ClickHouse/src/Functions/h3ToChildren.cpp

128 lines
4.0 KiB
C++

#if !defined(ARCADIA_BUILD)
# include "config_functions.h"
#endif
#if USE_H3
#include <Columns/ColumnArray.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypesNumber.h>
#include <Functions/FunctionFactory.h>
#include <Functions/IFunction.h>
#include <Common/typeid_cast.h>
#include <IO/WriteHelpers.h>
#include <common/range.h>
#include <constants.h>
#include <h3api.h>
static constexpr size_t MAX_ARRAY_SIZE = 1 << 30;
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int ARGUMENT_OUT_OF_BOUND;
extern const int TOO_LARGE_ARRAY_SIZE;
}
namespace
{
class FunctionH3ToChildren : public IFunction
{
public:
static constexpr auto name = "h3ToChildren";
static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionH3ToChildren>(); }
std::string getName() const override { return name; }
size_t getNumberOfArguments() const override { return 2; }
bool useDefaultImplementationForConstants() const override { return true; }
bool isSuitableForShortCircuitArgumentsExecution() const override { return true; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
const auto * arg = arguments[0].get();
if (!WhichDataType(arg).isUInt64())
throw Exception(
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
"Illegal type {} of argument {} of function {}. Must be UInt64",
arg->getName(), 1, getName());
arg = arguments[1].get();
if (!WhichDataType(arg).isUInt8())
throw Exception(
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
"Illegal type {} of argument {} of function {}. Must be UInt8",
arg->getName(), 2, getName());
return std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt64>());
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
{
const auto * col_hindex = arguments[0].column.get();
const auto * col_resolution = 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 : collections::range(0, input_rows_count))
{
const UInt64 parent_hindex = col_hindex->getUInt(row);
const UInt8 child_resolution = col_resolution->getUInt(row);
if (child_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 {}",
toString(child_resolution), getName(), toString(MAX_H3_RES));
const size_t vec_size = cellToChildrenSize(parent_hindex, child_resolution);
if (vec_size > MAX_ARRAY_SIZE)
throw Exception(
ErrorCodes::TOO_LARGE_ARRAY_SIZE,
"The result of function {} (array of {} elements) will be too large with resolution argument = {}",
getName(), toString(vec_size), toString(child_resolution));
hindex_vec.resize(vec_size);
cellToChildren(parent_hindex, child_resolution, 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;
}
return dst;
}
};
}
void registerFunctionH3ToChildren(FunctionFactory & factory)
{
factory.registerFunction<FunctionH3ToChildren>();
}
}
#endif