Move couple methods from Connection to PooledConnection

Methods `#onError()` and `#hasUnrecoverableErrors()` are only useful in pooled
connection and their implementations threw exceptions in regular connection.
This commit moves them to `PooledConnection` interface.

Author: lutovich

driver/src/main/java/org/neo4j/driver/internal/LeakLoggingNetworkSession.java

@@ -18,7 +18,7 @@
  */
 package org.neo4j.driver.internal;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Logger;
 
 import static java.lang.System.lineSeparator;
@@ -28,7 +28,7 @@ class LeakLoggingNetworkSession extends NetworkSession
     private final Logger log;
     private final String stackTrace;
 
-    LeakLoggingNetworkSession( Connection connection, Logger log )
+    LeakLoggingNetworkSession( PooledConnection connection, Logger log )
     {
         super( connection );
         this.log = log;

driver/src/main/java/org/neo4j/driver/internal/LeakLoggingNetworkSessionFactory.java

@@ -18,7 +18,7 @@
  */
 package org.neo4j.driver.internal;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.v1.Logging;
 import org.neo4j.driver.v1.Session;
@@ -35,7 +35,7 @@ class LeakLoggingNetworkSessionFactory implements SessionFactory
     }
 
     @Override
-    public Session newInstance( Connection connection )
+    public Session newInstance( PooledConnection connection )
     {
         return new LeakLoggingNetworkSession( connection, logger );
     }

driver/src/main/java/org/neo4j/driver/internal/NetworkSession.java

@@ -24,6 +24,7 @@
 
 import org.neo4j.driver.internal.logging.DevNullLogger;
 import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.internal.types.InternalTypeSystem;
 import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.v1.Record;
@@ -41,7 +42,7 @@
 
 public class NetworkSession implements Session
 {
-    private final Connection connection;
+    private final PooledConnection connection;
     private final String sessionId;
     private final Logger logger;
 
@@ -67,7 +68,7 @@ public void run()
     private ExplicitTransaction currentTransaction;
     private AtomicBoolean isOpen = new AtomicBoolean( true );
 
-    public NetworkSession( Connection connection )
+    public NetworkSession( PooledConnection connection )
     {
         this.connection = connection;
 

driver/src/main/java/org/neo4j/driver/internal/NetworkSessionFactory.java

@@ -18,13 +18,13 @@
  */
 package org.neo4j.driver.internal;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Session;
 
 class NetworkSessionFactory implements SessionFactory
 {
     @Override
-    public Session newInstance( Connection connection )
+    public Session newInstance( PooledConnection connection )
     {
         return new NetworkSession( connection );
     }

driver/src/main/java/org/neo4j/driver/internal/RoutingDriver.java

@@ -22,8 +22,8 @@
 import org.neo4j.driver.internal.cluster.RoutingSettings;
 import org.neo4j.driver.internal.net.BoltServerAddress;
 import org.neo4j.driver.internal.security.SecurityPlan;
-import org.neo4j.driver.internal.spi.Connection;
 import org.neo4j.driver.internal.spi.ConnectionPool;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.internal.util.Clock;
 import org.neo4j.driver.v1.AccessMode;
 import org.neo4j.driver.v1.Logging;
@@ -62,11 +62,11 @@ public RoutingDriver(
     @Override
     protected Session newSessionWithMode( AccessMode mode )
     {
-        Connection connection = acquireConnection( mode );
+        PooledConnection connection = acquireConnection( mode );
         return sessionFactory.newInstance( connection );
     }
 
-    private Connection acquireConnection( AccessMode role )
+    private PooledConnection acquireConnection( AccessMode role )
     {
         switch ( role )
         {

driver/src/main/java/org/neo4j/driver/internal/SessionFactory.java

@@ -18,10 +18,10 @@
  */
 package org.neo4j.driver.internal;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Session;
 
 interface SessionFactory
 {
-    Session newInstance( Connection connection );
+    Session newInstance( PooledConnection connection );
 }

driver/src/main/java/org/neo4j/driver/internal/cluster/LoadBalancer.java

@@ -22,7 +22,6 @@
 
 import org.neo4j.driver.internal.RoutingErrorHandler;
 import org.neo4j.driver.internal.net.BoltServerAddress;
-import org.neo4j.driver.internal.spi.Connection;
 import org.neo4j.driver.internal.spi.ConnectionPool;
 import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.internal.util.Clock;
@@ -75,13 +74,13 @@ private LoadBalancer(
         ensureRouting();
     }
 
-    public Connection acquireReadConnection() throws ServiceUnavailableException
+    public PooledConnection acquireReadConnection() throws ServiceUnavailableException
     {
         PooledConnection connection = acquireConnection( routingTable.readers() );
         return new RoutingPooledConnection( connection, this, AccessMode.READ );
     }
 
-    public Connection acquireWriteConnection() throws ServiceUnavailableException
+    public PooledConnection acquireWriteConnection() throws ServiceUnavailableException
     {
         PooledConnection connection = acquireConnection( routingTable.writers() );
         return new RoutingPooledConnection( connection, this, AccessMode.WRITE );

driver/src/main/java/org/neo4j/driver/internal/net/ConcurrencyGuardingConnection.java

@@ -185,18 +185,6 @@ public boolean isOpen()
         return delegate.isOpen();
     }
 
-    @Override
-    public void onError( Runnable runnable )
-    {
-        delegate.onError( runnable );
-    }
-
-    @Override
-    public boolean hasUnrecoverableErrors()
-    {
-        return delegate.hasUnrecoverableErrors();
-    }
-
     @Override
     public void resetAsync()
     {

driver/src/main/java/org/neo4j/driver/internal/net/SocketConnection.java

@@ -268,18 +268,6 @@ public boolean isOpen()
         return socket.isOpen();
     }
 
-    @Override
-    public void onError( Runnable runnable )
-    {
-        throw new UnsupportedOperationException( "Error subscribers are not supported on SocketConnection." );
-    }
-
-    @Override
-    public boolean hasUnrecoverableErrors()
-    {
-        throw new UnsupportedOperationException( "Unrecoverable error detection is not supported on SocketConnection." );
-    }
-
     @Override
     public synchronized void resetAsync()
     {

driver/src/main/java/org/neo4j/driver/internal/spi/Connection.java

@@ -98,18 +98,6 @@ public interface Connection extends AutoCloseable
      */
     boolean isOpen();
 
-    /**
-     * If there are any errors that occur on this connection, invoke the given
-     * runnable. This is used in the driver to clean up resources associated with
-     * the connection, like an open transaction.
-     *
-     * @param runnable To be run on error.
-     */
-    void onError( Runnable runnable );
-
-
-    boolean hasUnrecoverableErrors();
-
     /**
      * Asynchronously sending reset to the socket output channel.
      */

driver/src/main/java/org/neo4j/driver/internal/spi/PooledConnection.java

@@ -18,9 +18,36 @@
  */
 package org.neo4j.driver.internal.spi;
 
+import org.neo4j.driver.internal.util.Clock;
+
 public interface PooledConnection extends Connection
 {
+    /**
+     * If there are any errors that occur on this connection, invoke the given
+     * runnable. This is used in the driver to clean up resources associated with
+     * the connection, like an open transaction.
+     *
+     * @param runnable To be run on error.
+     */
+    void onError( Runnable runnable );
+
+    /**
+     * Check if this connection experienced any unrecoverable errors. Connections with unrecoverable errors should be
+     * closed and not returned to the pool for future reuse.
+     *
+     * @return {@code true} if any unrecoverable error happened, {@code false} otherwise.
+     */
+    boolean hasUnrecoverableErrors();
+
+    /**
+     * Timestamp of when this connection was used. This timestamp is updated when connection is returned to the pool.
+     *
+     * @return timestamp as returned by {@link Clock#millis()}.
+     */
     long lastUsedTimestamp();
 
+    /**
+     * Destroy this connection and associated network resources.
+     */
     void dispose();
 }

driver/src/test/java/org/neo4j/driver/internal/LeakLoggingNetworkSessionFactoryTest.java

@@ -20,7 +20,7 @@
 
 import org.junit.Test;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Logging;
 import org.neo4j.driver.v1.Session;
 
@@ -35,7 +35,7 @@ public void createsLeakLoggingNetworkSessions()
     {
         SessionFactory factory = new LeakLoggingNetworkSessionFactory( mock( Logging.class ) );
 
-        Session session = factory.newInstance( mock( Connection.class ) );
+        Session session = factory.newInstance( mock( PooledConnection.class ) );
 
         assertThat( session, instanceOf( LeakLoggingNetworkSession.class ) );
     }

driver/src/test/java/org/neo4j/driver/internal/LeakLoggingNetworkSessionTest.java

@@ -25,7 +25,7 @@
 
 import java.lang.reflect.Method;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.v1.Session;
 
@@ -83,9 +83,9 @@ private static void finalize( Session session ) throws Exception
         finalizeMethod.invoke( session );
     }
 
-    private static Connection connectionMock( boolean open )
+    private static PooledConnection connectionMock( boolean open )
     {
-        Connection connection = mock( Connection.class );
+        PooledConnection connection = mock( PooledConnection.class );
         when( connection.isOpen() ).thenReturn( open );
         return connection;
     }

driver/src/test/java/org/neo4j/driver/internal/NetworkSessionFactoryTest.java

@@ -20,7 +20,7 @@
 
 import org.junit.Test;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Session;
 
 import static org.hamcrest.Matchers.instanceOf;
@@ -34,7 +34,7 @@ public void createsNetworkSessions()
     {
         SessionFactory factory = new NetworkSessionFactory();
 
-        Session session = factory.newInstance( mock( Connection.class ) );
+        Session session = factory.newInstance( mock( PooledConnection.class ) );
 
         assertThat( session, instanceOf( NetworkSession.class ) );
     }

driver/src/test/java/org/neo4j/driver/internal/NetworkSessionTest.java

@@ -22,7 +22,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import org.neo4j.driver.internal.spi.Connection;
+import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.v1.Transaction;
 import org.neo4j.driver.v1.exceptions.ClientException;
 import org.neo4j.driver.v1.exceptions.ServiceUnavailableException;
@@ -40,8 +40,8 @@ public class NetworkSessionTest
     @Rule
     public ExpectedException exception = ExpectedException.none();
 
-    private final Connection mock = mock( Connection.class );
-    private NetworkSession sess = new NetworkSession( mock );
+    private final PooledConnection mock = mock( PooledConnection.class );
+    private final NetworkSession sess = new NetworkSession( mock );
 
     @Test
     public void shouldSendAllOnRun() throws Throwable
@@ -143,7 +143,7 @@ public void shouldNotAllowMoreTransactionsInSessionWhileConnectionClosed() throw
     public void shouldGetExceptionIfTryingToCloseSessionMoreThanOnce() throws Throwable
     {
         // Given
-        NetworkSession sess = new NetworkSession( mock(Connection.class) );
+        NetworkSession sess = new NetworkSession( mock( PooledConnection.class ) );
         try
         {
             sess.close();

driver/src/test/java/org/neo4j/driver/internal/RoutingDriverTest.java

@@ -32,7 +32,6 @@
 import org.neo4j.driver.internal.cluster.RoutingSettings;
 import org.neo4j.driver.internal.net.BoltServerAddress;
 import org.neo4j.driver.internal.spi.Collector;
-import org.neo4j.driver.internal.spi.Connection;
 import org.neo4j.driver.internal.spi.ConnectionPool;
 import org.neo4j.driver.internal.spi.PooledConnection;
 import org.neo4j.driver.internal.util.FakeClock;
@@ -425,7 +424,7 @@ void collect( Collector collector )
     private static class NetworkSessionWithAddressFactory implements SessionFactory
     {
         @Override
-        public Session newInstance( Connection connection )
+        public Session newInstance( PooledConnection connection )
         {
             return new NetworkSessionWithAddress( connection );
         }
@@ -435,7 +434,7 @@ private static class NetworkSessionWithAddress extends NetworkSession
     {
         final BoltServerAddress address;
 
-        NetworkSessionWithAddress( Connection connection )
+        NetworkSessionWithAddress( PooledConnection connection )
         {
             super( connection );
             this.address = connection.boltServerAddress();

driver/src/test/java/org/neo4j/driver/internal/cluster/LoadBalancerTest.java

@@ -160,7 +160,7 @@ public void shouldForgetAddressAndItsConnectionsOnServiceUnavailableWhileClosing
         BoltServerAddress address = new BoltServerAddress( "host", 42 );
 
         PooledConnection connection = newConnectionWithFailingSync( address );
-        Connection routingConnection = new RoutingPooledConnection( connection, loadBalancer, AccessMode.WRITE );
+        PooledConnection routingConnection = new RoutingPooledConnection( connection, loadBalancer, AccessMode.WRITE );
         NetworkSession session = new NetworkSession( routingConnection );
 
         assertThrowsSessionExpiredException( session );