ClickHouse/src/Functions/h3NumHexagons.cpp
2022-01-21 08:30:48 -08:00

96 lines
2.8 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 <constants.h>
#include <h3api.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int ILLEGAL_COLUMN;
extern const int ARGUMENT_OUT_OF_BOUND;
}
namespace
{
class FunctionH3NumHexagons : public IFunction
{
public:
static constexpr auto name = "h3NumHexagons";
static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionH3NumHexagons>(); }
std::string getName() const override { return name; }
size_t getNumberOfArguments() const override { return 1; }
bool useDefaultImplementationForConstants() const override { return true; }
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
const auto * arg = arguments[0].get();
if (!WhichDataType(arg).isUInt8())
throw Exception(
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
"Illegal type {} of argument {} of function {}. Must be UInt8",
arg->getName(), 1, getName());
return std::make_shared<DataTypeInt64>();
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
{
const auto * column = checkAndGetColumn<ColumnUInt8>(arguments[0].column.get());
if (!column)
throw Exception(
ErrorCodes::ILLEGAL_COLUMN,
"Illegal type {} of argument {} of function {}. Must be UInt8",
arguments[0].type->getName(),
1,
getName());
const auto & data = column->getData();
auto dst = ColumnVector<Int64>::create();
auto & dst_data = dst->getData();
dst_data.resize(input_rows_count);
for (size_t row = 0; row < input_rows_count; ++row)
{
const UInt8 resolution = data[row];
if (resolution > MAX_H3_RES)
throw Exception(
ErrorCodes::ARGUMENT_OUT_OF_BOUND,
"The argument 'resolution' ({}) of function {} is out of bounds because the maximum resolution in H3 library is ",
resolution, getName(), MAX_H3_RES);
Int64 res = getNumCells(resolution);
dst_data[row] = res;
}
return dst;
}
};
}
void registerFunctionH3NumHexagons(FunctionFactory & factory)
{
factory.registerFunction<FunctionH3NumHexagons>();
}
}
#endif