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.cassandra.tcm.listeners;
  
  import java.util.EnumSet;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.cassandra.tcm.ClusterMetadata;
  import org.apache.cassandra.tcm.ClusterMetadataService;
  import org.apache.cassandra.tcm.Transformation;
  import org.apache.cassandra.tcm.log.Entry;
  
  import static org.apache.cassandra.tcm.Transformation.Kind.FORCE_SNAPSHOT;
  import static org.apache.cassandra.tcm.Transformation.Kind.TRIGGER_SNAPSHOT;
  
  public class MetadataSnapshotListener implements LogListener
  {
      private static final Logger logger = LoggerFactory.getLogger(MetadataSnapshotListener.class);
  
      private static final EnumSet<Transformation.Kind> triggers = EnumSet.of(TRIGGER_SNAPSHOT, FORCE_SNAPSHOT);
  
      @Override
      public void notify(Entry entry, Transformation.Result result)
      {
          ClusterMetadata next = result.success().metadata;
          if (triggers.contains(entry.transform.kind()))
          {
              try
              {
                  ClusterMetadataService.instance().snapshotManager().storeSnapshot(next);
              }
              catch (Throwable e)
              {
                  logger.warn("Unable to serialize metadata snapshot triggered by TriggerSnapshot transformation", e);
              }
          }
      }
  }
  