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.cassandra.db.virtual.model;
  
  import java.lang.annotation.ElementType;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Target;
  
  import org.apache.cassandra.db.virtual.walker.RowWalker;
  
  /**
   * Annotation to mark a walk order for a {@link RowWalker}. Annotation is used on a method that returns a value and
   * represents a column value for a row. The columns order is defined by the column type and the column name
   * in lexicographical order (case-insensitive) and the same way as in CQL (partition key columns first,
   * then clustering columns, then regular columns).
   * <p>
   * The column {@link Column.Type} type is the same as the existing CQL {@code ColumnMetadata.Kind} and is used to
   * define the column types for the virtual tables.
   */
  @Retention(RetentionPolicy.SOURCE)
  @Target(ElementType.METHOD)
  public @interface Column
  {
      /**
       * The type of the column
       */
      Type type() default Type.REGULAR;
  
      /**
       * Be sure the order of the enum values is preserved as they are used in ordinal comparisons for the virtual tables.
       */
      enum Type
      {
          /**
           * The column is a partition key column.
           */
          PARTITION_KEY,
          /**
           * The column is a clustering column.
           */
          CLUSTERING,
          /**
           * The column is a regular column.
           */
          REGULAR
      }
  }
  