mapnik/plugins/input/geojson/geojson_memory_index_featureset.cpp
artemp 8ce7a1c43d refactor souce code files with the following rule: the physical filesytem path matches namespace structure
e.g `mapnik::geometry::centroid()` -> `$(MAPNIK_SOURCE)/include/mapnik/geometry/centroid.hpp`
2016-10-11 18:01:29 +02:00

82 lines
3.2 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2015 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/feature.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/json/feature_grammar.hpp>
#include <mapnik/util/utf_conv_win.hpp>
#include <mapnik/geometry/is_empty.hpp>
// stl
#include <string>
#include <vector>
#include "geojson_memory_index_featureset.hpp"
geojson_memory_index_featureset::geojson_memory_index_featureset(std::string const& filename,
array_type && index_array)
:
#ifdef _WINDOWS
file_(_wfopen(mapnik::utf8_to_utf16(filename).c_str(), L"rb"), std::fclose),
#else
file_(std::fopen(filename.c_str(),"rb"), std::fclose),
#endif
index_array_(std::move(index_array)),
index_itr_(index_array_.begin()),
index_end_(index_array_.end()),
ctx_(std::make_shared<mapnik::context_type>())
{
if (!file_) throw std::runtime_error("Can't open " + filename);
}
geojson_memory_index_featureset::~geojson_memory_index_featureset() {}
mapnik::feature_ptr geojson_memory_index_featureset::next()
{
while (index_itr_ != index_end_)
{
geojson_datasource::item_type const& item = *index_itr_++;
std::size_t file_offset = item.second.first;
std::size_t size = item.second.second;
std::fseek(file_.get(), file_offset, SEEK_SET);
std::vector<char> json;
json.resize(size);
std::fread(json.data(), size, 1, file_.get());
using chr_iterator_type = char const*;
chr_iterator_type start = json.data();
chr_iterator_type end = start + json.size();
static const mapnik::transcoder tr("utf8");
static const mapnik::json::feature_grammar<chr_iterator_type,mapnik::feature_impl> grammar(tr);
using namespace boost::spirit;
standard::space_type space;
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_, feature_id_++));
if (!qi::phrase_parse(start, end, (grammar)(boost::phoenix::ref(*feature)), space) || start != end)
{
throw std::runtime_error("Failed to parse geojson feature");
}
// skip empty geometries
if (mapnik::geometry::is_empty(feature->get_geometry()))
continue;
return feature;
}
return mapnik::feature_ptr();
}