PersistenceInvocationHandler.java

/*
** Module   : PersistenceInvocationHandler.java
** Abstract : Handler for the dynamic proxy of a persistence instance
**
** Copyright (c) 2024, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
** 001 SB  20240828 Created initial version.
** 002 OM  20240910 Fixed javadoc. Optimized imports.
** 003 OM  20241128 Multi-tenant runtime support: selected the proper persistence context, eventually
**                  based on [sharedDb] parameter.
** 004 ES  20250424 Handle StopConditionException through ErrorManager.
*/

/*
** 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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*/

package com.goldencode.p2j.persist;

import com.goldencode.p2j.util.*;
import com.goldencode.p2j.util.logging.*;
import java.lang.reflect.*;
import java.util.logging.Level;

/**
 * Handler for the dynamic proxy of a persistence instance. Used for situations where {@link Persistence}
 * methods are to be used but with slight exceptions or modifications in execution. To be used for
 * {@link UnsafePersistence}.
 */
class PersistenceInvocationHandler 
implements InvocationHandler
{
   /** The logger. */
   private static final CentralLogger LOG = CentralLogger.get(PersistenceInvocationHandler.class.getName());
   
   /** The persistence instance. */
   private final Persistence persistence;
   
   /**
    * The constructor.
    * 
    * @param   persistence
    *          The persistence instance to be used as a proxy.
    */
   public PersistenceInvocationHandler(Persistence persistence)
   {
      this.persistence = persistence;
   }
   
   /**
    * The function responsible for invoking and handling the invocation event.
    */
   @Override
   public Object invoke(Object proxy, Method method, Object[] args) 
   throws Throwable
   {
      // create a persistence context if there isn't one already
      BufferManager.get().getTxWrapperHelper().maybeActivateTxWrapper(
            persistence.getDatabase(Persistence.PRIVATE_CTX));
      persistence.setUnsafe(true, Persistence.PRIVATE_CTX);
      Object result = null;
      try
      {
         result = method.invoke(persistence, args);
      }
      catch (InvocationTargetException | IllegalAccessException | IllegalArgumentException exc)
      {
         Throwable cause = exc.getCause();
         if (cause instanceof PersistenceException)
         {
            if (LOG.isLoggable(Level.WARNING))
            {
               LOG.log(Level.WARNING,
                       "Query for database " + persistence.getDatabase(Persistence.PRIVATE_CTX) + 
                       " has failed in unsafe mode!");
            }
            
            throw cause;
         }
         else
         {
            ErrorManager.handleStopException(new StopConditionException(exc));
         }
      }
      finally
      {
         persistence.setUnsafe(false, Persistence.PRIVATE_CTX);
      }
      
      return result;
   }
}