mapnik/plugins/input/large_geojson/large_geojson_datasource.cpp

259 lines
8 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2014 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
*
*****************************************************************************/
#include "large_geojson_datasource.hpp"
#include "large_geojson_featureset.hpp"
#include <fstream>
#include <algorithm>
#include <functional>
// boost
#include <boost/algorithm/string.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/support_multi_pass.hpp>
#include <boost/spirit/home/support/iterators/detail/functor_input_policy.hpp>
// mapnik
#include <mapnik/unicode.hpp>
#include <mapnik/utils.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/feature_kv_iterator.hpp>
#include <mapnik/value_types.hpp>
#include <mapnik/box2d.hpp>
#include <mapnik/debug.hpp>
#include <mapnik/proj_transform.hpp>
#include <mapnik/projection.hpp>
#include <mapnik/util/geometry_to_ds_type.hpp>
#include <mapnik/util/variant.hpp>
#include <mapnik/util/file_io.hpp>
#include <mapnik/make_unique.hpp>
#include <mapnik/json/feature_collection_grammar.hpp>
#include <mapnik/json/extract_bounding_box_grammar_impl.hpp>
#include <mapnik/polygon_clipper.hpp> // boost::geometry - register box2d<double>
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(large_geojson_datasource)
struct attr_value_converter
{
mapnik::eAttributeType operator() (mapnik::value_integer) const
{
return mapnik::Integer;
}
mapnik::eAttributeType operator() (double) const
{
return mapnik::Double;
}
mapnik::eAttributeType operator() (float) const
{
return mapnik::Double;
}
mapnik::eAttributeType operator() (bool) const
{
return mapnik::Boolean;
}
mapnik::eAttributeType operator() (std::string const& ) const
{
return mapnik::String;
}
mapnik::eAttributeType operator() (mapnik::value_unicode_string const&) const
{
return mapnik::String;
}
mapnik::eAttributeType operator() (mapnik::value_null const& ) const
{
return mapnik::String;
}
};
large_geojson_datasource::large_geojson_datasource(parameters const& params)
: datasource(params),
type_(datasource::Vector),
desc_(large_geojson_datasource::name(),
*params.get<std::string>("encoding","utf-8")),
filename_(),
inline_string_(),
extent_(),
features_(),
tree_(nullptr)
{
boost::optional<std::string> inline_string = params.get<std::string>("inline");
if (inline_string)
{
inline_string_ = *inline_string;
}
else
{
boost::optional<std::string> file = params.get<std::string>("file");
if (!file) throw mapnik::datasource_exception("GeoJSON Plugin: missing <file> parameter");
boost::optional<std::string> base = params.get<std::string>("base");
if (base)
filename_ = *base + "/" + *file;
else
filename_ = *file;
}
if (!inline_string_.empty())
{
//parse_geojson(inline_string_);
}
else
{
mapnik::util::file file(filename_);
if (!file.open())
{
throw mapnik::datasource_exception("GeoJSON Plugin: could not open: '" + filename_ + "'");
}
std::vector<char> json;
json.resize(file.size());
std::fread(json.data(), file.size(), 1, file.get());
initialise_index(json.begin(), json.end());
}
}
template <typename Iterator>
void large_geojson_datasource::initialise_index(Iterator start, Iterator end)
{
mapnik::json::boxes boxes;
mapnik::json::extract_bounding_box_grammar<Iterator> g;
boost::spirit::standard_wide::space_type space;
if (!boost::spirit::qi::phrase_parse(start, end, (g)(boost::phoenix::ref(boxes)) , space))
{
throw mapnik::datasource_exception("GeoJSON Plugin: could not parse: '" + filename_ + "'");
}
std::cerr << "OK size=" << boxes.size() << std::endl;
std::cerr << "Populate index" << std::endl;
tree_ = std::make_unique<spatial_index_type>(boxes);
std::cerr << "Calculate total extent" << std::endl;
for (auto const& item : boxes)
{
auto const& box = std::get<0>(item);
if (!extent_.valid())
{
extent_ = box;
}
else
{
extent_.expand_to_include(box);
}
}
std::cerr << "Extent: " << extent_ << std::endl;
}
large_geojson_datasource::~large_geojson_datasource() {}
const char * large_geojson_datasource::name()
{
return "large-geojson";
}
boost::optional<mapnik::datasource::geometry_t> large_geojson_datasource::get_geometry_type() const
{
boost::optional<mapnik::datasource::geometry_t> result;
int multi_type = 0;
unsigned num_features = features_.size();
for (unsigned i = 0; i < num_features && i < 5; ++i)
{
mapnik::util::to_ds_type(features_[i]->paths(),result);
if (result)
{
int type = static_cast<int>(*result);
if (multi_type > 0 && multi_type != type)
{
result.reset(mapnik::datasource::Collection);
return result;
}
multi_type = type;
}
}
return result;
}
mapnik::datasource::datasource_t large_geojson_datasource::type() const
{
return type_;
}
mapnik::box2d<double> large_geojson_datasource::envelope() const
{
return extent_;
}
mapnik::layer_descriptor large_geojson_datasource::get_descriptor() const
{
return desc_;
}
mapnik::featureset_ptr large_geojson_datasource::features(mapnik::query const& q) const
{
// if the query box intersects our world extent then query for features
mapnik::box2d<double> const& box = q.get_bbox();
if (extent_.intersects(box))
{
#if BOOST_VERSION >= 105600
large_geojson_featureset::array_type index_array;
using item_type = large_geojson_featureset::array_type::value_type;
if (tree_)
{
tree_->query(boost::geometry::index::intersects(box),std::back_inserter(index_array));
std::cerr << "Query size=" << index_array.size() << std::endl;
std::cerr << "Sort index_array by offsets" << std::endl;
std::sort(index_array.begin(),index_array.end(), [](item_type const& item0, item_type const& item1) {return item0.second.first < item1.second.first;});
std::cerr << "Done" << std::endl;
return std::make_shared<large_geojson_featureset>(filename_, std::move(index_array));
}
#else
if (tree_)
{
return std::make_shared<large_geojson_featureset>(features_, tree_->find(box));
}
#endif
}
// otherwise return an empty featureset pointer
return mapnik::featureset_ptr();
}
mapnik::featureset_ptr large_geojson_datasource::features_at_point(mapnik::coord2d const& pt, double tol) const
{
mapnik::box2d<double> query_bbox(pt, pt);
query_bbox.pad(tol);
mapnik::query q(query_bbox);
std::vector<mapnik::attribute_descriptor> const& desc = desc_.get_descriptors();
std::vector<mapnik::attribute_descriptor>::const_iterator itr = desc.begin();
std::vector<mapnik::attribute_descriptor>::const_iterator end = desc.end();
for ( ;itr!=end;++itr)
{
q.add_property_name(itr->get_name());
}
return features(q);
}