdLength(id) + 1
 		+ getSerialisedLengthSpecLength(UniqueId.LENGTH) + UniqueId.LENGTH;
 	}
 
@@ -26,7 +28,7 @@ class SerialComponentImpl implements SerialComponent {
 		return 5; // Int32
 	}
 
-	public int getSerialisedUserDefinedIdLength(int id) {
+	public int getSerialisedStructIdLength(int id) {
 		assert id >= 0 && id <= 255;
 		return id < 32 ? 1 : 2;
 	}

components/net/sf/briar/serial/Tag.java

@@ -18,7 +18,7 @@ interface Tag {
 	static final byte MAP_START = -14; // 1111 0010
 	static final byte END = -15; // 1111 0001
 	static final byte NULL = -16; // 1111 0000
-	static final byte USER = -17; // 1110 1111
+	static final byte STRUCT = -17; // 1110 1111
 
 	static final int SHORT_MASK = 0xF0; // Match first four bits
 	static final int SHORT_STRING = 0x80; // 1000 xxxx
@@ -26,6 +26,6 @@ interface Tag {
 	static final int SHORT_LIST = 0xA0; // 1010 xxxx
 	static final int SHORT_MAP = 0xB0; // 1011 xxxx
 
-	static final int SHORT_USER_MASK = 0xE0; // Match first three bits
-	static final int SHORT_USER = 0xC0; // 110x xxxx
+	static final int SHORT_STRUCT_MASK = 0xE0; // Match first three bits
+	static final int SHORT_STRUCT = 0xC0; // 110x xxxx
 }

components/net/sf/briar/serial/WriterImpl.java

@@ -187,12 +187,12 @@ class WriterImpl implements Writer {
 		write(Tag.NULL);
 	}
 
-	public void writeUserDefinedId(int id) throws IOException {
+	public void writeStructId(int id) throws IOException {
 		if(id < 0 || id > 255) throw new IllegalArgumentException();
 		if(id < 32) {
-			write((byte) (Tag.SHORT_USER | id));
+			write((byte) (Tag.SHORT_STRUCT | id));
 		} else {
-			write(Tag.USER);
+			write(Tag.STRUCT);
 			write((byte) id);
 		}
 	}