ogrshapedatasource.cpp

用于读取TAB、MIF、SHP文件的类

/* -------------------------------------------------------------------- */
/*      Add layer to data source layer list.                            */
/* -------------------------------------------------------------------- */
    papoLayers = (OGRShapeLayer **)
        CPLRealloc( papoLayers,  sizeof(OGRShapeLayer *) * (nLayers+1) );
    papoLayers[nLayers++] = poLayer;
    
    return TRUE;
}

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

OGRLayer *
OGRShapeDataSource::CreateLayer( const char * pszLayerName,
                                 OGRSpatialReference *poSRS,
                                 OGRwkbGeometryType eType,
                                 char ** papszOptions )

{
    SHPHandle   hSHP;
    DBFHandle   hDBF;
    int         nShapeType;

/* -------------------------------------------------------------------- */
/*      Verify we are in update mode.                                   */
/* -------------------------------------------------------------------- */
    if( !bDSUpdate )
    {
        CPLError( CE_Failure, CPLE_NoWriteAccess,
                  "Data source %s opened read-only.\n"
                  "New layer %s cannot be created.\n",
                  pszName, pszLayerName );

        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Figure out what type of layer we need.                          */
/* -------------------------------------------------------------------- */
    if( eType == wkbUnknown || eType == wkbLineString )
        nShapeType = SHPT_ARC;
    else if( eType == wkbPoint )
        nShapeType = SHPT_POINT;
    else if( eType == wkbPolygon )
        nShapeType = SHPT_POLYGON;
    else if( eType == wkbMultiPoint )
        nShapeType = SHPT_MULTIPOINT;
    else if( eType == wkbPoint25D )
        nShapeType = SHPT_POINTZ;
    else if( eType == wkbLineString25D )
        nShapeType = SHPT_ARCZ;
    else if( eType == wkbMultiLineString )
        nShapeType = SHPT_ARC;
    else if( eType == wkbMultiLineString25D )
        nShapeType = SHPT_ARCZ;
    else if( eType == wkbPolygon25D )
        nShapeType = SHPT_POLYGONZ;
    else if( eType == wkbMultiPolygon )
        nShapeType = SHPT_POLYGON;
    else if( eType == wkbMultiPolygon25D )
        nShapeType = SHPT_POLYGONZ;
    else if( eType == wkbMultiPoint25D )
        nShapeType = SHPT_MULTIPOINTZ;
    else if( eType == wkbNone )
        nShapeType = SHPT_NULL;
    else
        nShapeType = -1;

/* -------------------------------------------------------------------- */
/*      Has the application overridden this with a special creation     */
/*      option?                                                         */
/* -------------------------------------------------------------------- */
    const char *pszOverride = CSLFetchNameValue( papszOptions, "SHPT" );

    if( pszOverride == NULL )
        /* ignore */;
    else if( EQUAL(pszOverride,"POINT") )
    {
        nShapeType = SHPT_POINT;
        eType = wkbPoint;
    }
    else if( EQUAL(pszOverride,"ARC") )
    {
        nShapeType = SHPT_ARC;
        eType = wkbLineString;
    }
    else if( EQUAL(pszOverride,"POLYGON") )
    {
        nShapeType = SHPT_POLYGON;
        eType = wkbPolygon;
    }
    else if( EQUAL(pszOverride,"MULTIPOINT") )
    {
        nShapeType = SHPT_MULTIPOINT;
        eType = wkbMultiPoint;
    }
    else if( EQUAL(pszOverride,"POINTZ") )
    {
        nShapeType = SHPT_POINTZ;
        eType = wkbPoint25D;
    }
    else if( EQUAL(pszOverride,"ARCZ") )
    {
        nShapeType = SHPT_ARCZ;
        eType = wkbLineString25D;
    }
    else if( EQUAL(pszOverride,"POLYGONZ") )
    {
        nShapeType = SHPT_POLYGONZ;
        eType = wkbPolygon25D;
    }
    else if( EQUAL(pszOverride,"MULTIPOINTZ") )
    {
        nShapeType = SHPT_MULTIPOINTZ;
        eType = wkbMultiPoint25D;
    }
    else if( EQUAL(pszOverride,"NONE") )
    {
        nShapeType = SHPT_NULL;
    }
    else
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Unknown SHPT value of `%s' passed to Shapefile layer\n"
                  "creation.  Creation aborted.\n",
                  pszOverride );

        return NULL;
    }

    if( nShapeType == -1 )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Geometry type of `%s' not supported in shapefiles.\n"
                  "Type can be overridden with a layer creation option\n"
                  "of SHPT=POINT/ARC/POLYGON/MULTIPOINT.\n",
                  OGRGeometryTypeToName(eType) );
        return NULL;
    }
    
/* -------------------------------------------------------------------- */
/*      What filename do we use, excluding the extension?               */
/* -------------------------------------------------------------------- */
    char *pszBasename;

    if( bSingleNewFile && nLayers == 0 )
    {
        char *pszPath = CPLStrdup(CPLGetPath(pszName));
        char *pszFBasename = CPLStrdup(CPLGetBasename(pszName));

        pszBasename = CPLStrdup(CPLFormFilename(pszPath, pszFBasename, NULL));

        CPLFree( pszFBasename );
        CPLFree( pszPath );
    }
    else if( bSingleNewFile )
    {
        char *pszPath = CPLStrdup(CPLGetPath(pszName));
        pszBasename = CPLStrdup(CPLFormFilename(pszPath,pszLayerName,NULL));
        CPLFree( pszPath );
    }
    else
        pszBasename = CPLStrdup(CPLFormFilename(pszName,pszLayerName,NULL));

/* -------------------------------------------------------------------- */
/*      Create the shapefile.                                           */
/* -------------------------------------------------------------------- */
    char        *pszFilename;

    if( nShapeType != SHPT_NULL )
    {
        pszFilename = CPLStrdup(CPLFormFilename( NULL, pszBasename, "shp" ));

        hSHP = SHPCreate( pszFilename, nShapeType );
        
        if( hSHP == NULL )
        {
            CPLError( CE_Failure, CPLE_OpenFailed,
                      "Failed to open Shapefile `%s'.\n",
                      pszFilename );
            CPLFree( pszFilename );
            CPLFree( pszBasename );
            return NULL;
        }
        CPLFree( pszFilename );
    }
    else
        hSHP = NULL;

/* -------------------------------------------------------------------- */
/*      Create a DBF file.                                              */
/* -------------------------------------------------------------------- */
    pszFilename = CPLStrdup(CPLFormFilename( NULL, pszBasename, "dbf" ));
    
    hDBF = DBFCreate( pszFilename );

    if( hDBF == NULL )
    {
        CPLError( CE_Failure, CPLE_OpenFailed,
                  "Failed to open Shape DBF file `%s'.\n",
                  pszFilename );
        CPLFree( pszFilename );
        CPLFree( pszBasename );
        return NULL;
    }

    CPLFree( pszFilename );

/* -------------------------------------------------------------------- */
/*      Create the .prj file, if required.                              */
/* -------------------------------------------------------------------- */
    if( poSRS != NULL )
    {
        char    *pszWKT = NULL;
        CPLString osPrjFile = CPLFormFilename( NULL, pszBasename, "prj");
        FILE    *fp;

        /* the shape layer needs it's own copy */
        poSRS = poSRS->Clone();
        poSRS->morphToESRI();

        if( poSRS->exportToWkt( &pszWKT ) == OGRERR_NONE 
            && (fp = VSIFOpen( osPrjFile, "wt" )) != NULL )
        {
            VSIFWrite( pszWKT, strlen(pszWKT), 1, fp );
            VSIFClose( fp );
        }

        CPLFree( pszWKT );
    }

/* -------------------------------------------------------------------- */
/*      Create the layer object.                                        */
/* -------------------------------------------------------------------- */
    OGRShapeLayer       *poLayer;

    poLayer = new OGRShapeLayer( pszBasename, hSHP, hDBF, poSRS, TRUE,
                                 eType );
    
    poLayer->InitializeIndexSupport( pszBasename );

    CPLFree( pszBasename );

/* -------------------------------------------------------------------- */
/*      Add layer to data source layer list.                            */
/* -------------------------------------------------------------------- */
    papoLayers = (OGRShapeLayer **)
        CPLRealloc( papoLayers,  sizeof(OGRShapeLayer *) * (nLayers+1) );
    
    papoLayers[nLayers++] = poLayer;

    return poLayer;
}

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

int OGRShapeDataSource::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,ODsCCreateLayer) )
        return TRUE;
    else
        return FALSE;
}

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

OGRLayer *OGRShapeDataSource::GetLayer( int iLayer )

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

/************************************************************************/
/*                             ExecuteSQL()                             */
/*                                                                      */
/*      We override this to provide special handling of CREATE          */
/*      SPATIAL INDEX commands.  Support forms are:                     */
/*                                                                      */
/*        CREATE SPATIAL INDEX ON layer_name [DEPTH n]                  */
/*        DROP SPATIAL INDEX ON layer_name                              */
/*        REPACK layer_name                                             */
/************************************************************************/

OGRLayer * OGRShapeDataSource::ExecuteSQL( const char *pszStatement,
                                           OGRGeometry *poSpatialFilter,
                                           const char *pszDialect )

{
/* ==================================================================== */
/*      Handle command to drop a spatial index.                         */
/* ==================================================================== */
    if( EQUALN(pszStatement, "REPACK ", 7) )
    {
        OGRShapeLayer *poLayer = (OGRShapeLayer *) 
            GetLayerByName( pszStatement + 7 );

        if( poLayer != NULL )
            poLayer->Repack();
        else
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "No such layer as '%s' in REPACK.", 
                      pszStatement + 7 );
        }
        return NULL;
    }
    
/* ==================================================================== */
/*      Handle command to drop a spatial index.                         */
/* ==================================================================== */
    if( EQUALN(pszStatement, "DROP SPATIAL INDEX ON ", 22) )
    {
        OGRShapeLayer *poLayer = (OGRShapeLayer *) 
            GetLayerByName( pszStatement + 22 );

        if( poLayer != NULL )
            poLayer->DropSpatialIndex();
        else
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "No such layer as '%s' in DROP SPATIAL INDEX.", 
                      pszStatement + 19 );
        }
        return NULL;
    }
    
/* ==================================================================== */
/*      Handle all comands except spatial index creation generically.   */
/* ==================================================================== */
    if( !EQUALN(pszStatement,"CREATE SPATIAL INDEX ON ",24) )
        return OGRDataSource::ExecuteSQL( pszStatement, poSpatialFilter, 
                                          pszDialect );

/* -------------------------------------------------------------------- */
/*      Parse into keywords.                                            */
/* -------------------------------------------------------------------- */
    char **papszTokens = CSLTokenizeString( pszStatement );
    
    if( CSLCount(papszTokens) < 5
        || !EQUAL(papszTokens[0],"CREATE")
        || !EQUAL(papszTokens[1],"SPATIAL")
        || !EQUAL(papszTokens[2],"INDEX") 
        || !EQUAL(papszTokens[3],"ON") 
        || CSLCount(papszTokens) > 7 
        || (CSLCount(papszTokens) == 7 && !EQUAL(papszTokens[5],"DEPTH")) )
    {
        CSLDestroy( papszTokens );
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Syntax error in CREATE SPATIAL INDEX command.\n"
                  "Was '%s'\n"
                  "Should be of form 'CREATE SPATIAL INDEX ON <table> [DEPTH <n>]'",
                  pszStatement );
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Get depth if provided.                                          */
/* -------------------------------------------------------------------- */
    int nDepth = 0;
    if( CSLCount(papszTokens) == 7 )
        nDepth = atoi(papszTokens[6]);

/* -------------------------------------------------------------------- */
/*      What layer are we operating on.                                 */
/* -------------------------------------------------------------------- */
    OGRShapeLayer *poLayer = (OGRShapeLayer *) GetLayerByName(papszTokens[4]);
    CSLDestroy( papszTokens );

    if( poLayer == NULL )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Layer %s not recognised.", 
                  papszTokens[4] );
        return NULL;
    }

    poLayer->CreateSpatialIndex( nDepth );
    return NULL;
}