content: /**
   * Copyright 2020 Alibaba Group Holding Limited.
   *
   * <p>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
   *
   * <p>http://www.apache.org/licenses/LICENSE-2.0
   *
   * <p>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 com.alibaba.graphscope.groot.coordinator.backup;
  
  import com.alibaba.graphscope.groot.common.schema.wrapper.GraphDef;
  import com.alibaba.graphscope.groot.coordinator.QuerySnapshotListener;
  import com.alibaba.graphscope.groot.coordinator.SchemaManager;
  import com.alibaba.graphscope.groot.frontend.SnapshotCache;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.concurrent.atomic.AtomicLong;
  
  public class LocalSnapshotListener implements QuerySnapshotListener {
      private static final Logger logger = LoggerFactory.getLogger(LocalSnapshotListener.class);
  
      private final SchemaManager schemaManager;
      private final SnapshotCache snapshotCache;
      private final AtomicLong lastDdlSnapshotId;
  
      public LocalSnapshotListener(SchemaManager schemaManager, SnapshotCache snapshotCache) {
          this.schemaManager = schemaManager;
          this.snapshotCache = snapshotCache;
          this.lastDdlSnapshotId = new AtomicLong(-1L);
      }
  
      @Override
      public void snapshotAdvanced(long snapshotId, long ddlSnapshotId) {
          logger.debug("snapshot advance to [{}]-[{}]", snapshotId, ddlSnapshotId);
          GraphDef graphDef = null;
          if (ddlSnapshotId > this.lastDdlSnapshotId.get()) {
              graphDef = this.schemaManager.getGraphDef();
          }
          this.snapshotCache.advanceQuerySnapshotId(snapshotId, graphDef);
          lastDdlSnapshotId.getAndUpdate(x -> Math.max(x, ddlSnapshotId));
      }
  }
  