content: /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.apache.activemq.store.kahadb.scheduler.legacy;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.List;
  import java.util.Set;
  
  import org.apache.activemq.store.kahadb.data.KahaAddScheduledJobCommand;
  import org.apache.activemq.store.kahadb.scheduler.JobSchedulerStoreImpl;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Used to upgrade a Legacy Job Scheduler store to the latest version this class
   * loads a found legacy scheduler store and generates new add commands for all
   * jobs currently in the store.
   */
  public class LegacyStoreReplayer {
  
      static final Logger LOG = LoggerFactory.getLogger(LegacyStoreReplayer.class);
  
      private LegacyJobSchedulerStoreImpl store;
      private final File legacyStoreDirectory;
  
      /**
       * Creates a new Legacy Store Replayer with the given target store
       * @param directory
       */
      public LegacyStoreReplayer(File directory) {
          this.legacyStoreDirectory = directory;
      }
  
      /**
       * Loads the legacy store and prepares it for replay into a newer Store instance.
       *
       * @throws IOException if an error occurs while reading in the legacy store.
       */
      public void load() throws IOException {
  
          store = new LegacyJobSchedulerStoreImpl();
          store.setDirectory(legacyStoreDirectory);
          store.setFailIfDatabaseIsLocked(true);
  
          try {
              store.start();
          } catch (IOException ioe) {
              LOG.warn("Legacy store load failed: ", ioe);
              throw ioe;
          } catch (Exception e) {
              LOG.warn("Legacy store load failed: ", e);
              throw new IOException(e);
          }
      }
  
      /**
       * Unloads a previously loaded legacy store to release any resources associated with it.
       *
       * Once a store is unloaded it cannot be replayed again until it has been reloaded.
       * @throws IOException
       */
      public void unload() throws IOException {
  
          if (store != null) {
              try {
                  store.stop();
              } catch (Exception e) {
                  LOG.warn("Legacy store unload failed: ", e);
                  throw new IOException(e);
              } finally {
                  store = null;
              }
          }
      }
  
      /**
       * Performs a replay of scheduled jobs into the target JobSchedulerStore.
       *
       * @param targetStore
       *      The JobSchedulerStore that will receive the replay events from the legacy store.
       *
       * @throws IOException if an error occurs during replay of the legacy store.
       */
      public void startReplay(JobSchedulerStoreImpl targetStore) throws IOException {
          checkLoaded();
  
          if (targetStore == null) {
              throw new IOException("Cannot replay to a null store");
          }
  
          try {
              Set<String> schedulers = store.getJobSchedulerNames();
              if (!schedulers.isEmpty()) {
  
                  for (String name : schedulers) {
                      LegacyJobSchedulerImpl scheduler = store.getJobScheduler(name);
                      LOG.info("Replay of legacy store {} starting.", name);
                      replayScheduler(scheduler, targetStore);
                  }
              }
  
              LOG.info("Replay of legacy store complate.");
          } catch (IOException ioe) {
              LOG.warn("Failed during replay of legacy store: ", ioe);
              throw ioe;
          } catch (Exception e) {
              LOG.warn("Failed during replay of legacy store: ", e);
              throw new IOException(e);
          }
      }
  
      private final void replayScheduler(LegacyJobSchedulerImpl legacy, JobSchedulerStoreImpl target) throws Exception {
          List<LegacyJobImpl> jobs = legacy.getAllJobs();
  
          String schedulerName = legacy.getName();
  
          for (LegacyJobImpl job : jobs) {
              LOG.trace("Storing job from legacy store to new store: {}", job);
              KahaAddScheduledJobCommand newJob = new KahaAddScheduledJobCommand();
              newJob.setScheduler(schedulerName);
              newJob.setJobId(job.getJobId());
              newJob.setStartTime(job.getStartTime());
              newJob.setCronEntry(job.getCronEntry());
              newJob.setDelay(job.getDelay());
              newJob.setPeriod(job.getPeriod());
              newJob.setRepeat(job.getRepeat());
              newJob.setNextExecutionTime(job.getNextExecutionTime());
              newJob.setPayload(job.getPayload());
  
              target.store(newJob);
          }
      }
  
      private final void checkLoaded() throws IOException {
          if (this.store == null) {
              throw new IOException("Cannot replay until legacy store is loaded.");
          }
      }
  }
  