persistentmanagerbase.java

This temp directory is used by the JVM for temporary file storage. The JVM is configured to use thi

/*
 * $Header: /home/cvs/jakarta-tomcat-catalina/catalina/src/share/org/apache/catalina/session/PersistentManagerBase.java,v 1.17 2004/02/06 11:51:13 remm Exp $
 * $Revision: 1.17 $
 * $Date: 2004/02/06 11:51:13 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
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 */


package org.apache.catalina.session;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.Session;
import org.apache.catalina.Store;
import org.apache.catalina.util.LifecycleSupport;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;


/**
 * Extends the <b>ManagerBase</b> class to implement most of the
 * functionality required by a Manager which supports any kind of
 * persistence, even if onlyfor  restarts.
 * <p>
 * <b>IMPLEMENTATION NOTE</b>:  Correct behavior of session storing and
 * reloading depends upon external calls to the <code>start()</code> and
 * <code>stop()</code> methods of this class at the correct times.
 *
 * @author Craig R. McClanahan
 * @author Jean-Francois Arcand
 * @version $Revision: 1.17 $ $Date: 2004/02/06 11:51:13 $
 */

public abstract class PersistentManagerBase
    extends ManagerBase
    implements Lifecycle, PropertyChangeListener {

    private static Log log = LogFactory.getLog(PersistentManagerBase.class);

    // ---------------------------------------------------- Security Classes

    private class PrivilegedStoreClear
        implements PrivilegedExceptionAction {

        PrivilegedStoreClear() {            
        }

        public Object run() throws Exception{
           store.clear();
           return null;
        }                       
    }   
     
    private class PrivilegedStoreRemove
        implements PrivilegedExceptionAction {

        private String id;    
            
        PrivilegedStoreRemove(String id) {     
            this.id = id;
        }

        public Object run() throws Exception{
           store.remove(id);
           return null;
        }                       
    }   
     
    private class PrivilegedStoreLoad
        implements PrivilegedExceptionAction {

        private String id;    
            
        PrivilegedStoreLoad(String id) {     
            this.id = id;
        }

        public Object run() throws Exception{
           return store.load(id);
        }                       
    }   
          
    private class PrivilegedStoreSave
        implements PrivilegedExceptionAction {

        private Session session;    
            
        PrivilegedStoreSave(Session session) {     
            this.session = session;
        }

        public Object run() throws Exception{
           store.save(session);
           return null;
        }                       
    }   
     
    private class PrivilegedStoreKeys
        implements PrivilegedExceptionAction {

        PrivilegedStoreKeys() {     
        }

        public Object run() throws Exception{
           return store.keys();
        }                       
    }

    // ----------------------------------------------------- Instance Variables


    /**
     * The descriptive information about this implementation.
     */
    private static final String info = "PersistentManagerBase/1.0";


    /**
     * The lifecycle event support for this component.
     */
    protected LifecycleSupport lifecycle = new LifecycleSupport(this);


    /**
     * The maximum number of active Sessions allowed, or -1 for no limit.
     */
    protected int maxActiveSessions = -1;


    /**
     * The descriptive name of this Manager implementation (for logging).
     */
    private static String name = "PersistentManagerBase";


    /**
     * Has this component been started yet?
     */
    protected boolean started = false;


    /**
     * Store object which will manage the Session store.
     */
    protected Store store = null;


    /**
     * Whether to save and reload sessions when the Manager <code>unload</code>
     * and <code>load</code> methods are called.
     */
    protected boolean saveOnRestart = true;


    /**
     * How long a session must be idle before it should be backed up.
     * -1 means sessions won't be backed up.
     */
    protected int maxIdleBackup = -1;


    /**
     * Minimum time a session must be idle before it is swapped to disk.
     * This overrides maxActiveSessions, to prevent thrashing if there are lots
     * of active sessions. Setting to -1 means it's ignored.
     */
    protected int minIdleSwap = -1;

    /**
     * The maximum time a session may be idle before it should be swapped
     * to file just on general principle. Setting this to -1 means sessions
     * should not be forced out.
     */
    protected int maxIdleSwap = -1;


    /**
     * Number of session creations that failed due to maxActiveSessions.
     */
    protected int rejectedSessions = 0;


    /**
     * Number of sessions that expired.
     */
    protected int expiredSessions = 0;


    /**
     * Processing time during session expiration and passivation.
     */
    protected long processingTime = 0;


    // ------------------------------------------------------------- Properties


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

        long timeNow = System.currentTimeMillis();

        this.processExpires();
        this.processPersistenceChecks();
        if ((this.getStore() != null)
            && (this.getStore() instanceof StoreBase)) {
            ((StoreBase) this.getStore()).processExpires();
        }

        long timeEnd = System.currentTimeMillis();
        processingTime += ( timeEnd - timeNow );

    }


    /**
     * 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.
     */
    public int getMaxIdleBackup() {

        return maxIdleBackup;

    }


    /**
     * 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.
     * <p>
     * Note that this is not a hard limit: sessions are checked
     * against this age limit periodically according to <b>checkInterval</b>.
     * This value should be considered to indicate when a session is
     * ripe for backing up.
     * <p>
     * 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.
     *
     * @param backup The number of seconds after their last accessed
     * time when they should be written to the Store.
     */
    public void setMaxIdleBackup (int backup) {

        if (backup == this.maxIdleBackup)
            return;
        int oldBackup = this.maxIdleBackup;
        this.maxIdleBackup = backup;
        support.firePropertyChange("maxIdleBackup",
                                   new Integer(oldBackup),
                                   new Integer(this.maxIdleBackup));

    }


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

        return maxIdleSwap;

    }


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

        if (max == this.maxIdleSwap)
            return;
        int oldMaxIdleSwap = this.maxIdleSwap;
        this.maxIdleSwap = max;
        support.firePropertyChange("maxIdleSwap",
                                   new Integer(oldMaxIdleSwap),
                                   new Integer(this.maxIdleSwap));

    }


    /**
     * 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.
     */
    public int getMinIdleSwap() {

        return minIdleSwap;

    }


    /**
     * 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.
     */
    public void setMinIdleSwap(int min) {

        if (this.minIdleSwap == min)
            return;
        int oldMinIdleSwap = this.minIdleSwap;
        this.minIdleSwap = min;
        support.firePropertyChange("minIdleSwap",
                                   new Integer(oldMinIdleSwap),
                                   new Integer(this.minIdleSwap));

    }


    /**
     * 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.
     *
     * @param container The associated Container
     */
    public void setContainer(Container container) {

        // De-register from the old Container (if any)
        if ((this.container != null) && (this.container instanceof Context))
            ((Context) this.container).removePropertyChangeListener(this);

        // Default processing provided by our superclass
        super.setContainer(container);

        // Register with the new Container (if any)
        if ((this.container != null) && (this.container instanceof Context)) {