mapnik/plugins/input/tiles/tiles_datasource.cpp

420 lines
16 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2025 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 "tiles_datasource.hpp"
#include "vector_tiles_featureset.hpp"
#include "raster_tiles_featureset.hpp"
#include "pmtiles_source.hpp"
#include "mbtiles_source.hpp"
#include "vector_tile_projection.hpp"
#include <mapnik/geom_util.hpp>
#include <mapnik/util/fs.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/datasource_plugin.hpp>
#include <mapnik/well_known_srs.hpp>
#include <string>
#include <algorithm>
#include <thread>
DATASOURCE_PLUGIN_IMPL(tiles_datasource_plugin, tiles_datasource);
DATASOURCE_PLUGIN_EXPORT(tiles_datasource_plugin);
DATASOURCE_PLUGIN_EMPTY_AFTER_LOAD(tiles_datasource_plugin);
DATASOURCE_PLUGIN_EMPTY_BEFORE_UNLOAD(tiles_datasource_plugin);
tiles_datasource::tiles_datasource(mapnik::parameters const& params)
: datasource(params),
desc_(tiles_datasource::name(), *params.get<std::string>("encoding", "utf-8"))
{
init(params);
}
tiles_datasource::~tiles_datasource() {}
mapnik::datasource::datasource_t tiles_datasource::type() const
{
if (source_ptr_ && source_ptr_->is_raster())
return datasource::Raster;
return datasource::Vector;
}
char const* tiles_datasource::name()
{
return "tiles";
}
mapnik::layer_descriptor tiles_datasource::get_descriptor() const
{
return desc_;
}
std::optional<mapnik::datasource_geometry_t> tiles_datasource::get_geometry_type() const
{
return mapnik::datasource_geometry_t::Collection;
}
mapnik::box2d<double> tiles_datasource::envelope() const
{
return extent_;
}
namespace {
boost::json::value const& xyz_metadata(std::string const& url_str)
{
static thread_local std::unordered_map<std::string, boost::json::value> metadata_cache;
auto itr = metadata_cache.find(url_str);
if (itr == metadata_cache.end())
{
auto meta = xyz_tiles::metadata(url_str);
auto result = metadata_cache.emplace(url_str, std::move(meta));
return result.first->second;
}
return itr->second;
}
} // namespace
void tiles_datasource::init_metadata(boost::json::value const& metadata)
{
if (!metadata.is_object())
return;
if (auto const* p = metadata.as_object().if_contains("bounds"))
{
if (p->is_array())
{
auto bounds_array = p->as_array();
if (bounds_array.size() == 4)
{
extent_ = {bounds_array[0].to_number<double>(),
bounds_array[1].to_number<double>(),
bounds_array[2].to_number<double>(),
bounds_array[3].to_number<double>()};
}
}
}
if (auto const* p = metadata.as_object().if_contains("minzoom"))
{
if (p->is_number())
minzoom_ = p->as_int64();
}
if (auto const* p = metadata.as_object().if_contains("maxzoom"))
{
if (p->is_number())
maxzoom_ = p->as_int64();
}
bool found = false;
auto const* layers = metadata.as_object().if_contains("vector_layers");
if (layers && layers->is_array() && layer_name_)
{
for (auto const& layer : layers->as_array())
{
is_vector_ = true;
std::string id = layer.at("id").as_string().c_str();
if (id == *layer_name_)
{
found = true;
if (auto const* p = layer.as_object().if_contains("minzoom"))
{
if (p->is_number())
minzoom_ = p->as_int64();
}
if (auto const* p = layer.as_object().if_contains("maxzoom"))
{
if (p->is_number())
maxzoom_ = p->as_int64();
}
for (auto const& field : layer.at("fields").as_object())
{
std::string name{field.key_c_str()};
if (field.value() == "String")
{
desc_.add_descriptor(mapnik::attribute_descriptor(name, mapnik::String));
}
else if (field.value() == "Number")
{
desc_.add_descriptor(mapnik::attribute_descriptor(name, mapnik::Float));
}
else if (field.value() == "Boolean")
{
desc_.add_descriptor(mapnik::attribute_descriptor(name, mapnik::Boolean));
}
}
break;
}
}
}
if (!found && is_vector_ && layer_name_)
{
throw mapnik::datasource_exception("Requested layer '" + *layer_name_ + "' not found.");
}
}
void tiles_datasource::init(mapnik::parameters const& params)
{
std::optional<std::string> file = params.get<std::string>("file");
std::optional<std::string> json_url = params.get<std::string>("url");
if (!file && !json_url)
{
throw mapnik::datasource_exception("Tiles Plugin: missing <file> or <json-url> parameter");
}
layer_name_ = params.get<std::string>("layer");
if (file)
{
std::optional<std::string> base = params.get<std::string>("base");
if (base)
{
database_path_ = *base + "/" + *file;
}
else
{
database_path_ = *file;
}
if (!mapnik::util::exists(database_path_))
{
throw mapnik::datasource_exception("Tiles Plugin: " + database_path_ + " does not exist");
}
if (database_path_.ends_with(".pmtiles"))
{
source_ptr_ = std::make_shared<mapnik::pmtiles_source>(database_path_);
}
else if (database_path_.ends_with(".mbtiles"))
{
source_ptr_ = std::make_shared<mapnik::mbtiles_source>(database_path_);
}
else
{
throw mapnik::datasource_exception("Unexpected file extension in tiles source: " + database_path_);
}
minzoom_ = source_ptr_->minzoom();
maxzoom_ = source_ptr_->maxzoom();
extent_ = source_ptr_->extent();
auto metadata = source_ptr_->metadata();
init_metadata(metadata);
}
else if (json_url)
{
if ((*json_url).ends_with(".json"))
{
extent_ = mapnik::box2d<double>(-180, -85.0511287, 180, 85.0511287);
auto metadata = xyz_metadata(*json_url);
init_metadata(metadata);
auto tiles = metadata.at("tiles");
for (auto const& tiles_url : tiles.as_array())
{
url_template_ = tiles_url.as_string();
}
}
else
{
extent_ = mapnik::box2d<double>(-180, -85.0511287, 180, 85.0511287);
if ((*json_url).ends_with(".mvt") || (*json_url).ends_with(".pbf"))
{
is_vector_ = true;
}
url_template_ = json_url;
}
}
// overwrite envelope with user supplied
std::optional<std::string> ext = params.get<std::string>("extent");
if (ext && !ext->empty())
{
extent_.from_string(*ext);
}
if (!extent_.valid())
{
throw mapnik::datasource_exception("Tiles Plugin: " + database_path_ + " extent is invalid.");
}
// Bounds are specified in EPSG:4326, therefore transformation is required.
mapnik::lonlat2merc(extent_.minx_, extent_.miny_);
mapnik::lonlat2merc(extent_.maxx_, extent_.maxy_);
// overwrite min/max zoom with user supplied values.
minzoom_ = *params.get<mapnik::value_integer>("minzoom", minzoom_);
maxzoom_ = *params.get<mapnik::value_integer>("maxzoom", maxzoom_);
// overwrite default max_threads
max_threads_ = *params.get<mapnik::value_integer>("max-threads", max_threads_);
}
mapnik::context_ptr tiles_datasource::get_context_with_attributes() const
{
mapnik::context_ptr context = std::make_shared<mapnik::context_type>();
std::vector<mapnik::attribute_descriptor> const& desc_ar = desc_.get_descriptors();
for (auto const& attr_info : desc_ar)
{
context->push(attr_info.get_name());
}
return context;
}
mapnik::context_ptr tiles_datasource::get_query_context(mapnik::query const& q) const
{
mapnik::context_ptr context = std::make_shared<mapnik::context_type>();
std::vector<mapnik::attribute_descriptor> const& desc_ar = desc_.get_descriptors();
for (auto const& name : q.property_names())
{
for (auto const& attr_info : desc_ar)
{
if (name == attr_info.get_name())
{
context->push(name);
break;
}
}
}
return context;
}
namespace {
constexpr double scales[] = {279541132.014, 139770566.007, 69885283.0036, 34942641.5018, 17471320.7509, 8735660.37545,
4367830.18772, 2183915.09386, 1091957.54693, 545978.773466, 272989.386733, 136494.693366,
68247.3466832, 34123.6733416, 17061.8366708, 8530.9183354, 4265.4591677, 2132.72958385,
1066.36479192, 533.182395962, 266.59119798, 133.29559899, 66.6477994952};
std::int64_t scale_to_zoom(double scale, std::int64_t minzoom, std::int64_t maxzoom)
{
for (std::int64_t zoom = 0; zoom < 22; ++zoom)
{
if (scale > std::ceil(scales[zoom]))
return std::min(zoom, maxzoom);
}
return maxzoom;
}
} // namespace
std::unordered_map<std::string, std::string>& tiles_datasource::tile_cache()
{
static thread_local std::unordered_map<std::string, std::string> tiles_cache;
return tiles_cache;
}
mapnik::featureset_ptr tiles_datasource::features(mapnik::query const& q) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "tiles_datasource::features");
#endif
auto& tiles_cache = tile_cache();
if (tiles_cache.size() > 64)
{
tiles_cache.clear();
}
if (q.get_bbox().intersects(extent_))
{
mapnik::box2d<double> bbox = q.get_bbox().intersect(extent_);
auto zoom = scale_to_zoom(q.scale_denominator(), minzoom_, maxzoom_);
mapnik::context_ptr context = get_query_context(q);
int tile_count = 1 << zoom;
auto xmin = static_cast<int>((bbox.minx() + mapnik::EARTH_CIRCUMFERENCE / 2) *
(tile_count / mapnik::EARTH_CIRCUMFERENCE));
auto xmax = static_cast<int>((bbox.maxx() + mapnik::EARTH_CIRCUMFERENCE / 2) *
(tile_count / mapnik::EARTH_CIRCUMFERENCE));
auto ymin = static_cast<int>(((mapnik::EARTH_CIRCUMFERENCE / 2) - bbox.maxy()) *
(tile_count / mapnik::EARTH_CIRCUMFERENCE));
auto ymax = static_cast<int>(((mapnik::EARTH_CIRCUMFERENCE / 2) - bbox.miny()) *
(tile_count / mapnik::EARTH_CIRCUMFERENCE));
std::string source_location = url_template_ ? *url_template_ : database_path_;
auto datasource_hash = std::hash<std::string>{}(source_location);
if (is_vector_ && layer_name_)
{
return std::make_shared<vector_tiles_featureset>(source_location,
context,
zoom,
xmin,
xmax,
ymin,
ymax,
bbox,
*layer_name_,
tiles_cache,
max_threads_,
datasource_hash);
}
else
{
return std::make_shared<raster_tiles_featureset>(source_location,
context,
bbox,
zoom,
xmin,
xmax,
ymin,
ymax,
tiles_cache,
max_threads_,
datasource_hash,
q.get_filter_factor());
}
}
return mapnik::featureset_ptr{};
}
mapnik::featureset_ptr tiles_datasource::features_at_point(mapnik::coord2d const& pt, double tol) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "tiles_datasource::features_at_point");
#endif
mapnik::filter_at_point filter(pt, tol);
mapnik::context_ptr context = get_context_with_attributes();
int tile_count = 1 << maxzoom_;
auto tile_x =
static_cast<int>((pt.x + mapnik::EARTH_CIRCUMFERENCE / 2) * (tile_count / mapnik::EARTH_CIRCUMFERENCE));
auto tile_y =
static_cast<int>(((mapnik::EARTH_CIRCUMFERENCE / 2) - pt.y) * (tile_count / mapnik::EARTH_CIRCUMFERENCE));
double x0 = tile_x * (mapnik::EARTH_CIRCUMFERENCE / tile_count) - 0.5 * mapnik::EARTH_CIRCUMFERENCE;
double y0 = -tile_y * (mapnik::EARTH_CIRCUMFERENCE / tile_count) + 0.5 * mapnik::EARTH_CIRCUMFERENCE;
double x1 = (tile_x + 1) * (mapnik::EARTH_CIRCUMFERENCE / tile_count) - 0.5 * mapnik::EARTH_CIRCUMFERENCE;
double y1 = -(tile_y + 1) * (mapnik::EARTH_CIRCUMFERENCE / tile_count) + 0.5 * mapnik::EARTH_CIRCUMFERENCE;
auto query_bbox = mapnik::box2d<double>{x0, y0, x1, y1};
std::string source_location = url_template_ ? *url_template_ : database_path_;
auto datasource_hash = std::hash<std::string>{}(source_location);
if (is_vector_ && layer_name_)
{
return std::make_shared<vector_tiles_featureset>(source_location,
context,
maxzoom_,
tile_x,
tile_x,
tile_y,
tile_y,
query_bbox,
*layer_name_,
tile_cache(),
max_threads_,
datasource_hash);
}
return mapnik::featureset_ptr();
}
#if !defined(_MSC_VER)
// Boost.Json header only
#include <boost/json/src.hpp>
#endif