integration/spark/src/main/java/org/apache/spark/sql/index/IndexTableUtil.java

/*
 * 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.spark.sql.index;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

import org.apache.carbondata.core.constants.CarbonCommonConstants;
import org.apache.carbondata.core.metadata.index.IndexType;
import org.apache.carbondata.core.metadata.schema.indextable.IndexMetadata;
import org.apache.carbondata.core.metadata.schema.indextable.IndexTableInfo;
import org.apache.carbondata.core.metadata.schema.table.CarbonTable;

import org.apache.spark.sql.secondaryindex.exception.IndexTableExistException;

public class IndexTableUtil {
  /**
   * adds index table info into parent table properties
   */
  public static String checkAndAddIndexTable(String gsonData, IndexTableInfo newIndexTable,
      boolean isSecondaryIndex) throws IndexTableExistException {
    IndexTableInfo[] indexTableInfos = IndexTableInfo.fromGson(gsonData);
    if (null == indexTableInfos) {
      indexTableInfos = new IndexTableInfo[0];
    }
    List<IndexTableInfo> indexTables = new ArrayList<>(Arrays.asList(indexTableInfos));
    if (isSecondaryIndex) {
      for (IndexTableInfo indexTable : indexTableInfos) {
        if (indexTable.getIndexProperties().get(CarbonCommonConstants.INDEX_PROVIDER)
            .equalsIgnoreCase(IndexType.SI.getIndexProviderName())) {
          if (indexTable.getIndexCols().size() == newIndexTable.getIndexCols().size()) {
            //If column order is not same, then also index table creation should be successful
            //eg., index1 is a,b,d and index2 is a,d,b. Both table creation should be successful
            boolean isColumnOrderSame = true;
            for (int i = 0; i < indexTable.getIndexCols().size(); i++) {
              if (!indexTable.getIndexCols().get(i)
                  .equalsIgnoreCase(newIndexTable.getIndexCols().get(i))) {
                isColumnOrderSame = false;
                break;
              }
            }
            if (isColumnOrderSame) {
              throw new IndexTableExistException("Index Table with selected columns already exist");
            }
          }
        }
      }
    }
    indexTables.add(newIndexTable);
    return IndexTableInfo.toGson(indexTables.toArray(new IndexTableInfo[0]));
  }

  public static void addIndexInfoToParentTable(CarbonTable parentTable, String indexProviderName,
      String indexName, Map<String, String> indexProperties) throws IOException {
    // set index information in parent table
    IndexMetadata parentIndexMetadata;
    Map<String, String> tableProperties =
        parentTable.getTableInfo().getFactTable().getTableProperties();
    if (tableProperties.get(parentTable.getCarbonTableIdentifier().getTableId()) != null) {
      parentIndexMetadata = parentTable.getIndexMetadata();
    } else {
      parentIndexMetadata = new IndexMetadata(false);
    }
    parentIndexMetadata.addIndexTableInfo(indexProviderName, indexName, indexProperties);

    tableProperties.put(parentTable.getCarbonTableIdentifier().getTableId(),
        parentIndexMetadata.serialize());
  }
}