ClickHouse/src/Functions/generateUUIDv4.cpp
2023-08-18 13:50:31 -07:00

110 lines
3.3 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsRandom.h>
#include <DataTypes/DataTypeUUID.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
#define DECLARE_SEVERAL_IMPLEMENTATIONS(...) \
DECLARE_DEFAULT_CODE (__VA_ARGS__) \
DECLARE_AVX2_SPECIFIC_CODE(__VA_ARGS__)
DECLARE_SEVERAL_IMPLEMENTATIONS(
class FunctionGenerateUUIDv4 : public IFunction
{
public:
static constexpr auto name = "generateUUIDv4";
String getName() const override
{
return name;
}
size_t getNumberOfArguments() const override { return 0; }
bool isDeterministicInScopeOfQuery() const override { return false; }
bool useDefaultImplementationForNulls() const override { return false; }
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
bool isVariadic() const override { return true; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
if (arguments.size() > 1)
throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH,
"Number of arguments for function {} doesn't match: passed {}, should be 0 or 1.",
getName(), arguments.size());
return std::make_shared<DataTypeUUID>();
}
bool isDeterministic() const override { return false; }
ColumnPtr executeImpl(const ColumnsWithTypeAndName &, const DataTypePtr &, size_t input_rows_count) const override
{
auto col_res = ColumnVector<UUID>::create();
typename ColumnVector<UUID>::Container & vec_to = col_res->getData();
size_t size = input_rows_count;
vec_to.resize(size);
/// RandImpl is target-dependent and is not the same in different TargetSpecific namespaces.
RandImpl::execute(reinterpret_cast<char *>(vec_to.data()), vec_to.size() * sizeof(UUID));
for (UUID & uuid : vec_to)
{
/// https://tools.ietf.org/html/rfc4122#section-4.4
UUIDHelpers::getHighBytes(uuid) = (UUIDHelpers::getHighBytes(uuid) & 0xffffffffffff0fffull) | 0x0000000000004000ull;
UUIDHelpers::getLowBytes(uuid) = (UUIDHelpers::getLowBytes(uuid) & 0x3fffffffffffffffull) | 0x8000000000000000ull;
}
return col_res;
}
};
) // DECLARE_SEVERAL_IMPLEMENTATIONS
#undef DECLARE_SEVERAL_IMPLEMENTATIONS
class FunctionGenerateUUIDv4 : public TargetSpecific::Default::FunctionGenerateUUIDv4
{
public:
explicit FunctionGenerateUUIDv4(ContextPtr context) : selector(context)
{
selector.registerImplementation<TargetArch::Default,
TargetSpecific::Default::FunctionGenerateUUIDv4>();
#if USE_MULTITARGET_CODE
selector.registerImplementation<TargetArch::AVX2,
TargetSpecific::AVX2::FunctionGenerateUUIDv4>();
#endif
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
{
return selector.selectAndExecute(arguments, result_type, input_rows_count);
}
static FunctionPtr create(ContextPtr context)
{
return std::make_shared<FunctionGenerateUUIDv4>(context);
}
private:
ImplementationSelector<IFunction> selector;
};
REGISTER_FUNCTION(GenerateUUIDv4)
{
factory.registerFunction<FunctionGenerateUUIDv4>();
}
}