ClickHouse/src/Functions/h3toGeo.cpp
2021-06-14 11:38:38 -07:00

95 lines
2.9 KiB
C++

#if !defined(ARCADIA_BUILD)
# include "config_functions.h"
#endif
#if USE_H3
#include <array>
#include <math.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnTuple.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypeTuple.h>
#include <DataTypes/DataTypesNumber.h>
#include <Functions/FunctionFactory.h>
#include <Functions/IFunction.h>
#include <Common/typeid_cast.h>
#include <ext/range.h>
#include <h3api.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
namespace
{
/// Implements the function h3ToGeo which takes a single argument (h3Index)
/// and returns the longitude and latitude that correspond to the provided h3 index
class FunctionH3ToGeo : public IFunction
{
public:
static constexpr auto name = "h3ToGeo";
static FunctionPtr create(ContextConstPtr) { return std::make_shared<FunctionH3ToGeo>(); }
std::string getName() const override { return name; }
size_t getNumberOfArguments() const override { return 1; }
bool useDefaultImplementationForConstants() const override { return true; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
const auto * arg = arguments[0].get();
if (!WhichDataType(arg).isUInt64())
throw Exception(
"Illegal type " + arg->getName() + " of argument " + std::to_string(1) + " of function " + getName() + ". Must be UInt64",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeTuple>(
DataTypes{std::make_shared<DataTypeFloat64>(), std::make_shared<DataTypeFloat64>()},
Strings{"longitude", "latitude"});
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
{
const auto * col_index = arguments[0].column.get();
ColumnPtr res_column;
auto latitude = ColumnFloat64::create(input_rows_count);
auto longitude = ColumnFloat64::create(input_rows_count);
ColumnFloat64::Container & lon_data = longitude->getData();
ColumnFloat64::Container & lat_data = latitude->getData();
for (const auto row : ext::range(0, input_rows_count))
{
const UInt64 h3index = col_index->getUInt(row);
GeoCoord coord;
h3ToGeo(h3index,&coord);
lon_data[row] = radsToDegs(coord.lon);
lat_data[row] = radsToDegs(coord.lat);
}
MutableColumns result;
result.emplace_back(std::move(longitude));
result.emplace_back(std::move(latitude));
return ColumnTuple::create(std::move(result));
}
};
}
void registerFunctionH3ToGeo(FunctionFactory & factory)
{
factory.registerFunction<FunctionH3ToGeo>();
}
}
#endif