Request reader and unit test.

api/net/sf/briar/api/protocol/Ack.java

@@ -12,5 +12,5 @@ public interface Ack {
 	static final int MAX_SIZE = (1024 * 1024) - 100;
 
 	/** Returns the IDs of the acknowledged batches. */
-	Collection<BatchId> getBatches();
+	Collection<BatchId> getBatchIds();
 }

api/net/sf/briar/api/protocol/Offer.java

@@ -12,5 +12,5 @@ public interface Offer {
 	static final int MAX_SIZE = (1024 * 1024) - 100;
 
 	/** Returns the message IDs contained in the offer. */
-	Collection<MessageId> getMessages();
+	Collection<MessageId> getMessageIds();
 }

api/net/sf/briar/api/protocol/Request.java

@@ -0,0 +1,19 @@
+package net.sf.briar.api.protocol;
+
+import java.util.BitSet;
+
+/** A packet requesting some or all of the messages from an offer. */
+public interface Request {
+
+	/**
+	 * The maximum size of a serialised request, exlcuding encryption and
+	 * authentication.
+	 */
+	static final int MAX_SIZE = (1024 * 1024) - 100;
+
+	/**
+	 * Returns a sequence of bits corresponding to the sequence of messages in
+	 * the offer, where the i^th bit is set if the i^th message should be sent.
+	 */
+	BitSet getBitmap();
+}

components/net/sf/briar/db/ReadWriteLockDatabaseComponent.java

@@ -597,7 +597,7 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			try {
 				messageStatusLock.writeLock().lock();
 				try {
-					Collection<BatchId> acks = a.getBatches();
+					Collection<BatchId> acks = a.getBatchIds();
 					for(BatchId ack : acks) {
 						Txn txn = db.startTransaction();
 						try {
@@ -676,7 +676,7 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				try {
 					subscriptionLock.readLock().lock();
 					try {
-						Collection<MessageId> offered = o.getMessages();
+						Collection<MessageId> offered = o.getMessageIds();
 						BitSet request = new BitSet(offered.size());
 						Txn txn = db.startTransaction();
 						try {

components/net/sf/briar/db/SynchronizedDatabaseComponent.java

@@ -440,7 +440,7 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			if(!containsContact(c)) throw new NoSuchContactException();
 			synchronized(messageLock) {
 				synchronized(messageStatusLock) {
-					Collection<BatchId> acks = a.getBatches();
+					Collection<BatchId> acks = a.getBatchIds();
 					for(BatchId ack : acks) {
 						Txn txn = db.startTransaction();
 						try {
@@ -497,7 +497,7 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			synchronized(messageLock) {
 				synchronized(messageStatusLock) {
 					synchronized(subscriptionLock) {
-						Collection<MessageId> offered = o.getMessages();
+						Collection<MessageId> offered = o.getMessageIds();
 						BitSet request = new BitSet(offered.size());
 						Txn txn = db.startTransaction();
 						try {

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

@@ -7,5 +7,5 @@ import net.sf.briar.api.protocol.BatchId;
 
 interface AckFactory {
 
-	Ack createAck(Collection<BatchId> batches);
+	Ack createAck(Collection<BatchId> acked);
 }

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

@@ -7,7 +7,7 @@ import net.sf.briar.api.protocol.BatchId;
 
 class AckFactoryImpl implements AckFactory {
 
-	public Ack createAck(Collection<BatchId> batches) {
-		return new AckImpl(batches);
+	public Ack createAck(Collection<BatchId> acked) {
+		return new AckImpl(acked);
 	}
 }

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

@@ -7,13 +7,13 @@ import net.sf.briar.api.protocol.BatchId;
 
 class AckImpl implements Ack {
 
-	private final Collection<BatchId> batches;
+	private final Collection<BatchId> acked;
 
-	AckImpl(Collection<BatchId> batches) {
-		this.batches = batches;
+	AckImpl(Collection<BatchId> acked) {
+		this.acked = acked;
 	}
 
-	public Collection<BatchId> getBatches() {
-		return batches;
+	public Collection<BatchId> getBatchIds() {
+		return acked;
 	}
 }

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

@@ -7,5 +7,5 @@ import net.sf.briar.api.protocol.Offer;
 
 interface OfferFactory {
 
-	Offer createOffer(Collection<MessageId> messages);
+	Offer createOffer(Collection<MessageId> offered);
 }

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

@@ -7,7 +7,7 @@ import net.sf.briar.api.protocol.Offer;
 
 class OfferFactoryImpl implements OfferFactory {
 
-	public Offer createOffer(Collection<MessageId> messages) {
-		return new OfferImpl(messages);
+	public Offer createOffer(Collection<MessageId> offered) {
+		return new OfferImpl(offered);
 	}
 }

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

@@ -7,13 +7,13 @@ import net.sf.briar.api.protocol.Offer;
 
 class OfferImpl implements Offer {
 
-	private final Collection<MessageId> messages;
+	private final Collection<MessageId> offered;
 
-	OfferImpl(Collection<MessageId> messages) {
-		this.messages = messages;
+	OfferImpl(Collection<MessageId> offered) {
+		this.offered = offered;
 	}
 
-	public Collection<MessageId> getMessages() {
-		return messages;
+	public Collection<MessageId> getMessageIds() {
+		return offered;
 	}
 }

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

@@ -23,19 +23,21 @@ public class ProtocolModule extends AbstractModule {
 		bind(BatchFactory.class).to(BatchFactoryImpl.class);
 		bind(GroupFactory.class).to(GroupFactoryImpl.class);
 		bind(OfferFactory.class).to(OfferFactoryImpl.class);
+		bind(RequestFactory.class).to(RequestFactoryImpl.class);
 		bind(SubscriptionFactory.class).to(SubscriptionFactoryImpl.class);
 		bind(TransportFactory.class).to(TransportFactoryImpl.class);
 		bind(MessageEncoder.class).to(MessageEncoderImpl.class);
 	}
 
 	@Provides
-	ObjectReader<BatchId> getBatchIdReader() {
-		return new BatchIdReader();
+	ObjectReader<Author> getAuthorReader(CryptoComponent crypto,
+			AuthorFactory authorFactory) {
+		return new AuthorReader(crypto, authorFactory);
 	}
 
 	@Provides
-	ObjectReader<MessageId> getMessageIdReader() {
-		return new MessageIdReader();
+	ObjectReader<BatchId> getBatchIdReader() {
+		return new BatchIdReader();
 	}
 
 	@Provides
@@ -45,9 +47,8 @@ public class ProtocolModule extends AbstractModule {
 	}
 
 	@Provides
-	ObjectReader<Author> getAuthorReader(CryptoComponent crypto,
-			AuthorFactory authorFactory) {
-		return new AuthorReader(crypto, authorFactory);
+	ObjectReader<MessageId> getMessageIdReader() {
+		return new MessageIdReader();
 	}
 
 	@Provides

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

@@ -0,0 +1,10 @@
+package net.sf.briar.protocol;
+
+import java.util.BitSet;
+
+import net.sf.briar.api.protocol.Request;
+
+interface RequestFactory {
+
+	Request createRequest(BitSet requested);
+}

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

@@ -0,0 +1,12 @@
+package net.sf.briar.protocol;
+
+import java.util.BitSet;
+
+import net.sf.briar.api.protocol.Request;
+
+class RequestFactoryImpl implements RequestFactory {
+
+	public Request createRequest(BitSet requested) {
+		return new RequestImpl(requested);
+	}
+}

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

@@ -0,0 +1,18 @@
+package net.sf.briar.protocol;
+
+import java.util.BitSet;
+
+import net.sf.briar.api.protocol.Request;
+
+class RequestImpl implements Request {
+
+	private final BitSet requested;
+
+	RequestImpl(BitSet requested) {
+		this.requested = requested;
+	}
+
+	public BitSet getBitmap() {
+		return requested;
+	}
+}

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

@@ -0,0 +1,41 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.util.BitSet;
+
+import net.sf.briar.api.protocol.Request;
+import net.sf.briar.api.protocol.Tags;
+import net.sf.briar.api.serial.Consumer;
+import net.sf.briar.api.serial.ObjectReader;
+import net.sf.briar.api.serial.Reader;
+
+import com.google.inject.Inject;
+
+class RequestReader implements ObjectReader<Request> {
+
+	private final RequestFactory requestFactory;
+
+	@Inject
+	RequestReader(RequestFactory requestFactory) {
+		this.requestFactory = requestFactory;
+	}
+
+	public Request readObject(Reader r) throws IOException {
+		// Initialise the consumer
+		Consumer counting = new CountingConsumer(Request.MAX_SIZE);
+		// Read the data
+		r.addConsumer(counting);
+		r.readUserDefinedTag(Tags.REQUEST);
+		byte[] bitmap = r.readBytes();
+		r.removeConsumer(counting);
+		// Convert the bitmap into a BitSet
+		BitSet b = new BitSet(bitmap.length * 8);
+		for(int i = 0; i < bitmap.length; i++) {
+			for(int j = 0; j < 8; j++) {
+				byte bit = (byte) (128 >> j);
+				if((bitmap[i] & bit) != 0) b.set(i * 8 + j);
+			}
+		}
+		return requestFactory.createRequest(b);
+	}
+}

test/net/sf/briar/db/DatabaseComponentTest.java

@@ -752,7 +752,7 @@ public abstract class DatabaseComponentTest extends TestCase {
 			allowing(database).containsContact(txn, contactId);
 			will(returnValue(true));
 			// Get the acked batches
-			oneOf(ack).getBatches();
+			oneOf(ack).getBatchIds();
 			will(returnValue(Collections.singletonList(batchId)));
 			oneOf(database).removeAckedBatch(txn, contactId, batchId);
 		}});
@@ -940,7 +940,7 @@ public abstract class DatabaseComponentTest extends TestCase {
 			allowing(database).containsContact(txn, contactId);
 			will(returnValue(true));
 			// Get the offered messages
-			oneOf(offer).getMessages();
+			oneOf(offer).getMessageIds();
 			will(returnValue(offered));
 			oneOf(database).setStatusSeenIfVisible(txn, contactId, messageId);
 			will(returnValue(false)); // Not visible - request message # 0

test/net/sf/briar/protocol/AckReaderTest.java

@@ -97,7 +97,7 @@ public class AckReaderTest extends TestCase {
 	}
 
 	private byte[] createAck(boolean tooBig) throws Exception {
-		ByteArrayOutputStream out = new ByteArrayOutputStream(Ack.MAX_SIZE);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		Writer w = writerFactory.createWriter(out);
 		w.writeUserDefinedTag(Tags.ACK);
 		w.writeListStart();

test/net/sf/briar/protocol/FileReadWriteTest.java

@@ -6,6 +6,7 @@ import java.io.FileOutputStream;
 import java.security.KeyPair;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.BitSet;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
@@ -24,6 +25,7 @@ import net.sf.briar.api.protocol.Message;
 import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.Offer;
+import net.sf.briar.api.protocol.Request;
 import net.sf.briar.api.protocol.Subscriptions;
 import net.sf.briar.api.protocol.Tags;
 import net.sf.briar.api.protocol.Transports;
@@ -32,6 +34,7 @@ import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.PacketWriterFactory;
+import net.sf.briar.api.protocol.writers.RequestWriter;
 import net.sf.briar.api.protocol.writers.SubscriptionWriter;
 import net.sf.briar.api.protocol.writers.TransportWriter;
 import net.sf.briar.api.serial.Reader;
@@ -61,6 +64,7 @@ public class FileReadWriteTest extends TestCase {
 	private final AckReader ackReader;
 	private final BatchReader batchReader;
 	private final OfferReader offerReader;
+	private final RequestReader requestReader;
 	private final SubscriptionReader subscriptionReader;
 	private final TransportReader transportReader;
 	private final Author author;
@@ -82,6 +86,7 @@ public class FileReadWriteTest extends TestCase {
 		ackReader = i.getInstance(AckReader.class);
 		batchReader = i.getInstance(BatchReader.class);
 		offerReader = i.getInstance(OfferReader.class);
+		requestReader = i.getInstance(RequestReader.class);
 		subscriptionReader = i.getInstance(SubscriptionReader.class);
 		transportReader = i.getInstance(TransportReader.class);
 		// Create two groups: one restricted, one unrestricted
@@ -135,6 +140,12 @@ public class FileReadWriteTest extends TestCase {
 		assertTrue(o.writeMessageId(message3.getId()));
 		o.finish();
 
+		RequestWriter r = packetWriterFactory.createRequestWriter(out);
+		BitSet requested = new BitSet(4);
+		requested.set(1);
+		requested.set(3);
+		r.writeBitmap(requested, 4);
+
 		SubscriptionWriter s =
 			packetWriterFactory.createSubscriptionWriter(out);
 		Collection<Group> subs = new ArrayList<Group>();
@@ -160,35 +171,47 @@ public class FileReadWriteTest extends TestCase {
 		reader.addObjectReader(Tags.ACK, ackReader);
 		reader.addObjectReader(Tags.BATCH, batchReader);
 		reader.addObjectReader(Tags.OFFER, offerReader);
+		reader.addObjectReader(Tags.REQUEST, requestReader);
 		reader.addObjectReader(Tags.SUBSCRIPTIONS, subscriptionReader);
 		reader.addObjectReader(Tags.TRANSPORTS, transportReader);
 
 		// Read the ack
 		assertTrue(reader.hasUserDefined(Tags.ACK));
 		Ack a = reader.readUserDefined(Tags.ACK, Ack.class);
-		assertEquals(Collections.singletonList(ack), a.getBatches());
+		assertEquals(Collections.singletonList(ack), a.getBatchIds());
 
 		// Read the batch
 		assertTrue(reader.hasUserDefined(Tags.BATCH));
 		Batch b = reader.readUserDefined(Tags.BATCH, Batch.class);
 		Collection<Message> messages = b.getMessages();
 		assertEquals(4, messages.size());
-		Iterator<Message> i = messages.iterator();
-		checkMessageEquality(message, i.next());
-		checkMessageEquality(message1, i.next());
-		checkMessageEquality(message2, i.next());
-		checkMessageEquality(message3, i.next());
+		Iterator<Message> it = messages.iterator();
+		checkMessageEquality(message, it.next());
+		checkMessageEquality(message1, it.next());
+		checkMessageEquality(message2, it.next());
+		checkMessageEquality(message3, it.next());
 
 		// Read the offer
 		assertTrue(reader.hasUserDefined(Tags.OFFER));
 		Offer o = reader.readUserDefined(Tags.OFFER, Offer.class);
-		Collection<MessageId> ids = o.getMessages();
-		assertEquals(4, ids.size());
-		Iterator<MessageId> i1 = ids.iterator();
-		assertEquals(message.getId(), i1.next());
-		assertEquals(message1.getId(), i1.next());
-		assertEquals(message2.getId(), i1.next());
-		assertEquals(message3.getId(), i1.next());
+		Collection<MessageId> offered = o.getMessageIds();
+		assertEquals(4, offered.size());
+		Iterator<MessageId> it1 = offered.iterator();
+		assertEquals(message.getId(), it1.next());
+		assertEquals(message1.getId(), it1.next());
+		assertEquals(message2.getId(), it1.next());
+		assertEquals(message3.getId(), it1.next());
+
+		// Read the request
+		assertTrue(reader.hasUserDefined(Tags.REQUEST));
+		Request r = reader.readUserDefined(Tags.REQUEST, Request.class);
+		BitSet requested = r.getBitmap();
+		assertFalse(requested.get(0));
+		assertTrue(requested.get(1));
+		assertFalse(requested.get(2));
+		assertTrue(requested.get(3));
+		// If there are any padding bits, they should all be zero
+		for(int i = 4; i < requested.size(); i++) assertFalse(requested.get(i));
 
 		// Read the subscriptions update
 		assertTrue(reader.hasUserDefined(Tags.SUBSCRIPTIONS));
@@ -196,9 +219,9 @@ public class FileReadWriteTest extends TestCase {
 				Subscriptions.class);
 		Collection<Group> subs = s.getSubscriptions();
 		assertEquals(2, subs.size());
-		Iterator<Group> i2 = subs.iterator();
-		checkGroupEquality(group, i2.next());
-		checkGroupEquality(group1, i2.next());
+		Iterator<Group> it2 = subs.iterator();
+		checkGroupEquality(group, it2.next());
+		checkGroupEquality(group1, it2.next());
 		assertTrue(s.getTimestamp() > start);
 		assertTrue(s.getTimestamp() <= System.currentTimeMillis());
 

test/net/sf/briar/protocol/RequestReaderTest.java

@@ -0,0 +1,133 @@
+package net.sf.briar.protocol;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+
+import junit.framework.TestCase;
+import net.sf.briar.api.protocol.Request;
+import net.sf.briar.api.protocol.Tags;
+import net.sf.briar.api.serial.FormatException;
+import net.sf.briar.api.serial.Reader;
+import net.sf.briar.api.serial.ReaderFactory;
+import net.sf.briar.api.serial.Writer;
+import net.sf.briar.api.serial.WriterFactory;
+import net.sf.briar.serial.SerialModule;
+
+import org.jmock.Expectations;
+import org.jmock.Mockery;
+import org.junit.Test;
+
+import com.google.inject.Guice;
+import com.google.inject.Injector;
+
+public class RequestReaderTest extends TestCase {
+
+	private final ReaderFactory readerFactory;
+	private final WriterFactory writerFactory;
+	private final Mockery context;
+
+	public RequestReaderTest() throws Exception {
+		super();
+		Injector i = Guice.createInjector(new SerialModule());
+		readerFactory = i.getInstance(ReaderFactory.class);
+		writerFactory = i.getInstance(WriterFactory.class);
+		context = new Mockery();
+	}
+
+	@Test
+	public void testFormatExceptionIfRequestIsTooLarge() throws Exception {
+		RequestFactory requestFactory = context.mock(RequestFactory.class);
+		RequestReader requestReader = new RequestReader(requestFactory);
+
+		byte[] b = createRequest(true);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		Reader reader = readerFactory.createReader(in);
+		reader.addObjectReader(Tags.REQUEST, requestReader);
+
+		try {
+			reader.readUserDefined(Tags.REQUEST, Request.class);
+			assertTrue(false);
+		} catch(FormatException expected) {}
+		context.assertIsSatisfied();
+	}
+
+	@Test
+	public void testNoFormatExceptionIfRequestIsMaximumSize() throws Exception {
+		final RequestFactory requestFactory =
+			context.mock(RequestFactory.class);
+		RequestReader requestReader = new RequestReader(requestFactory);
+		final Request request = context.mock(Request.class);
+		context.checking(new Expectations() {{
+			oneOf(requestFactory).createRequest(with(any(BitSet.class)));
+			will(returnValue(request));
+		}});
+
+		byte[] b = createRequest(false);
+		ByteArrayInputStream in = new ByteArrayInputStream(b);
+		Reader reader = readerFactory.createReader(in);
+		reader.addObjectReader(Tags.REQUEST, requestReader);
+
+		assertEquals(request, reader.readUserDefined(Tags.REQUEST,
+				Request.class));
+		context.assertIsSatisfied();
+	}
+
+	@Test
+	public void testBitmapDecoding() throws Exception {
+		// Test sizes from 0 to 1000 bits
+		for(int i = 0; i < 1000; i++) {
+			// Create a BitSet of size i with one in ten bits set (on average)
+			BitSet requested = new BitSet(i);
+			for(int j = 0; j < i; j++) if(Math.random() < 0.1) requested.set(j);
+			// Encode the BitSet as a bitmap
+			int bytes = i % 8 == 0 ? i / 8 : i / 8 + 1;
+			byte[] bitmap = new byte[bytes];
+			for(int j = 0; j < i; j++) {
+				if(requested.get(j)) {
+					int offset = j / 8;
+					byte bit = (byte) (128 >> j % 8);
+					bitmap[offset] |= bit;
+				}
+			}
+			// Create a serialised request containing the bitmap
+			byte[] b = createRequest(bitmap);
+			// Deserialise the request
+			ByteArrayInputStream in = new ByteArrayInputStream(b);
+			Reader reader = readerFactory.createReader(in);
+			RequestReader requestReader =
+				new RequestReader(new RequestFactoryImpl());
+			reader.addObjectReader(Tags.REQUEST, requestReader);
+			Request r = reader.readUserDefined(Tags.REQUEST, Request.class);
+			BitSet decoded = r.getBitmap();
+			// Check that the decoded BitSet matches the original - we can't
+			// use equals() because of padding, but the first i bits should
+			// match and the cardinalities should be equal, indicating that no
+			// padding bits are set
+			for(int j = 0; j < i; j++) {
+				assertEquals(requested.get(j), decoded.get(j));
+			}
+			assertEquals(requested.cardinality(), decoded.cardinality());
+		}
+	}
+
+	private byte[] createRequest(boolean tooBig) throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		Writer w = writerFactory.createWriter(out);
+		w.writeUserDefinedTag(Tags.REQUEST);
+		// Allow one byte for the REQUEST tag, one byte for the BYTES tag, and
+		// five bytes for the length as an int32
+		if(tooBig) w.writeBytes(new byte[Request.MAX_SIZE - 6]);
+		else w.writeBytes(new byte[Request.MAX_SIZE - 7]);
+		assertEquals(tooBig, out.size() > Request.MAX_SIZE);
+		return out.toByteArray();
+	}
+
+	private byte[] createRequest(byte[] bitmap) throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		Writer w = writerFactory.createWriter(out);
+		w.writeUserDefinedTag(Tags.REQUEST);
+		w.writeBytes(bitmap);
+		return out.toByteArray();
+	}
+}