Class SessionTransMgr

java.lang.Object
com.iizix.comm.session.SessionTransMgr
All Implemented Interfaces:
GCloseCodes, GManagementConstants, ITransactionCreator, ISessionStatistics, ISessionTransMgr, TransactionCommListener, GConstants
public class SessionTransMgr extends Object implements ISessionTransMgr, TransactionCommListener, ITransactionCreator, GConstants, GManagementConstants, GCloseCodes
The Session Transaction Manager is used for keeping track of transaction that have been received or sent to a client on session basis so that a remote session may re-establish a broken communication link.
Author:
Christopher Mindus

  • Field Details

    • MAX_UNANSWERED_HEARTBEATS

      public static final int MAX_UNANSWERED_HEARTBEATS
      The heartbeats in a row that may go without any inbound frame before the link is cut, 3.

      A peer that no longer answers is not noticed while the server's PINGs are written: behind a reverse proxy the TCP peer is the proxy, which acknowledges everything, and a suspended phone's kernel may acknowledge too, so TCP reports nothing and the session looks connected for as long as the dormant time-out. Any inbound frame - a PONG, a data frame - proves the peer reads and resets the count (onCommHeartBeat(TransactionComm, long), onCommData(TransactionComm, ReadTransaction, int)); when this many heartbeats in a row got none, doTimeoutCheck(long, long, long, long) closes the link hard from the server, with no close handshake (InternalWebSocket.close(true): Jetty's Session.disconnect), and the session takes the broken -> dormant path of a communication error, so a client that comes back reconnects as after any drop, within the dormant time-out. The cut comes between three and four heartbeat intervals after the last inbound frame: 90-120 s at a 30 s heartbeat, 135-180 s at the 45 s default. The link's idle time-out (SessionMgr.getLinkIdleTimeout) does not fire first: the PINGs the server writes reset it, and only inbound silence is counted here. A frozen desktop tab keeps answering PINGs from the Browser's network service and is not cut. No server setting: a constant (CC-FIX-WS-HEARTBEAT-SKIP, Set C).

      See Also:

    • MAX_DUPLICATE_DISTANCE

      public static final int MAX_DUPLICATE_DISTANCE
      How far behind the expected serial a received serial may be to count as a transaction already received, 0x7FFF: half of the serial cycle 0x0001-0xFFFF. A serial at most this far behind is a duplicate - the client re-sent it after a reconnection because the MT_NEXT_SERIAL that acknowledged it was lost with the link - and is dropped; one further away is ahead of the expected serial, a gap (processIncoming(ReadTransaction)).
      See Also:

  • Constructor Details

    • SessionTransMgr

      public SessionTransMgr(ITransactionProcessor processor)
      Creates a new session for a new transaction processor.
      Parameters:
      processor - The transaction processor.

  • Method Details

    • isReconnectionInstance

      public static boolean isReconnectionInstance(String reconnectID, String from)
      Checks if it's a valid reconnection session instance for an existing transaction processor and attempts reconnection.
      Returns:
      The instance of the Session Manager, null if the reconnection instance is not available.

    • getReconnectionProcessor

      public static ITransactionProcessor getReconnectionProcessor(String reconnectID)
      Gets the transaction processor of the session a reconnection names (CC-FIX-APP-DEFINITIONS, D-11): the client end point constructor asks it for the application of that session before it accepts the upgrade on a port configuration, so that a reconnection is gated as a new connection is.
      Parameters:
      reconnectID - The reconnection ID of the query.
      Returns:
      The processor, or null when the session has been disposed of or has none.

    • createReconnectionInstance

      public static SessionTransMgr createReconnectionInstance(SocketAddress address, String reconnectID, int nextSerialReconnect)
      Creates a reconnection session instance for an existing transaction processor and attempts reconnection.
      Returns:
      The instance of the Session Manager, null if the reconnection instance is not available.

    • assignTransactionComm

      public void assignTransactionComm(TransactionComm comm)
      Assigns the created transaction communications instance.

    • getProcessor

      public ITransactionProcessor getProcessor()
      Gets the transaction processor for unpackaged transactions.

    • getSessionStatistics

      public SessionStatistics getSessionStatistics()
      Gets the statistics instance of the session.
      Specified by:
      getSessionStatistics in interface ISessionStatistics
      Returns:
      The SessionStatistics instance.

    • dispose

      public void dispose(boolean doAbort)
      Dispose of this session by delegating it to the Session ID.
      Parameters:
      doAbort - Abort-flag, if true pending transaction are not sent.

    • getStatisticsSnapshot

      public SessionStatistics getStatisticsSnapshot()
      Gets the statistics as a snapshot.

    • getSession

      public SessionID getSession()
      Gets the session.
      Returns:
      The session.

    • getSessionID

      public String getSessionID()
      Gets the session identifier.
      Returns:
      The session identifier, or null if disposed of.

    • doDispose

      public void doDispose(boolean doAbort)
      Called when the session ID has been disposed of by a call to its dispose method.
      Specified by:
      doDispose in interface ISessionTransMgr
      Parameters:
      doAbort - Abort-flag, if true pending transaction are not sent.

    • getCurrentState

      public SessionConnectionStatistics.State getCurrentState()
      Gets the current state.

    • isConnected

      public boolean isConnected()
      Checks if current session is connected. Be careful, do not forget that a connection can become isConnected()==false when paused!

    • isDisconnected

      public boolean isDisconnected()
      Checks if current session is connected. Be careful, do not forget that a connection can become isConnected()==false when paused!

    • isPaused

      public boolean isPaused()
      Checks if current session is connected. Be careful, do not forget that a connection can become isConnected()==false when paused!

    • doPause

      public boolean doPause()
      Requests a pause of the session from the server.
      Returns:
      true if the session still had open communication connection, false otherwise. When false is returned, the session has NOT entered real pause state.

    • createTransaction

      public SendTransaction createTransaction()
      Creates a transaction for processing normal transactions.
      Specified by:
      createTransaction in interface ITransactionCreator
      Returns:
      The new Transaction instance.

    • onCommConnected

      public void onCommConnected(TransactionComm comm)
      Called when the communication link is connected.
      Specified by:
      onCommConnected in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.

    • onCommData

      public void onCommData(TransactionComm comm, ReadTransaction trans, int size)
      Called when the communication link has received data.
      Specified by:
      onCommData in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.
      trans - The transaction received.
      size - The size of the data received, as it may have been uncompressed.

    • onCommHeartBeat

      public void onCommHeartBeat(TransactionComm comm, long duration)
      Called when a heart-beat frame is received.
      Specified by:
      onCommHeartBeat in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.
      duration - Duration of the PING-PONG message exchange in milliseconds, recorded as the connection's lastHeartBeatDuration.

    • onCommTimeout

      public void onCommTimeout(TransactionComm comm, boolean isReadTimeout)
      Called when the communication link has timed out on a read or write operation.
      Specified by:
      onCommTimeout in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.
      isReadTimeout - Flag indicating read timeout when true, false indicates write timeout.

    • onCommError

      public void onCommError(TransactionComm comm, Throwable e)
      Called when the communication link is closed.
      Specified by:
      onCommError in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.
      e - The exception.

    • onCommClosing

      public void onCommClosing(TransactionComm comm)
      Called when the communication link is closing.
      Specified by:
      onCommClosing in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.

    • onCommClosed

      public void onCommClosed(TransactionComm comm, int code, String reason)
      Called when the communication link is closed.
      Specified by:
      onCommClosed in interface TransactionCommListener
      Parameters:
      comm - The transaction communication instance.

    • requestPingPong

      public void requestPingPong()
      Requests a ping-pong transaction.

    • sendTransaction

      public boolean sendTransaction(SendTransaction trans)
      Send a transaction to the client, assigning the transaction serial and processing statistics.
      Parameters:
      trans - The transaction to send.
      Returns:
      true for success, false for failure.

    • closeClientAuthenticationInfo

      public void closeClientAuthenticationInfo(String info)
      Sends a close management transaction indicating the User Name or Password were incorrect.
      Parameters:
      info - The information string.

    • closeClient

      public void closeClient(String msg)
      Sends a close management transaction with an message in HTML format for the close reason.
      Parameters:
      msg - The close reason in HTML format.

    • closeClient

      public void closeClient(int closeCode, String msg)
      Closes the client with a close code and a message, then disposes of the session: the reason the client reads is "iz!" + closeCode + "!" + msg, at most 123 bytes of UTF-8 in all (the WebSocket limit), which the caller keeps (CC-SERVER-RESTART-UPDATE-V5).
      Parameters:
      closeCode - The close code: GCloseCodes.CC_APPMSG, GCloseCodes.CC_SERVER_RESTART, ...
      msg - The message.