ClickHouse/src/Functions/h3kRing.cpp
Alexey Milovidov 8c9408f927 Checkpoint
2020-04-22 11:31:10 +03:00

102 lines
3.1 KiB
C++

#include "config_functions.h"
#if USE_H3
# include <vector>
# include <Columns/ColumnArray.h>
# include <Columns/ColumnsNumber.h>
# include <DataTypes/DataTypeArray.h>
# include <DataTypes/DataTypesNumber.h>
# include <DataTypes/IDataType.h>
# include <Functions/FunctionFactory.h>
# include <Functions/IFunction.h>
# include <Common/typeid_cast.h>
# include <ext/range.h>
# if __has_include(<h3/h3api.h>)
# include <h3/h3api.h>
# else
# include <h3api.h>
# endif
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
class FunctionH3KRing : public IFunction
{
public:
static constexpr auto name = "h3kRing";
static FunctionPtr create(const Context &) { return std::make_shared<FunctionH3KRing>(); }
std::string getName() const override { return name; }
size_t getNumberOfArguments() const override { return 2; }
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);
arg = arguments[1].get();
if (!isInteger(arg))
throw Exception(
"Illegal type " + arg->getName() + " of argument " + std::to_string(2) + " of function " + getName() + ". Must be integer",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeArray>(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();
const auto * col_k = block.getByPosition(arguments[1]).column.get();
auto dst = ColumnArray::create(ColumnUInt64::create());
auto & dst_data = dst->getData();
auto & dst_offsets = dst->getOffsets();
dst_offsets.resize(input_rows_count);
auto current_offset = 0;
std::vector<H3Index> hindex_vec;
for (const auto row : ext::range(0, input_rows_count))
{
const H3Index origin_hindex = col_hindex->getUInt(row);
const int k = col_k->getInt(row);
const auto vec_size = maxKringSize(k);
hindex_vec.resize(vec_size);
kRing(origin_hindex, k, hindex_vec.data());
dst_data.reserve(dst_data.size() + vec_size);
for (auto hindex : hindex_vec)
{
if (hindex != 0)
{
++current_offset;
dst_data.insert(hindex);
}
}
dst_offsets[row] = current_offset;
}
block.getByPosition(result).column = std::move(dst);
}
};
void registerFunctionH3KRing(FunctionFactory & factory)
{
factory.registerFunction<FunctionH3KRing>();
}
}
#endif