ClickHouse/dbms/src/Functions/stringToH3.cpp
2020-01-31 18:49:17 +01:00

98 lines
3.4 KiB
C++

#include "config_functions.h"
#if USE_H3
# include <Functions/GatherUtils/GatherUtils.h>
# include <Functions/GatherUtils/Sources.h>
# include <DataTypes/DataTypeString.h>
# include <DataTypes/DataTypesNumber.h>
# include <Columns/ColumnString.h>
# include <Functions/FunctionFactory.h>
# include <Functions/IFunction.h>
# include <Common/typeid_cast.h>
# include <h3api.h>
namespace DB
{
using namespace GatherUtils;
class FunctionStringToH3 : public IFunction
{
public:
static constexpr auto name = "stringToH3";
static FunctionPtr create(const Context &) { return std::make_shared<FunctionStringToH3>(); }
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).isStringOrFixedString())
throw Exception(
"Illegal type " + arg->getName() + " of argument " + std::to_string(1) + " of function " + getName() + ". Must be String or FixedString",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeUInt64>();
}
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<UInt64>::create();
auto & dst_data = dst->getData();
dst_data.resize(input_rows_count);
if (auto * h3index = checkAndGetColumn<ColumnString>(col_hindex))
execute<StringSource>(StringSource(*h3index), dst_data);
else if (auto * h3index_fixed = checkAndGetColumn<ColumnFixedString>(col_hindex))
execute<FixedStringSource>(FixedStringSource(*h3index_fixed), dst_data);
else if (const ColumnConst * h3index_const = checkAndGetColumnConst<ColumnString>(col_hindex))
execute<ConstSource<StringSource>>(ConstSource<StringSource>(*h3index_const), dst_data);
else if (const ColumnConst * h3index_const_fixed = checkAndGetColumnConst<ColumnFixedString>(col_hindex))
execute<ConstSource<FixedStringSource>>(ConstSource<FixedStringSource>(*h3index_const_fixed), dst_data);
else
throw Exception("Illegal column as argument of function " + getName(), ErrorCodes::ILLEGAL_COLUMN);
block.getByPosition(result).column = std::move(dst);
}
private:
template <typename H3IndexSource>
static void execute(H3IndexSource h3index_source, PaddedPODArray<UInt64> & res_data)
{
size_t row_num = 0;
while (!h3index_source.isEnd())
{
auto h3index = h3index_source.getWhole();
// covert to std::string and get the c_str to have the delimiting \0 at the end.
auto h3index_str = StringRef(h3index.data, h3index.size).toString();
res_data[row_num] = stringToH3(h3index_str.c_str());
if (res_data[row_num] == 0)
{
throw Exception("Invalid H3 index: " + h3index_str, ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
h3index_source.next();
++row_num;
}
}
};
void registerFunctionStringToH3(FunctionFactory & factory)
{
factory.registerFunction<FunctionStringToH3>();
}
}
#endif