ddfrecord.cpp

开源的电子海图程序

/*      Create new image of this whole field.                           */
/* -------------------------------------------------------------------- */
    char        *pachNewImage;
    int         nPreBytes, nPostBytes, nNewFieldSize;

    nNewFieldSize = poField->GetDataSize() - nInstanceSize + nRawDataSize;

    pachNewImage = (char *) CPLMalloc(nNewFieldSize);

    nPreBytes = pachWrkData - poField->GetData();
    nPostBytes = poField->GetDataSize() - nPreBytes - nInstanceSize;

    memcpy( pachNewImage, poField->GetData(), nPreBytes );
    memcpy( pachNewImage + nPreBytes + nRawDataSize, 
            poField->GetData() + nPreBytes + nInstanceSize,
            nPostBytes );
    memcpy( pachNewImage + nPreBytes, pachRawData, nRawDataSize );

/* -------------------------------------------------------------------- */
/*      Resize the field to the desired new size.                       */
/* -------------------------------------------------------------------- */
    ResizeField( poField, nNewFieldSize );

    memcpy( (void *) poField->GetData(), pachNewImage, nNewFieldSize );
    CPLFree( pachNewImage );

    return TRUE;
}

/************************************************************************/
/*                           UpdateFieldRaw()                           */
/************************************************************************/

int
DDFRecord::UpdateFieldRaw( DDFField *poField, int iIndexWithinField,
                           int nStartOffset, int nOldSize, 
                           const char *pachRawData, int nRawDataSize )

{
    int         iTarget, nRepeatCount;

/* -------------------------------------------------------------------- */
/*      Find which field we are to update.                              */
/* -------------------------------------------------------------------- */
    for( iTarget = 0; iTarget < nFieldCount; iTarget++ )
    {
        if( paoFields + iTarget == poField )
            break;
    }

    if( iTarget == nFieldCount )
        return FALSE;

    nRepeatCount = poField->GetRepeatCount();

    if( iIndexWithinField < 0 || iIndexWithinField >= nRepeatCount )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Figure out how much pre and post data there is.                 */
/* -------------------------------------------------------------------- */
    char *pachWrkData;
    int         nInstanceSize, nPostBytes, nPreBytes;
        
    pachWrkData = (char *) poField->GetInstanceData( iIndexWithinField, 
                                                     &nInstanceSize );
    nPreBytes = pachWrkData - poField->GetData() + nStartOffset;
    nPostBytes = poField->GetDataSize() - nPreBytes - nOldSize;

/* -------------------------------------------------------------------- */
/*      If we aren't changing the size, just copy over the existing     */
/*      data.                                                           */
/* -------------------------------------------------------------------- */
    if( nOldSize == nRawDataSize )
    {
        memcpy( pachWrkData + nStartOffset, pachRawData, nRawDataSize );
        return TRUE;
    }

/* -------------------------------------------------------------------- */
/*      If we are shrinking, move in the new data, and shuffle down     */
/*      the old before resizing.                                        */
/* -------------------------------------------------------------------- */
    if( nRawDataSize < nOldSize )
    {
        memcpy( ((char*) poField->GetData()) + nPreBytes, 
                pachRawData, nRawDataSize );
        memmove( ((char *) poField->GetData()) + nPreBytes + nRawDataSize, 
                 ((char *) poField->GetData()) + nPreBytes + nOldSize, 
                 nPostBytes );
    }

/* -------------------------------------------------------------------- */
/*      Resize the whole buffer.                                        */
/* -------------------------------------------------------------------- */
    if( !ResizeField( poField, 
                      poField->GetDataSize() - nOldSize + nRawDataSize ) )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      If we growing the buffer, shuffle up the post data, and         */
/*      move in our new values.                                         */
/* -------------------------------------------------------------------- */
    if( nRawDataSize >= nOldSize )
    {
        memmove( ((char *) poField->GetData()) + nPreBytes + nRawDataSize, 
                 ((char *) poField->GetData()) + nPreBytes + nOldSize, 
                 nPostBytes );
        memcpy( ((char*) poField->GetData()) + nPreBytes, 
                pachRawData, nRawDataSize );
    }

    return TRUE;
}

/************************************************************************/
/*                           ResetDirectory()                           */
/*                                                                      */
/*      Re-prepares the directory information for the record.           */
/************************************************************************/

int DDFRecord::ResetDirectory()

{
    int iField;

/* -------------------------------------------------------------------- */
/*      Eventually we should try to optimize the size of offset and     */
/*      field length.  For now we will use 5 for each which is          */
/*      pretty big.                                                     */
/* -------------------------------------------------------------------- */
    _sizeFieldPos = 5;
    _sizeFieldLength = 5;

/* -------------------------------------------------------------------- */
/*      Compute how large the directory needs to be.                    */
/* -------------------------------------------------------------------- */
    int nEntrySize, nDirSize;

    nEntrySize = _sizeFieldPos + _sizeFieldLength + _sizeFieldTag;
    nDirSize = nEntrySize * nFieldCount + 1;

/* -------------------------------------------------------------------- */
/*      If the directory size is different than what is currently       */
/*      reserved for it, we must resize.                                */
/* -------------------------------------------------------------------- */
    if( nDirSize != nFieldOffset )
    {
        char *pachNewData;
        int  nNewDataSize;

        nNewDataSize = nDataSize - nFieldOffset + nDirSize;
        pachNewData = (char *) CPLMalloc(nNewDataSize);
        memcpy( pachNewData + nDirSize, 
                pachData + nFieldOffset, 
                nNewDataSize - nDirSize );
     
        for( iField = 0; iField < nFieldCount; iField++ )
        {
            int nOffset;
            DDFField *poField = GetField( iField );

            nOffset = poField->GetData() - pachData - nFieldOffset + nDirSize;
            poField->Initialize( poField->GetFieldDefn(), 
                                 pachNewData + nOffset, 
                                 poField->GetDataSize() );
        }

        CPLFree( pachData );
        pachData = pachNewData;
        nDataSize = nNewDataSize;
        nFieldOffset = nDirSize;
    }

/* -------------------------------------------------------------------- */
/*      Now set each directory entry.                                   */
/* -------------------------------------------------------------------- */
    for( iField = 0; iField < nFieldCount; iField++ )
    {
        DDFField *poField = GetField( iField );
        DDFFieldDefn *poDefn = poField->GetFieldDefn();
        char      szFormat[128];

        sprintf( szFormat, "%%%ds%%0%dd%%0%dd", 
                 _sizeFieldTag, _sizeFieldLength, _sizeFieldPos );

        sprintf( pachData + nEntrySize * iField, szFormat, 
                 poDefn->GetName(), poField->GetDataSize(),
                 poField->GetData() - pachData - nFieldOffset );
    }

    pachData[nEntrySize * nFieldCount] = DDF_FIELD_TERMINATOR;
        
    return TRUE;
}

/************************************************************************/
/*                     CreateDefaultFieldInstance()                     */
/************************************************************************/

/**
 * Initialize default instance.
 *
 * This method is normally only used internally by the AddField() method
 * to initialize the new field instance with default subfield values.  It
 * installs default data for one instance of the field in the record
 * using the DDFFieldDefn::GetDefaultValue() method and 
 * DDFRecord::SetFieldRaw(). 
 *
 * @param poField the field within the record to be assign a default 
 * instance. 
 * @param iIndexWithinField the instance to set (may not have been tested with
 * values other than 0). 
 *
 * @return TRUE on success or FALSE on failure. 
 */

int DDFRecord::CreateDefaultFieldInstance( DDFField *poField, 
                                           int iIndexWithinField )

{
    int nRawSize, nSuccess;
    char *pachRawData;

    pachRawData = poField->GetFieldDefn()->GetDefaultValue( &nRawSize );
    if( pachRawData == NULL )
        return FALSE;

    nSuccess = SetFieldRaw( poField, iIndexWithinField, pachRawData, nRawSize);

    CPLFree( pachRawData );

    return nSuccess;
}

/************************************************************************/
/*                         SetStringSubfield()                          */
/************************************************************************/

/**
 * Set a string subfield in record.
 *
 * The value of a given subfield is replaced with a new string value 
 * formatted appropriately. 
 *
 * @param pszField the field name to operate on.
 * @param iFieldIndex the field index to operate on (zero based).
 * @param pszSubfield the subfield name to operate on. 
 * @param iSubfieldIndex the subfield index to operate on (zero based). 
 * @param pszValue the new string to place in the subfield.  This may be 
 * arbitrary binary bytes if nValueLength is specified. 
 * @param nValueLength the number of valid bytes in pszValue, may be -1 to 
 * internally fetch with strlen(). 
 * 
 * @return TRUE if successful, and FALSE if not. 
 */

int DDFRecord::SetStringSubfield( const char *pszField, int iFieldIndex, 
                                  const char *pszSubfield, int iSubfieldIndex,
                                  const char *pszValue, int nValueLength )

{
/* -------------------------------------------------------------------- */
/*      Fetch the field. If this fails, return zero.                    */
/* -------------------------------------------------------------------- */
    DDFField *poField; 

    poField = FindField( pszField, iFieldIndex );
    if( poField == NULL )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Get the subfield definition                                     */
/* -------------------------------------------------------------------- */
    DDFSubfieldDefn     *poSFDefn;

    poSFDefn = poField->GetFieldDefn()->FindSubfieldDefn( pszSubfield );
    if( poSFDefn == NULL )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      How long will the formatted value be?                           */
/* -------------------------------------------------------------------- */
    int nFormattedLen;

    if( !poSFDefn->FormatStringValue( NULL, 0, &nFormattedLen, pszValue,
                                      nValueLength ) )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Get a pointer to the data.                                      */
/* -------------------------------------------------------------------- */
    int         nMaxBytes;
    char *pachSubfieldData = (char *) 
        poField->GetSubfieldData(poSFDefn, &nMaxBytes,
                                 iSubfieldIndex);

/* -------------------------------------------------------------------- */
/*      Add new instance if we have run out of data.                    */
/* -------------------------------------------------------------------- */
    if( nMaxBytes == 0 
        || (nMaxBytes == 1 && pachSubfieldData[0] == DDF_FIELD_TERMINATOR) )
    {
        CreateDefaultFieldInstance( poField, iSubfieldIndex );

        // Refetch.
        pachSubfieldData = (char *) 
            poField->GetSubfieldData(poSFDefn, &nMaxBytes,
                                     iSubfieldIndex);
    }

/* -------------------------------------------------------------------- */
/*      If the new length matches the existing length, just overlay     */
/*      and return.                                                     */
/* -------------------------------------------------------------------- */
    int nExistingLength;

    poSFDefn->GetDataLength( pachSubfieldData, nMaxBytes, &nExistingLength );

    if( nExistingLength == nFormattedLen )
    {
        return poSFDefn->FormatStringValue( pachSubfieldData, nFormattedLen,
                                            NULL, pszValue, nValueLength );
    }

/* -------------------------------------------------------------------- */
/*      We will need to resize the raw data.                            */
/* -------------------------------------------------------------------- */
    const char *pachFieldInstData;
    int         nInstanceSize, nStartOffset, nSuccess;
    char *pachNewData;

    pachFieldInstData = poField->GetInstanceData( iFieldIndex,