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.keygenerator.directdictionary;
  
  import org.apache.carbondata.core.metadata.datatype.DataType;
  
  /**
   * The interface provides the method to generate dictionary key
   * and getting the actual value from the dictionaryKey for direct dictionary column.
   */
  public interface DirectDictionaryGenerator {
  
    /**
     * The method generate and returns the dictionary / surrogate key for direct dictionary column
     *
     * @param member The member string value
     * @return returns dictionary/ surrogate value
     */
    int generateDirectSurrogateKey(String member);
  
    /**
     * The method returns the actual value of the requested dictionary / surrogate
     *
     * @param key
     * @return dictionary actual member
     */
    Object getValueFromSurrogate(int key);
  
    int generateKey(long value);
  
    /**
     * The method generate and returns the dictionary / surrogate key for direct dictionary column
     * This Method is called while executing filter queries for getting direct surrogate members.
     * Currently the query engine layer only supports yyyy-MM-dd HH:mm:ss date format no matter
     * in which format the data is been stored, so while retrieving the direct surrogate value for
     * filter member first it should be converted in date form as per above format and needs to
     * retrieve time stamp.
     *
     * @param memberStr The member string value
     * @return returns dictionary/ surrogate value
     */
    int generateDirectSurrogateKey(String memberStr, String format);
  
    void initialize();
  
    /**
     * Return value datatype for this generator
     *
     * @return
     */
    DataType getReturnType();
  
  }
  