org.camunda.bpm.engine.impl.cmd.PurgeDatabaseAndCacheCmd Maven / Gradle / Ivy

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/*
 * Copyright 2016 camunda services GmbH.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package org.camunda.bpm.engine.impl.cmd;

import org.camunda.bpm.engine.ProcessEngineException;
import org.camunda.bpm.engine.impl.db.DbEntity;
import org.camunda.bpm.engine.impl.db.entitymanager.DbEntityManager;
import org.camunda.bpm.engine.impl.db.entitymanager.operation.DbBulkOperation;
import org.camunda.bpm.engine.impl.db.entitymanager.operation.DbOperationType;
import org.camunda.bpm.engine.impl.interceptor.Command;
import org.camunda.bpm.engine.impl.interceptor.CommandContext;
import org.camunda.bpm.engine.impl.management.DatabasePurgeReport;
import org.camunda.bpm.engine.impl.management.PurgeReport;
import org.camunda.bpm.engine.impl.persistence.deploy.cache.CachePurgeReport;
import org.camunda.bpm.engine.impl.persistence.deploy.cache.DeploymentCache;

import java.io.Serializable;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Purges the database and the deployment cache.
 * That means that each entity will be removed from the database and from the cache.
 * The command returns a purge report. That report contains information of the
 * deleted rows for each table and the values from the cache which are removed.
 *
 * @author Christopher Zell 
 */
public class PurgeDatabaseAndCacheCmd implements Command, Serializable {

  protected static final String DELETE_TABLE_DATA = "deleteTableData";
  protected static final String SELECT_TABLE_COUNT = "selectTableCount";
  protected static final String TABLE_NAME = "tableName";
  protected static final String EMPTY_STRING = "";

  public static final List TABLENAMES_EXCLUDED_FROM_DB_CLEAN_CHECK = Arrays.asList(
    "ACT_GE_PROPERTY"
  );

  @Override
  public PurgeReport execute(CommandContext commandContext) {
    PurgeReport purgeReport = new PurgeReport();

    // purge the database
    DatabasePurgeReport databasePurgeReport = purgeDatabase(commandContext);
    purgeReport.setDatabasePurgeReport(databasePurgeReport);

    // purge the deployment cache
    DeploymentCache deploymentCache = commandContext.getProcessEngineConfiguration().getDeploymentCache();
    CachePurgeReport cachePurgeReport = deploymentCache.purgeCache();
    purgeReport.setCachePurgeReport(cachePurgeReport);

    return purgeReport;
  }

  private DatabasePurgeReport purgeDatabase(CommandContext commandContext) {
    DbEntityManager dbEntityManager = commandContext.getDbEntityManager();
    // For MySQL and MariaDB we have to disable foreign key check,
    // to delete the table data as bulk operation (execution, incident etc.)
    // The flag will be reset by the DBEntityManager after flush.
    dbEntityManager.setIgnoreForeignKeysForNextFlush(true);
    List tablesNames = dbEntityManager.getTableNamesPresentInDatabase();
    String databaseTablePrefix = commandContext.getProcessEngineConfiguration().getDatabaseTablePrefix().trim();

    //for each table
    DatabasePurgeReport databasePurgeReport = new DatabasePurgeReport();
    for (String tableName : tablesNames) {
      String tableNameWithoutPrefix = tableName.replace(databaseTablePrefix, EMPTY_STRING);
      if (!TABLENAMES_EXCLUDED_FROM_DB_CLEAN_CHECK.contains(tableNameWithoutPrefix)) {

        // Check if table contains data
        Map param = new HashMap();
        param.put(TABLE_NAME, tableName);
        Long count = (Long) dbEntityManager.selectOne(SELECT_TABLE_COUNT, param);

        if (count > 0) {
          databasePurgeReport.addPurgeInformation(tableName, count);
          // Get corresponding entity classes for the table, which contains data
          List> entities = commandContext.getTableDataManager().getEntities(tableName);

          if (entities.isEmpty()) {
            throw new ProcessEngineException("No mapped implementation of "
                                            + DbEntity.class.getName()
                                            + " was found for: "
                                            + tableName);
          }

          // Delete the table data as bulk operation with the first entity
          Class entity = entities.get(0);
          DbBulkOperation deleteBulkOp = new DbBulkOperation(DbOperationType.DELETE_BULK, entity, DELETE_TABLE_DATA, param);
          dbEntityManager.getDbOperationManager().addOperation(deleteBulkOp);
        }
      }
    }
    return databasePurgeReport;
  }
}