001/*
002 * Copyright 2009-2014 UnboundID Corp.
003 * All Rights Reserved.
004 */
005/*
006 * Copyright (C) 2009-2014 UnboundID Corp.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU General Public License (GPLv2 only)
010 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
011 * as published by the Free Software Foundation.
012 *
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with this program; if not, see <http://www.gnu.org/licenses>.
020 */
021package com.unboundid.asn1;
022
023
024
025import java.io.Serializable;
026
027import com.unboundid.util.Mutable;
028import com.unboundid.util.ThreadSafety;
029import com.unboundid.util.ThreadSafetyLevel;
030
031
032
033/**
034 * This class provides a data structure which is used in the course of writing
035 * an ASN.1 sequence to an ASN.1 buffer.  It keeps track of the position at
036 * which the sequence value begins so that the appropriate length may be
037 * inserted after all embedded elements have been added.  The {@link #end}
038 * method must be called after all elements have been added to ensure that the
039 * length is properly computed and inserted into the associated buffer.
040 */
041@Mutable()
042@ThreadSafety(level=ThreadSafetyLevel.NOT_THREADSAFE)
043public final class ASN1BufferSequence
044       implements Serializable
045{
046  /**
047   * The serial version UID for this serializable class.
048   */
049  private static final long serialVersionUID = 7219098399193345629L;
050
051
052
053  // The ASN.1 buffer with which the sequence is associated.
054  private final ASN1Buffer buffer;
055
056  // The position in the ASN.1 buffer at which the first sequence value begins.
057  private final int valueStartPos;
058
059
060
061  /**
062   * Creates a new instance of this class for the provided ASN.1 buffer.
063   *
064   * @param  buffer  The ASN.1 buffer with which this object will be associated.
065   */
066  ASN1BufferSequence(final ASN1Buffer buffer)
067  {
068    this.buffer = buffer;
069
070    valueStartPos = buffer.length();
071  }
072
073
074
075  /**
076   * Updates the associated ASN.1 buffer to indicate that all sequence elements
077   * have been added and that the appropriate length should be inserted.
078   */
079  public void end()
080  {
081    buffer.endSequenceOrSet(valueStartPos);
082  }
083}