tabdatfile.cpp

linux下一款GIS程序源码

            WriteHeader();
        }

        m_numRecords = MAX(nRecordId, m_numRecords);

        nFileOffset = m_nFirstRecordPtr+(nRecordId-1)*m_nRecordSize;

        m_poRecordBlock->InitNewBlock(m_fp, m_nRecordSize, nFileOffset);

        /*-------------------------------------------------------------
         * The first char of the record is the active/deleted flag.
         * Automatically set it to ' ' (active).
         *------------------------------------------------------------*/
        m_poRecordBlock->WriteByte(' ');

    }

    m_nCurRecordId = nRecordId;

    return m_poRecordBlock;
}



/**********************************************************************
 *                   TABDATFile::CommitRecordToFile()
 *
 * Commit the data record previously initialized with GetRecordBlock()
 * to the file.  This function must be called after writing the data
 * values to a record otherwise the record will never make it to the
 * file.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int  TABDATFile::CommitRecordToFile()
{
    if (m_eAccessMode != TABWrite || m_poRecordBlock == NULL)
        return -1;

    return m_poRecordBlock->CommitToFile();
}



/**********************************************************************
 *                   TABDATFile::ValidateFieldInfoFromTAB()
 *
 * Check that the value read from the .TAB file by the caller are 
 * consistent with what is found in the .DAT header.
 *
 * Note that field ids are positive and start at 0.
 *
 * We have to use this function when opening a file for reading since 
 * the .DAT file does not contain the full field types information...
 * a .DAT file is actually a .DBF file in which the .DBF types are
 * handled in a special way... type 'C' fields are used to store binary 
 * values for most MapInfo types.
 *
 * For TABTableDBF, we actually have no validation to do since all types
 * are stored as strings internally, so we'll just convert from string.
 *
 * Returns a value >= 0 if OK, -1 on error.
 **********************************************************************/
int  TABDATFile::ValidateFieldInfoFromTAB(int iField, const char *pszName,
                                          TABFieldType eType,
                                          int nWidth, int nPrecision)
{
    int i = iField;  // Just to make things shorter

    assert(m_pasFieldDef);

    if (m_pasFieldDef == NULL || iField < 0 || iField >= m_numFields)
    {
        UGKError(ET_Failure, UGKErr_FileIO,
          "Invalid field %d (%s) in .TAB header. %s contains only %d fields.",
                 iField+1, pszName, m_pszFname, m_pasFieldDef? m_numFields:0);
        return -1;
    }

    /*-----------------------------------------------------------------
     * We used to check that the .TAB field name matched the .DAT
     * name stored internally, but apparently some tools that rename table
     * field names only update the .TAB file and not the .DAT, so we won't
     * do that name validation any more... we'll just check the type.
     *
     * With TABTableNative, we have to validate the field sizes as well
     * because .DAT files use char fields to store binary values.
     * With TABTableDBF, no need to validate field type since all
     * fields are stored as strings internally.
     *----------------------------------------------------------------*/
    if ((m_eTableType == TABTableNative && 
         ((eType == TABFChar && (m_pasFieldDef[i].cType != 'C' ||
                                m_pasFieldDef[i].byLength != nWidth )) ||
          (eType == TABFDecimal && (m_pasFieldDef[i].cType != 'N' ||
                                  m_pasFieldDef[i].byLength != nWidth||
                                   m_pasFieldDef[i].byDecimals!=nPrecision)) ||
          (eType == TABFInteger && (m_pasFieldDef[i].cType != 'C' ||
                                   m_pasFieldDef[i].byLength != 4  )) ||
          (eType == TABFSmallInt && (m_pasFieldDef[i].cType != 'C' ||
                                    m_pasFieldDef[i].byLength != 2 )) ||
          (eType == TABFFloat && (m_pasFieldDef[i].cType != 'C' ||
                                 m_pasFieldDef[i].byLength != 8    )) ||
          (eType == TABFDate && (m_pasFieldDef[i].cType != 'C' ||
                                m_pasFieldDef[i].byLength != 4     )) ||
          (eType == TABFLogical && (m_pasFieldDef[i].cType != 'L' ||
                                   m_pasFieldDef[i].byLength != 1  ))   ) ))
    {
        UGKError(ET_Failure, UGKErr_FileIO,
                 "Definition of field %d (%s) from .TAB file does not match "
                 "what is found in %s (name=%s, type=%c, width=%d, prec=%d)",
                 iField+1, pszName, m_pszFname,
                 m_pasFieldDef[i].szName, m_pasFieldDef[i].cType, 
      		
		m_pasFieldDef[i].byLength, m_pasFieldDef[i].byDecimals);
        return -1;
    }

    m_pasFieldDef[i].eTABType = eType;

    return 0;
}



/**********************************************************************
 *                   TABDATFile::AddField()
 *
 * Create a new field (column) in a newly created table.  This function
 * must be called after the file has been opened, but before writing the
 * first record.
 *
 * Returns the new field index (a value >= 0) if OK, -1 on error.
 **********************************************************************/
int  TABDATFile::AddField(const char *pszName, TABFieldType eType,
                          int nWidth, int nPrecision /*=0*/)
{
    if (m_eAccessMode != TABWrite || m_bWriteHeaderInitialized ||
        m_eTableType != TABTableNative)
    {
        UGKError(ET_Failure, UGKErr_NotSupported,
                 "Addition of new table fields is not supported after the "
                 "first data item has been written.");
        return -1;
    }

    /*-----------------------------------------------------------------
     * Validate field width... must be <= 254
     *----------------------------------------------------------------*/
    if (nWidth > 254)
    {
        UGKError(ET_Failure, UGKErr_IllegalArg,
                 "Invalid size (%d) for field '%s'.  "
                 "Size must be 254 or less.", nWidth, pszName);
        return -1;
    }

    /*-----------------------------------------------------------------
     * Map fields with width=0 (variable length in UGK) to a valid default
     *----------------------------------------------------------------*/
    if (eType == TABFDecimal && nWidth == 0)
        nWidth=20;
    else if (nWidth == 0)
        nWidth=254; /* char fields */

    if (m_numFields < 0)
        m_numFields = 0;

    m_numFields++;
    m_pasFieldDef = (TABDATFieldDef*)UGK_Realloc(m_pasFieldDef, 
                                          m_numFields*sizeof(TABDATFieldDef));

    strncpy(m_pasFieldDef[m_numFields-1].szName, pszName, 10);
    m_pasFieldDef[m_numFields-1].szName[10] = '\0';
    m_pasFieldDef[m_numFields-1].eTABType = eType;
    m_pasFieldDef[m_numFields-1].byLength = (UGKByte)nWidth;
    m_pasFieldDef[m_numFields-1].byDecimals = (UGKByte)nPrecision;

    switch(eType)
    {
      case TABFChar:
        m_pasFieldDef[m_numFields-1].cType = 'C';
        break;
      case TABFDecimal:
        m_pasFieldDef[m_numFields-1].cType = 'N';
        break;
      case TABFInteger:
        m_pasFieldDef[m_numFields-1].cType = 'C';
        m_pasFieldDef[m_numFields-1].byLength = 4;
        break;
      case TABFSmallInt:
        m_pasFieldDef[m_numFields-1].cType = 'C';
        m_pasFieldDef[m_numFields-1].byLength = 2;
        break;
      case TABFFloat:
        m_pasFieldDef[m_numFields-1].cType = 'C';
        m_pasFieldDef[m_numFields-1].byLength = 8;
        break;
      case TABFDate:
        m_pasFieldDef[m_numFields-1].cType = 'C';
        m_pasFieldDef[m_numFields-1].byLength = 4;
        break;
      case TABFLogical:
        m_pasFieldDef[m_numFields-1].cType = 'L';
        m_pasFieldDef[m_numFields-1].byLength = 1;
        break;
      default:
        UGKError(ET_Failure, UGKErr_NotSupported,
                 "Unsupported field type for field `%s'", pszName);
        return -1;
    }

    return 0;
}



/**********************************************************************
 *                   TABDATFile::GetFieldType()
 *
 * Returns the native field type for field # nFieldId as previously set
 * by ValidateFieldInfoFromTAB().
 *
 * Note that field ids are positive and start at 0.
 **********************************************************************/
TABFieldType TABDATFile::GetFieldType(int nFieldId)
{
    if (m_pasFieldDef == NULL || nFieldId < 0 || nFieldId >= m_numFields)
        return TABFUnknown;

    return m_pasFieldDef[nFieldId].eTABType;
}



/**********************************************************************
 *                   TABDATFile::GetFieldWidth()
 *
 * Returns the width for field # nFieldId as previously read from the
 * .DAT header.
 *
 * Note that field ids are positive and start at 0.
 **********************************************************************/
int   TABDATFile::GetFieldWidth(int nFieldId)
{
    if (m_pasFieldDef == NULL || nFieldId < 0 || nFieldId >= m_numFields)
        return 0;

    return m_pasFieldDef[nFieldId].byLength;
}



/**********************************************************************
 *                   TABDATFile::GetFieldPrecision()
 *
 * Returns the precision for field # nFieldId as previously read from the
 * .DAT header.
 *
 * Note that field ids are positive and start at 0.
 **********************************************************************/
int   TABDATFile::GetFieldPrecision(int nFieldId)
{
    if (m_pasFieldDef == NULL || nFieldId < 0 || nFieldId >= m_numFields)
        return 0;

    return m_pasFieldDef[nFieldId].byDecimals;
}


/**********************************************************************
 *                   TABDATFile::ReadCharField()
 *
 * Read the character field value at the current position in the data 
 * block.
 * 
 * Use GetRecordBlock() to position the data block to the beginning of
 * a record before attempting to read values.
 *
 * nWidth is the field length, as defined in the .DAT header.
 *
 * Returns a reference to an internal buffer that will be valid only until
 * the next field is read, or "" if the operation failed, in which case
 * CPLError() will have been called.
 **********************************************************************/
const char *TABDATFile::ReadCharField(int nWidth)
{
    // We know that character strings are limited to 254 chars in MapInfo
    static char szBuf[256];

    // If current record has been deleted, then return an acceptable 
    // default value.
    if (m_bCurRecordDeletedFlag)
        return "";

    if (m_poRecordBlock == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "Can't read field value: file is not opened.");
        return "";
    }

    if (nWidth < 1 || nWidth > 255)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "Illegal width for a char field: %d", nWidth);
        return "";
    }

    if (m_poRecordBlock->ReadBytes(nWidth, (UGKByte*)szBuf) != 0)
        return "";

    szBuf[nWidth] = '\0';

    // NATIVE tables are padded with '\0' chars, but DBF tables are padded
    // with spaces... get rid of the trailing spaces.
    if (m_eTableType == TABTableDBF)
    {
        int nLen = strlen(szBuf)-1;
        while(nLen>=0 && szBuf[nLen] == ' ')
            szBuf[nLen--] = '\0';
    }

    return szBuf;
}




/**********************************************************************
 *                   TABDATFile::ReadIntegerField()
 *
 * Read the integer field value at the current position in the data 
 * block.
 * 
 * Note: nWidth is used only with TABTableDBF types.
 *
 * CPLError() will have been called if something fails.
 **********************************************************************/
UGKInt32 TABDATFile::ReadIntegerField(int nWidth)
{
    // If current record has been deleted, then return an acceptable 
    // default value.
    if (m_bCurRecordDeletedFlag)
        return 0;

    if (m_poRecordBlock == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "Can't read field value: file is not opened.");
        return 0;
    }

    if (m_eTableType == TABTableDBF)
        return atoi(ReadCharField(nWidth));

    return m_poRecordBlock->ReadInt32();
}



/**********************************************************************
 *                   TABDATFile::ReadSmallIntField()
 *
 * Read the smallint field value at the current position in the data 
 * block.
 * 
 * Note: nWidth is used only with TABTableDBF types.
 *
 * CPLError() will have been called if something fails.
 **********************************************************************/
UGKInt16 TABDATFile::ReadSmallIntField(int nWidth)
{
    // If current record has been deleted, then return an acceptable 
    // default value.
    if (m_bCurRecordDeletedFlag)
        return 0;

    if (m_poRecordBlock == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "Can't read field value: file is not opened.");
        return 0;
    }

    if (m_eTableType == TABTableDBF)
        return atoi(ReadCharField(nWidth));

    return m_poRecordBlock->ReadInt16();
}



/**********************************************************************
 *                   TABDATFile::ReadFloatField()
 *
 * Read the float field value at the current position in the data 
 * block.
 * 
 * Note: nWidth is used only with TABTableDBF types.
 *
 * CPLError() will have been called if something fails.
 **********************************************************************/
double TABDATFile::ReadFloatField(int nWidth)
{
    // If current record has been deleted, then return an acceptable 
    // default value.
    if (m_bCurRecordDeletedFlag)
        return 0.0;

    if (m_poRecordBlock == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "Can't read field value: file is not opened.");
        return 0.0;
    }

    if (m_eTableType == TABTableDBF)
        return atof(ReadCharField(nWidth));

    return m_poRecordBlock->ReadDouble();
}




/**********************************************************************
 *                   TABDATFile::ReadLogicalField()
 *
 * Read the logical field value at the current position in the data 
 * block.
 *
 * The file contains either 0 or 1, and we return a string with 
 * "F" (false) or "T" (true)
 * 
 * Note: nWidth is used only with TABTableDBF types.
 *
 * CPLError() will have been called if something fails.
 **********************************************************************/
const char *TABDATFile::ReadLogicalField(int nWidth)
{
    UGKByte bValue;

    // If current record has been deleted, then return an acceptable 
    // default value.
    if (m_bCurRecordDeletedFlag)
        return "F";

    if (m_poRecordBlock == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "Can't read field value: file is not opened.");
        return "";
    }

    if (m_eTableType == TABTableDBF)
    {
        const char *pszVal = ReadCharField(nWidth);
        bValue = (pszVal && strchr("1YyTt", pszVal[0]) != NULL);
    }
    else
    {