mitab_ogr_datasource.cpp

mitab,读取MapInfo的地图文件

/* -------------------------------------------------------------------- */
/*      Is this a file or directory?                                    */
/* -------------------------------------------------------------------- */
    if( VSIStat( pszName, &stat ) != 0 
        || (!VSI_ISDIR(stat.st_mode) && !VSI_ISREG(stat.st_mode)) )
    {
        if( !bTestOpen )
        {
            CPLError( CE_Failure, CPLE_OpenFailed,
                      "%s is not a file or directory.\n"
                      "Unable to open as a Mapinfo dataset.\n",
                      pszName );
        }

        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      If it is a file, try to open as a Mapinfo file.                 */
/* -------------------------------------------------------------------- */
    if( VSI_ISREG(stat.st_mode) )
    {
        IMapInfoFile    *poFile;

        poFile = IMapInfoFile::SmartOpen( pszName, bTestOpen );
        if( poFile == NULL )
            return FALSE;

        m_nLayerCount = 1;
        m_papoLayers = (IMapInfoFile **) CPLMalloc(sizeof(void*));
        m_papoLayers[0] = poFile;

        m_pszDirectory = CPLStrdup( CPLGetPath(pszName) );
    }

/* -------------------------------------------------------------------- */
/*      Otherwise, we need to scan the whole directory for files        */
/*      ending in .tab or .mif.                                         */
/* -------------------------------------------------------------------- */
    else
    {
        char    **papszFileList = CPLReadDir( pszName );
        
        m_pszDirectory = CPLStrdup( pszName );

        for( int iFile = 0;
             papszFileList != NULL && papszFileList[iFile] != NULL;
             iFile++ )
        {
            IMapInfoFile *poFile;
            const char  *pszExtension = CPLGetExtension(papszFileList[iFile]);
            char        *pszSubFilename;

            if( !EQUAL(pszExtension,"tab") && !EQUAL(pszExtension,"mif") )
                continue;

            pszSubFilename = CPLStrdup(
                CPLFormFilename( m_pszDirectory, papszFileList[iFile], NULL ));

            poFile = IMapInfoFile::SmartOpen( pszSubFilename, bTestOpen );
            CPLFree( pszSubFilename );
            
            if( poFile == NULL )
            {
                CSLDestroy( papszFileList );
                return FALSE;
            }

            m_nLayerCount++;
            m_papoLayers = (IMapInfoFile **)
                CPLRealloc(m_papoLayers,sizeof(void*)*m_nLayerCount);
            m_papoLayers[m_nLayerCount-1] = poFile;
        }

        CSLDestroy( papszFileList );

        if( m_nLayerCount == 0 )
        {
            if( !bTestOpen )
                CPLError( CE_Failure, CPLE_OpenFailed,
                          "No mapinfo files found in directory %s.\n",
                          m_pszDirectory );
            
            return FALSE;
        }
    }

    return TRUE;
}

/************************************************************************/
/*                           GetLayerCount()                            */
/************************************************************************/

int OGRTABDataSource::GetLayerCount()

{
    if( m_bSingleFile && !m_bSingleLayerAlreadyCreated )
        return 0;
    else
        return m_nLayerCount;
}

/************************************************************************/
/*                              GetLayer()                              */
/************************************************************************/

OGRLayer *OGRTABDataSource::GetLayer( int iLayer )

{
    if( iLayer < 0 || iLayer >= GetLayerCount() )
        return NULL;
    else
        return m_papoLayers[iLayer];
}

/************************************************************************/
/*                            CreateLayer()                             */
/************************************************************************/

OGRLayer *
OGRTABDataSource::CreateLayer( const char * pszLayerName,
                               OGRSpatialReference *poSRSIn,
                               OGRwkbGeometryType /* eGeomTypeIn */,
                               char ** /* papszOptions */ )

{
    IMapInfoFile        *poFile;
    char                *pszFullFilename;

/* -------------------------------------------------------------------- */
/*      If it's a single file mode file, then we may have already       */
/*      instantiated the low level layer.   We would just need to       */
/*      reset the coordinate system and (potentially) bounds.           */
/* -------------------------------------------------------------------- */
    if( m_bSingleFile )
    {
        if( m_bSingleLayerAlreadyCreated )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Unable to create new layers in this single file dataset.");
            return NULL;
        }

        m_bSingleLayerAlreadyCreated = TRUE;

        poFile = (IMapInfoFile *) m_papoLayers[0];
    }

/* -------------------------------------------------------------------- */
/*      We need to initially create the file, and add it as a layer.    */
/* -------------------------------------------------------------------- */
    else
    {
        if( m_bCreateMIF )
        {
            pszFullFilename = CPLStrdup( CPLFormFilename( m_pszDirectory,
                                                          pszLayerName, "mif" ) );
            
            poFile = new MIFFile;
        }
        else
        {
            pszFullFilename = CPLStrdup( CPLFormFilename( m_pszDirectory,
                                                          pszLayerName, "tab" ) );
            
            poFile = new TABFile;
        }
        
        if( poFile->Open( pszFullFilename, "wb", FALSE ) != 0 )
        {
            CPLFree( pszFullFilename );
            delete poFile;
            return FALSE;
        }

        m_nLayerCount++;
        m_papoLayers = (IMapInfoFile **)
            CPLRealloc(m_papoLayers,sizeof(void*)*m_nLayerCount);
        m_papoLayers[m_nLayerCount-1] = poFile;

        CPLFree( pszFullFilename );
    }

/* -------------------------------------------------------------------- */
/*      Assign the coordinate system (if provided) and set              */
/*      reasonable bounds.                                              */
/* -------------------------------------------------------------------- */
    if( poSRSIn != NULL )
        poFile->SetSpatialRef( poSRSIn );

    if( !poFile->IsBoundsSet() && !m_bCreateMIF )
    {
        if( poSRSIn != NULL && poSRSIn->GetRoot() != NULL
            && EQUAL(poSRSIn->GetRoot()->GetValue(),"GEOGCS") )
            poFile->SetBounds( -1000, -1000, 1000, 1000 );
        else
            poFile->SetBounds( -30000000, -15000000, 30000000, 15000000 );
    }

    if (m_bQuickSpatialIndexMode && poFile->SetQuickSpatialIndexMode() != 0)
    {
        CPLError( CE_Warning, CPLE_AppDefined, 
                  "Setting Quick Spatial Index Mode failed.");
    }

    return poFile;
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRTABDataSource::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,ODsCCreateLayer) )
        return !m_bSingleFile || !m_bSingleLayerAlreadyCreated;
    else
        return FALSE;
}