ClickHouse/dbms/src/Functions/throwIf.cpp
2018-09-09 01:04:39 +03:00

92 lines
2.8 KiB
C++

#include <Functions/IFunction.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionHelpers.h>
#include <Columns/ColumnsNumber.h>
#include <Columns/ColumnsCommon.h>
#include <DataTypes/DataTypesNumber.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_COLUMN;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int FUNCTION_THROW_IF_VALUE_IS_NON_ZERO;
}
/// Throw an exception if the argument is non zero.
class FunctionThrowIf : public IFunction
{
public:
static constexpr auto name = "throwIf";
static FunctionPtr create(const Context &)
{
return std::make_shared<FunctionThrowIf>();
}
String getName() const override
{
return name;
}
size_t getNumberOfArguments() const override
{
return 1;
}
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
if (!isNumber(arguments.front()))
throw Exception{"Argument for function " + getName() + " must be number", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
return std::make_shared<DataTypeUInt8>();
}
bool useDefaultImplementationForConstants() const override { return true; }
void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t /*input_rows_count*/) override
{
const auto in = block.getByPosition(arguments.front()).column.get();
if ( !execute<UInt8>(block, in, result)
&& !execute<UInt16>(block, in, result)
&& !execute<UInt32>(block, in, result)
&& !execute<UInt64>(block, in, result)
&& !execute<Int8>(block, in, result)
&& !execute<Int16>(block, in, result)
&& !execute<Int32>(block, in, result)
&& !execute<Int64>(block, in, result)
&& !execute<Float32>(block, in, result)
&& !execute<Float64>(block, in, result))
throw Exception{"Illegal column " + in->getName() + " of first argument of function " + getName(), ErrorCodes::ILLEGAL_COLUMN};
}
template <typename T>
bool execute(Block & block, const IColumn * in_untyped, const size_t result)
{
if (const auto in = checkAndGetColumn<ColumnVector<T>>(in_untyped))
{
const auto & in_data = in->getData();
if (!memoryIsZero(in_data.data(), in_data.size() * sizeof(in_data[0])))
throw Exception("Value passed to 'throwIf' function is non zero", ErrorCodes::FUNCTION_THROW_IF_VALUE_IS_NON_ZERO);
/// We return non constant to avoid constant folding.
block.getByPosition(result).column = ColumnUInt8::create(in_data.size(), 0);
return true;
}
return false;
}
};
void registerFunctionThrowIf(FunctionFactory & factory)
{
factory.registerFunction<FunctionThrowIf>();
}
}