Connections now use two separate threads for writing and listening

- this should avoid dead locks, specifically when connecting to Jabit :/
- also, Java 8 features are now allowed in modules not needed by Android clients

demo/build.gradle

@@ -14,6 +14,8 @@ uploadArchives {
     }
 }
 
+sourceCompatibility = 1.8
+
 task fatCapsule(type: FatCapsule) {
     applicationClass 'ch.dissem.bitmessage.demo.Main'
 }

demo/src/main/java/ch/dissem/bitmessage/demo/Application.java

@@ -52,7 +52,7 @@ public class Application {
                 .messageRepo(new JdbcMessageRepository(jdbcConfig))
                 .networkHandler(new DefaultNetworkHandler())
                 .security(new BouncySecurity())
-//                .port(48444)
+                .port(48444)
                 .listener(new BitmessageContext.Listener() {
                     @Override
                     public void receive(Plaintext plaintext) {

domain/src/main/java/ch/dissem/bitmessage/factory/Factory.java

@@ -23,7 +23,6 @@ import ch.dissem.bitmessage.entity.Plaintext;
 import ch.dissem.bitmessage.entity.payload.*;
 import ch.dissem.bitmessage.entity.valueobject.PrivateKey;
 import ch.dissem.bitmessage.exception.NodeException;
-import ch.dissem.bitmessage.ports.Security;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -155,7 +154,7 @@ public class Factory {
             }
         }
         // fallback: just store the message - we don't really care what it is
-//        LOG.info("Unexpected object type: " + objectType);
+        LOG.trace("Unexpected object type: " + objectType);
         return GenericPayload.read(version, stream, streamNumber, length);
     }
 

domain/src/main/java/ch/dissem/bitmessage/ports/Inventory.java

@@ -26,17 +26,32 @@ import java.util.List;
  * The Inventory stores and retrieves objects, cleans up outdated objects and can tell which objects are still missing.
  */
 public interface Inventory {
+    /**
+     * Returns the IVs of all valid objects we have for the given streams
+     */
     List<InventoryVector> getInventory(long... streams);
 
+    /**
+     * Returns the IVs of all objects in the offer that we don't have already. Implementations are allowed to
+     * ignore the streams parameter, but it must be set when calling this method.
+     */
     List<InventoryVector> getMissing(List<InventoryVector> offer, long... streams);
 
     ObjectMessage getObject(InventoryVector vector);
 
+    /**
+     * This method is mainly used to search for public keys to newly added addresses or broadcasts from new
+     * subscriptions.
+     */
     List<ObjectMessage> getObjects(long stream, long version, ObjectType... types);
 
     void storeObject(ObjectMessage object);
 
     boolean contains(ObjectMessage object);
 
+    /**
+     * Deletes all objects that expired 5 minutes ago or earlier
+     * (so we don't accidentally request objects we just deleted)
+     */
     void cleanup();
 }

domain/src/main/resources/nodes.txt

@@ -12,7 +12,6 @@
 109.147.204.113:1195
 178.11.46.221:8444
 
-# Add named nodes at the end, as resolving them might take time
 dissem.ch:8444
 
 [stream 2]

networking/src/main/java/ch/dissem/bitmessage/networking/Connection.java

@@ -49,7 +49,7 @@ import static ch.dissem.bitmessage.utils.UnixTime.MINUTE;
 /**
  * A connection to a specific node
  */
-public class Connection implements Runnable {
+public class Connection {
     public static final int READ_TIMEOUT = 2000;
     private final static Logger LOG = LoggerFactory.getLogger(Connection.class);
     private static final int CONNECT_TIMEOUT = 5000;
@@ -63,13 +63,16 @@ public class Connection implements Runnable {
     private final Queue<MessagePayload> sendingQueue = new ConcurrentLinkedDeque<>();
     private final Map<InventoryVector, Long> requestedObjects;
     private final long syncTimeout;
+    private final ReaderRunnable reader = new ReaderRunnable();
+    private final WriterRunnable writer = new WriterRunnable();
 
-    private State state;
+    private volatile State state;
     private InputStream in;
     private OutputStream out;
     private int version;
     private long[] streams;
     private int readTimeoutCounter;
+    private boolean socketInitialized;
 
     public Connection(InternalContext context, Mode mode, Socket socket, MessageListener listener,
                       ConcurrentMap<InventoryVector, Long> requestedObjectsMap) throws IOException {
@@ -118,86 +121,6 @@ public class Connection implements Runnable {
         return node;
     }
 
-    @Override
-    public void run() {
-        try (Socket socket = this.socket) {
-            if (!socket.isConnected()) {
-                LOG.debug("Trying to connect to node " + node);
-                socket.connect(new InetSocketAddress(node.toInetAddress(), node.getPort()), CONNECT_TIMEOUT);
-            }
-            socket.setSoTimeout(READ_TIMEOUT);
-            this.in = socket.getInputStream();
-            this.out = socket.getOutputStream();
-            if (mode == CLIENT) {
-                send(new Version.Builder().defaults().addrFrom(host).addrRecv(node).build());
-            }
-            while (state != DISCONNECTED) {
-                try {
-                    NetworkMessage msg = Factory.getNetworkMessage(version, in);
-                    if (msg == null)
-                        continue;
-                    switch (state) {
-                        case ACTIVE:
-                            receiveMessage(msg.getPayload());
-                            sendQueue();
-                            break;
-
-                        default:
-                            switch (msg.getPayload().getCommand()) {
-                                case VERSION:
-                                    Version payload = (Version) msg.getPayload();
-                                    if (payload.getNonce() == ctx.getClientNonce()) {
-                                        LOG.info("Tried to connect to self, disconnecting.");
-                                        disconnect();
-                                    } else if (payload.getVersion() >= BitmessageContext.CURRENT_VERSION) {
-                                        this.version = payload.getVersion();
-                                        this.streams = payload.getStreams();
-                                        send(new VerAck());
-                                        switch (mode) {
-                                            case SERVER:
-                                                send(new Version.Builder().defaults().addrFrom(host).addrRecv(node).build());
-                                                break;
-                                            case CLIENT:
-                                                activateConnection();
-                                                break;
-                                        }
-                                    } else {
-                                        LOG.info("Received unsupported version " + payload.getVersion() + ", disconnecting.");
-                                        disconnect();
-                                    }
-                                    break;
-                                case VERACK:
-                                    switch (mode) {
-                                        case SERVER:
-                                            activateConnection();
-                                            break;
-                                        case CLIENT:
-                                            // NO OP
-                                            break;
-                                    }
-                                    break;
-                                default:
-                                    throw new NodeException("Command 'version' or 'verack' expected, but was '"
-                                            + msg.getPayload().getCommand() + "'");
-                            }
-                    }
-                    if (socket.isClosed() || syncFinished(msg)) disconnect();
-                } catch (SocketTimeoutException ignore) {
-                    if (state == ACTIVE) {
-                        sendQueue();
-                        if (syncFinished(null)) disconnect();
-                    }
-                }
-            }
-        } catch (IOException | NodeException e) {
-            disconnect();
-            LOG.debug("Disconnected from node " + node + ": " + e.getMessage());
-        } catch (RuntimeException e) {
-            disconnect();
-            throw e;
-        }
-    }
-
     @SuppressWarnings("RedundantIfStatement")
     private boolean syncFinished(NetworkMessage msg) {
         if (syncTimeout == 0 || state != ACTIVE) {
@@ -229,15 +152,6 @@ public class Connection implements Runnable {
         ctx.getNodeRegistry().offerAddresses(Collections.singletonList(node));
     }
 
-    private void sendQueue() {
-        if (sendingQueue.size() > 0) {
-            LOG.debug("Sending " + sendingQueue.size() + " messages to node " + node);
-        }
-        for (MessagePayload msg = sendingQueue.poll(); msg != null; msg = sendingQueue.poll()) {
-            send(msg);
-        }
-    }
-
     private void cleanupIvCache() {
         Long fiveMinutesAgo = UnixTime.now(-5 * MINUTE);
         for (Map.Entry<InventoryVector, Long> entry : ivCache.entrySet()) {
@@ -310,10 +224,12 @@ public class Connection implements Runnable {
             case OBJECT:
                 ObjectMessage objectMessage = (ObjectMessage) messagePayload;
                 try {
+                    if (ctx.getInventory().contains(objectMessage)) {
+                        LOG.debug("Received object " + objectMessage.getInventoryVector() + " - already in inventory");
+                        break;
+                    }
                     LOG.debug("Received object " + objectMessage.getInventoryVector());
                     security().checkProofOfWork(objectMessage, ctx.getNetworkNonceTrialsPerByte(), ctx.getNetworkExtraBytes());
-                    if (ctx.getInventory().contains(objectMessage))
-                        break;
                     listener.receive(objectMessage);
                     ctx.getInventory().storeObject(objectMessage);
                     // offer object to some random nodes so it gets distributed throughout the network:
@@ -392,14 +308,136 @@ public class Connection implements Runnable {
         return Objects.hash(node);
     }
 
-    public void request(InventoryVector key) {
+    private synchronized void initSocket(Socket socket) throws IOException {
-        sendingQueue.offer(new GetData.Builder()
+        if (!socketInitialized) {
-                        .addInventoryVector(key)
+            if (!socket.isConnected()) {
-                        .build()
+                LOG.debug("Trying to connect to node " + node);
-        );
+                socket.connect(new InetSocketAddress(node.toInetAddress(), node.getPort()), CONNECT_TIMEOUT);
+            }
+            socket.setSoTimeout(READ_TIMEOUT);
+            in = socket.getInputStream();
+            out = socket.getOutputStream();
+            if (!socket.isConnected()) {
+                LOG.debug("Trying to connect to node " + node);
+                socket.connect(new InetSocketAddress(node.toInetAddress(), node.getPort()), CONNECT_TIMEOUT);
+            }
+            socket.setSoTimeout(READ_TIMEOUT);
+            in = socket.getInputStream();
+            out = socket.getOutputStream();
+            socketInitialized = true;
+        }
+    }
+
+    public ReaderRunnable getReader() {
+        return reader;
+    }
+
+    public WriterRunnable getWriter() {
+        return writer;
     }
 
     public enum Mode {SERVER, CLIENT}
 
     public enum State {CONNECTING, ACTIVE, DISCONNECTED}
+
+    public class ReaderRunnable implements Runnable {
+        @Override
+        public void run() {
+            try (Socket socket = Connection.this.socket) {
+                initSocket(socket);
+                if (mode == CLIENT) {
+                    send(new Version.Builder().defaults().addrFrom(host).addrRecv(node).build());
+                }
+                while (state != DISCONNECTED) {
+                    try {
+                        NetworkMessage msg = Factory.getNetworkMessage(version, in);
+                        if (msg == null)
+                            continue;
+                        switch (state) {
+                            case ACTIVE:
+                                receiveMessage(msg.getPayload());
+                                break;
+
+                            default:
+                                switch (msg.getPayload().getCommand()) {
+                                    case VERSION:
+                                        Version payload = (Version) msg.getPayload();
+                                        if (payload.getNonce() == ctx.getClientNonce()) {
+                                            LOG.info("Tried to connect to self, disconnecting.");
+                                            disconnect();
+                                        } else if (payload.getVersion() >= BitmessageContext.CURRENT_VERSION) {
+                                            version = payload.getVersion();
+                                            streams = payload.getStreams();
+                                            send(new VerAck());
+                                            switch (mode) {
+                                                case SERVER:
+                                                    send(new Version.Builder().defaults().addrFrom(host).addrRecv(node).build());
+                                                    break;
+                                                case CLIENT:
+                                                    activateConnection();
+                                                    break;
+                                            }
+                                        } else {
+                                            LOG.info("Received unsupported version " + payload.getVersion() + ", disconnecting.");
+                                            disconnect();
+                                        }
+                                        break;
+                                    case VERACK:
+                                        switch (mode) {
+                                            case SERVER:
+                                                activateConnection();
+                                                break;
+                                            case CLIENT:
+                                                // NO OP
+                                                break;
+                                        }
+                                        break;
+                                    default:
+                                        throw new NodeException("Command 'version' or 'verack' expected, but was '"
+                                                + msg.getPayload().getCommand() + "'");
+                                }
+                        }
+                        if (socket.isClosed() || syncFinished(msg)) disconnect();
+                    } catch (SocketTimeoutException ignore) {
+                        if (state == ACTIVE) {
+                            if (syncFinished(null)) disconnect();
+                        }
+                    }
+                    Thread.yield();
+                }
+            } catch (IOException | NodeException e) {
+                disconnect();
+                LOG.debug("Reader disconnected from node " + node + ": " + e.getMessage());
+            } catch (RuntimeException e) {
+                LOG.debug("Reader disconnecting from node " + node + " due to error: " + e.getMessage(), e);
+                disconnect();
+            } finally {
+                try {
+                    socket.close();
+                } catch (Exception e) {
+                    LOG.debug(e.getMessage(), e);
+                }
+            }
+        }
+    }
+
+    public class WriterRunnable implements Runnable {
+        @Override
+        public void run() {
+            try (Socket socket = Connection.this.socket) {
+                initSocket(socket);
+                while (state != DISCONNECTED) {
+                    if (sendingQueue.size() > 0) {
+                        LOG.debug("Sending " + sendingQueue.size() + " messages to node " + node);
+                        send(sendingQueue.poll());
+                    } else {
+                        Thread.sleep(100);
+                    }
+                }
+            } catch (IOException | InterruptedException e) {
+                LOG.debug("Writer disconnected from node " + node + ": " + e.getMessage());
+                disconnect();
+            }
+        }
+    }
 }

networking/src/main/java/ch/dissem/bitmessage/networking/DefaultNetworkHandler.java

@@ -49,14 +49,17 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
     public final static int NETWORK_MAGIC_NUMBER = 8;
     private final static Logger LOG = LoggerFactory.getLogger(DefaultNetworkHandler.class);
     private final List<Connection> connections = new LinkedList<>();
+    private final ExecutorService pool;
     private InternalContext ctx;
     private ServerSocket serverSocket;
-    private ExecutorService pool;
+    private volatile boolean running;
-    private Thread serverThread;
-    private Thread connectionManager;
 
     private ConcurrentMap<InventoryVector, Long> requestedObjects = new ConcurrentHashMap<>();
 
+    public DefaultNetworkHandler() {
+        pool = Executors.newCachedThreadPool();
+    }
+
     @Override
     public void setContext(InternalContext context) {
         this.ctx = context;
@@ -65,9 +68,12 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
     @Override
     public Thread synchronize(InetAddress trustedHost, int port, MessageListener listener, long timeoutInSeconds) {
         try {
-            Thread t = new Thread(Connection.sync(ctx, trustedHost, port, listener, timeoutInSeconds));
+            Connection connection = Connection.sync(ctx, trustedHost, port, listener, timeoutInSeconds);
-            t.start();
+            Thread tr = new Thread(connection.getReader());
-            return t;
+            Thread tw = new Thread(connection.getWriter());
+            tr.start();
+            tw.start();
+            return tr;
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
@@ -78,14 +84,14 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
         if (listener == null) {
             throw new IllegalStateException("Listener must be set at start");
         }
-        if (pool != null && !pool.isShutdown()) {
+        if (running) {
             throw new IllegalStateException("Network already running - you need to stop first.");
         }
         try {
-            pool = Executors.newCachedThreadPool();
+            running = true;
             connections.clear();
             serverSocket = new ServerSocket(ctx.getPort());
-            serverThread = new Thread(new Runnable() {
+            pool.execute(new Runnable() {
                 @Override
                 public void run() {
                     while (!serverSocket.isClosed()) {
@@ -98,44 +104,46 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
                         }
                     }
                 }
-            }, "server");
+            });
-            serverThread.start();
+            pool.execute(new Runnable() {
-            connectionManager = new Thread(new Runnable() {
                 @Override
                 public void run() {
-                    while (!Thread.interrupted()) {
+                    try {
-                        try {
+                        while (running) {
-                            int active = 0;
+                            try {
-                            synchronized (connections) {
+                                int active = 0;
-                                for (Iterator<Connection> iterator = connections.iterator(); iterator.hasNext(); ) {
+                                synchronized (connections) {
-                                    Connection c = iterator.next();
+                                    for (Iterator<Connection> iterator = connections.iterator(); iterator.hasNext(); ) {
-                                    if (c.getState() == DISCONNECTED) {
+                                        Connection c = iterator.next();
-                                        // Remove the current element from the iterator and the list.
+                                        if (c.getState() == DISCONNECTED) {
-                                        iterator.remove();
+                                            // Remove the current element from the iterator and the list.
-                                    }
+                                            iterator.remove();
-                                    if (c.getState() == ACTIVE) {
+                                        }
-                                        active++;
+                                        if (c.getState() == ACTIVE) {
+                                            active++;
+                                        }
                                     }
                                 }
-                            }
+                                if (active < NETWORK_MAGIC_NUMBER) {
-                            if (active < NETWORK_MAGIC_NUMBER) {
+                                    List<NetworkAddress> addresses = ctx.getNodeRegistry().getKnownAddresses(
-                                List<NetworkAddress> addresses = ctx.getNodeRegistry().getKnownAddresses(
+                                            NETWORK_MAGIC_NUMBER - active, ctx.getStreams());
-                                        NETWORK_MAGIC_NUMBER - active, ctx.getStreams());
+                                    for (NetworkAddress address : addresses) {
-                                for (NetworkAddress address : addresses) {
+                                        startConnection(new Connection(ctx, CLIENT, address, listener, requestedObjects));
-                                    startConnection(new Connection(ctx, CLIENT, address, listener, requestedObjects));
+                                    }
                                 }
+                                Thread.sleep(30000);
+                            } catch (InterruptedException e) {
+                                running = false;
+                            } catch (Exception e) {
+                                LOG.error("Error in connection manager. Ignored.", e);
                             }
-                            Thread.sleep(30000);
-                        } catch (InterruptedException e) {
-                            Thread.currentThread().interrupt();
-                        } catch (Exception e) {
-                            LOG.error("Error in connection manager. Ignored.", e);
                         }
+                    } finally {
+                        LOG.debug("Connection manager shutting down.");
+                        running = false;
                     }
-                    LOG.debug("Connection manager shutting down.");
                 }
-            }, "connection-manager");
+            });
-            connectionManager.start();
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
@@ -143,18 +151,17 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
 
     @Override
     public boolean isRunning() {
-        return connectionManager != null && connectionManager.isAlive();
+        return running;
     }
 
     @Override
     public void stop() {
-        connectionManager.interrupt();
+        running = false;
         try {
             serverSocket.close();
         } catch (IOException e) {
             LOG.debug(e.getMessage(), e);
         }
-        pool.shutdown();
         synchronized (connections) {
             for (Connection c : connections) {
                 c.disconnect();
@@ -170,7 +177,8 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
             }
             connections.add(c);
         }
-        pool.execute(c);
+        pool.execute(c.getReader());
+        pool.execute(c.getWriter());
     }
 
     @Override
@@ -222,8 +230,7 @@ public class DefaultNetworkHandler implements NetworkHandler, ContextHolder {
             i++;
         }
         return new Property("network", null,
-                new Property("connectionManager",
+                new Property("connectionManager", running ? "running" : "stopped"),
-                        connectionManager != null && connectionManager.isAlive() ? "running" : "stopped"),
                 new Property("connections", null, streamProperties)
         );
     }

repositories/build.gradle

@@ -10,6 +10,8 @@ uploadArchives {
     }
 }
 
+sourceCompatibility = 1.8
+
 dependencies {
     compile project(':domain')
     compile 'org.flywaydb:flyway-core:3.2.1'

repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcInventory.java

@@ -27,12 +27,17 @@ import org.slf4j.LoggerFactory;
 import java.sql.*;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
+import static ch.dissem.bitmessage.utils.UnixTime.MINUTE;
 import static ch.dissem.bitmessage.utils.UnixTime.now;
 
 public class JdbcInventory extends JdbcHelper implements Inventory {
     private static final Logger LOG = LoggerFactory.getLogger(JdbcInventory.class);
 
+    private final Map<Long, Map<InventoryVector, Long>> cache = new ConcurrentHashMap<>();
+
     public JdbcInventory(JdbcConfig config) {
         super(config);
     }
@@ -40,36 +45,43 @@ public class JdbcInventory extends JdbcHelper implements Inventory {
     @Override
     public List<InventoryVector> getInventory(long... streams) {
         List<InventoryVector> result = new LinkedList<>();
-        try (Connection connection = config.getConnection()) {
+        for (long stream : streams) {
-            Statement stmt = connection.createStatement();
+            getCache(stream).entrySet().stream()
-            ResultSet rs = stmt.executeQuery("SELECT hash FROM Inventory WHERE expires > " + now() +
+                    .filter(e -> e.getValue() > now())
-                    " AND stream IN (" + join(streams) + ")");
+                    .forEach(e -> result.add(e.getKey()));
-            while (rs.next()) {
-                result.add(new InventoryVector(rs.getBytes("hash")));
-            }
-        } catch (SQLException e) {
-            LOG.error(e.getMessage(), e);
         }
         return result;
     }
 
-    private List<InventoryVector> getFullInventory(long... streams) {
+    private Map<InventoryVector, Long> getCache(long stream) {
-        List<InventoryVector> result = new LinkedList<>();
+        Map<InventoryVector, Long> result = cache.get(stream);
-        try (Connection connection = config.getConnection()) {
+        if (result == null) {
-            Statement stmt = connection.createStatement();
+            synchronized (cache) {
-            ResultSet rs = stmt.executeQuery("SELECT hash FROM Inventory WHERE stream IN (" + join(streams) + ")");
+                if (cache.get(stream) == null) {
-            while (rs.next()) {
+                    result = new ConcurrentHashMap<>();
-                result.add(new InventoryVector(rs.getBytes("hash")));
+                    cache.put(stream, result);
+
+                    try (Connection connection = config.getConnection()) {
+                        Statement stmt = connection.createStatement();
+                        ResultSet rs = stmt.executeQuery("SELECT hash, expires FROM Inventory WHERE expires > "
+                                + now(-5 * MINUTE) + " AND stream = " + stream);
+                        while (rs.next()) {
+                            result.put(new InventoryVector(rs.getBytes("hash")), rs.getLong("expires"));
+                        }
+                    } catch (SQLException e) {
+                        LOG.error(e.getMessage(), e);
+                    }
+                }
             }
-        } catch (SQLException e) {
-            LOG.error(e.getMessage(), e);
         }
         return result;
     }
 
     @Override
     public List<InventoryVector> getMissing(List<InventoryVector> offer, long... streams) {
-        offer.removeAll(getFullInventory(streams));
+        for (long stream : streams) {
+            getCache(stream).forEach((iv, t) -> offer.remove(iv));
+        }
         return offer;
     }
 
@@ -131,6 +143,7 @@ public class JdbcInventory extends JdbcHelper implements Inventory {
             ps.setLong(5, object.getType());
             ps.setLong(6, object.getVersion());
             ps.executeUpdate();
+            getCache(object.getStream()).put(iv, object.getExpiresTime());
         } catch (SQLException e) {
             LOG.debug("Error storing object of type " + object.getPayload().getClass().getSimpleName(), e);
         } catch (Exception e) {
@@ -140,28 +153,19 @@ public class JdbcInventory extends JdbcHelper implements Inventory {
 
     @Override
     public boolean contains(ObjectMessage object) {
-        try (Connection connection = config.getConnection()) {
+        return getCache(object.getStream()).entrySet().stream()
-            Statement stmt = connection.createStatement();
+                .anyMatch(x -> x.getKey().equals(object.getInventoryVector()));
-            ResultSet rs = stmt.executeQuery("SELECT count(1) FROM Inventory WHERE hash = X'"
-                    + object.getInventoryVector() + "'");
-            if (rs.next()) {
-                return rs.getInt(1) > 0;
-            } else {
-                throw new RuntimeException("Couldn't query if inventory contains " + object.getInventoryVector());
-            }
-        } catch (Exception e) {
-            LOG.error(e.getMessage(), e);
-            throw new RuntimeException(e);
-        }
     }
 
     @Override
     public void cleanup() {
         try (Connection connection = config.getConnection()) {
-            // We delete only objects that expired 5 minutes ago or earlier, so we don't request objects we just deleted
+            connection.createStatement().executeUpdate("DELETE FROM Inventory WHERE expires < " + now(-5 * MINUTE));
-            connection.createStatement().executeUpdate("DELETE FROM Inventory WHERE expires < " + (now() - 300));
         } catch (SQLException e) {
             LOG.debug(e.getMessage(), e);
         }
+        for (Map<InventoryVector, Long> c : cache.values()) {
+            c.entrySet().removeIf(e -> e.getValue() < now(-5 * MINUTE));
+        }
     }
 }