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     */
021    package com.unboundid.asn1;
022    
023    
024    
025    import java.io.Serializable;
026    
027    
028    
029    
030    /**
031     * This class provides a data structure which is used in the course of writing
032     * an ASN.1 sequence to an ASN.1 buffer.  It keeps track of the position at
033     * which the sequence value begins so that the appropriate length may be
034     * inserted after all embedded elements have been added.  The {@code end}
035     * method must be called after all elements have been added to ensure that the
036     * length is properly computed and inserted into the associated buffer.
037     */
038    public final class ASN1BufferSequence
039           implements Serializable
040    {
041      /**
042       * The serial version UID for this serializable class.
043       */
044      private static final long serialVersionUID = 7219098399193345629L;
045    
046    
047    
048      // The ASN.1 buffer with which the sequence is associated.
049      private final ASN1Buffer buffer;
050    
051      // The position in the ASN.1 buffer at which the first sequence value begins.
052      private final int valueStartPos;
053    
054    
055    
056      /**
057       * Creates a new instance of this class for the provided ASN.1 buffer.
058       *
059       * @param  buffer  The ASN.1 buffer with which this object will be associated.
060       */
061      ASN1BufferSequence(final ASN1Buffer buffer)
062      {
063        this.buffer = buffer;
064    
065        valueStartPos = buffer.length();
066      }
067    
068    
069    
070      /**
071       * Updates the associated ASN.1 buffer to indicate that all sequence elements
072       * have been added and that the appropriate length should be inserted.
073       */
074      public void end()
075      {
076        buffer.endSequenceOrSet(valueStartPos);
077      }
078    }