ogrpgeolayer.cpp

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/******************************************************************************
 * $Id: ogrpgeolayer.cpp 10646 2007-01-18 02:38:10Z warmerdam $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements OGRPGeoLayer class, code shared between 
 *           the direct table access, and the generic SQL results.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2005, Frank Warmerdam <[e-mail]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "cpl_conv.h"
#include "ogr_pgeo.h"
#include "cpl_string.h"

CPL_CVSID("$Id: ogrpgeolayer.cpp 10646 2007-01-18 02:38:10Z warmerdam $");

/************************************************************************/
/*                            OGRPGeoLayer()                            */
/************************************************************************/

OGRPGeoLayer::OGRPGeoLayer()

{
    poDS = NULL;

    pszGeomColumn = NULL;
    pszFIDColumn = NULL;

    poStmt = NULL;

    iNextShapeId = 0;

    poSRS = NULL;
    nSRSId = -2; // we haven't even queried the database for it yet. 
}

/************************************************************************/
/*                            ~OGRPGeoLayer()                             */
/************************************************************************/

OGRPGeoLayer::~OGRPGeoLayer()

{
    if( m_nFeaturesRead > 0 && poFeatureDefn != NULL )
    {
        CPLDebug( "PGeo", "%d features read on layer '%s'.",
                  (int) m_nFeaturesRead, 
                  poFeatureDefn->GetName() );
    }

    if( poStmt != NULL )
    {
        delete poStmt;
        poStmt = NULL;
    }

    if( poFeatureDefn != NULL )
    {
        poFeatureDefn->Release();
        poFeatureDefn = NULL;
    }

    CPLFree( pszGeomColumn );
    CPLFree( panFieldOrdinals ); 
    CPLFree( pszFIDColumn );

    if( poSRS != NULL )
    {
        poSRS->Release();
        poSRS = NULL;
    }
}

/************************************************************************/
/*                          BuildFeatureDefn()                          */
/*                                                                      */
/*      Build feature definition from a set of column definitions       */
/*      set on a statement.  Sift out geometry and FID fields.          */
/************************************************************************/

CPLErr OGRPGeoLayer::BuildFeatureDefn( const char *pszLayerName, 
                                       CPLODBCStatement *poStmt )

{
    poFeatureDefn = new OGRFeatureDefn( pszLayerName );
    int    nRawColumns = poStmt->GetColCount();

    poFeatureDefn->Reference();

    panFieldOrdinals = (int *) CPLMalloc( sizeof(int) * nRawColumns );

    for( int iCol = 0; iCol < nRawColumns; iCol++ )
    {
        OGRFieldDefn    oField( poStmt->GetColName(iCol), OFTString );

        oField.SetWidth( MAX(0,poStmt->GetColSize( iCol )) );

        if( pszGeomColumn != NULL 
            && EQUAL(poStmt->GetColName(iCol),pszGeomColumn) )
            continue;

        if( pszFIDColumn == NULL 
            && EQUAL(poStmt->GetColName(iCol),"OBJECTID") )
        {
            pszFIDColumn = CPLStrdup(poStmt->GetColName(iCol));
        }

        if( pszGeomColumn == NULL 
            && EQUAL(poStmt->GetColName(iCol),"Shape") )
        {
            pszGeomColumn = CPLStrdup(poStmt->GetColName(iCol));
            continue;
        }
        
        switch( poStmt->GetColType(iCol) )
        {
          case SQL_INTEGER:
            oField.SetType( OFTInteger );
            break;

          case SQL_BINARY:
          case SQL_VARBINARY:
          case SQL_LONGVARBINARY:
            oField.SetType( OFTBinary );
            break;

          case SQL_DECIMAL:
            oField.SetType( OFTReal );
            oField.SetPrecision( poStmt->GetColPrecision(iCol) );
            break;

          case SQL_FLOAT:
          case SQL_REAL:
          case SQL_DOUBLE:
            oField.SetType( OFTReal );
            oField.SetWidth( 0 );
            break;

          default:
            /* leave it as OFTString */;
        }

        poFeatureDefn->AddFieldDefn( &oField );
        panFieldOrdinals[poFeatureDefn->GetFieldCount() - 1] = iCol+1;
    }

    return CE_None;
}


/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGRPGeoLayer::ResetReading()

{
    iNextShapeId = 0;
}

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

OGRFeature *OGRPGeoLayer::GetNextFeature()

{
    for( ; TRUE; )
    {
        OGRFeature      *poFeature;

        poFeature = GetNextRawFeature();
        if( poFeature == NULL )
            return NULL;

        if( (m_poFilterGeom == NULL
            || FilterGeometry( poFeature->GetGeometryRef() ) )
            && (m_poAttrQuery == NULL
                || m_poAttrQuery->Evaluate( poFeature )) )
            return poFeature;

        delete poFeature;
    }
}

/************************************************************************/
/*                         GetNextRawFeature()                          */
/************************************************************************/

OGRFeature *OGRPGeoLayer::GetNextRawFeature()

{
    if( GetStatement() == NULL )
        return NULL;

/* -------------------------------------------------------------------- */
/*      If we are marked to restart then do so, and fetch a record.     */
/* -------------------------------------------------------------------- */
    if( !poStmt->Fetch() )
    {
        delete poStmt;
        poStmt = NULL;
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Create a feature from the current result.                       */
/* -------------------------------------------------------------------- */
    int         iField;
    OGRFeature *poFeature = new OGRFeature( poFeatureDefn );

    if( pszFIDColumn != NULL && poStmt->GetColId(pszFIDColumn) > -1 )
        poFeature->SetFID( 
            atoi(poStmt->GetColData(poStmt->GetColId(pszFIDColumn))) );
    else
        poFeature->SetFID( iNextShapeId );

    iNextShapeId++;
    m_nFeaturesRead++;

/* -------------------------------------------------------------------- */
/*      Set the fields.                                                 */
/* -------------------------------------------------------------------- */
    for( iField = 0; iField < poFeatureDefn->GetFieldCount(); iField++ )
    {
        int iSrcField = panFieldOrdinals[iField]-1;
        const char *pszValue = poStmt->GetColData( iSrcField );

        if( pszValue == NULL )
            /* no value */;
        else if( poFeature->GetFieldDefnRef(iField)->GetType() == OFTBinary )
            poFeature->SetField( iField, 
                                 poStmt->GetColDataLength(iSrcField),
                                 (GByte *) pszValue );
        else
            poFeature->SetField( iField, pszValue );
    }

/* -------------------------------------------------------------------- */
/*      Try to extract a geometry.                                      */
/* -------------------------------------------------------------------- */
    if( pszGeomColumn != NULL )
    {
        int iField = poStmt->GetColId( pszGeomColumn );
        GByte *pabyShape = (GByte *) poStmt->GetColData( iField );
        int nBytes = poStmt->GetColDataLength(iField);
        OGRGeometry *poGeom = NULL;

        if( pabyShape != NULL )
            createFromShapeBin( pabyShape, &poGeom, nBytes );

        if( poGeom != NULL )
        {
            poGeom->assignSpatialReference( poSRS );
            poFeature->SetGeometryDirectly( poGeom );
        }
    }

    return poFeature;
}

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

OGRFeature *OGRPGeoLayer::GetFeature( long nFeatureId )

{
    /* This should be implemented directly! */

    return OGRLayer::GetFeature( nFeatureId );
}

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

int OGRPGeoLayer::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,OLCRandomRead) )
        return FALSE;

    else if( EQUAL(pszCap,OLCFastFeatureCount) )
        return FALSE;

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

    else if( EQUAL(pszCap,OLCTransactions) )
        return FALSE;

    else 
        return FALSE;
}

/************************************************************************/
/*                           GetSpatialRef()                            */
/************************************************************************/

OGRSpatialReference *OGRPGeoLayer::GetSpatialRef()

{
    return poSRS;
}

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

void OGRPGeoLayer::LookupSRID( int nSRID )

{
/* -------------------------------------------------------------------- */
/*      Fetch the corresponding WKT from the SpatialRef table.          */
/* -------------------------------------------------------------------- */
    CPLODBCStatement oStmt( poDS->GetSession() );
        
    oStmt.Appendf( "SELECT srtext FROM GDB_SpatialRefs WHERE srid = %d",
                  nSRID );

    if( !oStmt.ExecuteSQL() )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "'%s' failed.\n%s", 
                  oStmt.GetCommand(),
                  poDS->GetSession()->GetLastError() );
        return;
    }

    if( !oStmt.Fetch() )
    {
        CPLError( CE_Warning, CPLE_AppDefined,
                  "SRID %d lookup failed.\n%s", 
                  nSRID, poDS->GetSession()->GetLastError() );
        return;
    }