Package py4j

Class CallbackClient

java.lang.Object
py4j.CallbackClient
All Implemented Interfaces:
Py4JPythonClient
Direct Known Subclasses:
PythonClient

public class CallbackClient extends Object implements Py4JPythonClient

A CallbackClient is responsible for managing communication channels: channels are created as needed (e.g., one per concurrent thread) and are closed after a certain time.

Author:
Barthelemy Dagenais
  • Field Details

    • DEFAULT_ADDRESS

      public static final String DEFAULT_ADDRESS
      See Also:
    • port

      protected final int port
    • address

      protected final InetAddress address
    • socketFactory

      protected final SocketFactory socketFactory
    • connections

      protected final Deque<Py4JClientConnection> connections
    • lock

      protected final Lock lock
    • DEFAULT_MIN_CONNECTION_TIME

      public static final long DEFAULT_MIN_CONNECTION_TIME
      See Also:
    • DEFAULT_MIN_CONNECTION_TIME_UNIT

      public static final TimeUnit DEFAULT_MIN_CONNECTION_TIME_UNIT
    • minConnectionTime

      protected final long minConnectionTime
    • minConnectionTimeUnit

      protected final TimeUnit minConnectionTimeUnit
    • enableMemoryManagement

      protected final boolean enableMemoryManagement
    • readTimeout

      protected final int readTimeout
    • authToken

      protected final String authToken
  • Constructor Details

    • CallbackClient

      public CallbackClient(int port)
    • CallbackClient

      public CallbackClient(int port, InetAddress address)
    • CallbackClient

      public CallbackClient(int port, InetAddress address, String authToken)
    • CallbackClient

      public CallbackClient(int port, InetAddress address, long minConnectionTime, TimeUnit minConnectionTimeUnit)
    • CallbackClient

      public CallbackClient(int port, InetAddress address, long minConnectionTime, TimeUnit minConnectionTimeUnit, SocketFactory socketFactory)
      Parameters:
      port - The port used by channels to connect to the Python side.
      address - The addressed used by channels to connect to the Python side..
      minConnectionTime - The minimum connection time: channels are guaranteed to stay connected for this time after sending a command.
      minConnectionTimeUnit - The minimum coonnection time unit.
      socketFactory - The non-null factory to make Sockets.
    • CallbackClient

      public CallbackClient(int port, InetAddress address, long minConnectionTime, TimeUnit minConnectionTimeUnit, SocketFactory socketFactory, boolean enableMemoryManagement)
      Parameters:
      port - The port used by channels to connect to the Python side.
      address - The addressed used by channels to connect to the Python side..
      minConnectionTime - The minimum connection time: channels are guaranteed to stay connected for this time after sending a command.
      minConnectionTimeUnit - The minimum coonnection time unit.
      socketFactory - The non-null factory to make Sockets.
      enableMemoryManagement - If False, we do not send tell the Python side when a PythonProxy is no longer used by the Java side.
    • CallbackClient

      public CallbackClient(int port, InetAddress address, long minConnectionTime, TimeUnit minConnectionTimeUnit, SocketFactory socketFactory, boolean enableMemoryManagement, int readTimeout)
      Parameters:
      port - The port used by channels to connect to the Python side.
      address - The addressed used by channels to connect to the Python side..
      minConnectionTime - The minimum connection time: channels are guaranteed to stay connected for this time after sending a command.
      minConnectionTimeUnit - The minimum coonnection time unit.
      socketFactory - The non-null factory to make Sockets.
      enableMemoryManagement - If False, we do not send tell the Python side when a PythonProxy is no longer used by the Java side.
      readTimeout - Time in milliseconds (0 = infinite). Once a Python program is connected, if a GatewayServer does not receive a request (e.g., a method call) after this time, the connection with the Python program is closed.
    • CallbackClient

      public CallbackClient(int port, InetAddress address, String authToken, long minConnectionTime, TimeUnit minConnectionTimeUnit, SocketFactory socketFactory, boolean enableMemoryManagement, int readTimeout)
      Parameters:
      port - The port used by channels to connect to the Python side.
      address - The addressed used by channels to connect to the Python side.
      authToken - Token for authenticating with the callback server.
      minConnectionTime - The minimum connection time: channels are guaranteed to stay connected for this time after sending a command.
      minConnectionTimeUnit - The minimum coonnection time unit.
      socketFactory - The non-null factory to make Sockets.
      enableMemoryManagement - If False, we do not send tell the Python side when a PythonProxy is no longer used by the Java side.
      readTimeout - Time in milliseconds (0 = infinite). Once a Python program is connected, if a GatewayServer does not receive a request (e.g., a method call) after this time, the connection with the Python program is closed.
  • Method Details

    • getAddress

      public InetAddress getAddress()
      Specified by:
      getAddress in interface Py4JPythonClient
    • isMemoryManagementEnabled

      public boolean isMemoryManagementEnabled()
      Specified by:
      isMemoryManagementEnabled in interface Py4JPythonClient
    • getConnection

      protected Py4JClientConnection getConnection() throws IOException
      Throws:
      IOException
    • getConnectionLock

      protected Py4JClientConnection getConnectionLock()
    • getPort

      public int getPort()
      Specified by:
      getPort in interface Py4JPythonClient
    • getReadTimeout

      public int getReadTimeout()
      Specified by:
      getReadTimeout in interface Py4JPythonClient
    • copyWith

      public Py4JPythonClient copyWith(InetAddress pythonAddress, int pythonPort)

      Creates a callback client which connects to the given address and port, but retains all the other settings (like the minConnectionTime and the socketFactory. This method is useful if for some reason your CallbackServer changes its address or you come to know of the address after Gateway has already instantiated.

      Specified by:
      copyWith in interface Py4JPythonClient
      Parameters:
      pythonAddress - The address used by a PythonProxyHandler to connect to a Python gateway.
      pythonPort - The port used by a PythonProxyHandler to connect to a Python gateway. Essentially the port used for Python callbacks.
    • giveBackConnection

      protected void giveBackConnection(Py4JClientConnection cc)
    • periodicCleanup

      public void periodicCleanup()

      Closes communication channels that have not been used for a time specified at the creation of the callback client.

      Clients should not directly call this method: it is called by a periodic cleaner thread.

    • sendCommand

      public String sendCommand(String command)

      Sends a command to the Python side. This method is typically used by Python proxies to call Python methods or to request the garbage collection of a proxy.

      Specified by:
      sendCommand in interface Py4JPythonClient
      Parameters:
      command - The command to send.
      Returns:
      The response.
    • sendCommand

      public String sendCommand(String command, boolean blocking)

      Sends a command to the Python side. This method is typically used by Python proxies to call Python methods or to request the garbage collection of a proxy.

      Specified by:
      sendCommand in interface Py4JPythonClient
      Parameters:
      command - The command to send.
      blocking - If the CallbackClient should wait for an answer (default should be True, except for critical cases such as a finalizer sending a command).
      Returns:
      The response.
    • getPythonServerEntryPoint

      public Object getPythonServerEntryPoint(Gateway gateway, Class[] interfacesToImplement)
      Description copied from interface: Py4JPythonClient

      Gets a reference to the entry point on the Python side. This is often necessary if Java is driving the communication because Java cannot call static methods, initialize Python objects or load Python modules yet.

      Specified by:
      getPythonServerEntryPoint in interface Py4JPythonClient
      Returns:
    • shouldRetrySendCommand

      protected boolean shouldRetrySendCommand(Py4JClientConnection cc, Py4JNetworkException pne)
    • setupCleaner

      protected void setupCleaner()
    • shutdown

      public void shutdown()

      Closes all active channels, stops the periodic cleanup of channels and mark the client as shutting down. No more commands can be sent after this method has been called, except commands that were initiated before the shutdown method was called..

      Specified by:
      shutdown in interface Py4JPythonClient