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#include <mbgl/style/tile_source_impl.hpp>
#include <mbgl/style/source_observer.hpp>
#include <mbgl/style/parser.hpp>
#include <mbgl/util/tileset.hpp>
#include <mbgl/util/mapbox.hpp>
#include <mbgl/storage/file_source.hpp>
#include <mbgl/platform/log.hpp>
#include <rapidjson/document.h>
#include <rapidjson/error/en.h>
#include <sstream>
namespace mbgl {
namespace style {
namespace {
void parseTileJSONMember(const JSValue& value, std::vector<std::string>& target, const char* name) {
if (!value.HasMember(name)) {
return;
}
const JSValue& property = value[name];
if (!property.IsArray()) {
return;
}
for (rapidjson::SizeType i = 0; i < property.Size(); i++) {
if (!property[i].IsString()) {
return;
}
}
for (rapidjson::SizeType i = 0; i < property.Size(); i++) {
target.emplace_back(std::string(property[i].GetString(), property[i].GetStringLength()));
}
}
void parseTileJSONMember(const JSValue& value, std::string& target, const char* name) {
if (!value.HasMember(name)) {
return;
}
const JSValue& property = value[name];
if (!property.IsString()) {
return;
}
target = { property.GetString(), property.GetStringLength() };
}
void parseTileJSONMember(const JSValue& value, uint8_t& target, const char* name) {
if (!value.HasMember(name)) {
return;
}
const JSValue& property = value[name];
if (!property.IsUint()) {
return;
}
unsigned int uint = property.GetUint();
if (uint > std::numeric_limits<uint8_t>::max()) {
return;
}
target = uint;
}
Tileset parseTileJSON(const JSValue& value) {
Tileset result;
parseTileJSONMember(value, result.tiles, "tiles");
parseTileJSONMember(value, result.zoomRange.min, "minzoom");
parseTileJSONMember(value, result.zoomRange.max, "maxzoom");
parseTileJSONMember(value, result.attribution, "attribution");
return result;
}
} // end namespace
Tileset TileSourceImpl::parseTileJSON(const std::string& json, const std::string& sourceURL, SourceType type, uint16_t tileSize) {
rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> document;
document.Parse<0>(json.c_str());
if (document.HasParseError()) {
std::stringstream message;
message << document.GetErrorOffset() << " - " << rapidjson::GetParseError_En(document.GetParseError());
throw std::runtime_error(message.str());
}
Tileset result = mbgl::style::parseTileJSON(document);
// TODO: Remove this hack by delivering proper URLs in the TileJSON to begin with.
if (util::mapbox::isMapboxURL(sourceURL)) {
for (auto& url : result.tiles) {
url = util::mapbox::canonicalizeTileURL(url, type, tileSize);
}
}
return result;
}
optional<variant<std::string, Tileset>> TileSourceImpl::parseURLOrTileset(const JSValue& value) {
if (!value.HasMember("url")) {
return { mbgl::style::parseTileJSON(value) };
}
const JSValue& urlVal = value["url"];
if (!urlVal.IsString()) {
Log::Error(Event::ParseStyle, "source url must be a string");
return {};
}
return { std::string(urlVal.GetString(), urlVal.GetStringLength()) };
}
TileSourceImpl::TileSourceImpl(SourceType type_, std::string id_, Source& base_,
variant<std::string, Tileset> urlOrTileset_,
uint16_t tileSize_)
: Impl(type_, std::move(id_), base_),
urlOrTileset(std::move(urlOrTileset_)),
tileSize(tileSize_) {
}
TileSourceImpl::~TileSourceImpl() = default;
void TileSourceImpl::load(FileSource& fileSource) {
if (urlOrTileset.is<Tileset>()) {
tileset = urlOrTileset.get<Tileset>();
loaded = true;
return;
}
if (req) {
return;
}
const std::string& url = urlOrTileset.get<std::string>();
req = fileSource.request(Resource::source(url), [this, url](Response res) {
if (res.error) {
observer->onSourceError(base, std::make_exception_ptr(std::runtime_error(res.error->message)));
} else if (res.notModified) {
return;
} else if (res.noContent) {
observer->onSourceError(base, std::make_exception_ptr(std::runtime_error("unexpectedly empty TileJSON")));
} else {
Tileset newTileset;
// Create a new copy of the Tileset object that holds the base values we've parsed
// from the stylesheet. Then merge in the values parsed from the TileJSON we retrieved
// via the URL.
try {
newTileset = parseTileJSON(*res.data, url, type, tileSize);
} catch (...) {
observer->onSourceError(base, std::current_exception());
return;
}
// Check whether previous information specifies different tile
if (tileset.tiles != newTileset.tiles) {
// Tile URLs changed: force tiles to be reloaded.
invalidateTiles();
// Tile size changed: We need to recalculate the tiles we need to load because we
// might have to load tiles for a different zoom level
// This is done automatically when we trigger the onSourceLoaded observer below.
// Min/Max zoom changed: We need to recalculate what tiles to load, if we have tiles
// loaded that are outside the new zoom range
// This is done automatically when we trigger the onSourceLoaded observer below.
// Attribution changed: We need to notify the embedding application that this
// changed. See https://github.com/mapbox/mapbox-gl-native/issues/2723
// This is not yet implemented.
// Center/bounds changed: We're not using these values currently
}
tileset = newTileset;
loaded = true;
observer->onSourceLoaded(base);
}
});
}
Range<uint8_t> TileSourceImpl::getZoomRange() {
assert(loaded);
return tileset.zoomRange;
}
} // namespace style
} // namespace mbgl
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