ClickHouse/src/Functions/rowNumberInBlock.cpp
2020-04-03 18:14:31 +03:00

65 lines
1.4 KiB
C++

#include <Functions/IFunctionImpl.h>
#include <Functions/FunctionFactory.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypesNumber.h>
namespace DB
{
class FunctionRowNumberInBlock : public IFunction
{
public:
static constexpr auto name = "rowNumberInBlock";
static FunctionPtr create(const Context &)
{
return std::make_shared<FunctionRowNumberInBlock>();
}
/// Get the name of the function.
String getName() const override
{
return name;
}
bool isStateful() const override
{
return true;
}
size_t getNumberOfArguments() const override
{
return 0;
}
bool isDeterministic() const override { return false; }
bool isDeterministicInScopeOfQuery() const override
{
return false;
}
DataTypePtr getReturnTypeImpl(const DataTypes & /*arguments*/) const override
{
return std::make_shared<DataTypeUInt64>();
}
void executeImpl(Block & block, const ColumnNumbers &, size_t result, size_t input_rows_count) override
{
auto column = ColumnUInt64::create();
auto & data = column->getData();
data.resize(input_rows_count);
for (size_t i = 0; i < input_rows_count; ++i)
data[i] = i;
block.getByPosition(result).column = std::move(column);
}
};
void registerFunctionRowNumberInBlock(FunctionFactory & factory)
{
factory.registerFunction<FunctionRowNumberInBlock>();
}
}