DBFAddNativeFieldType()

int SHPAPI_CALL DBFAddNativeFieldType	(	DBFHandle	hDBF,
		const char *	pszFieldName,
		char	chType,
		int	nWidth,
		int	nDecimals
	)

Definition at line 844 of file dbfopen.c.

{
    char        *pszFInfo;
    int         i;
    int         nOldRecordLength, nOldHeaderLength;
    char        *pszRecord;
    char        chFieldFill;
    SAOffset    nRecordOffset;
 
    /* make sure that everything is written in .dbf */
    if( !DBFFlushRecord( psDBF ) )
        return -1;
 
    if( psDBF->nHeaderLength + XBASE_FLDHDR_SZ > 65535 )
    {
        char szMessage[128];
        snprintf( szMessage, sizeof(szMessage),
                  "Cannot add field %s. Header length limit reached "
                  "(max 65535 bytes, 2046 fields).",
                  pszFieldName );
        psDBF->sHooks.Error( szMessage );
        return -1;
    }
 
/* -------------------------------------------------------------------- */
/*      Do some checking to ensure we can add records to this file.     */
/* -------------------------------------------------------------------- */
    if( nWidth < 1 )
        return -1;
 
    if( nWidth > XBASE_FLD_MAX_WIDTH )
        nWidth = XBASE_FLD_MAX_WIDTH;
 
    if( psDBF->nRecordLength + nWidth > 65535 )
    {
        char szMessage[128];
        snprintf( szMessage, sizeof(szMessage),
                  "Cannot add field %s. Record length limit reached "
                  "(max 65535 bytes).",
                  pszFieldName );
        psDBF->sHooks.Error( szMessage );
        return -1;
    }
 
    nOldRecordLength = psDBF->nRecordLength;
    nOldHeaderLength = psDBF->nHeaderLength;
 
/* -------------------------------------------------------------------- */
/*      SfRealloc all the arrays larger to hold the additional field      */
/*      information.                                                    */
/* -------------------------------------------------------------------- */
    psDBF->nFields++;
 
    psDBF->panFieldOffset = STATIC_CAST(int *,
        SfRealloc( psDBF->panFieldOffset, sizeof(int) * psDBF->nFields ));
 
    psDBF->panFieldSize = STATIC_CAST(int *,
        SfRealloc( psDBF->panFieldSize, sizeof(int) * psDBF->nFields ));
 
    psDBF->panFieldDecimals = STATIC_CAST(int *,
        SfRealloc( psDBF->panFieldDecimals, sizeof(int) * psDBF->nFields ));
 
    psDBF->pachFieldType = STATIC_CAST(char *,
        SfRealloc( psDBF->pachFieldType, sizeof(char) * psDBF->nFields ));
 
/* -------------------------------------------------------------------- */
/*      Assign the new field information fields.                        */
/* -------------------------------------------------------------------- */
    psDBF->panFieldOffset[psDBF->nFields-1] = psDBF->nRecordLength;
    psDBF->nRecordLength += nWidth;
    psDBF->panFieldSize[psDBF->nFields-1] = nWidth;
    psDBF->panFieldDecimals[psDBF->nFields-1] = nDecimals;
    psDBF->pachFieldType[psDBF->nFields-1] = chType;
 
/* -------------------------------------------------------------------- */
/*      Extend the required header information.                         */
/* -------------------------------------------------------------------- */
    psDBF->nHeaderLength += XBASE_FLDHDR_SZ;
    psDBF->bUpdated = FALSE;
 
    psDBF->pszHeader = STATIC_CAST(char *, SfRealloc(psDBF->pszHeader,
                                          psDBF->nFields*XBASE_FLDHDR_SZ));
 
    pszFInfo = psDBF->pszHeader + XBASE_FLDHDR_SZ * (psDBF->nFields-1);
 
    for( i = 0; i < XBASE_FLDHDR_SZ; i++ )
        pszFInfo[i] = '\0';
 
    strncpy( pszFInfo, pszFieldName, XBASE_FLDNAME_LEN_WRITE );
 
    pszFInfo[11] = psDBF->pachFieldType[psDBF->nFields-1];
 
    if( chType == 'C' )
    {
        pszFInfo[16] = STATIC_CAST(unsigned char, nWidth % 256);
        pszFInfo[17] = STATIC_CAST(unsigned char, nWidth / 256);
    }
    else
    {
        pszFInfo[16] = STATIC_CAST(unsigned char, nWidth);
        pszFInfo[17] = STATIC_CAST(unsigned char, nDecimals);
    }
 
/* -------------------------------------------------------------------- */
/*      Make the current record buffer appropriately larger.            */
/* -------------------------------------------------------------------- */
    psDBF->pszCurrentRecord = STATIC_CAST(char *, SfRealloc(psDBF->pszCurrentRecord,
                                                 psDBF->nRecordLength));
 
    /* we're done if dealing with new .dbf */
    if( psDBF->bNoHeader )
        return( psDBF->nFields - 1 );
 
/* -------------------------------------------------------------------- */
/*      For existing .dbf file, shift records                           */
/* -------------------------------------------------------------------- */
 
    /* alloc record */
    pszRecord = STATIC_CAST(char *, malloc(sizeof(char) * psDBF->nRecordLength));
 
    chFieldFill = DBFGetNullCharacter(chType);
 
    for (i = psDBF->nRecords-1; i >= 0; --i)
    {
        nRecordOffset = nOldRecordLength * STATIC_CAST(SAOffset, i) + nOldHeaderLength;
 
        /* load record */
        psDBF->sHooks.FSeek( psDBF->fp, nRecordOffset, 0 );
        psDBF->sHooks.FRead( pszRecord, nOldRecordLength, 1, psDBF->fp );
 
        /* set new field's value to NULL */
        memset(pszRecord + nOldRecordLength, chFieldFill, nWidth);
 
        nRecordOffset = psDBF->nRecordLength * STATIC_CAST(SAOffset, i) + psDBF->nHeaderLength;
 
        /* move record to the new place*/
        psDBF->sHooks.FSeek( psDBF->fp, nRecordOffset, 0 );
        psDBF->sHooks.FWrite( pszRecord, psDBF->nRecordLength, 1, psDBF->fp );
    }
 
    if( psDBF->bWriteEndOfFileChar )
    {
        char ch = END_OF_FILE_CHARACTER;
 
        nRecordOffset =
            psDBF->nRecordLength * STATIC_CAST(SAOffset,psDBF->nRecords) + psDBF->nHeaderLength;
 
        psDBF->sHooks.FSeek( psDBF->fp, nRecordOffset, 0 );
        psDBF->sHooks.FWrite( &ch, 1, 1, psDBF->fp );
    }
 
    /* free record */
    free(pszRecord);
 
    /* force update of header with new header, record length and new field */
    psDBF->bNoHeader = TRUE;
    DBFUpdateHeader( psDBF );
 
    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;
    psDBF->bUpdated = TRUE;
 
    return( psDBF->nFields-1 );
}

References DBFInfo::bCurrentRecordModified, DBFInfo::bNoHeader, DBFInfo::bUpdated, DBFInfo::bWriteEndOfFileChar, DBFFlushRecord(), DBFGetNullCharacter(), DBFUpdateHeader(), END_OF_FILE_CHARACTER, SAHooks::Error, FALSE, DBFInfo::fp, SAHooks::FRead, free(), SAHooks::FSeek, SAHooks::FWrite, malloc(), DBFInfo::nCurrentRecord, DBFInfo::nFields, DBFInfo::nHeaderLength, DBFInfo::nRecordLength, DBFInfo::nRecords, DBFInfo::pachFieldType, DBFInfo::panFieldDecimals, DBFInfo::panFieldOffset, DBFInfo::panFieldSize, DBFInfo::pszCurrentRecord, DBFInfo::pszHeader, SfRealloc(), DBFInfo::sHooks, STATIC_CAST, TRUE, XBASE_FLD_MAX_WIDTH, XBASE_FLDHDR_SZ, and XBASE_FLDNAME_LEN_WRITE.

Referenced by DBFAddField().

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