ogrsdelayer.cpp

来自「支持各种栅格图像和矢量图像读取的库」· C++ 代码 · 共 1,305 行 · 第 1/4 页

              SE_BLOB_INFO sBlobVal;

              nSDEErr = SE_stream_get_blob( hStream, anFieldMap[i]+1, 
                                            &sBlobVal );
              if( nSDEErr == SE_SUCCESS )
              {
                  poFeat->SetField( i, 
                                    sBlobVal.blob_length, 
                                    (GByte *) sBlobVal.blob_buffer );
                  SE_blob_free( &sBlobVal );
              }
              else if( nSDEErr != SE_NULL_VALUE )
              {
                  poDS->IssueSDEError( nSDEErr, "SE_stream_get_blob" );
                  return NULL;
              }
          }
          break;

          case SE_DATE_TYPE:
          {
              struct tm sDateVal;

              nSDEErr = SE_stream_get_date( hStream, anFieldMap[i]+1, 
                                            &sDateVal );
              if( nSDEErr == SE_SUCCESS )
              {
                  char szDate[128];
                  strftime( szDate, sizeof(szDate), "%T %m/%d/%Y", &sDateVal );
                  poFeat->SetField( i, szDate );
              }
              else if( nSDEErr != SE_NULL_VALUE )
              {
                  poDS->IssueSDEError( nSDEErr, "SE_stream_get_date" );
                  return NULL;
              }
          }
          break;

        }
    }

/* -------------------------------------------------------------------- */
/*      Apply FID.                                                      */
/* -------------------------------------------------------------------- */
    if( iFIDColumn != -1 )
        poFeat->SetFID( poFeat->GetFieldAsInteger( iFIDColumn ) );
    else
        poFeat->SetFID( nNextFID++ );

/* -------------------------------------------------------------------- */
/*      Fetch geometry.                                                 */
/* -------------------------------------------------------------------- */
    if( iShapeColumn != -1 )
    {
        SE_SHAPE hShape = 0;

        nSDEErr = SE_shape_create( NULL, &hShape );

        if( nSDEErr != SE_SUCCESS )
            poDS->IssueSDEError( nSDEErr, "SE_shape_create" );
        else
        {
            nSDEErr = SE_stream_get_shape( hStream, (short) (iShapeColumn+1), 
                                           hShape );
            if( nSDEErr != SE_SUCCESS )
                poDS->IssueSDEError( nSDEErr, "SE_stream_get_shape" );
        }

        if( nSDEErr == SE_SUCCESS )
            poFeat->SetGeometryDirectly( TranslateSDEGeometry( hShape ) );

        SE_shape_free( hShape );
    }

    return poFeat;
}

/************************************************************************/
/*                           GetNextFeature()                           */
/************************************************************************/

OGRFeature *OGRSDELayer::GetNextFeature()

{
    int nSDEErr;

/* -------------------------------------------------------------------- */
/*      Make sure we have an installed query executed.                  */
/* -------------------------------------------------------------------- */
    if( !bQueryInstalled && !InstallQuery( FALSE ) )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Fetch the next record.                                          */
/* -------------------------------------------------------------------- */
    while( TRUE )
    {
        nSDEErr = SE_stream_fetch( hStream );
        if( nSDEErr == SE_FINISHED )
        {
            bQueryInstalled = FALSE;
            return NULL;
        }
        else if( nSDEErr != SE_SUCCESS )
        {
            poDS->IssueSDEError( nSDEErr, "SE_stream_fetch" );
            return NULL;
        }
        
        m_nFeaturesRead++;

/* -------------------------------------------------------------------- */
/*      Translate into an OGRFeature.                                   */
/* -------------------------------------------------------------------- */
        OGRFeature *poFeature;

        poFeature = TranslateSDERecord();

        if( poFeature != NULL )
        {
            if( m_poFilterGeom == NULL
                || m_bFilterIsEnvelope
                || FilterGeometry( poFeature->GetGeometryRef() ) )
                return poFeature;

            delete poFeature;
        }
    }        
}

/************************************************************************/
/*                             GetFeature()                             */
/************************************************************************/

OGRFeature *OGRSDELayer::GetFeature( long nFeatureId )

{
    int nSDEErr;
    
    if( iFIDColumn == -1 )
        return OGRLayer::GetFeature( nFeatureId );

/* -------------------------------------------------------------------- */
/*      Our direct row access will terminate any active queries.        */
/* -------------------------------------------------------------------- */
    ResetReading(); 

/* -------------------------------------------------------------------- */
/*      Create stream, or reset it.                                     */
/* -------------------------------------------------------------------- */
    if( hStream == NULL )
    {
        nSDEErr = SE_stream_create( poDS->GetConnection(), &hStream );
        if( nSDEErr != SE_SUCCESS) {
            poDS->IssueSDEError( nSDEErr, "SE_stream_create" );
            return FALSE;
        }
    }
    else
    {
        nSDEErr = SE_stream_close( hStream, TRUE );
    }

/* -------------------------------------------------------------------- */
/*      We want to fetch all the columns, just like we normally         */
/*      would for GetNextFeature().                                     */
/* -------------------------------------------------------------------- */
    nSDEErr = SE_stream_fetch_row( hStream, poFeatureDefn->GetName(), 
                                   nFeatureId, 
                                   CSLCount( papszAllColumns ), 
                                   (const char **) papszAllColumns );
    if( nSDEErr != SE_SUCCESS )
    {
        poDS->IssueSDEError( nSDEErr, "SE_stream_fetch_row" );
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      We got our row, now translate it.                               */
/* -------------------------------------------------------------------- */
    return TranslateSDERecord();
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/*                                                                      */
/*      Issue a special "counter only" query that will just fetch       */
/*      objectids, and count the result set.  This will inherently      */
/*      include all the spatial and attribute filtering logic in the    */
/*      database.  It would be nice if we could also use a COUNT()      */
/*      operator in the database.                                       */
/************************************************************************/

int OGRSDELayer::GetFeatureCount( int bForce )

{
/* -------------------------------------------------------------------- */
/*      If there is no attribute or spatial filter in place, then       */
/*      use the SDE function call to obtain the number of               */
/*      features. The performance difference between this and manual    */
/*      iteration is significant.                                       */
/* -------------------------------------------------------------------- */
    if( osAttributeFilter.empty() && m_poFilterGeom == NULL 
        && NeedLayerInfo() )
    {
        SE_LAYER_STATS layerstats = {0};
        char szTableName[SE_QUALIFIED_TABLE_NAME];
        char szShapeColumn[SE_MAX_COLUMN_LEN];
        int nSDEErr;

        szTableName[0] = '\0';
        szShapeColumn[0] = '\0';
      
        nSDEErr = SE_layerinfo_get_spatial_column( hLayerInfo, szTableName, szShapeColumn );
        if( nSDEErr != SE_SUCCESS )
        {
            poDS->IssueSDEError( nSDEErr, "SE_layerinfo_get_spatial_column" );
            return -1;
        }
      
        nSDEErr = SE_layer_get_statistics( poDS->GetConnection(), szTableName, szShapeColumn,
                                           &layerstats);
        if( nSDEErr != SE_SUCCESS )
        {
            poDS->IssueSDEError( nSDEErr, "SE_layer_get_statistics" );
            return -1;
        }

        return layerstats.TotalFeatures;
    }

/* -------------------------------------------------------------------- */
/*      Otherwise use direct reading of the result set, though we       */
/*      skip translating into OGRFeatures at least.                     */
/* -------------------------------------------------------------------- */
    int nSDEErr, nFeatureCount = 0;

    ResetReading();
    if( !InstallQuery( TRUE ) )
        return -1;

    for( nSDEErr = SE_stream_fetch( hStream ); 
         nSDEErr == SE_SUCCESS;
         nSDEErr = SE_stream_fetch( hStream ) )
    {
        nFeatureCount++;
    }

    if( nSDEErr != SE_FINISHED )
    {
        poDS->IssueSDEError( nSDEErr, "SE_stream_fetch" );
        return -1;
    }
        
    ResetReading();

    return nFeatureCount;
}

/************************************************************************/
/*                             GetExtent()                              */
/************************************************************************/

OGRErr OGRSDELayer::GetExtent (OGREnvelope *psExtent, int bForce)

{
    if( !NeedLayerInfo() )
        return OGRERR_FAILURE;

    SE_ENVELOPE  sEnvelope;
    int nSDEErr;

    nSDEErr = SE_layerinfo_get_envelope( hLayerInfo, &sEnvelope );
    if( nSDEErr != SE_SUCCESS )
    {
        poDS->IssueSDEError( nSDEErr, "SE_layerinfo_get_envelope" );
        return OGRERR_FAILURE;
    }

    psExtent->MinX = sEnvelope.minx;
    psExtent->MinY = sEnvelope.miny;
    psExtent->MaxX = sEnvelope.maxx;
    psExtent->MaxY = sEnvelope.maxy;

    return OGRERR_NONE;
}

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

int OGRSDELayer::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,OLCRandomRead) )
        return iFIDColumn != -1;

    else if( EQUAL(pszCap,OLCFastFeatureCount) 
             && osAttributeFilter.empty()
             && m_poFilterGeom == NULL )
        return TRUE;

    else if( EQUAL(pszCap,OLCFastSpatialFilter) )
        return TRUE;

    else if( EQUAL(pszCap,OLCFastGetExtent) )
        return TRUE;

    else 
        return FALSE;
}
/************************************************************************/
/*                           GetSpatialRef()                            */
/************************************************************************/

OGRSpatialReference *OGRSDELayer::GetSpatialRef()

{
    NeedLayerInfo();

    return poSRS;
}