Allow retransmission if faster.

* This commit introduces an estimated time of arrival (eta) to the
message status which helps to decide whether a message should be
retransmitted over a faster transport.

bramble-core/src/test/java/org/briarproject/bramble/crypto/ScryptKdfTest.java

@@ -11,6 +11,8 @@ import java.util.HashSet;
 import java.util.Set;
 
 import static junit.framework.TestCase.assertTrue;
+
+import org.briarproject.bramble.test.ArrayClock;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;
@@ -74,24 +76,4 @@ public class ScryptKdfTest extends BrambleTestCase {
 		PasswordBasedKdf kdf = new ScryptKdf(clock);
 		assertEquals(256, kdf.chooseCostParameter());
 	}
-
-	private static class ArrayClock implements Clock {
-
-		private final long[] times;
-		private int index = 0;
-
-		private ArrayClock(long... times) {
-			this.times = times;
-		}
-
-		@Override
-		public long currentTimeMillis() {
-			return times[index++];
-		}
-
-		@Override
-		public void sleep(long milliseconds) throws InterruptedException {
-			Thread.sleep(milliseconds);
-		}
-	}
 }

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -871,15 +871,15 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).containsContact(txn, contactId);
 			will(returnValue(true));
 			oneOf(database).getMessagesToSend(txn, contactId,
-					MAX_MESSAGE_LENGTH * 2);
+					MAX_MESSAGE_LENGTH * 2, maxLatency);
 			will(returnValue(ids));
 			oneOf(database).getMessage(txn, messageId);
 			will(returnValue(message));
-			oneOf(database).updateExpiryTime(txn, contactId, messageId,
+			oneOf(database).updateExpiryTimeAndEta(txn, contactId, messageId,
 					maxLatency);
 			oneOf(database).getMessage(txn, messageId1);
 			will(returnValue(message1));
-			oneOf(database).updateExpiryTime(txn, contactId, messageId1,
+			oneOf(database).updateExpiryTimeAndEta(txn, contactId, messageId1,
 					maxLatency);
 			oneOf(database).lowerRequestedFlag(txn, contactId, ids);
 			oneOf(database).commitTransaction(txn);
@@ -907,11 +907,11 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(txn));
 			oneOf(database).containsContact(txn, contactId);
 			will(returnValue(true));
-			oneOf(database).getMessagesToOffer(txn, contactId, 123);
+			oneOf(database).getMessagesToOffer(txn, contactId, 123, maxLatency);
 			will(returnValue(ids));
-			oneOf(database).updateExpiryTime(txn, contactId, messageId,
+			oneOf(database).updateExpiryTimeAndEta(txn, contactId, messageId,
 					maxLatency);
-			oneOf(database).updateExpiryTime(txn, contactId, messageId1,
+			oneOf(database).updateExpiryTimeAndEta(txn, contactId, messageId1,
 					maxLatency);
 			oneOf(database).commitTransaction(txn);
 		}});
@@ -967,15 +967,15 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).containsContact(txn, contactId);
 			will(returnValue(true));
 			oneOf(database).getRequestedMessagesToSend(txn, contactId,
-					MAX_MESSAGE_LENGTH * 2);
+					MAX_MESSAGE_LENGTH * 2, maxLatency);
 			will(returnValue(ids));
 			oneOf(database).getMessage(txn, messageId);
 			will(returnValue(message));
-			oneOf(database).updateExpiryTime(txn, contactId, messageId,
+			oneOf(database).updateExpiryTimeAndEta(txn, contactId, messageId,
 					maxLatency);
 			oneOf(database).getMessage(txn, messageId1);
 			will(returnValue(message1));
-			oneOf(database).updateExpiryTime(txn, contactId, messageId1,
+			oneOf(database).updateExpiryTimeAndEta(txn, contactId, messageId1,
 					maxLatency);
 			oneOf(database).lowerRequestedFlag(txn, contactId, ids);
 			oneOf(database).commitTransaction(txn);

bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceTest.java

@@ -96,6 +96,9 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 	 */
 	private static final int STEADY_STATE_BLOCKS = 5;
 
+	// All our transports use a maximum latency of 30 seconds
+	private static final int MAX_LATENCY = 30 * 1000;
+
 	protected final File testDir = getTestDirectory();
 	private final File resultsFile = new File(getTestName() + ".tsv");
 	protected final Random random = new Random();
@@ -448,7 +451,7 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 		benchmark(name, db -> {
 			Connection txn = db.startTransaction();
 			db.getMessagesToOffer(txn, pickRandom(contacts).getId(),
-					MAX_MESSAGE_IDS);
+					MAX_MESSAGE_IDS, MAX_LATENCY);
 			db.commitTransaction(txn);
 		});
 	}
@@ -470,7 +473,7 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 		benchmark(name, db -> {
 			Connection txn = db.startTransaction();
 			db.getMessagesToSend(txn, pickRandom(contacts).getId(),
-					MAX_MESSAGE_IDS);
+					MAX_MESSAGE_IDS, MAX_LATENCY);
 			db.commitTransaction(txn);
 		});
 	}
@@ -521,7 +524,7 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 		benchmark(name, db -> {
 			Connection txn = db.startTransaction();
 			db.getRequestedMessagesToSend(txn, pickRandom(contacts).getId(),
-					MAX_MESSAGE_IDS);
+					MAX_MESSAGE_IDS, MAX_LATENCY);
 			db.commitTransaction(txn);
 		});
 	}

bramble-core/src/test/java/org/briarproject/bramble/db/JdbcDatabaseTest.java

@@ -26,6 +26,7 @@ import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.system.SystemClock;
+import org.briarproject.bramble.test.ArrayClock;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestDatabaseConfig;
 import org.briarproject.bramble.test.TestMessageFactory;
@@ -60,6 +61,7 @@ import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERE
 import static org.briarproject.bramble.api.sync.ValidationManager.State.INVALID;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.PENDING;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.UNKNOWN;
+import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
 import static org.briarproject.bramble.test.TestUtils.getClientId;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
@@ -82,6 +84,9 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 	private static final int ONE_MEGABYTE = 1024 * 1024;
 	private static final int MAX_SIZE = 5 * ONE_MEGABYTE;
+	// All our transports use a maximum latency of 30 seconds
+	private static final int MAX_LATENCY = 30 * 1000;
+
 
 	private final SecretKey key = getSecretKey();
 	private final File testDir = getTestDirectory();
@@ -199,16 +204,16 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// The contact has not seen the message, so it should be sendable
 		Collection<MessageId> ids =
-				db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+				db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 
 		// Changing the status to seen = true should make the message unsendable
 		db.raiseSeenFlag(txn, contactId, messageId);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		db.commitTransaction(txn);
@@ -230,30 +235,30 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// The message has not been validated, so it should not be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
-				ONE_MEGABYTE);
+				ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Marking the message delivered should make it sendable
 		db.setMessageState(txn, messageId, DELIVERED);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 
 		// Marking the message invalid should make it unsendable
 		db.setMessageState(txn, messageId, INVALID);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Marking the message pending should make it unsendable
 		db.setMessageState(txn, messageId, PENDING);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		db.commitTransaction(txn);
@@ -274,37 +279,37 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// The group is invisible, so the message should not be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
-				ONE_MEGABYTE);
+				ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Making the group visible should not make the message sendable
 		db.addGroupVisibility(txn, contactId, groupId, false);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Sharing the group should make the message sendable
 		db.setGroupVisibility(txn, contactId, groupId, true);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 
 		// Unsharing the group should make the message unsendable
 		db.setGroupVisibility(txn, contactId, groupId, false);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Making the group invisible should make the message unsendable
 		db.removeGroupVisibility(txn, contactId, groupId);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		db.commitTransaction(txn);
@@ -326,16 +331,16 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// The message is not shared, so it should not be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
-				ONE_MEGABYTE);
+				ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Sharing the message should make it sendable
 		db.setMessageShared(txn, messageId);
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 
 		db.commitTransaction(txn);
@@ -356,12 +361,13 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.addMessage(txn, message, DELIVERED, true, null);
 
 		// The message is sendable, but too large to send
-		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
-				message.getRawLength() - 1);
+		Collection<MessageId> ids =
+				db.getMessagesToSend(txn, contactId, message.getRawLength() - 1,
+						MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-
 		// The message is just the right size to send
-		ids = db.getMessagesToSend(txn, contactId, message.getRawLength());
+		ids = db.getMessagesToSend(txn, contactId, message.getRawLength(),
+				MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 
 		db.commitTransaction(txn);
@@ -424,19 +430,19 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Retrieve the message from the database and mark it as sent
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
-				ONE_MEGABYTE);
+				ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
-		db.updateExpiryTime(txn, contactId, messageId, Integer.MAX_VALUE);
+		db.updateExpiryTimeAndEta(txn, contactId, messageId, Integer.MAX_VALUE);
 
 		// The message should no longer be sendable
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Pretend that the message was acked
 		db.raiseSeenFlag(txn, contactId, messageId);
 
 		// The message still should not be sendable
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		db.commitTransaction(txn);
@@ -1517,7 +1523,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertFalse(status.isSeen());
 
 		// Pretend the message was sent to the contact
-		db.updateExpiryTime(txn, contactId, messageId, Integer.MAX_VALUE);
+		db.updateExpiryTimeAndEta(txn, contactId, messageId, Integer.MAX_VALUE);
 
 		// The message should be sent but not seen
 		status = db.getMessageStatus(txn, contactId, messageId);
@@ -1636,9 +1642,9 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// The message should be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
-				ONE_MEGABYTE);
+				ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 
 		// The message should be available
@@ -1655,9 +1661,9 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertTrue(db.containsVisibleMessage(txn, contactId, messageId));
 
 		// The message should not be sendable
-		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE);
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
-		ids = db.getMessagesToOffer(txn, contactId, 100);
+		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 
 		// Requesting the message should throw an exception
@@ -1761,12 +1767,12 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Update the message's expiry time as though we sent it - now the
 		// message should be sendable after one round-trip
-		db.updateExpiryTime(txn, contactId, messageId, 1000);
+		db.updateExpiryTimeAndEta(txn, contactId, messageId, 1000);
 		assertEquals(now + 2000, db.getNextSendTime(txn, contactId));
 
 		// Update the message's expiry time again - now it should be sendable
 		// after two round-trips
-		db.updateExpiryTime(txn, contactId, messageId, 1000);
+		db.updateExpiryTimeAndEta(txn, contactId, messageId, 1000);
 		assertEquals(now + 4000, db.getNextSendTime(txn, contactId));
 
 		// Delete the message - there should be no messages to send
@@ -1809,6 +1815,52 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
+	@Test
+	public void testFasterMessageRetransmission() throws Exception {
+		long now = System.currentTimeMillis();
+		long steps[] = {now, now, now + MAX_LATENCY, now + MAX_LATENCY,
+				now + 1 + MAX_LATENCY * 2};
+		Database<Connection> db = open(false, new ArrayClock(steps));
+		Connection txn = db.startTransaction();
+
+		// Add a contact, a shared group and a shared message
+		db.addLocalAuthor(txn, localAuthor);
+		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
+				true, true));
+		db.addGroup(txn, group);
+		db.addGroupVisibility(txn, contactId, groupId, true);
+		db.addMessage(txn, message, DELIVERED, true, null);
+
+		// Time: now
+		// Retrieve the message from the database and mark it as sent
+		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
+				ONE_MEGABYTE, MAX_LATENCY);
+		assertEquals(singletonList(messageId), ids);
+		// Time: now
+		db.updateExpiryTimeAndEta(txn, contactId, messageId, MAX_LATENCY);
+
+		// Time: now + MAX_LATENCY
+		// The message should no longer be sendable via transports with
+		// with an equal or higher ETA
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
+		assertTrue(ids.isEmpty());
+
+		// Time: now + MAX_LATENCY
+		// The message should be sendable via a transport with a faster ETA
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE,
+				MAX_LATENCY / 2 - 1);
+		assertEquals(singletonList(messageId), ids);
+
+		// Time: now + 1 + MAX_LATENCY * 2
+		// The message expired and should be sendable by every transport.
+		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
+		assertEquals(singletonList(messageId), ids);
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+
 	private Database<Connection> open(boolean resume) throws Exception {
 		return open(resume, new TestMessageFactory(), new SystemClock());
 	}
@@ -1846,7 +1898,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 	@After
 	public void tearDown() {
-		TestUtils.deleteTestDirectory(testDir);
+		deleteTestDirectory(testDir);
 	}
 
 	private static class StoppedClock implements Clock {