# RemoteIdentityManager.java

    /*
    ** Module   : RemoteIdentityManager.java
    ** Abstract : IdentityManager implementation which delegates to a remote server.
    **
    ** Copyright (c) 2004-2024, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- ---------------------------------Description----------------------------------
    ** 001 SVL 20080111  @36796  Created initial version. IdentityManager
    **                           implementation which delegates to a remote
    **                           server.
    ** 002 ECF 20080806  @39307  Modified to conform to new IdentityManager API.
    ** 003 SVL 20080901  @39649  Added reclaimKeys() function.
    ** 004 ECF 20200906          New ORM implementation.
    ** 005 OM  20241128          Multi-tenant runtime support: selected the proper persistence context, eventually
    **                           based on [sharedDb] parameter.
    */

    /*
    ** 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.
    **
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    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
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    **
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    **
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    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
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    */

    package com.goldencode.p2j.persist.remote;

    import com.goldencode.p2j.persist.*;
    import com.goldencode.p2j.persist.id.*;

    /**
     * A specialized implementation of {@link
     * com.goldencode.p2j.persist.id.IdentityManager IdentityManager} which
     * delegates requests for database record identity services to the remote P2J
     * server which is authoritative for the target database. This is necessary
     * in cases where business logic dynamically connects to a remote database
     * which is not managed by the current P2J server instance, since unique
     * primary key generation action must be serialized through a identity manager
     * which is authoritative for the target database.
     * <p>
     * An instance of this class works with a local proxy for a remote instance of
     * {@link IdentityManagerMultiplexer} residing at the target server. The
     * remote object may manage multiple databases, each of which is assigned a
     * unique database identifier. When the database is {@link
     * #setPersistence(Persistence) set} into a <code>RemoteIdentityManager</code>
     * instance, the associated identifier is requested from the remote
     * multiplexer.  The ID returned by the multiplexer is used on all subsequent
     * service requests sent by the <code>IdentityManager</code> instance.
     *
     * @see     RemotePersistence
     * @author  SVL
     */
    public class RemoteIdentityManager
    implements IdentityManager
    {
       /** Identity manager multiplexer which will service remote requests */
       private final IdentityManagerMultiplexer multiplexer;

       /** Multiplex ID for the remote database associated with this object */
       private int mpID = -1;

       /**
        * Constructor which stores a proxy to the remote object which will
        * service identity manager requests for the remote database.
        *
        * @param   multiplexer
        *          Identity manager multiplexer which will service remote requests.
        */
       public RemoteIdentityManager(IdentityManagerMultiplexer multiplexer)
       {
          this.multiplexer = multiplexer;
       }

       /**
        * Set the name of the physical database with which this identity manager is associated.
        *
        * @param   persistence
        *          Persistence service object.
        */
       public void setPersistence(Persistence persistence)
       {
          if (mpID >= 0)
          {
             throw new IllegalStateException("Database can only be set once");
          }

          Database database = persistence.getDatabase(Persistence.META_CTX);
          mpID = multiplexer.getMultiplexID(database.getName());
       }

       /**
        * Return the next primary key for the specified table.
        *
        * @param   table
        *          Table for which the next primary key will be returned.
        *
        * @return  The next primary key for the given table.
        *
        * @throws  PersistenceException
        *          if there is an error determining the next primary key ID.
        */
       public Long nextPrimaryKey(String table)
       throws PersistenceException
       {
          return multiplexer.nextPrimaryKey(mpID, table);
       }

       /**
        * Inform the identity manager that the given primary keys can be reused.
        *
        * @param   keys
        *          Keys for reuse.
        */
       public void reclaimKeys(Long[] keys)
       {
          multiplexer.reclaimKeys(mpID, keys);
       }
    }