ClickHouse/src/Functions/getSetting.cpp
Alexander Tokmakov 70d1adfe4b
Better formatting for exception messages (#45449)
* save format string for NetException

* format exceptions

* format exceptions 2

* format exceptions 3

* format exceptions 4

* format exceptions 5

* format exceptions 6

* fix

* format exceptions 7

* format exceptions 8

* Update MergeTreeIndexGin.cpp

* Update AggregateFunctionMap.cpp

* Update AggregateFunctionMap.cpp

* fix
2023-01-24 00:13:58 +03:00

74 lines
2.5 KiB
C++

#include <Functions/IFunction.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionHelpers.h>
#include <DataTypes/FieldToDataType.h>
#include <Interpreters/convertFieldToType.h>
#include <Interpreters/Context.h>
#include <Core/Field.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int ILLEGAL_COLUMN;
}
namespace
{
/// Get the value of a setting.
class FunctionGetSetting : public IFunction, WithContext
{
public:
static constexpr auto name = "getSetting";
static FunctionPtr create(ContextPtr context_) { return std::make_shared<FunctionGetSetting>(context_); }
explicit FunctionGetSetting(ContextPtr context_) : WithContext(context_) {}
String getName() const override { return name; }
bool isDeterministic() const override { return false; }
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
size_t getNumberOfArguments() const override { return 1; }
ColumnNumbers getArgumentsThatAreAlwaysConstant() const override { return {0}; }
DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
{
auto value = getValue(arguments);
return applyVisitor(FieldToDataType{}, value);
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
{
auto value = getValue(arguments);
return result_type->createColumnConst(input_rows_count, convertFieldToType(value, *result_type));
}
private:
Field getValue(const ColumnsWithTypeAndName & arguments) const
{
if (!isString(arguments[0].type))
throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
"The argument of function {} should be a constant string with the name of a setting",
String{name});
const auto * column = arguments[0].column.get();
if (!column || !checkAndGetColumnConstStringOrFixedString(column))
throw Exception(ErrorCodes::ILLEGAL_COLUMN,
"The argument of function {} should be a constant string with the name of a setting",
String{name});
std::string_view setting_name{column->getDataAt(0).toView()};
return getContext()->getSettingsRef().get(setting_name);
}
};
}
REGISTER_FUNCTION(GetSetting)
{
factory.registerFunction<FunctionGetSetting>();
}
}