ddfrecord.cpp

开源的电子海图程序

/******************************************************************************
 * $Id: ddfrecord.cpp,v 1.1.1.1 2004/12/29 07:54:55 jay-be-em Exp $
 *
 * Project:  ISO 8211 Access
 * Purpose:  Implements the DDFRecord class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 1999, Frank Warmerdam
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************
 *
 * $Log: ddfrecord.cpp,v $
 * Revision 1.1.1.1  2004/12/29 07:54:55  jay-be-em
 * Initial import
 *
 * Revision 1.24  2004/02/18 14:09:42  warmerda
 * doc fixups
 *
 * Revision 1.23  2003/12/08 20:32:48  warmerda
 * Added some improved error checking in DDFRecord() on the leader values.
 * Try reading extra bytes to find field terminator if the last byte in
 * a record isn't the field terminator.
 *
 * Revision 1.22  2003/12/02 16:50:21  warmerda
 * fixed problems with writing some kinds of records
 *
 * Revision 1.21  2003/11/12 21:21:55  warmerda
 * fixed to include field terminators when creating fields
 *
 * Revision 1.20  2003/09/17 21:11:07  warmerda
 * try to create new default field instance when needed
 *
 * Revision 1.19  2003/09/15 20:46:53  warmerda
 * supressed some warnings in SetFieldRaw if field empty
 *
 * Revision 1.18  2003/09/11 19:56:35  warmerda
 * avoid warnings
 *
 * Revision 1.17  2003/09/03 20:36:26  warmerda
 * added subfield writing support
 *
 * Revision 1.16  2003/07/03 15:38:46  warmerda
 * some write capabilities added
 *
 * Revision 1.15  2002/08/08 12:39:18  warmerda
 * Added support for variable length records as per bugzilla bug 181.
 *
 * Revision 1.14  2001/08/30 21:08:19  warmerda
 * expand tabs
 *
 * Revision 1.13  2001/08/27 19:09:00  warmerda
 * added GetInstanceData() method on DDFField
 *
 * Revision 1.12  2001/08/24 19:41:19  warmerda
 * fixed cloning problems
 *
 * Revision 1.11  2001/08/24 16:30:55  warmerda
 * added DDFRecord update in place methods for S57 updating
 *
 * Revision 1.10  2001/07/18 04:51:57  warmerda
 * added CPL_CVSID
 *
 * Revision 1.9  2000/02/15 17:55:53  warmerda
 * Improved error message for corrupt DDF files.
 *
 * Revision 1.8  1999/11/18 19:03:04  warmerda
 * expanded tabs
 *
 * Revision 1.7  1999/09/03 14:14:39  warmerda
 * fix cloning
 *
 * Revision 1.6  1999/09/02 03:10:01  warmerda
 * fixed subtle problem with rewinding modules with reusable headers
 *
 * Revision 1.5  1999/05/08 20:16:20  warmerda
 * added some record validity testing
 *
 * Revision 1.4  1999/05/07 14:12:24  warmerda
 * added record cloning, and subfield value fetches
 *
 * Revision 1.3  1999/05/06 14:48:28  warmerda
 * Fixed EOF handling in files with reused headers
 *
 * Revision 1.2  1999/05/06 14:24:29  warmerda
 * minor optimization, don't emit an error on EOF
 *
 * Revision 1.1  1999/04/27 18:45:05  warmerda
 * New
 *
 */

#include "iso8211.h"
#include "cpl_conv.h"

CPL_CVSID("$Id: ddfrecord.cpp,v 1.1.1.1 2004/12/29 07:54:55 jay-be-em Exp $");

static const size_t nLeaderSize = 24;

/************************************************************************/
/*                             DDFRecord()                              */
/************************************************************************/

DDFRecord::DDFRecord( DDFModule * poModuleIn )

{
    poModule = poModuleIn;

    nReuseHeader = FALSE;

    nFieldOffset = 0;

    nDataSize = 0;
    pachData = NULL;

    nFieldCount = 0;
    paoFields = NULL;

    bIsClone = FALSE;

    _sizeFieldTag = 4;
    _sizeFieldPos = 0;
    _sizeFieldLength = 0;
}

/************************************************************************/
/*                             ~DDFRecord()                             */
/************************************************************************/

DDFRecord::~DDFRecord()

{
    Clear();

    if( bIsClone )
        poModule->RemoveCloneRecord( this );
}

/************************************************************************/
/*                                Dump()                                */
/************************************************************************/

/**
 * Write out record contents to debugging file.
 *
 * A variety of information about this record, and all it's fields and
 * subfields is written to the given debugging file handle.  Note that
 * field definition information (ala DDFFieldDefn) isn't written.
 *
 * @param fp The standard io file handle to write to.  ie. stderr
 */

void DDFRecord::Dump( FILE * fp )

{
    fprintf( fp, "DDFRecord:\n" );
    fprintf( fp, "    nReuseHeader = %d\n", nReuseHeader );
    fprintf( fp, "    nDataSize = %d\n", nDataSize );
    fprintf( fp, 
             "    _sizeFieldLength=%d, _sizeFieldPos=%d, _sizeFieldTag=%d\n",
             _sizeFieldLength, _sizeFieldPos, _sizeFieldTag );

    for( int i = 0; i < nFieldCount; i++ )
    {
        paoFields[i].Dump( fp );
    }
}

/************************************************************************/
/*                                Read()                                */
/*                                                                      */
/*      Read a record of data from the file, and parse the header to    */
/*      build a field list for the record (or reuse the existing one    */
/*      if reusing headers).  It is expected that the file pointer      */
/*      will be positioned at the beginning of a data record.  It is    */
/*      the DDFModule's responsibility to do so.                        */
/*                                                                      */
/*      This method should only be called by the DDFModule class.       */
/************************************************************************/

int DDFRecord::Read()

{
/* -------------------------------------------------------------------- */
/*      Redefine the record on the basis of the header if needed.       */
/*      As a side effect this will read the data for the record as well.*/
/* -------------------------------------------------------------------- */
    if( !nReuseHeader )
    {
        return( ReadHeader() );
    }

/* -------------------------------------------------------------------- */
/*      Otherwise we read just the data and carefully overlay it on     */
/*      the previous records data without disturbing the rest of the    */
/*      record.                                                         */
/* -------------------------------------------------------------------- */
    size_t      nReadBytes;

    nReadBytes = VSIFRead( pachData + nFieldOffset, 1,
                           nDataSize - nFieldOffset,
                           poModule->GetFP() );
    if( nReadBytes != (size_t) (nDataSize - nFieldOffset)
        && nReadBytes == 0
        && VSIFEof( poModule->GetFP() ) )
    {
        return FALSE;
    }
    else if( nReadBytes != (size_t) (nDataSize - nFieldOffset) )
    {
        CPLError( CE_Failure, CPLE_FileIO,
                  "Data record is short on DDF file.\n" );
        
        return FALSE;
    }

    // notdef: eventually we may have to do something at this point to 
    // notify the DDFField's that their data values have changed. 
    
    return TRUE;
}

/************************************************************************/
/*                               Write()                                */
/************************************************************************/

/**
 * Write record out to module.
 *
 * This method writes the current record to the module to which it is 
 * attached.  Normally this would be at the end of the file, and only used
 * for modules newly created with DDFModule::Create().  Rewriting existing
 * records is not supported at this time.  Calling Write() multiple times
 * on a DDFRecord will result it multiple copies being written at the end of
 * the module.
 *
 * @return TRUE on success or FALSE on failure.
 */

int DDFRecord::Write()

{
    if( !ResetDirectory() )
        return FALSE;
    
/* -------------------------------------------------------------------- */
/*      Prepare leader.                                                 */
/* -------------------------------------------------------------------- */
    char szLeader[nLeaderSize+1];

    memset( szLeader, ' ', nLeaderSize );

    sprintf( szLeader+0, "%05d", nDataSize + nLeaderSize );
    szLeader[5] = ' ';
    szLeader[6] = 'D';
    
    sprintf( szLeader + 12, "%05d", nFieldOffset + nLeaderSize );
    szLeader[17] = ' ';

    szLeader[20] = (char) ('0' + _sizeFieldLength);
    szLeader[21] = (char) ('0' + _sizeFieldPos);
    szLeader[22] = '0';
    szLeader[23] = (char) ('0' + _sizeFieldTag);

    /* notdef: lots of stuff missing */

/* -------------------------------------------------------------------- */
/*      Write the leader.                                               */
/* -------------------------------------------------------------------- */
    VSIFWrite( szLeader, nLeaderSize, 1, poModule->GetFP() );

/* -------------------------------------------------------------------- */
/*      Write the remainder of the record.                              */
/* -------------------------------------------------------------------- */
    VSIFWrite( pachData, nDataSize, 1, poModule->GetFP() );
    
    return TRUE;
}

/************************************************************************/
/*                               Clear()                                */
/*                                                                      */
/*      Clear any information associated with the last header in        */
/*      preparation for reading a new header.                           */
/************************************************************************/

void DDFRecord::Clear()

{
    if( paoFields != NULL )
        delete[] paoFields;

    paoFields = NULL;
    nFieldCount = 0;

    if( pachData != NULL )
        CPLFree( pachData );

    pachData = NULL;
    nDataSize = 0;
    nReuseHeader = FALSE;
}

/************************************************************************/
/*                             ReadHeader()                             */
/*                                                                      */
/*      This perform the header reading and parsing job for the         */
/*      Read() method.  It reads the header, and builds a field         */
/*      list.                                                           */
/************************************************************************/

int DDFRecord::ReadHeader()

{
/* -------------------------------------------------------------------- */
/*      Clear any existing information.                                 */
/* -------------------------------------------------------------------- */
    Clear();