ogrpgdatasource.cpp

来自「支持各种栅格图像和矢量图像读取的库」· C++ 代码 · 共 1,355 行 · 第 1/4 页

                pszGeometryType = "POINT";
                break;

            case wkbLineString:
                pszGeometryType = "LINESTRING";
                break;

            case wkbPolygon:
                pszGeometryType = "POLYGON";
                break;

            case wkbMultiPoint:
                pszGeometryType = "MULTIPOINT";
                break;

            case wkbMultiLineString:
                pszGeometryType = "MULTILINESTRING";
                break;

            case wkbMultiPolygon:
                pszGeometryType = "MULTIPOLYGON";
                break;

            case wkbGeometryCollection:
                pszGeometryType = "GEOMETRYCOLLECTION";
                break;

            default:
                pszGeometryType = "GEOMETRY";
                break;

        }

        sprintf( szCommand,
                 "select AddGeometryColumn('%s','%s','%s',%d,'%s',%d)",
                 pszSchemaName, pszTableName, pszGFldName, nSRSId, pszGeometryType,
                 nDimension );

        CPLDebug( "OGR_PG", "PQexec(%s)", szCommand );
        hResult = PQexec(hPGConn, szCommand);

        if( !hResult
            || PQresultStatus(hResult) != PGRES_TUPLES_OK )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "AddGeometryColumn failed for layer %s, layer creation has failed.",
                      pszLayerName );

            CPLFree( pszLayerName );
            CPLFree( pszSchemaName );

            OGRPGClearResult( hResult );

            hResult = PQexec(hPGConn, "ROLLBACK");
            OGRPGClearResult( hResult );

            return NULL;
        }

        OGRPGClearResult( hResult );
    }

/* -------------------------------------------------------------------- */
/*      Complete, and commit the transaction.                           */
/* -------------------------------------------------------------------- */
    hResult = PQexec(hPGConn, "COMMIT");
    OGRPGClearResult( hResult );

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

    poLayer = new OGRPGTableLayer( this, pszTableName, pszSchemaName, TRUE, nSRSId );

    poLayer->SetLaunderFlag( CSLFetchBoolean(papszOptions,"LAUNDER",TRUE) );
    poLayer->SetPrecisionFlag( CSLFetchBoolean(papszOptions,"PRECISION",TRUE));

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

    papoLayers[nLayers++] = poLayer;

    CPLFree( pszLayerName );
    CPLFree( pszSchemaName );

    return poLayer;
}

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

int OGRPGDataSource::TestCapability( const char * pszCap )

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

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

OGRLayer *OGRPGDataSource::GetLayer( int iLayer )

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

/************************************************************************/
/*                           GetLayerByName()                           */
/************************************************************************/

OGRLayer *OGRPGDataSource::GetLayerByName( const char *pszName )

{
    if ( ! pszName )
        return NULL;

    int  i;
    
    int count = GetLayerCount();
    /* first a case sensitive check */
    for( i = 0; i < count; i++ )
    {
        OGRPGTableLayer *poLayer = papoLayers[i];

        if( strcmp( pszName, poLayer->GetLayerDefn()->GetName() ) == 0 )
            return poLayer;
    }
        
    /* then case insensitive */
    for( i = 0; i < count; i++ )
    {
        OGRPGTableLayer *poLayer = papoLayers[i];

        if( EQUAL( pszName, poLayer->GetLayerDefn()->GetName() ) )
            return poLayer;
    }
    
    if( OpenTable( pszName, NULL, TRUE, FALSE ) )
        return GetLayer(count);
    else
        return NULL;
}


/************************************************************************/
/*                        OGRPGNoticeProcessor()                        */
/************************************************************************/

static void OGRPGNoticeProcessor( void *arg, const char * pszMessage )

{
    CPLDebug( "OGR_PG_NOTICE", "%s", pszMessage );
}

/************************************************************************/
/*                      InitializeMetadataTables()                      */
/*                                                                      */
/*      Create the metadata tables (SPATIAL_REF_SYS and                 */
/*      GEOMETRY_COLUMNS).                                              */
/************************************************************************/

OGRErr OGRPGDataSource::InitializeMetadataTables()

{
    // implement later.
    return OGRERR_FAILURE;
}

/************************************************************************/
/*                              FetchSRS()                              */
/*                                                                      */
/*      Return a SRS corresponding to a particular id.  Note that       */
/*      reference counting should be honoured on the returned           */
/*      OGRSpatialReference, as handles may be cached.                  */
/************************************************************************/

OGRSpatialReference *OGRPGDataSource::FetchSRS( int nId )

{
    if( nId < 0 )
        return NULL;

/* -------------------------------------------------------------------- */
/*      First, we look through our SRID cache, is it there?             */
/* -------------------------------------------------------------------- */
    int  i;

    for( i = 0; i < nKnownSRID; i++ )
    {
        if( panSRID[i] == nId )
            return papoSRS[i];
    }

/* -------------------------------------------------------------------- */
/*      Try looking up in spatial_ref_sys table.                        */
/* -------------------------------------------------------------------- */
    PGresult        *hResult = NULL;
    char            szCommand[1024];
    OGRSpatialReference *poSRS = NULL;

    SoftStartTransaction();

    sprintf( szCommand,
             "SELECT srtext FROM spatial_ref_sys "
             "WHERE srid = %d",
             nId );
    hResult = PQexec(hPGConn, szCommand );

    if( hResult
        && PQresultStatus(hResult) == PGRES_TUPLES_OK
        && PQntuples(hResult) == 1 )
    {
        char *pszWKT;

        pszWKT = PQgetvalue(hResult,0,0);
        poSRS = new OGRSpatialReference();
        if( poSRS->importFromWkt( &pszWKT ) != OGRERR_NONE )
        {
            delete poSRS;
            poSRS = NULL;
        }
    }

    OGRPGClearResult( hResult );
    SoftCommit();

/* -------------------------------------------------------------------- */
/*      Add to the cache.                                               */
/* -------------------------------------------------------------------- */
    panSRID = (int *) CPLRealloc(panSRID,sizeof(int) * (nKnownSRID+1) );
    papoSRS = (OGRSpatialReference **)
        CPLRealloc(papoSRS, sizeof(void*) * (nKnownSRID + 1) );
    panSRID[nKnownSRID] = nId;
    papoSRS[nKnownSRID] = poSRS;
    nKnownSRID++;

    return poSRS;
}

/************************************************************************/
/*                             FetchSRSId()                             */
/*                                                                      */
/*      Fetch the id corresponding to an SRS, and if not found, add     */
/*      it to the table.                                                */
/************************************************************************/

int OGRPGDataSource::FetchSRSId( OGRSpatialReference * poSRS )

{
    PGresult            *hResult = NULL;
    char                szCommand[10000];
    char                *pszWKT = NULL;
    int                 nSRSId = -1;

    if( poSRS == NULL )
        return -1;

/* -------------------------------------------------------------------- */
/*      Translate SRS to WKT.                                           */
/* -------------------------------------------------------------------- */
    if( poSRS->exportToWkt( &pszWKT ) != OGRERR_NONE )
        return -1;

    CPLAssert( strlen(pszWKT) < sizeof(szCommand) - 500 );


/* -------------------------------------------------------------------- */
/*      Try to find in the existing table.                              */
/* -------------------------------------------------------------------- */
    hResult = PQexec(hPGConn, "BEGIN");
    OGRPGClearResult( hResult );

    sprintf( szCommand,
             "SELECT srid FROM spatial_ref_sys WHERE srtext = '%s'",
             pszWKT );
    hResult = PQexec(hPGConn, szCommand );
    CPLFree( pszWKT );  // CM:  Added to prevent mem leaks
    pszWKT = NULL;      // CM:  Added

/* -------------------------------------------------------------------- */
/*      We got it!  Return it.                                          */
/* -------------------------------------------------------------------- */
    if( hResult && PQresultStatus(hResult) == PGRES_TUPLES_OK
        && PQntuples(hResult) > 0 )
    {
        // TODO: mloskot - replace with strtol() function.
        // atoi does not provide any level of diagnostics.
        // What about adding CPLAtoi() ? 

        nSRSId = atoi(PQgetvalue( hResult, 0, 0 ));

        OGRPGClearResult( hResult );

        hResult = PQexec(hPGConn, "COMMIT");
        OGRPGClearResult( hResult );

        return nSRSId;
    }

/* -------------------------------------------------------------------- */
/*      If the command actually failed, then the metadata table is      */
/*      likely missing. Try defining it.                                */
/* -------------------------------------------------------------------- */
    int         bTableMissing;

    bTableMissing =
        hResult == NULL || PQresultStatus(hResult) == PGRES_NONFATAL_ERROR;

    hResult = PQexec(hPGConn, "COMMIT");
    OGRPGClearResult( hResult );

    if( bTableMissing )
    {
        if( InitializeMetadataTables() != OGRERR_NONE )
            return -1;
    }

/* -------------------------------------------------------------------- */
/*      Get the current maximum srid in the srs table.                  */
/* -------------------------------------------------------------------- */
    hResult = PQexec(hPGConn, "BEGIN");
    OGRPGClearResult( hResult );

    hResult = PQexec(hPGConn, "SELECT MAX(srid) FROM spatial_ref_sys" );

    if( hResult && PQresultStatus(hResult) == PGRES_TUPLES_OK )