ogrfmedatasource.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

/* -------------------------------------------------------------------- */
/*      Is there a Coordsys statement in the user directives?           */
/* -------------------------------------------------------------------- */
    OGRSpatialReference *poSRS = ExtractSRS();

    CPLDebug( kPROVIDERNAME, "got the SRS parsed");

    bCoordSysOverride = poSRS != NULL;

/* -------------------------------------------------------------------- */
/*      Allocate an FME string, and feature for use here and            */
/*      elsewhere.                                                      */
/* -------------------------------------------------------------------- */
    poFMEFeature = poSession->createFeature();
    poFMEString = poSession->createString();

/* -------------------------------------------------------------------- */
/*      Are we going to use the direct access DB mechanism, or the      */
/*      spatiallly cached (dumb reader) mechanism.                      */
/* -------------------------------------------------------------------- */
    bUseCaching = !EQUALN(pszReaderName,"SDE",3) 
               && !EQUALN(pszReaderName,"ORACLE",6);

/* -------------------------------------------------------------------- */
/*      Is there already a cache for this dataset?  If so, we will      */
/*      use it.                                                         */
/* -------------------------------------------------------------------- */
#ifdef SUPPORT_PERSISTENT_CACHE
    OGRFMECacheIndex   oCacheIndex( 
                           CPLFormFilename(GetTmpDir(), "ogrfmeds", "ind" ) );
    CPLXMLNode        *psMatchDS = NULL;

    if( bUseCaching && oCacheIndex.Lock() && oCacheIndex.Load() )
    {
        int bNeedSave = oCacheIndex.ExpireOldCaches( poSession );

        psMatchDS = oCacheIndex.FindMatch( pszReaderName, pszDataset, 
                                           *poUserDirectives );

        if( psMatchDS != NULL )
        {
            oCacheIndex.Reference( psMatchDS );
            oCacheIndex.Save();

            psMatchDS = CPLCloneXMLTree( psMatchDS );
            oCacheIndex.Unlock();

        }
        else
        {
            if( bNeedSave )
                oCacheIndex.Save();

            oCacheIndex.Unlock();
        }

        if( psMatchDS != NULL )
        {
            if( InitializeFromXML( psMatchDS ) )
            {
                CPLDestroyXMLNode( psMatchDS );
                ReleaseSession();

                return TRUE;
            }

            CPLDestroyXMLNode( psMatchDS );
        }
    }
#endif /* def SUPPORT_PERSISTENT_CACHE */

/* -------------------------------------------------------------------- */
/*      Create a reader.                                                */
/* -------------------------------------------------------------------- */
    IFMEStringArray     *poParms = poSession->createStringArray();

    for( i = 0; i < (int) poUserDirectives->entries(); i++ )
        CPLDebug( kPROVIDERNAME, "oUserDirectives(%d) = '%s'", 
                  i, (*poUserDirectives)(i) );

    poReader = poSession->createReader(pszReaderName, FME_FALSE, 
                                       poUserDirectives);
    if( poReader == NULL )
    {
        CPLFMEError( poSession,
                     "Failed to create reader of type `%s'.\n",
                     pszReaderName );
        ReleaseSession();
        return FALSE;
    }

    CPLDebug( kPROVIDERNAME, "%p:reader created.", this );

/* -------------------------------------------------------------------- */
/*      Now try to open the dataset.                                    */
/* -------------------------------------------------------------------- */
    err = poReader->open( pszDataset, *poParms );
    if( err )
    {
        CPLFMEError( poSession,
                     "Failed to open dataset `%s' with reader of type `%s'.\n",
                     pszDataset, pszReaderName );
        ReleaseSession();
        return FALSE;
    }

    CPLDebug( kPROVIDERNAME, "%p:reader opened.", this );

/* -------------------------------------------------------------------- */
/*      There are some circumstances where we want to keep a            */
/*      "connection" open for a data source.  Offer this reader for     */
/*      connection caching.                                             */
/* -------------------------------------------------------------------- */
    OfferForConnectionCaching( poReader, pszReaderName, 
                               pszDataset );

/* -------------------------------------------------------------------- */
/*      Create a layer for each schema feature.                         */
/* -------------------------------------------------------------------- */
    FME_Boolean         eEndOfSchema;

    while( TRUE )
    {
        err = poReader->readSchema( *poFMEFeature, eEndOfSchema );
        if( err )
        {
            CPLFMEError( poSession, "IFMEReader::readSchema() failed." );
            ReleaseSession();
            return FALSE;
        }

        if( eEndOfSchema == FME_TRUE )
            break;

        CPLDebug( kPROVIDERNAME, "%p:readSchema() got %s.", 
                  this, poFMEFeature->getFeatureType() );

        OGRFMELayer     *poNewLayer = NULL;

        if( bUseCaching )
            poNewLayer = new OGRFMELayerCached( this );
        else
            poNewLayer = new OGRFMELayerDB( this, pszReaderName, pszDataset,
                                            poUserDirectives );

        if( !poNewLayer->Initialize( poFMEFeature, poSRS ) )
        {
            CPLDebug( kPROVIDERNAME, "%p:Initialize() failed.", this );
            delete poNewLayer;
            ReleaseSession();
            return FALSE;
        }

        papoLayers = (OGRFMELayer **)
            CPLRealloc(papoLayers, sizeof(void*) * ++nLayers );
        papoLayers[nLayers-1] = poNewLayer;
    }

    poSession->destroyStringArray( poParms );

    if( poSRS != NULL )
        OSRDestroySpatialReference( poSRS );

    CPLDebug( kPROVIDERNAME, "%p:schema read.", this );

/* -------------------------------------------------------------------- */
/*      Do we want to build our own index/caches for each layer?        */
/* -------------------------------------------------------------------- */
    if( bUseCaching )
        BuildSpatialIndexes();

    CPLDebug( kPROVIDERNAME, "%p:Open() successful.", this );

    ReleaseSession();

/* -------------------------------------------------------------------- */
/*      If we are caching, add this cache to the cache index.           */
/* -------------------------------------------------------------------- */
#ifdef SUPPORT_PERSISTENT_CACHE
    if( bUseCaching && oCacheIndex.Lock() && oCacheIndex.Load() )
    {
        CPLXMLNode *psXML = SerializeToXML();

        oCacheIndex.Add( psXML  ); // cache index takes ownership of tree
        oCacheIndex.Reference( psXML );
        oCacheIndex.Save();
        oCacheIndex.Unlock();
    }
#endif

    return TRUE;
}

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

OGRLayer *OGRFMEDataSource::GetLayer( int iLayer )

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

/************************************************************************/
/*                        BuildSpatialIndexes()                         */
/*                                                                      */
/*      Import all the features, building per-layer spatial             */
/*      caches with indexing.                                           */
/************************************************************************/

void OGRFMEDataSource::BuildSpatialIndexes()

{
    CacheLayerInfo     *pasCLI;
    int                iLayer;

    pasCLI = (CacheLayerInfo *) CPLCalloc(sizeof(CacheLayerInfo),nLayers);

/* -------------------------------------------------------------------- */
/*      Create index files with "temp file" names.                      */
/* -------------------------------------------------------------------- */
    for( iLayer = 0; iLayer < nLayers; iLayer++ )
    {
        CacheLayerInfo *psCLI = pasCLI + iLayer;

        psCLI->pszCoordSys = NULL;

        psCLI->pszIndFile = 
            BuildTmpNam( papoLayers[iLayer]->GetLayerDefn()->GetName() );

        psCLI->poIndex = 
            poSession->createSpatialIndex( psCLI->pszIndFile, "WRITE", NULL );
        
        if( psCLI->poIndex == NULL || psCLI->poIndex->open() != 0 )
        {
            CPLDebug( kPROVIDERNAME, 
                      "Serious error creating or opening spatial index ... bailing." );
            return;
        }

        // our special marker meaning unset.
        psCLI->eBestGeomType = (OGRwkbGeometryType) 500; 
    }

/* -------------------------------------------------------------------- */
/*      Read all features, and store them into appropriate spatial      */
/*      indexes.                                                        */
/* -------------------------------------------------------------------- */
    while( ReadFMEFeature() )
    {
        CacheLayerInfo *psCLI = NULL;

        poFMEFeature->getFeatureType( *poFMEString );
        
        for( iLayer = 0; iLayer < nLayers; iLayer++ )
        {
            if( EQUAL(papoLayers[iLayer]->GetLayerDefn()->GetName(),
                      poFMEString->data()) )
            {
                psCLI = pasCLI + iLayer;
                break;
            }
        }
        
        if( psCLI == NULL )
        {
            CPLDebug( "FME_LOG", 
                      "Skipping %s feature, doesn't match a layer.", 
                      poFMEString->data() );
            continue;
        }

        psCLI->poIndex->store( *poFMEFeature );

        // Aggregate to extents.
        FME_Real64  dfMinX, dfMaxX, dfMinY, dfMaxY;

        poFMEFeature->boundingBox( dfMinX, dfMaxX, dfMinY, dfMaxY );
        
        if( psCLI->poIndex->entries() == 1 )
        {
            psCLI->sExtent.MinX = dfMinX;
            psCLI->sExtent.MaxX = dfMaxX;
            psCLI->sExtent.MinY = dfMinY;
            psCLI->sExtent.MaxY = dfMaxY;
        }
        else
        {
            psCLI->sExtent.MinX = MIN(psCLI->sExtent.MinX,dfMinX);
            psCLI->sExtent.MaxX = MAX(psCLI->sExtent.MaxX,dfMaxX);
            psCLI->sExtent.MinY = MIN(psCLI->sExtent.MinY,dfMinY);
            psCLI->sExtent.MaxY = MAX(psCLI->sExtent.MaxY,dfMaxY);
        }

        // Update best geometry type to use based on this geometry.
        ClarifyGeometryClass( poFMEFeature, psCLI->eBestGeomType );

        // Check on coordsys.
        if( poFMEFeature->getCoordSys() != NULL
            && strlen(poFMEFeature->getCoordSys()) > 0 )
        {
            if( psCLI->pszCoordSys == NULL )
                psCLI->pszCoordSys = CPLStrdup(poFMEFeature->getCoordSys());
            else
            {
                if( !EQUAL(psCLI->pszCoordSys,poFMEFeature->getCoordSys()) )
                    CPLDebug( "FME_OLEDB", 
                              "Conflicting coordsys %s (vs. %s) on layer %s.",
                              poFMEFeature->getCoordSys(), 
                              psCLI->pszCoordSys, 
                              papoLayers[iLayer]->GetLayerDefn()->GetName() );
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Close indexes and assign to layers.                             */
/* -------------------------------------------------------------------- */
    for( iLayer = 0; iLayer < nLayers; iLayer++ )
    {
        OGRFMELayerCached * poLayer = (OGRFMELayerCached *) papoLayers[iLayer];
        CacheLayerInfo *psCLI = pasCLI + iLayer;

        // If there are no features, we destroy the layer.
        if( psCLI->poIndex->entries() == 0 )
        {
            CPLDebug( "FME_LOG", "Drop layer %s, there are not features.",
                      poLayer->GetLayerDefn()->GetName() );
            psCLI->poIndex->close(FME_TRUE);

            delete poLayer;
            papoLayers[iLayer] = NULL;
        }
        else
        {
            OGRSpatialReference *poSpatialRef = NULL;

            psCLI->poIndex->close(FME_FALSE);
            poSession->destroySpatialIndex( psCLI->poIndex );
            
            if( psCLI->pszCoordSys != NULL && !bCoordSysOverride )
            {
                CPLDebug("FME_OLEDB", 
                         "Applying COORDSYS=%s to layer %s from feature scan.",
                         psCLI->pszCoordSys, 
                         papoLayers[iLayer]->GetLayerDefn()->GetName() );
                       
                poSpatialRef = FME2OGRSpatialRef( psCLI->pszCoordSys );
            }

            poLayer->AssignIndex( psCLI->pszIndFile, &(psCLI->sExtent),
                                  poSpatialRef );
            if( psCLI->eBestGeomType != 500 
                && psCLI->eBestGeomType 
                         != poLayer->GetLayerDefn()->GetGeomType() )
            {