mapnik/plugins/input/shape/shape_index_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
 *
 *****************************************************************************/

// stl
#include <fstream>

// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/feature_factory.hpp>

#include <mapnik/warning.hpp>
MAPNIK_DISABLE_WARNING_PUSH
#include <mapnik/warning_ignore.hpp>
#include <boost/algorithm/string.hpp>
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
#include <boost/interprocess/streams/bufferstream.hpp>
#endif
MAPNIK_DISABLE_WARNING_POP

#include "shape_index_featureset.hpp"
#include "shape_utils.hpp"
#include <mapnik/util/spatial_index.hpp>

using mapnik::feature_factory;

template<typename filterT>
shape_index_featureset<filterT>::shape_index_featureset(filterT const& filter,
                                                        std::unique_ptr<shape_io>&& shape_ptr,
                                                        std::set<std::string> const& attribute_names,
                                                        std::string const& encoding,
                                                        std::string const& shape_name,
                                                        int row_limit)
    : filter_(filter)
    , ctx_(std::make_shared<mapnik::context_type>())
    , shape_ptr_(std::move(shape_ptr))
    , tr_(new mapnik::transcoder(encoding))
    , positions_()
    , itr_()
    , attr_ids_()
    , row_limit_(row_limit)
    , count_(0)
    , feature_bbox_()
{
    shape_ptr_->shp().skip(100);
    setup_attributes(ctx_, attribute_names, shape_name, *shape_ptr_, attr_ids_);

    auto index = shape_ptr_->index();
    if (index)
    {
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
        mapnik::util::spatial_index<mapnik::detail::node,
                                    filterT,
                                    boost::interprocess::ibufferstream,
                                    mapnik::box2d<typename filterT::value_type>>::query(filter,
                                                                                        index->file(),
                                                                                        positions_);
#else
        mapnik::util::spatial_index<mapnik::detail::node,
                                    filterT,
                                    std::ifstream,
                                    mapnik::box2d<typename filterT::value_type>>::query(filter,
                                                                                        index->file(),
                                                                                        positions_);
#endif
    }
    // filter
    positions_.erase(std::remove_if(positions_.begin(),
                                    positions_.end(),
                                    [&](mapnik::detail::node const& pos) { return !pos.box.intersects(filter.box_); }),
                     positions_.end());
    std::sort(positions_.begin(), positions_.end(), [](mapnik::detail::node const& n0, mapnik::detail::node const& n1) {
        return n0.offset != n1.offset ? n0.offset < n1.offset : n0.start < n1.start;
    });
    MAPNIK_LOG_DEBUG(shape) << "shape_index_featureset: Query size=" << positions_.size();
    itr_ = positions_.begin();
}

template<typename filterT>
feature_ptr shape_index_featureset<filterT>::next()
{
    if (row_limit_ && count_ >= row_limit_)
    {
        return feature_ptr();
    }

    while (itr_ != positions_.end())
    {
        std::uint64_t offset = itr_->offset;
        shape_ptr_->move_to(offset);
        std::vector<std::pair<int, int>> parts;
        while (itr_ != positions_.end() && itr_->offset == offset)
        {
            if (itr_->start != -1)
                parts.emplace_back(itr_->start, itr_->end);
            ++itr_;
        }
        mapnik::value_integer feature_id = shape_ptr_->id();
        shape_file::record_type record(shape_ptr_->reclength_ * 2);
        shape_ptr_->shp().read_record(record);
        int type = record.read_ndr_integer();
        feature_ptr feature(feature_factory::create(ctx_, feature_id));

        switch (type)
        {
            case shape_io::shape_point:
            case shape_io::shape_pointm:
            case shape_io::shape_pointz: {
                double x = record.read_double();
                double y = record.read_double();
                feature->set_geometry(mapnik::geometry::point<double>(x, y));
                break;
            }
            case shape_io::shape_multipoint:
            case shape_io::shape_multipointm:
            case shape_io::shape_multipointz: {
                shape_io::read_bbox(record, feature_bbox_);
                // if (!filter_.pass(feature_bbox_)) continue;
                int num_points = record.read_ndr_integer();
                mapnik::geometry::multi_point<double> multi_point;
                for (int i = 0; i < num_points; ++i)
                {
                    double x = record.read_double();
                    double y = record.read_double();
                    multi_point.emplace_back(mapnik::geometry::point<double>(x, y));
                }
                feature->set_geometry(std::move(multi_point));
                break;
            }
            case shape_io::shape_polyline:
            case shape_io::shape_polylinem:
            case shape_io::shape_polylinez: {
                shape_io::read_bbox(record, feature_bbox_);
                // if (!filter_.pass(feature_bbox_)) continue;
                if (parts.size() < 2)
                    feature->set_geometry(shape_io::read_polyline(record));
                else
                    feature->set_geometry(shape_io::read_polyline_parts(record, parts));
                break;
            }
            case shape_io::shape_polygon:
            case shape_io::shape_polygonm:
            case shape_io::shape_polygonz: {
                shape_io::read_bbox(record, feature_bbox_);
                // if (!filter_.pass(feature_bbox_)) continue;
                if (parts.size() < 2)
                    feature->set_geometry(shape_io::read_polygon(record));
                else
                    feature->set_geometry(shape_io::read_polygon_parts(record, parts));
                break;
            }
            default:
                MAPNIK_LOG_DEBUG(shape) << "shape_index_featureset: Unsupported type" << type;
                return feature_ptr();
        }

        if (attr_ids_.size())
        {
            shape_ptr_->dbf().move_to(shape_ptr_->id_);
            try
            {
                for (auto id : attr_ids_)
                {
                    shape_ptr_->dbf().add_attribute(id, *tr_, *feature);
                }
            } catch (...)
            {
                MAPNIK_LOG_ERROR(shape) << "Shape Plugin: error processing attributes";
            }
        }
        ++count_;
        return feature;
    }

    MAPNIK_LOG_DEBUG(shape) << "shape_index_featureset: " << count_ << " features";
    return feature_ptr();
}

template<typename filterT>
shape_index_featureset<filterT>::~shape_index_featureset()
{}

template class shape_index_featureset<mapnik::bounding_box_filter<float>>;
template class shape_index_featureset<mapnik::at_point_filter<float>>;