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.bookkeeper.metastore;
  
  import java.util.Set;
  
  /**
   * Metastore Scannable Table.
   */
  public interface MetastoreScannableTable extends MetastoreTable {
  
      // Used by cursor, etc when they want to start at the beginning of a table
      String EMPTY_START_KEY = null;
      // Last row in a table.
      String EMPTY_END_KEY = null;
      /**
       * The order to loop over a table.
       */
      enum Order {
          ASC,
          DESC
      }
  
      /**
       * Open a cursor to loop over the entries belonging to a key range,
       * which returns all fields for each entry.
       *
       * <p>Return Code:<br/>
       * {@link MSException.Code.OK}: an opened cursor<br/>
       * {@link MSException.Code.IllegalOp}/{@link MSException.Code.ServiceDown}:
       * other issues
       *
       * @param firstKey
       *            Key to start scanning. If it is {@link EMPTY_START_KEY}, it starts
       *            from first key (inclusive).
       * @param firstInclusive
       *            true if firstKey is to be included in the returned view.
       * @param lastKey
       *            Key to stop scanning. If it is {@link EMPTY_END_KEY}, scan ends at
       *            the lastKey of the table (inclusive).
       * @param lastInclusive
       *            true if lastKey is to be included in the returned view.
       * @param order
       *            the order to loop over the entries
       * @param cb
       *            Callback to return an opened cursor.
       * @param ctx
       *            Callback context
       */
      void openCursor(String firstKey, boolean firstInclusive,
                             String lastKey, boolean lastInclusive,
                             Order order,
                             MetastoreCallback<MetastoreCursor> cb,
                             Object ctx);
  
      /**
       * Open a cursor to loop over the entries belonging to a key range,
       * which returns the specified <code>fields</code> for each entry.
       *
       * <p>Return Code:<br/>
       * {@link MSException.Code.OK}: an opened cursor<br/>
       * {@link MSException.Code.IllegalOp}/{@link MSException.Code.ServiceDown}:
       * other issues
       *
       * @param firstKey
       *            Key to start scanning. If it is {@link EMPTY_START_KEY}, it starts
       *            from first key (inclusive).
       * @param firstInclusive
       *            true if firstKey is to be included in the returned view.
       * @param lastKey
       *            Key to stop scanning. If it is {@link EMPTY_END_KEY}, scan ends at
       *            the lastKey of the table (inclusive).
       * @param lastInclusive
       *            true if lastKey is to be included in the returned view.
       * @param order
       *            the order to loop over the entries
       * @param fields
       *            Fields to select
       * @param cb
       *            Callback to return an opened cursor.
       * @param ctx
       *            Callback context
       */
      void openCursor(String firstKey, boolean firstInclusive,
                             String lastKey, boolean lastInclusive,
                             Order order, Set<String> fields,
                             MetastoreCallback<MetastoreCursor> cb,
                             Object ctx);
  
  }
  