ClickHouse/dbms/src/Functions/h3HexAreaM2.cpp
2020-02-02 23:13:06 +03:00

84 lines
2.4 KiB
C++

#include "config_functions.h"
#if USE_H3
# include <Columns/ColumnsNumber.h>
# include <DataTypes/DataTypesNumber.h>
# include <Functions/FunctionFactory.h>
# include <Functions/IFunction.h>
# include <IO/WriteHelpers.h>
# include <Common/typeid_cast.h>
# include <ext/range.h>
# if __has_include(<h3/h3api.h>)
# include <h3/h3api.h>
# include <h3/constants.h>
# else
# include <h3api.h>
# include <constants.h>
# endif
namespace DB
{
namespace ErrorCodes
{
extern const int ARGUMENT_OUT_OF_BOUND;
}
class FunctionH3HexAreaM2 : public IFunction
{
public:
static constexpr auto name = "h3HexAreaM2";
static FunctionPtr create(const Context &) { return std::make_shared<FunctionH3HexAreaM2>(); }
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
{
auto arg = arguments[0].get();
if (!WhichDataType(arg).isUInt8())
throw Exception(
"Illegal type " + arg->getName() + " of argument " + std::to_string(1) + " of function " + getName() + ". Must be UInt8",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeFloat64>();
}
void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t input_rows_count) override
{
const auto col_hindex = block.getByPosition(arguments[0]).column.get();
auto dst = ColumnVector<Float64>::create();
auto & dst_data = dst->getData();
dst_data.resize(input_rows_count);
for (const auto row : ext::range(0, input_rows_count))
{
const UInt64 resolution = col_hindex->getUInt(row);
if (resolution > MAX_H3_RES)
throw Exception("The argument 'resolution' (" + toString(resolution) + ") of function " + getName()
+ " is out of bounds because the maximum resolution in H3 library is " + toString(MAX_H3_RES), ErrorCodes::ARGUMENT_OUT_OF_BOUND);
Float64 res = hexAreaM2(resolution);
dst_data[row] = res;
}
block.getByPosition(result).column = std::move(dst);
}
};
void registerFunctionH3HexAreaM2(FunctionFactory & factory)
{
factory.registerFunction<FunctionH3HexAreaM2>();
}
}
#endif