mapnik/utils/mapnik-index/process_geojson_file_x3.cpp

347 lines
11 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
*
*****************************************************************************/
#include "process_geojson_file_x3.hpp"
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
#pragma GCC diagnostic push
#include <mapnik/warning_ignore.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/streams/bufferstream.hpp>
#include <boost/spirit/home/x3.hpp>
#pragma GCC diagnostic pop
#include <mapnik/mapped_memory_cache.hpp>
#else
#include <mapnik/util/file_io.hpp>
#endif
#include <mapnik/feature.hpp>
#include <mapnik/json/json_grammar_config.hpp>
#include <mapnik/json/geojson_grammar_x3_def.hpp>
#include <mapnik/json/unicode_string_grammar_x3_def.hpp>
#include <mapnik/json/positions_grammar_x3_def.hpp>
namespace {
template <typename T>
struct feature_validate_callback
{
feature_validate_callback(mapnik::box2d<T> const& box)
: box_(box) {}
void operator() (mapnik::feature_ptr const& f) const
{
if (box_ != box_)
{
throw std::runtime_error("Bounding boxes mismatch validation feature");
}
}
mapnik::box2d<T> const& box_;
};
using box_type = mapnik::box2d<float>;
using boxes_type = std::vector<std::pair<box_type, std::pair<std::size_t, std::size_t>>>;
//using base_iterator_type = char const*;
//const mapnik::json::extract_bounding_box_grammar<base_iterator_type, boxes_type> geojson_datasource_static_bbox_grammar;
//const mapnik::transcoder tr("utf8");
//const mapnik::json::feature_grammar_callback<base_iterator_type, mapnik::feature_impl, feature_validate_callback<float>> fc_grammar(tr);
}
namespace mapnik { namespace json {
template <typename Box>
struct calculate_bounding_box
{
calculate_bounding_box(Box & box)
: box_(box) {}
void operator()(mapnik::json::point const& pt) const
{
box_.init(pt.x, pt.y);
}
void operator()(mapnik::json::ring const& ring) const
{
for (auto const& pt : ring)
{
if (!box_.valid()) box_.init(pt.x, pt.y);
else box_.expand_to_include(pt.x, pt.y);
}
}
void operator()(mapnik::json::rings const& rings) const
{
for (auto const& ring : rings)
{
operator()(ring);
break; // consider first ring only
}
}
void operator()(mapnik::json::rings_array const& rings_array) const
{
for (auto const& rings : rings_array)
{
operator()(rings);
}
}
template <typename T>
void operator() (T const& ) const {}
Box & box_;
};
namespace grammar {
namespace x3 = boost::spirit::x3;
using x3::lit;
using x3::omit;
using x3::raw;
using x3::char_;
using x3::eps;
struct feature_callback_tag;
auto on_feature_callback = [] (auto const& ctx)
{
// call our callback
x3::get<feature_callback_tag>(ctx)(_attr(ctx));
};
namespace {
auto const& geojson_value = geojson_grammar();
//auto const& key_value_ = key_value_grammar();
//auto const& json_string = mapnik::json::unicode_string_grammar();
}
// extract bounding box from GeoJSON Feature
struct bracket_tag ;
auto check_brackets = [](auto const& ctx)
{
_pass(ctx) = (x3::get<bracket_tag>(ctx) > 0);
};
auto open_bracket = [](auto const& ctx)
{
++x3::get<bracket_tag>(ctx);
};
auto close_bracket = [](auto const& ctx)
{
--x3::get<bracket_tag>(ctx);
};
auto assign_range = [](auto const& ctx)
{
std::get<0>(_val(ctx)) = std::move(_attr(ctx));
};
auto assign_bbox = [](auto const& ctx)
{
std::get<1>(_val(ctx)) = std::move(_attr(ctx));
};
auto extract_bounding_box = [](auto const& ctx)
{
mapnik::box2d<float> bbox;
calculate_bounding_box<mapnik::box2d<float>> visitor(bbox);
mapnik::util::apply_visitor(visitor, _attr(ctx));
_val(ctx) = std::move(bbox);
};
auto const coordinates_rule = x3::rule<struct coordinates_rule_tag, mapnik::box2d<float> > {}
= lit("\"coordinates\"") >> lit(':') >> positions_rule[extract_bounding_box];
auto const bounding_box = x3::rule<struct bounding_box_rule_tag, std::tuple<boost::iterator_range<char const*>,mapnik::box2d<float>>> {}
= raw[lit('{')[open_bracket] >> *(eps[check_brackets] >>
(lit("\"FeatureCollection\"") > eps(false)
|
lit('{')[open_bracket]
|
lit('}')[close_bracket]
|
coordinates_rule[assign_bbox]
|
omit[json_string]
|
omit[char_]))][assign_range];
auto const feature = bounding_box[on_feature_callback];
auto const key_value_ = omit[json_string] > lit(':') > omit[geojson_value] ;
auto const features = lit("\"features\"")
> lit(':') > lit('[') > -(omit[feature] % lit(',')) > lit(']');
auto const type = lit("\"type\"") > lit(':') > lit("\"FeatureCollection\"");
auto const feature_collection = x3::rule<struct feature_collection_tag> {}
= lit('{') > (( type | features | key_value_) % lit(',')) > lit('}');
}}}
namespace {
struct collect_features
{
collect_features(std::vector<mapnik::json::json_value> & values)
: values_(values) {}
void operator() (mapnik::json::json_value && val) const
{
values_.push_back(std::move(val));
}
std::vector<mapnik::json::json_value> & values_;
};
template <typename Iterator, typename Boxes>
struct extract_positions
{
extract_positions(Iterator start, Boxes & boxes)
: start_(start),
boxes_(boxes) {}
template <typename T>
void operator() (T const& val) const
{
auto const& r = std::get<0>(val);
mapnik::box2d<float> const& bbox = std::get<1>(val);
auto offset = std::distance(start_, r.begin());
auto size = std::distance(r.begin(), r.end());
boxes_.emplace_back(std::make_pair(bbox,std::make_pair(offset, size)));
//boxes_.emplace_back(std::make_tuple(bbox,offset, size));
//std::clog << offset << ":" << size << " " << bbox << std::endl;
}
Iterator start_;
Boxes & boxes_;
};
}
namespace mapnik { namespace detail {
template <typename T>
std::pair<bool,typename T::value_type::first_type> process_geojson_file_x3(T & boxes, std::string const& filename, bool validate_features, bool verbose)
{
using box_type = typename T::value_type::first_type;
box_type extent;
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
mapnik::mapped_region_ptr mapped_region;
boost::optional<mapnik::mapped_region_ptr> memory =
mapnik::mapped_memory_cache::instance().find(filename, true);
if (!memory)
{
std::clog << "Error : cannot memory map " << filename << std::endl;
return std::make_pair(false, extent);
}
else
{
mapped_region = *memory;
}
char const* start = reinterpret_cast<char const*>(mapped_region->get_address());
char const* end = start + mapped_region->get_size();
#else
mapnik::util::file file(filename);
if (!file)
{
std::clog << "Error : cannot open " << filename << std::endl;
return std::make_pair(false, extent);
}
std::string file_buffer;
file_buffer.resize(file.size());
std::fread(&file_buffer[0], file.size(), 1, file.get());
char const* start = file_buffer.c_str();
char const* end = start + file_buffer.length();
#endif
using namespace boost::spirit;
using space_type = mapnik::json::grammar::space_type;
auto const* itr = start;
extract_positions<char const*, boxes_type> callback(itr, boxes);
mapnik::json::grammar::keys_map keys;
std::size_t bracket_counter = 0;
auto feature_collection_impl = x3::with<mapnik::json::grammar::bracket_tag>(std::ref(bracket_counter))
[x3::with<mapnik::json::keys_tag>(std::ref(keys))
[x3::with<mapnik::json::grammar::feature_callback_tag>(std::ref(callback))
[mapnik::json::grammar::feature_collection]
]];
try
{
bool result = x3::phrase_parse(itr, end, feature_collection_impl, space_type());
if (!result)
{
std::clog << "mapnik-index (GeoJSON) : could not extract bounding boxes from : '" << filename << "'" << std::endl;
return std::make_pair(false, extent);
}
}
catch (x3::expectation_failure<char const*> const& ex)
{
std::clog << ex.what() << std::endl;
std::clog << "Expected: " << ex.which();
std::clog << " Got: \"" << std::string(ex.where(), ex.where() + 200) << '"' << std::endl;
return std::make_pair(false, extent);
}
catch (std::exception const& ex)
{
std::clog << "Exception caught:" << ex.what() << std::endl;
return std::make_pair(false, extent);
}
mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
//std::size_t start_id = 1;
for (auto const& item : boxes)
{
if (item.first.valid())
{
if (!extent.valid()) extent = item.first;
else extent.expand_to_include(item.first);
if (validate_features)
{
std::clog << "FIXME" << std::endl;
return std::make_pair(false, extent);
#if 0
base_iterator_type feat_itr = start + item.second.first;
base_iterator_type feat_end = feat_itr + item.second.second;
feature_validate_callback<float> callback(item.first);
bool result = boost::spirit::::phrase_parse(feat_itr, feat_end, (fc_grammar)
(boost::phoenix::ref(ctx), boost::phoenix::ref(start_id), boost::phoenix::ref(callback)),
space);
if (!result || feat_itr != feat_end)
{
if (verbose) std::clog << std::string(start + item.second.first, feat_end ) << std::endl;
return std::make_pair(false, extent);
}
#endif
}
}
}
return std::make_pair(true, extent);
}
template std::pair<bool,box_type> process_geojson_file_x3(boxes_type&, std::string const&, bool, bool);
}}