001    /*
002     * Copyright 2009-2016 UnboundID Corp.
003     * All Rights Reserved.
004     */
005    /*
006     * Copyright (C) 2009-2016 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    import com.unboundid.util.Mutable;
028    import com.unboundid.util.ThreadSafety;
029    import 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)
043    public 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    }