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.banyandb;
  
  import com.google.common.collect.ImmutableSet;
  import org.apache.skywalking.banyandb.v1.client.AbstractQuery;
  import org.apache.skywalking.banyandb.v1.client.RowEntity;
  import org.apache.skywalking.banyandb.v1.client.StreamQuery;
  import org.apache.skywalking.banyandb.v1.client.StreamQueryResponse;
  import org.apache.skywalking.banyandb.v1.client.TimestampRange;
  import org.apache.skywalking.oap.server.core.analysis.topn.TopN;
  import org.apache.skywalking.oap.server.core.query.enumeration.Order;
  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.query.IRecordsQueryDAO;
  import org.apache.skywalking.oap.server.library.util.StringUtil;
  import org.apache.skywalking.oap.server.storage.plugin.banyandb.stream.AbstractBanyanDBDAO;
  import org.apache.skywalking.oap.server.storage.plugin.banyandb.util.ByteUtil;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Set;
  
  public class BanyanDBRecordsQueryDAO extends AbstractBanyanDBDAO implements IRecordsQueryDAO {
  
      public BanyanDBRecordsQueryDAO(BanyanDBStorageClient client) {
          super(client);
      }
  
      @Override
      public List<Record> readRecords(RecordCondition condition, String valueColumnName, Duration duration) throws IOException {
          final String modelName = condition.getName();
          final TimestampRange timestampRange = new TimestampRange(duration.getStartTimestamp(), duration.getEndTimestamp());
          final Set<String> tags = ImmutableSet.of(TopN.ENTITY_ID, TopN.STATEMENT, TopN.TRACE_ID, valueColumnName);
          StreamQueryResponse resp = query(modelName, tags,
                  timestampRange, new QueryBuilder<StreamQuery>() {
                      @Override
                      protected void apply(StreamQuery query) {
                          query.and(eq(TopN.ENTITY_ID, condition.getParentEntity().buildId()));
                          if (condition.getOrder() == Order.DES) {
                              query.setOrderBy(new StreamQuery.OrderBy(valueColumnName, AbstractQuery.Sort.DESC));
                          } else {
                              query.setOrderBy(new StreamQuery.OrderBy(valueColumnName, AbstractQuery.Sort.ASC));
                          }
                          query.setLimit(condition.getTopN());
                      }
                  });
  
          if (resp.size() == 0) {
              return Collections.emptyList();
          }
  
          MetadataRegistry.Schema schema = MetadataRegistry.INSTANCE.findRecordMetadata(modelName);
          if (schema == null) {
              throw new IOException("schema is not registered");
          }
  
          MetadataRegistry.ColumnSpec spec = schema.getSpec(valueColumnName);
          if (spec == null) {
              throw new IOException("field spec is not registered");
          }
  
          List<Record> results = new ArrayList<>(condition.getTopN());
  
          for (final RowEntity e : resp.getElements()) {
              Record record = new Record();
              final String refId = e.getTagValue(TopN.TRACE_ID);
              record.setName(e.getTagValue(TopN.STATEMENT));
              record.setRefId(StringUtil.isEmpty(refId) ? "" : refId);
              record.setId(record.getRefId());
              record.setValue(extractFieldValueAsString(spec, valueColumnName, e));
              results.add(record);
          }
  
          return results;
      }
  
      private String extractFieldValueAsString(MetadataRegistry.ColumnSpec spec, String fieldName, RowEntity e) throws IOException {
          if (double.class.equals(spec.getColumnClass())) {
              return String.valueOf(ByteUtil.bytes2Double(e.getTagValue(fieldName)).longValue());
          } else if (String.class.equals(spec.getColumnClass())) {
              return e.getTagValue(fieldName);
          } else {
              return String.valueOf(((Number) e.getTagValue(fieldName)).longValue());
          }
      }
  }
  