ogrshapelayer.cpp

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/******************************************************************************
 * $Id: ogrshapelayer.cpp 10682 2007-01-23 21:53:38Z warmerdam $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements OGRShapeLayer class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 1999,  Les Technologies SoftMap Inc.
 *
 * 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 "ogrshape.h"
#include "cpl_conv.h"
#include "cpl_string.h"

#if defined(_WIN32_WCE)
#  include <wce_errno.h>
#endif

CPL_CVSID("$Id: ogrshapelayer.cpp 10682 2007-01-23 21:53:38Z warmerdam $");

/************************************************************************/
/*                           OGRShapeLayer()                            */
/************************************************************************/

OGRShapeLayer::OGRShapeLayer( const char * pszName,
                              SHPHandle hSHPIn, DBFHandle hDBFIn, 
                              OGRSpatialReference *poSRSIn, int bUpdate,
                              OGRwkbGeometryType eReqType )

{
    poSRS = poSRSIn;

    pszFullName = CPLStrdup(pszName);
    
    hSHP = hSHPIn;
    hDBF = hDBFIn;
    bUpdateAccess = bUpdate;

    iNextShapeId = 0;
    panMatchingFIDs = NULL;

    bCheckedForQIX = FALSE;
    fpQIX = NULL;

    bHeaderDirty = FALSE;

    if( hSHP != NULL )
        nTotalShapeCount = hSHP->nRecords;
    else 
        nTotalShapeCount = hDBF->nRecords;
    
    poFeatureDefn = SHPReadOGRFeatureDefn( CPLGetBasename(pszName), 
                                           hSHP, hDBF );

    eRequestedGeomType = eReqType;
}

/************************************************************************/
/*                           ~OGRShapeLayer()                           */
/************************************************************************/

OGRShapeLayer::~OGRShapeLayer()

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

    CPLFree( panMatchingFIDs );
    panMatchingFIDs = NULL;

    CPLFree( pszFullName );

    poFeatureDefn->Release();
    poSRS->Release();

    if( hDBF != NULL )
        DBFClose( hDBF );

    if( hSHP != NULL )
        SHPClose( hSHP );

    if( fpQIX != NULL )
        VSIFClose( fpQIX );
}

/************************************************************************/
/*                            CheckForQIX()                             */
/************************************************************************/

int OGRShapeLayer::CheckForQIX()

{
    const char *pszQIXFilename;

    if( bCheckedForQIX )
        return fpQIX != NULL;

    pszQIXFilename = CPLResetExtension( pszFullName, "qix" );

    fpQIX = VSIFOpen( pszQIXFilename, "rb" );

    bCheckedForQIX = TRUE;

    return fpQIX != NULL;
}

/************************************************************************/
/*                            ScanIndices()                             */
/*                                                                      */
/*      Utilize optional spatial and attribute indices if they are      */
/*      available.                                                      */
/************************************************************************/

int OGRShapeLayer::ScanIndices()

{
    iMatchingFID = 0;

/* -------------------------------------------------------------------- */
/*      Utilize attribute index if appropriate.                         */
/* -------------------------------------------------------------------- */
    if( m_poAttrQuery != NULL )
    {
        CPLAssert( panMatchingFIDs == NULL );
        panMatchingFIDs = m_poAttrQuery->EvaluateAgainstIndices( this,
                                                                 NULL );
    }

/* -------------------------------------------------------------------- */
/*      Check for spatial index if we have a spatial query.             */
/* -------------------------------------------------------------------- */
    if( m_poFilterGeom != NULL && !bCheckedForQIX )
        CheckForQIX();

/* -------------------------------------------------------------------- */
/*      Utilize spatial index if appropriate.                           */
/* -------------------------------------------------------------------- */
    if( m_poFilterGeom && fpQIX )
    {
        int nSpatialFIDCount, *panSpatialFIDs;
        double adfBoundsMin[4], adfBoundsMax[4];
        OGREnvelope oEnvelope;

        m_poFilterGeom->getEnvelope( &oEnvelope );

        adfBoundsMin[0] = oEnvelope.MinX;
        adfBoundsMin[1] = oEnvelope.MinY;
        adfBoundsMin[2] = 0.0;
        adfBoundsMin[3] = 0.0;
        adfBoundsMax[0] = oEnvelope.MaxX;
        adfBoundsMax[1] = oEnvelope.MaxY;
        adfBoundsMax[2] = 0.0;
        adfBoundsMax[3] = 0.0;

        panSpatialFIDs = SHPSearchDiskTree( fpQIX, 
                                            adfBoundsMin, adfBoundsMax, 
                                            &nSpatialFIDCount );
        CPLDebug( "SHAPE", "Used spatial index, got %d matches.", 
                  nSpatialFIDCount );

        // Use resulting list as matching FID list (but reallocate and
        // terminate with OGRNullFID).

        if( panMatchingFIDs == NULL )
        {
            int i;

            panMatchingFIDs = (long *) 
                CPLMalloc(sizeof(long) * (nSpatialFIDCount+1) );
            for( i = 0; i < nSpatialFIDCount; i++ )
                panMatchingFIDs[i] = (long) panSpatialFIDs[i];
            panMatchingFIDs[nSpatialFIDCount] = OGRNullFID;
            free( panSpatialFIDs );
        }

        // Cull attribute index matches based on those in the spatial index
        // result set.  We assume that the attribute results are in sorted
        // order.
        else
        {
            int iRead, iWrite=0, iSpatial=0;

            for( iRead = 0; panMatchingFIDs[iRead] != OGRNullFID; iRead++ )
            {
                while( iSpatial < nSpatialFIDCount
                       && panSpatialFIDs[iSpatial] < panMatchingFIDs[iRead] )
                    iSpatial++;

                if( iSpatial == nSpatialFIDCount )
                    continue;

                if( panSpatialFIDs[iSpatial] == panMatchingFIDs[iRead] )
                    panMatchingFIDs[iWrite++] = panMatchingFIDs[iRead];
            }
            panMatchingFIDs[iWrite] = OGRNullFID;
        }
    }

    return TRUE;
}

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

void OGRShapeLayer::ResetReading()

{
/* -------------------------------------------------------------------- */
/*      Clear previous index search result, if any.                     */
/* -------------------------------------------------------------------- */
    CPLFree( panMatchingFIDs );
    panMatchingFIDs = NULL;
    iMatchingFID = 0;

    iNextShapeId = 0;

    if( bHeaderDirty )
        SyncToDisk();
}

/************************************************************************/
/*                           SetNextByIndex()                           */
/*                                                                      */
/*      If we already have an FID list, we can easily resposition       */
/*      ourselves in it.                                                */
/************************************************************************/

OGRErr OGRShapeLayer::SetNextByIndex( long nIndex )

{
    // Eventually we should try to use panMatchingFIDs list 
    // if available and appropriate. 
    if( m_poFilterGeom != NULL || m_poAttrQuery != NULL )
        return OGRLayer::SetNextByIndex( nIndex );

    iNextShapeId = nIndex;

    return OGRERR_NONE;
}

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

OGRFeature *OGRShapeLayer::GetNextFeature()

{
    OGRFeature  *poFeature = NULL;

/* -------------------------------------------------------------------- */
/*      Collect a matching list if we have attribute or spatial         */
/*      indices.  Only do this on the first request for a given pass    */
/*      of course.                                                      */
/* -------------------------------------------------------------------- */
    if( (m_poAttrQuery != NULL || m_poFilterGeom != NULL)
        && iNextShapeId == 0 && panMatchingFIDs == NULL )
    {
        ScanIndices();
    }
    
/* -------------------------------------------------------------------- */
/*      Loop till we find a feature matching our criteria.              */
/* -------------------------------------------------------------------- */
    while( TRUE )
    {
        if( panMatchingFIDs != NULL )
        {
            if( panMatchingFIDs[iMatchingFID] == OGRNullFID )
            {
                return NULL;
            }

            poFeature = SHPReadOGRFeature( hSHP, hDBF, poFeatureDefn, 
                                           panMatchingFIDs[iMatchingFID++] );
        }
        else
        {
            if( iNextShapeId >= nTotalShapeCount )
            {
                return NULL;
            }
    
            if( hDBF && DBFIsRecordDeleted( hDBF, iNextShapeId ) )
                poFeature = NULL;
            else
                poFeature = SHPReadOGRFeature( hSHP, hDBF, poFeatureDefn,
                                               iNextShapeId );

            iNextShapeId++;
        }

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

            m_nFeaturesRead++;

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

            delete poFeature;
        }
    }        

    /*
     * NEVER SHOULD GET HERE
     */
    CPLAssert(!"OGRShapeLayer::GetNextFeature(): Execution never should get here!");
}

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

OGRFeature *OGRShapeLayer::GetFeature( long nFeatureId )

{
    OGRFeature *poFeature = NULL;
    poFeature = SHPReadOGRFeature( hSHP, hDBF, poFeatureDefn, nFeatureId );

    if( poFeature != NULL )
    {
        if( poFeature->GetGeometryRef() != NULL )
            poFeature->GetGeometryRef()->assignSpatialReference( poSRS );

        m_nFeaturesRead++;
    
        return poFeature;
    }