archive-gh-me/mapnik
1
0
Fork 0
mirror of https://github.com/mapnik/mapnik.git synced 2025-12-08 20:13:09 +00:00
Code Issues Projects Releases Wiki Activity

implement get_geometry_type() for 'large json' strategy

Browse Source 
@springmeyer - we should talk re: validity of this approach. I know the baclground but still.
This commit is contained in:
artemp 2015-02-12 15:50:13 +01:00
parent e8f397c41c
commit bb57ebd258
1 changed files with 59 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
plugins/input/geojson/geojson_datasource.cpp
View File

@ -292,19 +292,69 @@ boost::optional<mapnik::datasource::geometry_t> geojson_datasource::get_geometry
{
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)
if (cache_features_)
{
mapnik::util::to_ds_type(features_[i]->paths(),result);
if (result)
unsigned num_features = features_.size();
for (unsigned i = 0; i < num_features && i < 5; ++i)
{
int type = static_cast<int>(*result);
if (multi_type > 0 && multi_type != type)
mapnik::util::to_ds_type(features_[i]->paths(),result);
if (result)
{
result.reset(mapnik::datasource::Collection);
return result;
int type = static_cast<int>(*result);
if (multi_type > 0 && multi_type != type)
{
result.reset(mapnik::datasource::Collection);
return result;
}
multi_type = type;
}
}
}
else
{
mapnik::util::file file(filename_);
if (!file.open())
{
throw mapnik::datasource_exception("GeoJSON Plugin: could not open: '" + filename_ + "'");
}
auto itr = tree_->qbegin(boost::geometry::index::intersects(extent_));
auto end = tree_->qend();
mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
for (std::size_t count = 0; itr !=end && count < 5; ++itr,++count)
{
geojson_datasource::item_type const& item = *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;
ascii::space_type space;
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx,1));
if (!qi::phrase_parse(start, end, (grammar)(boost::phoenix::ref(*feature)), space))
{
throw std::runtime_error("Failed to parse geojson feature");
}
mapnik::util::to_ds_type(feature->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;
}
multi_type = type;
}
}
return result;