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.core.query;
  
  import org.apache.skywalking.oap.server.core.query.input.Duration;
  import org.apache.skywalking.oap.server.core.query.input.RecordCondition;
  import org.apache.skywalking.oap.server.core.query.type.Record;
  import org.apache.skywalking.oap.server.core.storage.StorageModule;
  import org.apache.skywalking.oap.server.core.storage.annotation.ValueColumnMetadata;
  import org.apache.skywalking.oap.server.core.storage.query.IRecordsQueryDAO;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.library.module.Service;
  
  import java.io.IOException;
  import java.util.List;
  
  public class RecordQueryService implements Service {
      private final ModuleManager moduleManager;
      private IRecordsQueryDAO recordsQueryDAO;
  
      public RecordQueryService(ModuleManager manager) {
          this.moduleManager = manager;
      }
  
      private IRecordsQueryDAO getRecordsQueryDAO() {
          if (recordsQueryDAO == null) {
              this.recordsQueryDAO = moduleManager.find(StorageModule.NAME)
                  .provider()
                  .getService(IRecordsQueryDAO.class);
          }
          return recordsQueryDAO;
      }
  
      public List<Record> readRecords(RecordCondition condition, Duration duration) throws IOException {
          return getRecordsQueryDAO().readRecords(
              condition, ValueColumnMetadata.INSTANCE.getValueCName(condition.getName()), duration);
      }
  }
  