fieldDeltaRec.java

/*

   fieldDeltaRec.java

   The fieldDeltaRec class is used to record the changes that have
   been made to a particular field in a DBObject.  This class is used
   by the DBObjectDeltaRec class to keep track of changes to fields.

   Created: 7 July 1998

   Module By: Jonathan Abbey, jonabbey@arlut.utexas.edu

   -----------------------------------------------------------------------

   Ganymede Directory Management System

   Copyright (C) 1996-2013
   The University of Texas at Austin

   Ganymede is a registered trademark of The University of Texas at Austin

   Contact information

   Author Email: ganymede_author@arlut.utexas.edu
   Email mailing list: ganymede@arlut.utexas.edu

   US Mail:

   Computer Science Division
   Applied Research Laboratories
   The University of Texas at Austin
   PO Box 8029, Austin TX 78713-8029

   Telephone: (512) 835-3200

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

package arlut.csd.ganymede.server;

import java.util.Vector;

import arlut.csd.Util.VectorUtils;

/*------------------------------------------------------------------------------
                                                                           class
                                                                   fieldDeltaRec

------------------------------------------------------------------------------*/

/**
 * <p>The fieldDeltaRec class is used to record the changes that have
 * been made to a particular field in a DBObject.  This class is used
 * by the DBObjectDeltaRec class to keep track of changes to
 * fields.</p>
 *
 * @see arlut.csd.ganymede.server.DBObjectDeltaRec
 * @see arlut.csd.ganymede.server.DBField
 */

final class fieldDeltaRec {

  short fieldcode;
  boolean vector;
  DBField scalarValue = null;
  Vector addValues = null;
  Vector delValues = null;

  /* -- */

  /**
   * <p>Scalar value constructor.  This constructor may actually be
   * used for vector fields when those vector fields are newly
   * defined.. in this case, we are actually doing a complete
   * definition of the field, rather than just a vector add/remove
   * record.</p>
   *
   * <p>If <scalar> is null, this fieldDeltaRec is recording the
   * deletion of a field.</p>
   */

  fieldDeltaRec(short fieldcode, DBField scalar)
  {
    this.fieldcode = fieldcode;
    this.scalarValue = scalar;
    vector = false;
  }

  /**
   * Vector constructor.  This constructor is used when we are doing a
   * vector differential record.
   */

  fieldDeltaRec(short fieldcode)
  {
    this.fieldcode = fieldcode;
    vector = true;
  }

  /**
   * This method is used to record a vector of values that have been
   * added to this vector field.
   */

  void addValues(Vector values)
  {
    for (Object value: values)
      {
        this.addValue(value);
      }
  }

  /**
   * This method is used to record a value that has been added
   * to this vector field.
   */

  void addValue(Object value)
  {
    if (!this.vector)
      {
        throw new IllegalStateException();
      }

    if (addValues == null)
      {
        addValues = new Vector();
      }

    if (delValues != null && delValues.contains(value))
      {
        delValues.removeElement(value);
      }
    else if (!addValues.contains(value))
      {
        addValues.add(value);
      }
  }

  /**
   * This method is used to record a vector of values that have been
   * removed to this vector field.
   */

  void delValues(Vector values)
  {
    for (Object value: values)
      {
        this.delValue(value);
      }
  }

  /**
   * This method is used to record a value that has been removed
   * from this vector field.
   */

  void delValue(Object value)
  {
    if (!this.vector)
      {
        throw new IllegalStateException();
      }

    if (delValues == null)
      {
        delValues = new Vector();
      }

    if (addValues != null && addValues.contains(value))
      {
        addValues.removeElement(value);
      }
    else if (!delValues.contains(value))
      {
        delValues.add(value);
      }
  }

  /**
   * <p>This method generates a diagnostic representation of this
   * fieldDeltaRec.</p>
   *
   * <p>This method will probably fail with an exception if the field
   * 'scalarValue' has not been initialized with a plausible
   * owner.</p>
   */

  public String toString()
  {
    if (!vector)
      {
        if (scalarValue == null)
          {
            return "<field: " + fieldcode + ", *deleting*>";
          }

        return "<field: " + fieldcode + ", new val = " + scalarValue.getValueString() + ">";
      }

    StringBuilder result = new StringBuilder();

    result.append("<field: ");
    result.append(fieldcode);
    result.append(", adding: ");
    result.append(VectorUtils.vectorString(addValues));
    result.append(", deleting: ");
    result.append(VectorUtils.vectorString(delValues));
    result.append(">");

    return result.toString();
  }
}