blob: d6b8946e760ef40e36fb77289ba7ff2f4e376037 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
#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>();
}
}
|
