mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-18 04:12:19 +00:00
85 lines
2.8 KiB
C++
85 lines
2.8 KiB
C++
#include <Functions/IFunction.h>
|
|
#include <Functions/FunctionHelpers.h>
|
|
#include <Functions/FunctionFactory.h>
|
|
#include <DataTypes/DataTypeArray.h>
|
|
#include <DataTypes/DataTypesNumber.h>
|
|
#include <Columns/ColumnArray.h>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
|
|
extern const int TOO_LARGE_ARRAY_SIZE;
|
|
}
|
|
|
|
/// Reasonable threshold.
|
|
static constexpr size_t max_arrays_size_in_block = 1000000000;
|
|
|
|
|
|
/* arrayWithConstant(num, const) - make array of constants with length num.
|
|
* arrayWithConstant(3, 'hello') = ['hello', 'hello', 'hello']
|
|
* arrayWithConstant(1, 'hello') = ['hello']
|
|
* arrayWithConstant(0, 'hello') = []
|
|
*/
|
|
|
|
class FunctionArrayWithConstant : public IFunction
|
|
{
|
|
public:
|
|
static constexpr auto name = "arrayWithConstant";
|
|
|
|
static FunctionPtr create(const Context &) { return std::make_shared<FunctionArrayWithConstant>(); }
|
|
|
|
String getName() const override { return name; }
|
|
size_t getNumberOfArguments() const override { return 2; }
|
|
|
|
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
|
|
{
|
|
if (!isNumber(arguments[0]))
|
|
throw Exception("Illegal type " + arguments[0]->getName() +
|
|
" of argument of function " + getName() +
|
|
", expected Integer", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
|
|
return std::make_shared<DataTypeArray>(arguments[1]);
|
|
}
|
|
|
|
bool useDefaultImplementationForConstants() const override { return true; }
|
|
bool useDefaultImplementationForNulls() const override { return false; }
|
|
|
|
void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t num_rows) override
|
|
{
|
|
const auto * col_num = block.getByPosition(arguments[0]).column.get();
|
|
const auto * col_value = block.getByPosition(arguments[1]).column.get();
|
|
|
|
auto offsets_col = ColumnArray::ColumnOffsets::create();
|
|
ColumnArray::Offsets & offsets = offsets_col->getData();
|
|
offsets.reserve(num_rows);
|
|
|
|
ColumnArray::Offset offset = 0;
|
|
for (size_t i = 0; i < num_rows; ++i)
|
|
{
|
|
auto array_size = col_num->getInt(i);
|
|
|
|
if (unlikely(array_size < 0))
|
|
throw Exception("Array size cannot be negative: while executing function " + getName(), ErrorCodes::TOO_LARGE_ARRAY_SIZE);
|
|
|
|
offset += array_size;
|
|
|
|
if (unlikely(offset > max_arrays_size_in_block))
|
|
throw Exception("Too large array size while executing function " + getName(), ErrorCodes::TOO_LARGE_ARRAY_SIZE);
|
|
|
|
offsets.push_back(offset);
|
|
}
|
|
|
|
block.getByPosition(result).column = ColumnArray::create(col_value->replicate(offsets), std::move(offsets_col));
|
|
}
|
|
};
|
|
|
|
void registerFunctionArrayWithConstant(FunctionFactory & factory)
|
|
{
|
|
factory.registerFunction<FunctionArrayWithConstant>();
|
|
}
|
|
|
|
}
|