jackcess/src/java/com/healthmarketscience/jackcess/IndexCodes.java

/*
Copyright (c) 2008 Health Market Science, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
USA

You can contact Health Market Science at info@healthmarketscience.com
or at the following address:

Health Market Science
2700 Horizon Drive
Suite 200
King of Prussia, PA 19406
*/

package com.healthmarketscience.jackcess;


/**
 * Various constants used for creating index entries.
 *
 * @author James Ahlborn
 */
public class IndexCodes {

  static final byte ASC_START_FLAG = (byte)0x7F;
  static final byte ASC_NULL_FLAG = (byte)0x00;
  static final byte DESC_START_FLAG = (byte)0x80;
  static final byte DESC_NULL_FLAG = (byte)0xFF;

  static final byte MID_GUID = (byte)0x09;
  static final byte ASC_END_GUID = (byte)0x08;
  static final byte DESC_END_GUID = (byte)0xF7;

  static final byte ASC_BOOLEAN_TRUE = (byte)0x00;
  static final byte ASC_BOOLEAN_FALSE = (byte)0xFF;
  
  static final byte DESC_BOOLEAN_TRUE = ASC_BOOLEAN_FALSE;
  static final byte DESC_BOOLEAN_FALSE = ASC_BOOLEAN_TRUE;


  static boolean isNullEntry(byte startEntryFlag) {
    return((startEntryFlag == ASC_NULL_FLAG) ||
           (startEntryFlag == DESC_NULL_FLAG));
  }
  
  static byte getNullEntryFlag(boolean isAscending) {
    return(isAscending ? ASC_NULL_FLAG : DESC_NULL_FLAG);
  }
  
  static byte getStartEntryFlag(boolean isAscending) {
    return(isAscending ? ASC_START_FLAG : DESC_START_FLAG);
  }
  
}