/*
 * $Header: /home/cvs/jakarta-tomcat/src/share/org/apache/tomcat/session/ManagerBase.java,v 1.3 2000/01/26 17:45:09 costin Exp $
 * $Revision: 1.3 $
 * $Date: 2000/01/26 17:45:09 $
 *
 * ====================================================================
 *
 * 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 apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 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
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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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]
 *
 */ 


package org.apache.tomcat.session;


import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpSession;
import org.apache.tomcat.catalina.*;
import org.apache.tomcat.util.SessionUtil;


/**
 * Minimal implementation of the <b>Manager</b> interface that supports
 * no session persistence or distributable capabilities.  This class may
 * be subclassed to create more sophisticated Manager implementations.
 *
 * @author Craig R. McClanahan
 * @version $Revision: 1.3 $ $Date: 2000/01/26 17:45:09 $
 */

public abstract class ManagerBase implements Manager {


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


    /**
     * The Container with which this Manager is associated.
     */
    protected Container container;


    /**
     * The distributable flag for Sessions created by this Manager.  If this
     * flag is set to <code>true</code>, any user attributes added to a
     * session controlled by this Manager must be Serializable.
     */
    protected boolean distributable;


    /**
     * The descriptive information string for this implementation.
     */
    private static final String info = "ManagerBase/1.0";


    /**
     * The default maximum inactive interval for Sessions created by
     * this Manager.
     */
    protected int maxInactiveInterval = 60;


    /**
     * The set of previously recycled Sessions for this Manager.
     */
    protected Vector recycled = new Vector();


    /**
     * The set of currently active Sessions for this Manager, keyed by
     * session identifier.
     */
    protected Hashtable sessions = new Hashtable();


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


    /**
     * Return the Container with which this Manager is associated.
     */
    public Container getContainer() {

	return (this.container);

    }


    /**
     * Set the Container with which this Manager is associated.
     *
     * @param container The newly associated Container
     */
    public void setContainer(Container container) {

	this.container = container;

    }


    /**
     * Return the distributable flag for the sessions supported by
     * this Manager.
     */
    public boolean getDistributable() {

	return (this.distributable);

    }


    /**
     * Set the distributable flag for the sessions supported by this
     * Manager.  If this flag is set, all user data objects added to
     * sessions associated with this manager must implement Serializable.
     *
     * @param distributable The new distributable flag
     */
    public void setDistributable(boolean distributable) {

	this.distributable = distributable;

    }


    /**
     * Return descriptive information about this Manager implementation and
     * the corresponding version number, in the format
     * <code>&lt;description&gt;/&lt;version&gt;</code>.
     */
    public String getInfo() {

	return (this.info);

    }


    /**
     * Return the default maximum inactive interval (in seconds)
     * for Sessions created by this Manager.
     */
    public int getMaxInactiveInterval() {

	return (this.maxInactiveInterval);

    }


    /**
     * Set the default maximum inactive interval (in seconds)
     * for Sessions created by this Manager.
     *
     * @param interval The new default value
     */
    public void setMaxInactiveInterval(int interval) {

	this.maxInactiveInterval = interval;

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Construct and return a new session object, based on the default
     * settings specified by this Manager's properties.  The session
     * id will be assigned by this method, and available via the getId()
     * method of the returned session.  If a new session cannot be created
     * for any reason, return <code>null</code>.
     *
     * @exception IllegalStateException if a new session cannot be
     *  instantiated for any reason
     */
    public Session createSession() {

	// Recycle or create a Session instance
	StandardSession session = null;
	synchronized (recycled) {
	    int size = recycled.size();
	    if (size > 0) {
		session = (StandardSession) recycled.elementAt(size - 1);
		recycled.removeElementAt(size - 1);
	    }
	}
	if (session == null)
	    session = new StandardSession(this);

	// Initialize the properties of the new session and return it
	session.setNew(true);
	session.setValid(true);
	session.setCreationTime(System.currentTimeMillis());
	session.setMaxInactiveInterval(this.maxInactiveInterval);
	session.setId(SessionUtil.generateSessionId());

	return (session);

    }


    /**
     * Return the active Session, associated with this Manager, with the
     * specified session id (if any); otherwise return <code>null</code>.
     *
     * @param id The session id for the session to be returned
     *
     * @exception ClassNotFoundException if a deserialization error occurs
     *  while processing this request
     * @exception IllegalStateException if a new session cannot be
     *  instantiated for any reason
     * @exception IOException if an input/output error occurs while
     *  processing this request
     */
    public Session findSession(String id) throws IOException {

	if (id == null)
	    return (null);
	return ((Session) sessions.get(id));

    }


    /**
     * Return the set of active Sessions associated with this Manager.
     * If this Manager has no active Sessions, a zero-length array is returned.
     */
    public Session[] findSessions() {

	synchronized (sessions) {
	    Vector keys = new Vector();
	    Enumeration ids = sessions.keys();
	    while (ids.hasMoreElements()) {
		String id = (String) ids.nextElement();
		keys.addElement(id);
	    }
	    Session results[] = new Session[keys.size()];
	    for (int i = 0; i < results.length; i++) {
		String key = (String) keys.elementAt(i);
		results[i] = (Session) sessions.get(key);
	    }
	    return (results);
	}

    }


    // -------------------------------------------------------- Package Methods


    /**
     * Add this Session to the set of active Sessions for this Manager.
     *
     * @param session Session to be added
     */
    void add(StandardSession session) {

	sessions.put(session.getId(), session);

    }


    /**
     * Add this Session to the recycle collection for this Manager.
     *
     * @param session Session to be recycled
     */
    void recycle(StandardSession session) {

	recycled.addElement(session);

    }


    /**
     * Remove this Session from the active Sessions for this Manager.
     *
     * @param session Session to be removed
     */
    void remove(StandardSession session) {

	sessions.remove(session.getId());

    }


}

