Reflect discovered properties back to the remote peer.

bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyConstants.java

@@ -12,6 +12,11 @@ public interface TransportPropertyConstants {
 	 */
 	int MAX_PROPERTY_LENGTH = 100;
 
+	/**
+	 * Prefix for keys that represent reflected properties.
+	 */
+	String REFLECTED_PROPERTY_PREFIX = "u:";
+
 	/**
 	 * Message metadata key for the transport ID of a local or remote update,
 	 * as a BDF string.

bramble-core/src/main/java/org/briarproject/bramble/properties/TransportPropertyManagerImpl.java

@@ -44,6 +44,7 @@ import static org.briarproject.bramble.api.properties.TransportPropertyConstants
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_TRANSPORT_ID;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_VERSION;
+import static org.briarproject.bramble.api.properties.TransportPropertyConstants.REFLECTED_PROPERTY_PREFIX;
 
 @Immutable
 @NotNullByDefault
@@ -162,15 +163,27 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		if (props.isEmpty()) return;
 		try {
 			db.transaction(false, txn -> {
-				Group g = getContactGroup(db.getContact(txn, c));
+				Contact contact = db.getContact(txn, c);
+				Group g = getContactGroup(contact);
 				BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(
 						txn, g.getId());
 				BdfDictionary discovered =
 						meta.getOptionalDictionary(GROUP_KEY_DISCOVERED);
-				if (discovered == null) discovered = new BdfDictionary();
-				discovered.putAll(props);
-				meta.put(GROUP_KEY_DISCOVERED, discovered);
-				clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
+				BdfDictionary merged;
+				boolean changed;
+				if (discovered == null) {
+					merged = new BdfDictionary(props);
+					changed = true;
+				} else {
+					merged = new BdfDictionary(discovered);
+					merged.putAll(props);
+					changed = !merged.equals(discovered);
+				}
+				if (changed) {
+					meta.put(GROUP_KEY_DISCOVERED, merged);
+					clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
+					updateLocalProperties(txn, contact, t);
+				}
 			});
 		} catch (FormatException e) {
 			throw new DbException(e);
@@ -235,6 +248,24 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		});
 	}
 
+	private void updateLocalProperties(Transaction txn, Contact c,
+			TransportId t) throws DbException {
+		try {
+			TransportProperties local;
+			LatestUpdate latest = findLatest(txn, localGroup.getId(), t, true);
+			if (latest == null) {
+				local = new TransportProperties();
+			} else {
+				BdfList message = clientHelper.getMessageAsList(txn,
+						latest.messageId);
+				local = parseProperties(message);
+			}
+			storeLocalProperties(txn, c, t, local);
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
 	private void storeContactIdsForContactGroups(Transaction txn)
 			throws DbException {
 		try {
@@ -333,18 +364,10 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 					storeMessage(txn, localGroup.getId(), t, merged, version,
 							true, false);
 					// Delete the previous update, if any
-					if (latest != null)
-						db.removeMessage(txn, latest.messageId);
+					if (latest != null) db.removeMessage(txn, latest.messageId);
 					// Store the merged properties in each contact's group
 					for (Contact c : db.getContacts(txn)) {
-						Group g = getContactGroup(c);
-						latest = findLatest(txn, g.getId(), t, true);
-						version = latest == null ? 1 : latest.version + 1;
-						storeMessage(txn, g.getId(), t, merged, version,
-								true, true);
-						// Delete the previous update, if any
-						if (latest != null)
-							db.removeMessage(txn, latest.messageId);
+						storeLocalProperties(txn, c, t, merged);
 					}
 				}
 			});
@@ -353,6 +376,34 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		}
 	}
 
+	private void storeLocalProperties(Transaction txn, Contact c,
+			TransportId t, TransportProperties p)
+			throws DbException, FormatException {
+		Group g = getContactGroup(c);
+		LatestUpdate latest = findLatest(txn, g.getId(), t, true);
+		long version = latest == null ? 1 : latest.version + 1;
+		// Reflect any remote properties we've discovered
+		BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(txn,
+				g.getId());
+		BdfDictionary discovered =
+				meta.getOptionalDictionary(GROUP_KEY_DISCOVERED);
+		TransportProperties combined;
+		if (discovered == null) {
+			combined = p;
+		} else {
+			combined = new TransportProperties(p);
+			TransportProperties d = clientHelper
+					.parseAndValidateTransportProperties(discovered);
+			for (Entry<String, String> e : d.entrySet()) {
+				String key = REFLECTED_PROPERTY_PREFIX + e.getKey();
+				combined.put(key, e.getValue());
+			}
+		}
+		storeMessage(txn, g.getId(), t, combined, version, true, true);
+		// Delete the previous update, if any
+		if (latest != null) db.removeMessage(txn, latest.messageId);
+	}
+
 	private Group getContactGroup(Contact c) {
 		return contactGroupFactory.createContactGroup(CLIENT_ID,
 				MAJOR_VERSION, c);

bramble-core/src/test/java/org/briarproject/bramble/properties/TransportPropertyManagerImplTest.java

@@ -61,23 +61,28 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	private final Clock clock = context.mock(Clock.class);
 
 	private final Group localGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
-	private final BdfDictionary fooPropertiesDict = BdfDictionary.of(
-			new BdfEntry("fooKey1", "fooValue1"),
-			new BdfEntry("fooKey2", "fooValue2")
-	);
-	private final BdfDictionary barPropertiesDict = BdfDictionary.of(
-			new BdfEntry("barKey1", "barValue1"),
-			new BdfEntry("barKey2", "barValue2")
-	);
+	private final BdfDictionary fooPropertiesDict, barPropertiesDict;
+	private final BdfDictionary discoveredPropertiesDict, mergedPropertiesDict;
 	private final TransportProperties fooProperties, barProperties;
+	private final TransportProperties discoveredProperties;
 
-	public TransportPropertyManagerImplTest() throws Exception {
+	public TransportPropertyManagerImplTest() {
 		fooProperties = new TransportProperties();
-		for (String key : fooPropertiesDict.keySet())
-			fooProperties.put(key, fooPropertiesDict.getString(key));
+		fooProperties.put("fooKey1", "fooValue1");
+		fooProperties.put("fooKey2", "fooValue2");
+		fooPropertiesDict = new BdfDictionary(fooProperties);
+
 		barProperties = new TransportProperties();
-		for (String key : barPropertiesDict.keySet())
-			barProperties.put(key, barPropertiesDict.getString(key));
+		barProperties.put("barKey1", "barValue1");
+		barProperties.put("barKey2", "barValue2");
+		barPropertiesDict = new BdfDictionary(barProperties);
+
+		discoveredProperties = new TransportProperties();
+		discoveredProperties.put("fooKey3", "fooValue3");
+		discoveredPropertiesDict = new BdfDictionary(discoveredProperties);
+
+		mergedPropertiesDict = new BdfDictionary(fooProperties);
+		mergedPropertiesDict.put("u:fooKey3", "fooValue3");
 	}
 
 	private TransportPropertyManagerImpl createInstance() {
@@ -657,6 +662,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
 			will(returnValue(emptyMap()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(new BdfDictionary()));
 			expectStoreMessage(txn, contactGroup.getId(), "foo",
 					fooPropertiesDict, 1, true, true);
 		}});
@@ -665,6 +673,49 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
 	}
 
+	@Test
+	public void testMergingNewPropertiesCreatesUpdateWithReflectedProperties()
+			throws Exception {
+		Transaction txn = new Transaction(null, false);
+		Contact contact = getContact();
+		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
+		BdfDictionary contactGroupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_DISCOVERED, discoveredPropertiesDict)
+		);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			// There are no existing properties to merge with
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					localGroup.getId());
+			will(returnValue(emptyMap()));
+			// Store the new properties in the local group, version 1
+			expectStoreMessage(txn, localGroup.getId(), "foo",
+					fooPropertiesDict, 1, true, false);
+			// Store the new properties in each contact's group, version 1
+			oneOf(db).getContacts(txn);
+			will(returnValue(singletonList(contact)));
+			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
+					MAJOR_VERSION, contact);
+			will(returnValue(contactGroup));
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(emptyMap()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(contactGroupMeta));
+			// Reflect discovered properties
+			oneOf(clientHelper).parseAndValidateTransportProperties(
+					discoveredPropertiesDict);
+			will(returnValue(discoveredProperties));
+			expectStoreMessage(txn, contactGroup.getId(), "foo",
+					mergedPropertiesDict, 1, true, true);
+		}});
+
+		TransportPropertyManagerImpl t = createInstance();
+		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
+	}
+
 	@Test
 	public void testMergingUpdatedPropertiesCreatesUpdate() throws Exception {
 		Transaction txn = new Transaction(null, false);
@@ -713,6 +764,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
 			will(returnValue(contactGroupMessageMetadata));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(new BdfDictionary()));
 			expectStoreMessage(txn, contactGroup.getId(), "foo",
 					fooPropertiesDict, 2, true, true);
 			// Delete the previous update
@@ -723,6 +777,75 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
 	}
 
+	@Test
+	public void testMergingUpdatedPropertiesCreatesUpdateWithReflectedProperties()
+			throws Exception {
+		Transaction txn = new Transaction(null, false);
+		Contact contact = getContact();
+		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
+		BdfDictionary contactGroupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_DISCOVERED, discoveredPropertiesDict)
+		);
+		BdfDictionary oldMetadata = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry(MSG_KEY_LOCAL, true)
+		);
+		MessageId localGroupUpdateId = new MessageId(getRandomId());
+		Map<MessageId, BdfDictionary> localGroupMessageMetadata =
+				singletonMap(localGroupUpdateId, oldMetadata);
+		MessageId contactGroupUpdateId = new MessageId(getRandomId());
+		Map<MessageId, BdfDictionary> contactGroupMessageMetadata =
+				singletonMap(contactGroupUpdateId, oldMetadata);
+		TransportProperties oldProperties = new TransportProperties();
+		oldProperties.put("fooKey1", "oldFooValue1");
+		BdfDictionary oldPropertiesDict = BdfDictionary.of(
+				new BdfEntry("fooKey1", "oldFooValue1")
+		);
+		BdfList oldUpdate = BdfList.of("foo", 1, oldPropertiesDict);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			// Merge the new properties with the existing properties
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					localGroup.getId());
+			will(returnValue(localGroupMessageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, localGroupUpdateId);
+			will(returnValue(oldUpdate));
+			oneOf(clientHelper).parseAndValidateTransportProperties(
+					oldPropertiesDict);
+			will(returnValue(oldProperties));
+			// Store the merged properties in the local group, version 2
+			expectStoreMessage(txn, localGroup.getId(), "foo",
+					fooPropertiesDict, 2, true, false);
+			// Delete the previous update
+			oneOf(db).removeMessage(txn, localGroupUpdateId);
+			// Store the merged properties in each contact's group, version 2
+			oneOf(db).getContacts(txn);
+			will(returnValue(singletonList(contact)));
+			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
+					MAJOR_VERSION, contact);
+			will(returnValue(contactGroup));
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(contactGroupMessageMetadata));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(contactGroupMeta));
+			// Reflect discovered properties
+			oneOf(clientHelper).parseAndValidateTransportProperties(
+					discoveredPropertiesDict);
+			will(returnValue(discoveredProperties));
+			expectStoreMessage(txn, contactGroup.getId(), "foo",
+					mergedPropertiesDict, 2, true, true);
+			// Delete the previous update
+			oneOf(db).removeMessage(txn, contactGroupUpdateId);
+		}});
+
+		TransportPropertyManagerImpl t = createInstance();
+		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
+	}
+
 	private void expectGetLocalProperties(Transaction txn) throws Exception {
 		Map<MessageId, BdfDictionary> messageMetadata = new LinkedHashMap<>();
 		// The latest update for transport "foo" should be returned