Reorganise validation code (no functional changes).

bramble-core/src/main/java/org/briarproject/bramble/BrambleCoreEagerSingletons.java

@@ -8,7 +8,7 @@ import org.briarproject.bramble.lifecycle.LifecycleModule;
 import org.briarproject.bramble.plugin.PluginModule;
 import org.briarproject.bramble.properties.PropertiesModule;
 import org.briarproject.bramble.reporting.ReportingModule;
-import org.briarproject.bramble.sync.SyncModule;
+import org.briarproject.bramble.sync.validation.ValidationModule;
 import org.briarproject.bramble.system.SystemModule;
 import org.briarproject.bramble.transport.TransportModule;
 import org.briarproject.bramble.versioning.VersioningModule;
@@ -31,11 +31,11 @@ public interface BrambleCoreEagerSingletons {
 
 	void inject(ReportingModule.EagerSingletons init);
 
-	void inject(SyncModule.EagerSingletons init);
-
 	void inject(SystemModule.EagerSingletons init);
 
 	void inject(TransportModule.EagerSingletons init);
 
+	void inject(ValidationModule.EagerSingletons init);
+
 	void inject(VersioningModule.EagerSingletons init);
 }

bramble-core/src/main/java/org/briarproject/bramble/BrambleCoreModule.java

@@ -19,6 +19,7 @@ import org.briarproject.bramble.reporting.ReportingModule;
 import org.briarproject.bramble.settings.SettingsModule;
 import org.briarproject.bramble.socks.SocksModule;
 import org.briarproject.bramble.sync.SyncModule;
+import org.briarproject.bramble.sync.validation.ValidationModule;
 import org.briarproject.bramble.system.SystemModule;
 import org.briarproject.bramble.transport.TransportModule;
 import org.briarproject.bramble.versioning.VersioningModule;
@@ -47,6 +48,7 @@ import dagger.Module;
 		SyncModule.class,
 		SystemModule.class,
 		TransportModule.class,
+		ValidationModule.class,
 		VersioningModule.class
 })
 public class BrambleCoreModule {
@@ -60,9 +62,9 @@ public class BrambleCoreModule {
 		c.inject(new PluginModule.EagerSingletons());
 		c.inject(new PropertiesModule.EagerSingletons());
 		c.inject(new ReportingModule.EagerSingletons());
-		c.inject(new SyncModule.EagerSingletons());
 		c.inject(new SystemModule.EagerSingletons());
 		c.inject(new TransportModule.EagerSingletons());
+		c.inject(new ValidationModule.EagerSingletons());
 		c.inject(new VersioningModule.EagerSingletons());
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/Database.java

@@ -22,7 +22,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
-import org.briarproject.bramble.api.sync.ValidationManager.State;
+import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.transport.KeySet;
 import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
@@ -106,7 +106,7 @@ interface Database<T> {
 	 * @param sender the contact from whom the message was received, or null
 	 * if the message was created locally.
 	 */
-	void addMessage(T txn, Message m, State state, boolean shared,
+	void addMessage(T txn, Message m, MessageState state, boolean shared,
 			@Nullable ContactId sender) throws DbException;
 
 	/**
@@ -114,7 +114,7 @@ interface Database<T> {
 	 * in the given state.
 	 */
 	void addMessageDependency(T txn, Message dependent, MessageId dependency,
-			State dependentState) throws DbException;
+			MessageState dependentState) throws DbException;
 
 	/**
 	 * Records that a message has been offered by the given contact.
@@ -310,11 +310,11 @@ interface Database<T> {
 	/**
 	 * Returns the IDs and states of all dependencies of the given message.
 	 * For missing dependencies and dependencies in other groups, the state
-	 * {@link State UNKNOWN} is returned.
+	 * {@link MessageState UNKNOWN} is returned.
 	 * <p/>
 	 * Read-only.
 	 */
-	Map<MessageId, State> getMessageDependencies(T txn, MessageId m)
+	Map<MessageId, MessageState> getMessageDependencies(T txn, MessageId m)
 			throws DbException;
 
 	/**
@@ -324,7 +324,7 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	Map<MessageId, State> getMessageDependents(T txn, MessageId m)
+	Map<MessageId, MessageState> getMessageDependents(T txn, MessageId m)
 			throws DbException;
 
 	/**
@@ -383,7 +383,7 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	State getMessageState(T txn, MessageId m) throws DbException;
+	MessageState getMessageState(T txn, MessageId m) throws DbException;
 
 	/**
 	 * Returns the status of all delivered messages in the given group with
@@ -637,7 +637,8 @@ interface Database<T> {
 	/**
 	 * Sets the validation and delivery state of the given message.
 	 */
-	void setMessageState(T txn, MessageId m, State state) throws DbException;
+	void setMessageState(T txn, MessageId m, MessageState state)
+			throws DbException;
 
 	/**
 	 * Sets the reordering window for the given key set and transport in the

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -43,7 +43,6 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
-import org.briarproject.bramble.api.sync.ValidationManager.State;
 import org.briarproject.bramble.api.sync.event.GroupAddedEvent;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.bramble.api.sync.event.GroupVisibilityUpdatedEvent;
@@ -55,6 +54,7 @@ import org.briarproject.bramble.api.sync.event.MessageToAckEvent;
 import org.briarproject.bramble.api.sync.event.MessageToRequestEvent;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
+import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.transport.KeySet;
 import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
@@ -75,8 +75,8 @@ import javax.inject.Inject;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.UNKNOWN;
+import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.db.DatabaseConstants.MAX_OFFERED_MESSAGES;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -579,7 +579,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public State getMessageState(Transaction transaction, MessageId m)
+	public MessageState getMessageState(Transaction transaction, MessageId m)
 			throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsMessage(txn, m))
@@ -619,8 +619,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public Map<MessageId, State> getMessageDependencies(Transaction transaction,
-			MessageId m) throws DbException {
+	public Map<MessageId, MessageState> getMessageDependencies(
+			Transaction transaction, MessageId m) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsMessage(txn, m))
 			throw new NoSuchMessageException();
@@ -628,8 +628,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public Map<MessageId, State> getMessageDependents(Transaction transaction,
-			MessageId m) throws DbException {
+	public Map<MessageId, MessageState> getMessageDependents(
+			Transaction transaction, MessageId m) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsMessage(txn, m))
 			throw new NoSuchMessageException();
@@ -918,7 +918,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public void setMessageState(Transaction transaction, MessageId m,
-			State state) throws DbException {
+			MessageState state) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsMessage(txn, m))
@@ -935,10 +935,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		T txn = unbox(transaction);
 		if (!db.containsMessage(txn, dependent.getId()))
 			throw new NoSuchMessageException();
-		State dependentState = db.getMessageState(txn, dependent.getId());
+		MessageState dependentState =
+				db.getMessageState(txn, dependent.getId());
 		for (MessageId dependency : dependencies) {
-			db.addMessageDependency(txn, dependent, dependency,
-					dependentState);
+			db.addMessageDependency(txn, dependent, dependency, dependentState);
 		}
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java

@@ -24,7 +24,7 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
-import org.briarproject.bramble.api.sync.ValidationManager.State;
+import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.KeySet;
@@ -64,9 +64,9 @@ import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
-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.api.sync.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
+import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.db.DatabaseConstants.DB_SETTINGS_NAMESPACE;
 import static org.briarproject.bramble.db.DatabaseConstants.LAST_COMPACTED_KEY;
 import static org.briarproject.bramble.db.DatabaseConstants.MAX_COMPACTION_INTERVAL_MS;
@@ -724,7 +724,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			while (rs.next()) {
 				MessageId id = new MessageId(rs.getBytes(1));
 				long timestamp = rs.getLong(2);
-				State state = State.fromValue(rs.getInt(3));
+				MessageState state = MessageState.fromValue(rs.getInt(3));
 				boolean messageShared = rs.getBoolean(4);
 				int length = rs.getInt(5);
 				boolean deleted = rs.getBoolean(6);
@@ -767,7 +767,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void addMessage(Connection txn, Message m, State state,
+	public void addMessage(Connection txn, Message m, MessageState state,
 			boolean messageShared, @Nullable ContactId sender)
 			throws DbException {
 		PreparedStatement ps = null;
@@ -847,7 +847,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	private void addStatus(Connection txn, MessageId m, ContactId c, GroupId g,
-			long timestamp, int length, State state, boolean groupShared,
+			long timestamp, int length, MessageState state, boolean groupShared,
 			boolean messageShared, boolean deleted, boolean seen)
 			throws DbException {
 		PreparedStatement ps = null;
@@ -880,7 +880,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	@Override
 	public void addMessageDependency(Connection txn, Message dependent,
-			MessageId dependency, State dependentState) throws DbException {
+			MessageId dependency, MessageState dependentState)
+			throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -891,9 +892,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setBytes(1, dependency.getBytes());
 			ps.setBytes(2, dependent.getGroupId().getBytes());
 			rs = ps.executeQuery();
-			State dependencyState = null;
+			MessageState dependencyState = null;
 			if (rs.next()) {
-				dependencyState = State.fromValue(rs.getInt(1));
+				dependencyState = MessageState.fromValue(rs.getInt(1));
 				if (rs.next()) throw new DbStateException();
 			}
 			rs.close();
@@ -1813,7 +1814,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Map<MessageId, State> getMessageDependencies(Connection txn,
+	public Map<MessageId, MessageState> getMessageDependencies(Connection txn,
 			MessageId m) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
@@ -1824,10 +1825,10 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, State> dependencies = new HashMap<>();
+			Map<MessageId, MessageState> dependencies = new HashMap<>();
 			while (rs.next()) {
 				MessageId dependency = new MessageId(rs.getBytes(1));
-				State state = State.fromValue(rs.getInt(2));
+				MessageState state = MessageState.fromValue(rs.getInt(2));
 				if (rs.wasNull())
 					state = UNKNOWN; // Missing or in a different group
 				dependencies.put(dependency, state);
@@ -1843,7 +1844,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Map<MessageId, State> getMessageDependents(Connection txn,
+	public Map<MessageId, MessageState> getMessageDependents(Connection txn,
 			MessageId m) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
@@ -1857,10 +1858,10 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, State> dependents = new HashMap<>();
+			Map<MessageId, MessageState> dependents = new HashMap<>();
 			while (rs.next()) {
 				MessageId dependent = new MessageId(rs.getBytes(1));
-				State state = State.fromValue(rs.getInt(2));
+				MessageState state = MessageState.fromValue(rs.getInt(2));
 				dependents.put(dependent, state);
 			}
 			rs.close();
@@ -1874,7 +1875,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public State getMessageState(Connection txn, MessageId m)
+	public MessageState getMessageState(Connection txn, MessageId m)
 			throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
@@ -1884,7 +1885,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
 			if (!rs.next()) throw new DbStateException();
-			State state = State.fromValue(rs.getInt(1));
+			MessageState state = MessageState.fromValue(rs.getInt(1));
 			if (rs.next()) throw new DbStateException();
 			rs.close();
 			ps.close();
@@ -2032,7 +2033,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	private Collection<MessageId> getMessagesInState(Connection txn,
-			State state) throws DbException {
+			MessageState state) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -2359,7 +2360,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs = ps.executeQuery();
 			if (!rs.next()) throw new DbStateException();
 			GroupId g = new GroupId(rs.getBytes(1));
-			State state = State.fromValue(rs.getInt(2));
+			MessageState state = MessageState.fromValue(rs.getInt(2));
 			rs.close();
 			ps.close();
 			// Insert any keys that don't already exist
@@ -2865,7 +2866,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void setMessageState(Connection txn, MessageId m, State state)
+	public void setMessageState(Connection txn, MessageId m, MessageState state)
 			throws DbException {
 		PreparedStatement ps = null;
 		try {

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

@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.data.MetadataEncoder;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.ValidationManager;
+import org.briarproject.bramble.api.sync.validation.ValidationManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 

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

@@ -24,7 +24,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.InvalidMessageException;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.ValidationManager.IncomingMessageHook;
+import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager.ClientVersioningHook;

bramble-core/src/main/java/org/briarproject/bramble/sync/SyncModule.java

@@ -1,23 +1,11 @@
 package org.briarproject.bramble.sync;
 
-import org.briarproject.bramble.PoliteExecutor;
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.CryptoExecutor;
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.sync.GroupFactory;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.SyncRecordReaderFactory;
 import org.briarproject.bramble.api.sync.SyncRecordWriterFactory;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.sync.ValidationManager;
-import org.briarproject.bramble.api.system.Clock;
 
-import java.util.concurrent.Executor;
-
-import javax.inject.Inject;
 import javax.inject.Singleton;
 
 import dagger.Module;
@@ -26,29 +14,14 @@ import dagger.Provides;
 @Module
 public class SyncModule {
 
-	public static class EagerSingletons {
-		@Inject
-		ValidationManager validationManager;
-	}
-
-	/**
-	 * The maximum number of validation tasks to delegate to the crypto
-	 * executor concurrently.
-	 * <p>
-	 * The number of available processors can change during the lifetime of the
-	 * JVM, so this is just a reasonable guess.
-	 */
-	private static final int MAX_CONCURRENT_VALIDATION_TASKS =
-			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
-
 	@Provides
-	GroupFactory provideGroupFactory(CryptoComponent crypto) {
-		return new GroupFactoryImpl(crypto);
+	GroupFactory provideGroupFactory(GroupFactoryImpl groupFactory) {
+		return groupFactory;
 	}
 
 	@Provides
-	MessageFactory provideMessageFactory(CryptoComponent crypto) {
-		return new MessageFactoryImpl(crypto);
+	MessageFactory provideMessageFactory(MessageFactoryImpl messageFactory) {
+		return messageFactory;
 	}
 
 	@Provides
@@ -65,30 +38,8 @@ public class SyncModule {
 
 	@Provides
 	@Singleton
-	SyncSessionFactory provideSyncSessionFactory(DatabaseComponent db,
-			@DatabaseExecutor Executor dbExecutor, EventBus eventBus,
-			Clock clock, SyncRecordReaderFactory recordReaderFactory,
-			SyncRecordWriterFactory recordWriterFactory) {
-		return new SyncSessionFactoryImpl(db, dbExecutor, eventBus, clock,
-				recordReaderFactory, recordWriterFactory);
-	}
-
-	@Provides
-	@Singleton
-	ValidationManager provideValidationManager(
-			LifecycleManager lifecycleManager, EventBus eventBus,
-			ValidationManagerImpl validationManager) {
-		lifecycleManager.registerService(validationManager);
-		eventBus.addListener(validationManager);
-		return validationManager;
-	}
-
-	@Provides
-	@Singleton
-	@ValidationExecutor
-	Executor provideValidationExecutor(
-			@CryptoExecutor Executor cryptoExecutor) {
-		return new PoliteExecutor("ValidationExecutor", cryptoExecutor,
-				MAX_CONCURRENT_VALIDATION_TASKS);
+	SyncSessionFactory provideSyncSessionFactory(
+			SyncSessionFactoryImpl syncSessionFactory) {
+		return syncSessionFactory;
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/sync/validation/ValidationExecutor.java

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.sync;
+package org.briarproject.bramble.sync.validation;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;

bramble-core/src/main/java/org/briarproject/bramble/sync/validation/ValidationManagerImpl.java

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.sync;
+package org.briarproject.bramble.sync.validation;
 
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.db.DatabaseComponent;
@@ -18,8 +18,11 @@ import org.briarproject.bramble.api.sync.InvalidMessageException;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageContext;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.ValidationManager;
 import org.briarproject.bramble.api.sync.event.MessageAddedEvent;
+import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
+import org.briarproject.bramble.api.sync.validation.MessageState;
+import org.briarproject.bramble.api.sync.validation.MessageValidator;
+import org.briarproject.bramble.api.sync.validation.ValidationManager;
 import org.briarproject.bramble.api.versioning.ClientMajorVersion;
 
 import java.util.Collection;
@@ -37,9 +40,9 @@ import javax.inject.Inject;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
-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.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.INVALID;
+import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @ThreadSafe
@@ -166,9 +169,9 @@ class ValidationManagerImpl implements ValidationManager, Service,
 				// Check if message is still pending
 				if (db.getMessageState(txn, id) == PENDING) {
 					// Check if dependencies are valid and delivered
-					Map<MessageId, State> states =
+					Map<MessageId, MessageState> states =
 							db.getMessageDependencies(txn, id);
-					for (Entry<MessageId, State> e : states.entrySet()) {
+					for (Entry<MessageId, MessageState> e : states.entrySet()) {
 						if (e.getValue() == INVALID) anyInvalid = true;
 						if (e.getValue() != DELIVERED) allDelivered = false;
 					}
@@ -256,9 +259,9 @@ class ValidationManagerImpl implements ValidationManager, Service,
 				if (!dependencies.isEmpty()) {
 					db.addMessageDependencies(txn, m, dependencies);
 					// Check if dependencies are valid and delivered
-					Map<MessageId, State> states =
+					Map<MessageId, MessageState> states =
 							db.getMessageDependencies(txn, id);
-					for (Entry<MessageId, State> e : states.entrySet()) {
+					for (Entry<MessageId, MessageState> e : states.entrySet()) {
 						if (e.getValue() == INVALID) anyInvalid = true;
 						if (e.getValue() != DELIVERED) allDelivered = false;
 					}
@@ -322,8 +325,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	@DatabaseExecutor
 	private void addPendingDependents(Transaction txn, MessageId m,
 			Queue<MessageId> pending) throws DbException {
-		Map<MessageId, State> states = db.getMessageDependents(txn, m);
-		for (Entry<MessageId, State> e : states.entrySet()) {
+		Map<MessageId, MessageState> states = db.getMessageDependents(txn, m);
+		for (Entry<MessageId, MessageState> e : states.entrySet()) {
 			if (e.getValue() == PENDING) pending.add(e.getKey());
 		}
 	}
@@ -411,8 +414,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	@DatabaseExecutor
 	private void addDependentsToInvalidate(Transaction txn,
 			MessageId m, Queue<MessageId> invalidate) throws DbException {
-		Map<MessageId, State> states = db.getMessageDependents(txn, m);
-		for (Entry<MessageId, State> e : states.entrySet()) {
+		Map<MessageId, MessageState> states = db.getMessageDependents(txn, m);
+		for (Entry<MessageId, MessageState> e : states.entrySet()) {
 			if (e.getValue() != INVALID) invalidate.add(e.getKey());
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/sync/validation/ValidationModule.java

@@ -0,0 +1,53 @@
+package org.briarproject.bramble.sync.validation;
+
+import org.briarproject.bramble.PoliteExecutor;
+import org.briarproject.bramble.api.crypto.CryptoExecutor;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.sync.validation.ValidationManager;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class ValidationModule {
+
+	public static class EagerSingletons {
+		@Inject
+		ValidationManager validationManager;
+	}
+
+	/**
+	 * The maximum number of validation tasks to delegate to the crypto
+	 * executor concurrently.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
+	 */
+	private static final int MAX_CONCURRENT_VALIDATION_TASKS =
+			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
+
+	@Provides
+	@Singleton
+	ValidationManager provideValidationManager(
+			LifecycleManager lifecycleManager, EventBus eventBus,
+			ValidationManagerImpl validationManager) {
+		lifecycleManager.registerService(validationManager);
+		eventBus.addListener(validationManager);
+		return validationManager;
+	}
+
+	@Provides
+	@Singleton
+	@ValidationExecutor
+	Executor provideValidationExecutor(
+			@CryptoExecutor Executor cryptoExecutor) {
+		return new PoliteExecutor("ValidationExecutor", cryptoExecutor,
+				MAX_CONCURRENT_VALIDATION_TASKS);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java

@@ -23,7 +23,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.InvalidMessageException;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.ValidationManager.IncomingMessageHook;
+import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientMajorVersion;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;

bramble-core/src/main/java/org/briarproject/bramble/versioning/VersioningModule.java

@@ -4,7 +4,7 @@ import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.data.MetadataEncoder;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.sync.ValidationManager;
+import org.briarproject.bramble.api.sync.validation.ValidationManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 

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

@@ -64,8 +64,8 @@ import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_LENGTH;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.UNKNOWN;
+import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.api.transport.TransportConstants.REORDERING_WINDOW_SIZE;
 import static org.briarproject.bramble.db.DatabaseConstants.MAX_OFFERED_MESSAGES;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;

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

@@ -11,7 +11,7 @@ import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.ValidationManager.State;
+import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.UTest;
 import org.junit.After;
@@ -33,7 +33,7 @@ import java.util.logging.Logger;
 
 import static java.util.logging.Level.OFF;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
 import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
@@ -565,7 +565,8 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 				for (int k = 0; k < MESSAGES_PER_GROUP; k++) {
 					Message m = getMessage(g.getId());
 					messages.add(m);
-					State state = State.fromValue(random.nextInt(4));
+					MessageState state =
+							MessageState.fromValue(random.nextInt(4));
 					boolean shared = random.nextBoolean();
 					ContactId sender = random.nextBoolean() ? c : null;
 					db.addMessage(txn, m, state, shared, sender);

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

@@ -18,7 +18,7 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
-import org.briarproject.bramble.api.sync.ValidationManager.State;
+import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.KeySet;
@@ -58,10 +58,10 @@ import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
-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.api.sync.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.INVALID;
+import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
+import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.db.DatabaseConstants.DB_SETTINGS_NAMESPACE;
 import static org.briarproject.bramble.db.DatabaseConstants.LAST_COMPACTED_KEY;
 import static org.briarproject.bramble.db.DatabaseConstants.MAX_COMPACTION_INTERVAL_MS;
@@ -1309,7 +1309,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.addMessageDependency(txn, message1, messageId3, PENDING);
 		db.addMessageDependency(txn, message2, messageId4, INVALID);
 
-		Map<MessageId, State> dependencies;
+		Map<MessageId, MessageState> dependencies;
 
 		// Retrieve dependencies for root
 		dependencies = db.getMessageDependencies(txn, messageId);
@@ -1333,7 +1333,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		dependencies = db.getMessageDependencies(txn, messageId4);
 		assertEquals(0, dependencies.size());
 
-		Map<MessageId, State> dependents;
+		Map<MessageId, MessageState> dependents;
 
 		// Root message does not have dependents
 		dependents = db.getMessageDependents(txn, messageId);
@@ -1408,7 +1408,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.addMessageDependency(txn, message, messageId3, PENDING);
 
 		// Retrieve the dependencies for the root
-		Map<MessageId, State> dependencies;
+		Map<MessageId, MessageState> dependencies;
 		dependencies = db.getMessageDependencies(txn, messageId);
 
 		// The cross-group dependency should have state UNKNOWN
@@ -1421,7 +1421,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(DELIVERED, dependencies.get(messageId3));
 
 		// Retrieve the dependents for the message in the second group
-		Map<MessageId, State> dependents;
+		Map<MessageId, MessageState> dependents;
 		dependents = db.getMessageDependents(txn, messageId1);
 
 		// The cross-group dependent should be excluded

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncIntegrationTestComponent.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.sync;
 
 import org.briarproject.bramble.crypto.CryptoModule;
 import org.briarproject.bramble.record.RecordModule;
+import org.briarproject.bramble.sync.validation.ValidationModule;
 import org.briarproject.bramble.system.SystemModule;
 import org.briarproject.bramble.test.TestSecureRandomModule;
 import org.briarproject.bramble.transport.TransportModule;
@@ -17,6 +18,7 @@ import dagger.Component;
 		RecordModule.class,
 		SyncModule.class,
 		SystemModule.class,
+		ValidationModule.class,
 		TransportModule.class
 })
 interface SyncIntegrationTestComponent {

bramble-core/src/test/java/org/briarproject/bramble/sync/validation/ValidationManagerImplTest.java

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.sync;
+package org.briarproject.bramble.sync.validation;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DatabaseComponent;
@@ -13,10 +13,10 @@ import org.briarproject.bramble.api.sync.InvalidMessageException;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageContext;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.ValidationManager.IncomingMessageHook;
-import org.briarproject.bramble.api.sync.ValidationManager.MessageValidator;
-import org.briarproject.bramble.api.sync.ValidationManager.State;
 import org.briarproject.bramble.api.sync.event.MessageAddedEvent;
+import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
+import org.briarproject.bramble.api.sync.validation.MessageState;
+import org.briarproject.bramble.api.sync.validation.MessageValidator;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
 import org.briarproject.bramble.test.ImmediateExecutor;
@@ -32,10 +32,10 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
-import static org.briarproject.bramble.api.sync.ValidationManager.State.DELIVERED;
-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.api.sync.validation.MessageState.DELIVERED;
+import static org.briarproject.bramble.api.sync.validation.MessageState.INVALID;
+import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
+import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.test.TestUtils.getClientId;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
@@ -559,7 +559,7 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 	public void testRecursiveInvalidation() throws Exception {
 		MessageId messageId3 = new MessageId(getRandomId());
 		MessageId messageId4 = new MessageId(getRandomId());
-		Map<MessageId, State> twoDependents = new LinkedHashMap<>();
+		Map<MessageId, MessageState> twoDependents = new LinkedHashMap<>();
 		twoDependents.put(messageId1, PENDING);
 		twoDependents.put(messageId2, PENDING);
 		Transaction txn = new Transaction(null, true);
@@ -643,10 +643,10 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 		Message message4 = getMessage(groupId);
 		MessageId messageId3 = message3.getId();
 		MessageId messageId4 = message4.getId();
-		Map<MessageId, State> twoDependents = new LinkedHashMap<>();
+		Map<MessageId, MessageState> twoDependents = new LinkedHashMap<>();
 		twoDependents.put(messageId1, PENDING);
 		twoDependents.put(messageId2, PENDING);
-		Map<MessageId, State> twoDependencies = new LinkedHashMap<>();
+		Map<MessageId, MessageState> twoDependencies = new LinkedHashMap<>();
 		twoDependencies.put(messageId1, DELIVERED);
 		twoDependencies.put(messageId2, DELIVERED);
 		Transaction txn = new Transaction(null, true);
@@ -765,7 +765,7 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testOnlyReadyPendingDependentsGetDelivered() throws Exception {
-		Map<MessageId, State> twoDependencies = new LinkedHashMap<>();
+		Map<MessageId, MessageState> twoDependencies = new LinkedHashMap<>();
 		twoDependencies.put(messageId, DELIVERED);
 		twoDependencies.put(messageId2, UNKNOWN);
 		Transaction txn = new Transaction(null, true);