code: /*
   * 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.skywalking.oap.server.storage.plugin.elasticsearch.cache;
  
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.library.elasticsearch.requests.search.BoolQueryBuilder;
  import org.apache.skywalking.library.elasticsearch.requests.search.Query;
  import org.apache.skywalking.library.elasticsearch.requests.search.Search;
  import org.apache.skywalking.oap.server.core.analysis.manual.networkalias.NetworkAddressAlias;
  import org.apache.skywalking.oap.server.core.storage.cache.INetworkAddressAliasDAO;
  import org.apache.skywalking.oap.server.library.client.elasticsearch.ElasticSearchClient;
  import org.apache.skywalking.oap.server.library.client.elasticsearch.ElasticSearchScroller;
  import org.apache.skywalking.oap.server.storage.plugin.elasticsearch.StorageModuleElasticsearchConfig;
  import org.apache.skywalking.oap.server.storage.plugin.elasticsearch.base.ElasticSearchConverter;
  import org.apache.skywalking.oap.server.storage.plugin.elasticsearch.base.EsDAO;
  import org.apache.skywalking.oap.server.storage.plugin.elasticsearch.base.IndexController;
  
  import java.util.Collections;
  import java.util.List;
  
  @Slf4j
  public class NetworkAddressAliasEsDAO extends EsDAO implements INetworkAddressAliasDAO {
      protected final int resultWindowMaxSize;
      protected final int scrollingBatchSize;
  
      public NetworkAddressAliasEsDAO(ElasticSearchClient client,
                                      StorageModuleElasticsearchConfig config) {
          super(client);
          this.resultWindowMaxSize = config.getResultWindowMaxSize();
          this.scrollingBatchSize = config.getScrollingBatchSize();
      }
  
      @Override
      public List<NetworkAddressAlias> loadLastUpdate(long timeBucketInMinute) {
          final String index =
              IndexController.LogicIndicesRegister.getPhysicalTableName(NetworkAddressAlias.INDEX_NAME);
          try {
              final int batchSize = Math.min(resultWindowMaxSize, scrollingBatchSize);
              final BoolQueryBuilder query = Query.bool();
              if (IndexController.LogicIndicesRegister.isMergedTable(NetworkAddressAlias.INDEX_NAME)) {
                  query.must(Query.term(IndexController.LogicIndicesRegister.METRIC_TABLE_NAME, NetworkAddressAlias.INDEX_NAME));
              }
              query.must(Query.range(NetworkAddressAlias.LAST_UPDATE_TIME_BUCKET)
                               .gte(timeBucketInMinute));
  
              final var search = Search.builder().query(query).size(batchSize).build();
              final var builder = new NetworkAddressAlias.Builder();
  
              final var scroller = ElasticSearchScroller
                  .<NetworkAddressAlias>builder()
                  .client(getClient())
                  .search(search)
                  .index(index)
                  .queryMaxSize(resultWindowMaxSize)
                  .resultConverter(searchHit -> builder.storage2Entity(
                      new ElasticSearchConverter.ToEntity(NetworkAddressAlias.INDEX_NAME, searchHit.getSource())))
                  .build();
              return scroller.scroll();
          } catch (Throwable t) {
              log.error(t.getMessage(), t);
              return Collections.emptyList();
          }
      }
  }
  