mapnik/plugins/input/ogr/ogr_featureset.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2021 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

// mapnik
#include <mapnik/global.hpp>
#include <mapnik/value/types.hpp>
#include <mapnik/debug.hpp>
#include <mapnik/geometry/box2d.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/feature_layer_desc.hpp>
#include <mapnik/wkb.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/value/types.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/geometry/correct.hpp>

// ogr
#include "ogr_featureset.hpp"
#include "ogr_converter.hpp"

using mapnik::box2d;
using mapnik::feature_factory;
using mapnik::feature_ptr;
using mapnik::geometry_utils;
using mapnik::query;
using mapnik::transcoder;

ogr_featureset::ogr_featureset(mapnik::context_ptr const& ctx,
                               OGRLayer& layer,
                               OGRGeometry& extent,
                               std::string const& encoding)
    : ctx_(ctx)
    , layer_(layer)
    , layerdef_(layer.GetLayerDefn())
    , tr_(new transcoder(encoding))
    , fidcolumn_(layer_.GetFIDColumn())
    , count_(0)

{
    layer_.SetSpatialFilter(&extent);
}

ogr_featureset::ogr_featureset(mapnik::context_ptr const& ctx,
                               OGRLayer& layer,
                               mapnik::box2d<double> const& extent,
                               std::string const& encoding)
    : ctx_(ctx)
    , layer_(layer)
    , layerdef_(layer.GetLayerDefn())
    , tr_(new transcoder(encoding))
    , fidcolumn_(layer_.GetFIDColumn())
    , // TODO - unused
    count_(0)
{
    layer_.SetSpatialFilterRect(extent.minx(), extent.miny(), extent.maxx(), extent.maxy());
}

ogr_featureset::~ogr_featureset() {}

feature_ptr ogr_featureset::next()
{
    if (count_ == 0)
    {
        // Reset the layer reading on the first feature read
        // this is a hack, but needed due to https://github.com/mapnik/mapnik/issues/2048
        // Proper solution is to avoid storing layer state in featureset
        layer_.ResetReading();
    }
    OGRFeature* poFeature;
    while ((poFeature = layer_.GetNextFeature()) != nullptr)
    {
        // ogr feature ids start at 0, so add one to stay
        // consistent with other mapnik datasources that start at 1
        mapnik::value_integer feature_id = (poFeature->GetFID() + 1);
        feature_ptr feature(feature_factory::create(ctx_, feature_id));

        OGRGeometry* geom = poFeature->GetGeometryRef();
        if (geom && !geom->IsEmpty())
        {
            auto geom_corrected = ogr_converter::convert_geometry(geom);
            mapnik::geometry::correct(geom_corrected);
            feature->set_geometry(std::move(geom_corrected));
        }
        else
        {
            MAPNIK_LOG_DEBUG(ogr) << "ogr_featureset: Feature with null geometry=" << poFeature->GetFID();
            OGRFeature::DestroyFeature(poFeature);
            continue;
        }

        ++count_;

        int fld_count = layerdef_->GetFieldCount();
        for (int i = 0; i < fld_count; i++)
        {
            OGRFieldDefn* fld = layerdef_->GetFieldDefn(i);
            const OGRFieldType type_oid = fld->GetType();
            const std::string fld_name = fld->GetNameRef();

            switch (type_oid)
            {
                case OFTInteger: {
                    feature->put<mapnik::value_integer>(fld_name, poFeature->GetFieldAsInteger(i));
                    break;
                }
#if GDAL_VERSION_MAJOR >= 2
                case OFTInteger64: {
                    feature->put<mapnik::value_integer>(fld_name, poFeature->GetFieldAsInteger64(i));
                    break;
                }
#endif

                case OFTReal: {
                    feature->put(fld_name, poFeature->GetFieldAsDouble(i));
                    break;
                }

                case OFTString:
                case OFTWideString: // deprecated !
                {
                    feature->put(fld_name, tr_->transcode(poFeature->GetFieldAsString(i)));
                    break;
                }

                case OFTIntegerList:
#if GDAL_VERSION_MAJOR >= 2
                case OFTInteger64List:
#endif
                case OFTRealList:
                case OFTStringList:
                case OFTWideStringList: // deprecated !
                {
                    MAPNIK_LOG_WARN(ogr) << "ogr_featureset: Unhandled type_oid=" << type_oid;
                    break;
                }

                case OFTBinary: {
                    MAPNIK_LOG_WARN(ogr) << "ogr_featureset: Unhandled type_oid=" << type_oid;
                    // feature->put(name,feat->GetFieldAsBinary (i, size));
                    break;
                }

                case OFTDate:
                case OFTTime:
                case OFTDateTime: // unhandled !
                {
                    MAPNIK_LOG_WARN(ogr) << "ogr_featureset: Unhandled type_oid=" << type_oid;
                    break;
                }

                default: // unknown
                {
                    MAPNIK_LOG_WARN(ogr) << "ogr_featureset: Unknown type_oid=" << type_oid;
                    break;
                }
            }
        }
        OGRFeature::DestroyFeature(poFeature);
        return feature;
    }

    MAPNIK_LOG_DEBUG(ogr) << "ogr_featureset: " << count_ << " features";

    return feature_ptr();
}