Package org.apache.catalina.session

Class PersistentManagerBase

  • All Implemented Interfaces:
    PropertyChangeListener, EventListener, Lifecycle, Manager
    Direct Known Subclasses:
    PersistentManager, ReplicationManagerBase
    public abstract class PersistentManagerBase
extends ManagerBase
implements Lifecycle, PropertyChangeListener
    Extends the ManagerBase class to implement most of the functionality required by a Manager which supports any kind of persistence, even if only for restarts.

    IMPLEMENTATION NOTE: Correct behavior of session storing and reloading depends upon external calls to the start() and stop() methods of this class at the correct times.

    Version:
    $Revision: 1.16 $ $Date: 2007/05/05 05:32:19 $
    Author:
    Craig R. McClanahan, Jean-Francois Arcand

    • Field Detail

      • lifecycle

        protected LifecycleSupport lifecycle
        The lifecycle event support for this component.

      • name

        protected static final String name
        The descriptive name of this Manager implementation (for logging).
        See Also:
        Constant Field Values

      • invalidatedSessions

        protected ConcurrentHashMap<String,​Long> invalidatedSessions
        The set of invalidated Sessions for this Manager, keyed by session identifier.

    • Constructor Detail

      • PersistentManagerBase

        public PersistentManagerBase()

    • Method Detail

      • backgroundProcess

        public void backgroundProcess()
        Perform the background processes for this Manager

      • getMaxIdleBackup

        public int getMaxIdleBackup()
        Indicates how many seconds old a session can get, after its last use in a request, before it should be backed up to the store. -1 means sessions are not backed up.

      • setMaxIdleBackup

        public void setMaxIdleBackup​(int backup)
        Sets the option to back sessions up to the Store after they are used in a request. Sessions remain available in memory after being backed up, so they are not passivated as they are when swapped out. The value set indicates how old a session may get (since its last use) before it must be backed up: -1 means sessions are not backed up.

        Note that this is not a hard limit: sessions are checked against this age limit periodically according to checkInterval. This value should be considered to indicate when a session is ripe for backing up.

        So it is possible that a session may be idle for maxIdleBackup + checkInterval seconds, plus the time it takes to handle other session expiration, swapping, etc. tasks.

        Parameters:
        backup - The number of seconds after their last accessed time when they should be written to the Store.

      • getMaxIdleSwap

        public int getMaxIdleSwap()
        The time in seconds after which a session should be swapped out of memory to disk.

      • setMaxIdleSwap

        public void setMaxIdleSwap​(int max)
        Sets the time in seconds after which a session should be swapped out of memory to disk.

      • getMinIdleSwap

        public int getMinIdleSwap()
        The minimum time in seconds that a session must be idle before it can be swapped out of memory, or -1 if it can be swapped out at any time.

      • setMinIdleSwap

        public void setMinIdleSwap​(int min)
        Sets the minimum time in seconds that a session must be idle before it can be swapped out of memory due to maxActiveSession. Set it to -1 if it can be swapped out at any time.

      • setContainer

        public void setContainer​(Container container)
        Set the Container with which this Manager has been associated. If it is a Context (the usual case), listen for changes to the session timeout property.
        Specified by:
        setContainer in interface Manager
        Overrides:
        setContainer in class ManagerBase
        Parameters:
        container - The associated Container

      • getInfo

        public String getInfo()
        Return descriptive information about this Manager implementation and the corresponding version number, in the format <description>/<version>.
        Specified by:
        getInfo in interface Manager
        Overrides:
        getInfo in class ManagerBase

      • isLoaded

        public boolean isLoaded​(String id)
        Return true, if the session id is loaded in memory otherwise false is returned
        Parameters:
        id - The session id for the session to be searched for
        Throws:
        IOException - if an input/output error occurs while processing this request

      • getMaxActiveSessions

        public int getMaxActiveSessions()
        Return the maximum number of active Sessions allowed, or -1 for no limit.

      • setMaxActiveSessions

        public void setMaxActiveSessions​(int max)
        Set the maximum number of active Sessions allowed, or -1 for no limit.
        Parameters:
        max - The new maximum number of sessions

      • getName

        public String getName()
        Return the descriptive short name of this Manager implementation.
        Overrides:
        getName in class ManagerBase

      • isStarted

        protected boolean isStarted()
        Get the started status.

      • setStarted

        protected void setStarted​(boolean started)
        Set the started flag

      • setStore

        public void setStore​(Store store)
        Set the Store object which will manage persistent Session storage for this Manager.
        Parameters:
        store - the associated Store

      • getStore

        public Store getStore()
        Return the Store object which manages persistent Session storage for this Manager.

      • getSaveOnRestart

        public boolean getSaveOnRestart()
        Indicates whether sessions are saved when the Manager is shut down properly. This requires the unload() method to be called.

      • setSaveOnRestart

        public void setSaveOnRestart​(boolean saveOnRestart)
        Set the option to save sessions to the Store when the Manager is shut down, then loaded when the Manager starts again. If set to false, any sessions found in the Store may still be picked up when the Manager is started again.
        Parameters:
        saveOnRestart - true if sessions should be saved on restart, false if they should be ignored.

      • clearStore

        public void clearStore()
        Clear all sessions from the Store.

      • processExpires

        protected void processExpires()
        Invalidate all sessions that have expired. Hercules: modified method

      • processPersistenceChecks

        public void processPersistenceChecks()
        Called by the background thread after active sessions have been checked for expiration, to allow sessions to be swapped out, backed up, etc.

      • processInvalidatedSessions

        protected void processInvalidatedSessions()
        Purges those session ids from the map of invalidated session ids whose time has come up

      • createSession

        public Session createSession()
        Return a new session object as long as the number of active sessions does not exceed maxActiveSessions. If there aren't too many active sessions, or if there is no limit, a session is created or retrieved from the recycled pool.
        Specified by:
        createSession in interface Manager
        Overrides:
        createSession in class ManagerBase
        Returns:
        the new session
        Throws:
        IllegalStateException - if a new session cannot be instantiated for any reason

      • createSession

        public Session createSession​(String sessionId)
        Construct and return a new session object, based on the default settings specified by this Manager's properties, using the specified session id. IMPLEMENTATION NOTE: This method must be kept in sync with the createSession method that takes no arguments.
        Specified by:
        createSession in interface Manager
        Overrides:
        createSession in class ManagerBase
        Parameters:
        sessionId - the session id to assign to the new session
        Returns:
        the new session, or null if a session with the requested id already exists
        Throws:
        IllegalStateException - if a new session cannot be instantiated for any reason

      • findSession

        public Session findSession​(String id)
                    throws IOException
        Return the active Session, associated with this Manager, with the specified session id (if any); otherwise return null. This method checks the persistence store if persistence is enabled, otherwise just uses the functionality from ManagerBase.
        Specified by:
        findSession in interface Manager
        Overrides:
        findSession in class ManagerBase
        Parameters:
        id - The session id for the session to be returned
        Throws:
        IllegalStateException - if a new session cannot be instantiated for any reason
        IOException - if an input/output error occurs while processing this request

      • findSession

        public Session findSession​(String id,
                           boolean removeCachedCopy)
                    throws IOException
        Return the active Session, associated with this Manager, with the specified session id (if any); otherwise return null. This method first removes the cached copy if removeCachedCopy = true. Then this method checks the persistence store if persistence is enabled, otherwise just uses the functionality from ManagerBase.
        Parameters:
        id - The session id for the session to be returned
        removeCachedCopy -
        Throws:
        IllegalStateException - if a new session cannot be instantiated for any reason
        IOException - if an input/output error occurs while processing this request

      • superFindSession

        protected Session superFindSession​(String id)
                            throws IOException
        used by subclasses of PersistentManagerBase Hercules: added method
        Throws:
        IOException

      • removeSuper

        public void removeSuper​(Session session)
        Remove this Session from the active Sessions for this Manager, but not from the Store. (Used by the PersistentValve)
        Parameters:
        session - Session to be removed

      • load

        public void load()
        Load all sessions found in the persistence mechanism, assuming they are marked as valid and have not passed their expiration limit. If persistence is not supported, this method returns without doing anything.

        Note that by default, this method is not called by the MiddleManager class. In order to use it, a subclass must specifically call it, for example in the start() and/or processPersistenceChecks() methods.

        Specified by:
        load in interface Manager

      • remove

        public void remove​(Session session)
        Remove this Session from the active Sessions for this Manager, and from the Store.
        Specified by:
        remove in interface Manager
        Overrides:
        remove in class ManagerBase
        Parameters:
        session - Session to be removed

      • remove

        public void remove​(Session session,
                   boolean persistentRemove)
        Remove this Session from the active Sessions for this Manager, and from the Store.
        Parameters:
        session - Session to be removed
        persistentRemove - - do we remove persistent session too

      • addToInvalidatedSessions

        public void addToInvalidatedSessions​(String sessionId)
        Add this Session id to the set of invalidated Session ids for this Manager.
        Parameters:
        sessionId - session id to be added

      • removeFromInvalidatedSessions

        public void removeFromInvalidatedSessions​(String sessionId)
        Removes the given session id from the map of invalidated session ids.
        Parameters:
        sessionId - The session id to remove

      • isSessionIdValid

        public boolean isSessionIdValid​(String sessionId)
        Returns:
        true if the given session id is not contained in the map of invalidated session ids, false otherwise

      • unload

        public void unload()
        Save all currently active sessions in the appropriate persistence mechanism, if any. If persistence is not supported, this method returns without doing anything.

        Note that by default, this method is not called by the MiddleManager class. In order to use it, a subclass must specifically call it, for example in the stop() and/or processPersistenceChecks() methods.

        Specified by:
        unload in interface Manager

      • swapIn

        protected Session swapIn​(String id)
                  throws IOException
        Look for a session in the Store and, if found, restore it in the Manager's list of active sessions if appropriate. The session will be removed from the Store after swapping in, but will not be added to the active session list if it is invalid or past its expiration.
        Throws:
        IOException

      • swapIn

        protected Session swapIn​(String id,
                         String version)
                  throws IOException
        Look for a session in the Store and, if found, restore it in the Manager's list of active sessions if appropriate. The session will be removed from the Store after swapping in, but will not be added to the active session list if it is invalid or past its expiration.
        Parameters:
        id - The session id
        version - The requested session version
        Throws:
        IOException

      • swapOut

        protected void swapOut​(Session session)
                throws IOException
        Remove the session from the Manager's list of active sessions and write it out to the Store. If the session is past its expiration or invalid, this method does nothing.
        Parameters:
        session - The Session to write out.
        Throws:
        IOException

      • writeSession

        protected void writeSession​(Session session)
                     throws IOException
        Write the provided session to the Store without modifying the copy in memory or triggering passivation events. Does nothing if the session is invalid or past its expiration.
        Throws:
        IOException

      • addLifecycleListener

        public void addLifecycleListener​(LifecycleListener listener)
        Add a lifecycle event listener to this component.
        Specified by:
        addLifecycleListener in interface Lifecycle
        Parameters:
        listener - The listener to add

      • removeLifecycleListener

        public void removeLifecycleListener​(LifecycleListener listener)
        Remove a lifecycle event listener from this component.
        Specified by:
        removeLifecycleListener in interface Lifecycle
        Parameters:
        listener - The listener to remove

      • start

        public void start()
           throws LifecycleException
        Prepare for the beginning of active use of the public methods of this component. This method should be called after configure(), and before any of the public methods of the component are utilized.
        Specified by:
        start in interface Lifecycle
        Throws:
        LifecycleException - if this component detects a fatal error that prevents this component from being used

      • stop

        public void stop()
          throws LifecycleException
        Gracefully terminate the active use of the public methods of this component. This method should be the last one called on a given instance of this component.
        Specified by:
        stop in interface Lifecycle
        Throws:
        LifecycleException - if this component detects a fatal error that needs to be reported

      • processMaxIdleSwaps

        protected void processMaxIdleSwaps()
        Swap idle sessions out to Store if they are idle too long.

      • processMaxActiveSwaps

        protected void processMaxActiveSwaps()
        Swap idle sessions out to Store if too many are active Hercules: modified method

      • processMaxIdleBackups

        protected void processMaxIdleBackups()
        Back up idle sessions. Hercules: modified method