112 lines
4.1 KiB
C++
112 lines
4.1 KiB
C++
/*****************************************************************************
|
|
*
|
|
* This file is part of Mapnik (c++ mapping toolkit)
|
|
*
|
|
* Copyright (C) 2024 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 "geojson_index_featureset.hpp"
|
|
#include <mapnik/feature.hpp>
|
|
#include <mapnik/feature_factory.hpp>
|
|
#include <mapnik/util/utf_conv_win.hpp>
|
|
#include <mapnik/util/conversions.hpp>
|
|
#include <mapnik/geometry/is_empty.hpp>
|
|
#include <mapnik/json/parse_feature.hpp>
|
|
#include <mapnik/json/json_grammar_config.hpp>
|
|
// stl
|
|
#include <string>
|
|
#include <vector>
|
|
#include <fstream>
|
|
#include <algorithm>
|
|
|
|
geojson_index_featureset::geojson_index_featureset(std::string const& filename,
|
|
mapnik::bounding_box_filter<float> const& filter)
|
|
:
|
|
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
|
|
//
|
|
#elif defined(_WIN32)
|
|
file_(_wfopen(mapnik::utf8_to_utf16(filename).c_str(), L"rb"), std::fclose)
|
|
,
|
|
#else
|
|
file_(std::fopen(filename.c_str(), "rb"), std::fclose)
|
|
,
|
|
#endif
|
|
ctx_(std::make_shared<mapnik::context_type>())
|
|
{
|
|
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
|
|
const auto memory = mapnik::mapped_memory_cache::instance().find(filename, true);
|
|
if (memory.has_value())
|
|
{
|
|
mapped_region_ = *memory;
|
|
}
|
|
else
|
|
{
|
|
throw std::runtime_error("could not create file mapping for " + filename);
|
|
}
|
|
#else
|
|
if (!file_)
|
|
throw std::runtime_error("Can't open " + filename);
|
|
#endif
|
|
std::string indexname = filename + ".index";
|
|
std::ifstream index(indexname.c_str(), std::ios::binary);
|
|
if (!index)
|
|
throw mapnik::datasource_exception("GeoJSON Plugin: can't open index file " + indexname);
|
|
mapnik::util::spatial_index<value_type, mapnik::bounding_box_filter<float>, std::ifstream, mapnik::box2d<float>>::
|
|
query(filter, index, positions_);
|
|
|
|
positions_.erase(std::remove_if(positions_.begin(),
|
|
positions_.end(),
|
|
[&](value_type const& pos) { return !pos.box.intersects(filter.box_); }),
|
|
positions_.end());
|
|
|
|
std::sort(positions_.begin(), positions_.end(), [](value_type const& lhs, value_type const& rhs) {
|
|
return lhs.off < rhs.off;
|
|
});
|
|
itr_ = positions_.begin();
|
|
}
|
|
|
|
geojson_index_featureset::~geojson_index_featureset() {}
|
|
|
|
mapnik::feature_ptr geojson_index_featureset::next()
|
|
{
|
|
while (itr_ != positions_.end())
|
|
{
|
|
auto pos = *itr_++;
|
|
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
|
|
char const* start = static_cast<char const*>(mapped_region_->get_address()) + pos.off;
|
|
char const* end = start + pos.size;
|
|
#else
|
|
std::fseek(file_.get(), pos.off, SEEK_SET);
|
|
std::vector<char> record;
|
|
record.resize(pos.size);
|
|
auto count = std::fread(record.data(), pos.size, 1, file_.get());
|
|
auto const* start = record.data();
|
|
auto const* end = (count == 1) ? start + record.size() : start;
|
|
#endif
|
|
static const mapnik::transcoder tr("utf8");
|
|
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_, feature_id_++));
|
|
using mapnik::json::grammar::iterator_type;
|
|
mapnik::json::parse_feature(start, end, *feature, tr); // throw on failure
|
|
// skip empty geometries
|
|
if (mapnik::geometry::is_empty(feature->get_geometry()))
|
|
continue;
|
|
return feature;
|
|
}
|
|
return mapnik::feature_ptr();
|
|
}
|