# SessionIdHolder.java

    /*
    ** Module   : SessionIdHolder.java
    ** Abstract : Holds the numeric ID of the user in the current session
    **
    ** Copyright (c) 2013-2023, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --------------------------------Description----------------------------------
    ** 001 IAS 20200819 Created initial version.
    ** 002 GBB 20230825 SecurityManager session methods calls updated.
    */

    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.persist.meta;

    import java.util.*;

    import com.goldencode.p2j.security.*;
    import com.goldencode.p2j.security.SecurityManager;
    import com.goldencode.p2j.util.*;

    /** Numeric ID of the user in the current session */
    public class SessionIdHolder
    extends ContextLocal<integer>
    {
        /** Security manager */
        private final SecurityManager securityManager;

        /** List of reclaimed user numbers */
        private final List<integer> reclaimedSessionIDs;

        /** Highest allocated session ID to date (may no longer be active) */
        private int highSessionID = 0;

        /**
         * Constructor
         */
        public SessionIdHolder()
        {
           super();
           securityManager = SecurityManager.getInstance();
           reclaimedSessionIDs = (securityManager == null ? new LinkedList<>() : null);
        }

        /**
         * Initialize
         *
         * @return numeric ID of the user in the current session
         */
        @Override
        protected integer initialValue()
        {
           integer sessionID;

           if (securityManager != null)
           {
              sessionID = new integer(securityManager.sessionSm.getSessionId());
           }
           else
           {
              // fallback method, though we should always have a security manager in server mode
              synchronized (this)
              {
                 if (reclaimedSessionIDs.size() > 0)
                 {
                    sessionID = reclaimedSessionIDs.remove(0);
                 }
                 else
                 {
                    sessionID = new integer(++highSessionID);
                 }
              }
           }

           return sessionID;
        }

        /**
         * Cleanup
         * @param value
         *      user ID to be released
         *
         */
        protected void cleanup(integer value)
        {
           if (securityManager == null)
           {
              synchronized (this)
              {
                 reclaimedSessionIDs.add(value);
              }
           }
        }
    }