ClickHouse/src/Functions/s2GetNeighbors.cpp
2023-12-26 12:58:50 +01:00

127 lines
3.4 KiB
C++

#include "config.h"
#if USE_S2_GEOMETRY
#include <Columns/ColumnArray.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeArray.h>
#include <Functions/FunctionFactory.h>
#include <Common/typeid_cast.h>
#include <base/range.h>
#include "s2_fwd.h"
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int BAD_ARGUMENTS;
extern const int ILLEGAL_COLUMN;
}
namespace
{
/**
* Each cell in s2 library is a quadrilateral bounded by four geodesics.
* So, each cell has 4 neighbors
*/
class FunctionS2GetNeighbors : public IFunction
{
public:
static constexpr auto name = "s2GetNeighbors";
static FunctionPtr create(ContextPtr)
{
return std::make_shared<FunctionS2GetNeighbors>();
}
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 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());
return std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt64>());
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
{
auto non_const_arguments = arguments;
for (auto & argument : non_const_arguments)
argument.column = argument.column->convertToFullColumnIfConst();
const auto * col_id = checkAndGetColumn<ColumnUInt64>(non_const_arguments[0].column.get());
if (!col_id)
throw Exception(
ErrorCodes::ILLEGAL_COLUMN,
"Illegal type {} of argument {} of function {}. Must be UInt64",
arguments[0].type->getName(),
1,
getName());
const auto & data_id = col_id->getData();
auto dst = ColumnArray::create(ColumnUInt64::create());
auto & dst_data = dst->getData();
auto & dst_offsets = dst->getOffsets();
dst_offsets.resize(input_rows_count);
size_t current_offset = 0;
for (size_t row = 0; row < input_rows_count; ++row)
{
const UInt64 id = data_id[row];
S2CellId cell_id(id);
if (!cell_id.is_valid())
throw Exception(ErrorCodes::BAD_ARGUMENTS, "Cell (id {}) is not valid in function {}", id, getName());
S2CellId neighbors[4];
cell_id.GetEdgeNeighbors(neighbors);
dst_data.reserve(dst_data.size() + 4);
for (auto & neighbor : neighbors)
{
++current_offset;
dst_data.insert(neighbor.id());
}
dst_offsets[row] = current_offset;
}
return dst;
}
};
}
REGISTER_FUNCTION(S2GetNeighbors)
{
factory.registerFunction<FunctionS2GetNeighbors>();
}
}
#endif