ogrpglayer.cpp

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/******************************************************************************
 * $Id: ogrpglayer.cpp 11226 2007-04-08 14:54:41Z mloskot $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements OGRPGLayer class  which implements shared handling
 *           of feature geometry and so forth needed by OGRPGResultLayer and
 *           OGRPGTableLayer.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2000, Frank Warmerdam
 *
 * 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 "ogr_pg.h"
#include "ogrpgutility.h"
#include "ogr_p.h"
#include "cpl_conv.h"
#include "cpl_string.h"

CPL_CVSID("$Id: ogrpglayer.cpp 11226 2007-04-08 14:54:41Z mloskot $");

#define CURSOR_PAGE     500

// These originally are defined in libpq-fs.h.

#ifndef INV_WRITE
#define INV_WRITE               0x00020000
#define INV_READ                0x00040000
#endif

/* Flags for creating WKB format for PostGIS */
#define WKBZOFFSET 0x80000000
#define WKBMOFFSET 0x40000000
#define WKBSRIDFLAG 0x20000000
#define WKBBBOXFLAG 0x10000000

/************************************************************************/
/*                           OGRPGLayer()                               */
/************************************************************************/

OGRPGLayer::OGRPGLayer()

{
    poDS = NULL;

    bHasWkb = FALSE;
    bWkbAsOid = FALSE;
    bHasPostGISGeometry = FALSE;
    pszGeomColumn = NULL;
    pszQueryStatement = NULL;

    bHasFid = FALSE;
    pszFIDColumn = NULL;

    iNextShapeId = 0;
    nResultOffset = 0;

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

    /* Eventually we may need to make these a unique name */
    pszCursorName = "OGRPGLayerReader";
    hCursorResult = NULL;
    bCursorActive = FALSE;

    poFeatureDefn = NULL;
}

/************************************************************************/
/*                            ~OGRPGLayer()                             */
/************************************************************************/

OGRPGLayer::~OGRPGLayer()

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

    ResetReading();

    CPLFree( pszGeomColumn );
    CPLFree( pszFIDColumn );
    CPLFree( pszQueryStatement );

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

    if( poFeatureDefn )
        poFeatureDefn->Release();
}

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

void OGRPGLayer::ResetReading()

{
    PGconn      *hPGConn = poDS->GetPGConn();
    char        szCommand[1024];

    iNextShapeId = 0;

    if( hCursorResult != NULL )
    {
        OGRPGClearResult( hCursorResult );

        if( bCursorActive )
        {
            sprintf( szCommand, "CLOSE %s", pszCursorName );

            hCursorResult = PQexec(hPGConn, szCommand);
            OGRPGClearResult( hCursorResult );
        }

        poDS->FlushSoftTransaction();

        hCursorResult = NULL;
    }
}

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

OGRFeature *OGRPGLayer::GetNextFeature()

{

    for( ; TRUE; )
    {
        OGRFeature      *poFeature;

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

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

        delete poFeature;
    }
}
/************************************************************************/
/*                          RecordToFeature()                           */
/*                                                                      */
/*      Convert the indicated record of the current result set into     */
/*      a feature.                                                      */
/************************************************************************/

OGRFeature *OGRPGLayer::RecordToFeature( int iRecord )

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

    poFeature->SetFID( iNextShapeId );
    m_nFeaturesRead++;

/* ==================================================================== */
/*      Transfer all result fields we can.                              */
/* ==================================================================== */
    for( iField = 0;
         iField < PQnfields(hCursorResult);
         iField++ )
    {
        int     iOGRField;

/* -------------------------------------------------------------------- */
/*      Handle FID.                                                     */
/* -------------------------------------------------------------------- */
        if( bHasFid && EQUAL(PQfname(hCursorResult,iField),pszFIDColumn) )
            poFeature->SetFID( atoi(PQgetvalue(hCursorResult,iRecord,iField)));

/* -------------------------------------------------------------------- */
/*      Handle PostGIS geometry                                         */
/* -------------------------------------------------------------------- */
        if( bHasPostGISGeometry
            && (EQUAL(PQfname(hCursorResult,iField),pszGeomColumn)
                || EQUAL(PQfname(hCursorResult,iField),"asEWKT")
                || EQUAL(PQfname(hCursorResult,iField),"asText") ) )
        {
            char        *pszWKT;
            char        *pszPostSRID;
            OGRGeometry *poGeometry = NULL;

            pszWKT = PQgetvalue( hCursorResult, iRecord, iField );
            pszPostSRID = pszWKT;

            // optionally strip off PostGIS SRID identifier.  This
            // happens if we got a raw geometry field.
            if( EQUALN(pszPostSRID,"SRID=",5) )
            {
                while( *pszPostSRID != '\0' && *pszPostSRID != ';' )
                    pszPostSRID++;
                if( *pszPostSRID == ';' )
                    pszPostSRID++;
            }

            if( EQUALN(pszPostSRID,"00",2) || EQUALN(pszPostSRID,"01",2) )
            {
                poGeometry =
                    HEXToGeometry(
                        PQgetvalue( hCursorResult, iRecord, iField ) );
            }
            else
                OGRGeometryFactory::createFromWkt( &pszPostSRID, NULL,
                                                   &poGeometry );
            if( poGeometry != NULL )
                poFeature->SetGeometryDirectly( poGeometry );

            continue;
        }
/* -------------------------------------------------------------------- */
/*      Handle raw binary geometry ... this hasn't been tested in a     */
/*      while.                                                          */
/* -------------------------------------------------------------------- */
        else if( EQUAL(PQfname(hCursorResult,iField),"WKB_GEOMETRY") )
        {
            if( bWkbAsOid )
            {
                poFeature->SetGeometryDirectly(
                    OIDToGeometry( (Oid) atoi(
                        PQgetvalue( hCursorResult,
                                    iRecord, iField ) ) ) );
            }
            else
            {
                poFeature->SetGeometryDirectly(
                    BYTEAToGeometry(
                        PQgetvalue( hCursorResult,
                                    iRecord, iField ) ) );
            }
            continue;
        }
        /* Handle binary cursor result */
        else if ( EQUAL(PQfname(hCursorResult,iField),"AsBinary") )
        {
            GByte * pabyWkb = (GByte *)PQgetvalue( hCursorResult,
                                                   iRecord, iField);



            OGRGeometry * poGeom = NULL;
            OGRGeometryFactory::createFromWkb(pabyWkb,NULL,&poGeom);
            poFeature->SetGeometryDirectly( poGeom );
            continue;
        }

/* -------------------------------------------------------------------- */
/*      Transfer regular data fields.                                   */
/* -------------------------------------------------------------------- */
        iOGRField =
            poFeatureDefn->GetFieldIndex(PQfname(hCursorResult,iField));

        if( iOGRField < 0 )
            continue;

        if( PQgetisnull( hCursorResult, iRecord, iField ) )
            continue;

        OGRFieldType eOGRType = 
            poFeatureDefn->GetFieldDefn(iOGRField)->GetType();

        if( eOGRType == OFTIntegerList)
        {
            int *panList, nCount, i;

#if !defined(PG_PRE74)
            if ( PQfformat( hCursorResult, iField ) == 1 ) // Binary data representation
            {
                char * pData = PQgetvalue( hCursorResult, iRecord, iField );

                // goto number of array elements
                pData += 3 * sizeof(int);
                memcpy( &nCount, pData, sizeof(int) );
                CPL_MSBPTR32( &nCount );

                panList = (int *) CPLCalloc(sizeof(int),nCount);

                // goto first array element
                pData += 2 * sizeof(int);

                for( i = 0; i < nCount; i++ )
                {
                    // get element size
                    int nSize = *(int *)(pData);
                    CPL_MSBPTR32( &nSize );

                    CPLAssert( nSize == sizeof(int) );

                    pData += sizeof(int);

                    memcpy( &panList[i], pData, nSize );
                    CPL_MSBPTR32(&panList[i]);

                    pData += nSize;
                }
            }
            else
#endif /* notdef PG_PRE74 */
            {
                char **papszTokens;
                papszTokens = CSLTokenizeStringComplex(
                    PQgetvalue( hCursorResult, iRecord, iField ),
                    "{,}", FALSE, FALSE );

                nCount = CSLCount(papszTokens);
                panList = (int *) CPLCalloc(sizeof(int),nCount);

                for( i = 0; i < nCount; i++ )
                    panList[i] = atoi(papszTokens[i]);
                CSLDestroy( papszTokens );
            }
            poFeature->SetField( iOGRField, nCount, panList );
            CPLFree( panList );
        }

        else if( eOGRType == OFTRealList )
        {