content: /*
   * 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.carbondata.core.metadata;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.carbondata.core.metadata.schema.table.CarbonTable;
  import org.apache.carbondata.core.metadata.schema.table.TableInfo;
  import org.apache.carbondata.core.metadata.schema.table.column.CarbonDimension;
  import org.apache.carbondata.core.util.CarbonProperties;
  
  import net.jodah.expiringmap.ExpirationPolicy;
  import net.jodah.expiringmap.ExpiringMap;
  
  /**
   * Class which persist the information about the tables present the carbon schemas
   */
  public final class CarbonMetadata {
  
    /**
     * meta data instance
     */
    private static final CarbonMetadata INSTANCE = new CarbonMetadata();
  
    /**
     * holds the list of tableInfo currently present
     */
    private ExpiringMap<String, CarbonTable> tableInfoMap;
  
    private CarbonMetadata() {
      // creating a concurrent map as it will be updated by multiple thread
      tableInfoMap = ExpiringMap.builder()
          .expiration(CarbonProperties.getInstance().getMetaCacheExpirationTime(), TimeUnit.SECONDS)
          .expirationPolicy(ExpirationPolicy.ACCESSED).build();
    }
  
    public static CarbonMetadata getInstance() {
      return INSTANCE;
    }
  
    /**
     * removed the table information
     *
     * @param tableUniqueName
     */
    public void removeTable(String tableUniqueName) {
      tableInfoMap.remove(convertToLowerCase(tableUniqueName));
    }
  
    /**
     * removed the table information
     *
     * @param databaseName
     * @param tableName
     */
    public void removeTable(String databaseName, String tableName) {
      removeTable(CarbonTable.buildUniqueName(databaseName, tableName));
    }
  
    /**
     * method load the table
     *
     * @param tableInfo
     */
    public void loadTableMetadata(TableInfo tableInfo) {
      CarbonTable carbonTable = tableInfoMap.get(convertToLowerCase(tableInfo.getTableUniqueName()));
      if (null == carbonTable ||
          carbonTable.getTableLastUpdatedTime() < tableInfo.getLastUpdatedTime()) {
        carbonTable = CarbonTable.buildFromTableInfo(tableInfo);
        tableInfoMap.put(convertToLowerCase(tableInfo.getTableUniqueName()), carbonTable);
      }
    }
  
    /**
     * Below method to get the loaded carbon table
     *
     * @param tableUniqueName
     * @return
     */
    public CarbonTable getCarbonTable(String tableUniqueName) {
      return tableInfoMap.get(convertToLowerCase(tableUniqueName));
    }
  
    /**
     * Below method to get the loaded carbon table
     *
     * @param databaseName
     * @param tableName
     * @return
     */
    public CarbonTable getCarbonTable(String databaseName, String tableName) {
      return getCarbonTable(CarbonTable.buildUniqueName(databaseName, tableName));
    }
  
    /**
     * @return the number of tables present in the schema
     */
    public int getNumberOfTables() {
      return tableInfoMap.size();
    }
  
    /**
     * returns the given string in lowercase
     * @param table
     * @return
     */
    public String convertToLowerCase(String table) {
      return table.toLowerCase();
    }
  
    /**
     * method will return dimension instance based on the column identifier
     * and table instance passed to it.
     *
     * @param carbonTable
     * @param columnIdentifier
     * @return CarbonDimension instance
     */
    public CarbonDimension getCarbonDimensionBasedOnColIdentifier(CarbonTable carbonTable,
        String columnIdentifier) {
      List<CarbonDimension> listOfCarbonDims = carbonTable.getVisibleDimensions();
      for (CarbonDimension dimension : listOfCarbonDims) {
        if (dimension.getColumnId().equalsIgnoreCase(columnIdentifier)) {
          return dimension;
        }
        if (dimension.getNumberOfChild() > 0) {
          CarbonDimension childDim =
              getCarbonChildDimsBasedOnColIdentifier(columnIdentifier, dimension);
          if (null != childDim) {
            return childDim;
          }
        }
      }
      return null;
    }
  
    /**
     * Below method will be used to get the dimension based on column identifier
     * for complex dimension children
     *
     * @param columnIdentifier column identifier
     * @param dimension        parent dimension
     * @return children dimension
     */
    private CarbonDimension getCarbonChildDimsBasedOnColIdentifier(String columnIdentifier,
        CarbonDimension dimension) {
      for (int i = 0; i < dimension.getNumberOfChild(); i++) {
        if (dimension.getListOfChildDimensions().get(i).getColumnId()
            .equalsIgnoreCase(columnIdentifier)) {
          return dimension.getListOfChildDimensions().get(i);
        } else if (dimension.getListOfChildDimensions().get(i).getNumberOfChild() > 0) {
          CarbonDimension childDim = getCarbonChildDimsBasedOnColIdentifier(columnIdentifier,
              dimension.getListOfChildDimensions().get(i));
          if (null != childDim) {
            return childDim;
          }
        }
      }
      return null;
    }
  
    public List<CarbonTable> getAllTables() {
      return new ArrayList<>(tableInfoMap.values());
    }
  
    public void clearAll() {
      tableInfoMap.clear();
    }
  }
  