content: /*
   * Copyright (C) 2012-2023 52°North Spatial Information Research GmbH
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published
   * by the Free Software Foundation.
   *
   * If the program is linked with libraries which are licensed under one of
   * the following licenses, the combination of the program with the linked
   * library is not considered a "derivative work" of the program:
   *
   *     - Apache License, version 2.0
   *     - Apache Software License, version 1.0
   *     - GNU Lesser General Public License, version 3
   *     - Mozilla Public License, versions 1.0, 1.1 and 2.0
   *     - Common Development and Distribution License (CDDL), version 1.0
   *
   * Therefore the distribution of the program linked with libraries licensed
   * under the aforementioned licenses, is permitted by the copyright holders
   * if the distribution is compliant with both the GNU General Public
   * License version 2 and the aforementioned licenses.
   *
   * 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 General
   * Public License for more details.
   */
  package org.n52.sos.ds.cache;
  
  import org.n52.iceland.util.action.CompositeParallelAction;
  import org.n52.series.db.old.HibernateSessionStore;
  import org.n52.shetland.ogc.ows.exception.OwsExceptionReport;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * @author <a href="mailto:c.autermann@52north.org">Christian Autermann</a>
   * @author <a href="mailto:shane@axiomalaska.com">Shane StClair</a>
   *
   * @since 4.0.0
   */
  public abstract class AbstractQueueingDatasourceCacheUpdate<T extends AbstractThreadableDatasourceCacheUpdate>
          extends AbstractDatasourceCacheUpdate {
      private static final Logger LOGGER = LoggerFactory.getLogger(AbstractQueueingDatasourceCacheUpdate.class);
  
      private final int threads;
  
      private final String threadGroupName;
  
      private final ThreadLocalSessionFactory sessionFactory;
  
      public AbstractQueueingDatasourceCacheUpdate(int threads, String threadGroupName,
              HibernateSessionStore sessionStore) {
          this.threads = threads;
          this.threadGroupName = threadGroupName;
          this.sessionFactory = new ThreadLocalSessionFactory(sessionStore);
      }
  
      protected abstract T[] getUpdatesToExecute() throws OwsExceptionReport;
  
      @Override
      public void execute() {
          LOGGER.debug("AbstractQueueingDatasourceCacheUpdate init");
          T[] updatesToExecute;
          try {
              updatesToExecute = getUpdatesToExecute();
          } catch (OwsExceptionReport ex) {
              getErrors().add(ex);
              return;
          }
          CompositeParallelAction<AbstractThreadableDatasourceCacheUpdate> compositeParallelAction =
                  new CompositeParallelAction<AbstractThreadableDatasourceCacheUpdate>(threads, threadGroupName,
                          updatesToExecute) {
  
                  @Override
                  protected void pre(AbstractThreadableDatasourceCacheUpdate action) {
                      action.setCache(getCache());
                      action.setErrors(getErrors());
                      action.setSessionFactory(sessionFactory);
                      action.setDbQueryFactory(getDbQueryFactory());
                  }
  
                  @Override
                  protected void post(AbstractThreadableDatasourceCacheUpdate action) {
                      if (action.getSession() != null) {
                          try {
                              action.getSession().clear();
                          } catch (Exception e) {
                              LOGGER.error("Error while returning connection after cache update!", e);
                          }
                      }
                  }
              };
          // execute multiple threads
          compositeParallelAction.execute();
  
          try {
              sessionFactory.close();
          } catch (Exception e) {
              LOGGER.error("Error while closing SessionFactory", e);
          }
      }
  }
  