mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-16 11:22:12 +00:00
4088c0a7f3
Automated register all functions with below naming convention by iterating through the symbols: void DB::registerXXX(DB::FunctionFactory &)
93 lines
2.7 KiB
C++
93 lines
2.7 KiB
C++
#include <Functions/IFunction.h>
|
|
#include <Functions/FunctionFactory.h>
|
|
#include <Functions/FunctionHelpers.h>
|
|
#include <DataTypes/DataTypeString.h>
|
|
#include <Columns/ColumnString.h>
|
|
#include <Interpreters/Context.h>
|
|
#include <Common/Macros.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 macro from configuration file.
|
|
* For example, it may be used as a sophisticated replacement for the function 'hostName' if servers have complicated hostnames
|
|
* but you still need to distinguish them by some convenient names.
|
|
*/
|
|
class FunctionGetMacro : public IFunction
|
|
{
|
|
private:
|
|
MultiVersion<Macros>::Version macros;
|
|
bool is_distributed;
|
|
|
|
public:
|
|
static constexpr auto name = "getMacro";
|
|
static FunctionPtr create(ContextPtr context)
|
|
{
|
|
return std::make_shared<FunctionGetMacro>(context->getMacros(), context->isDistributed());
|
|
}
|
|
|
|
explicit FunctionGetMacro(MultiVersion<Macros>::Version macros_, bool is_distributed_)
|
|
: macros(std::move(macros_)), is_distributed(is_distributed_)
|
|
{
|
|
}
|
|
|
|
String getName() const override
|
|
{
|
|
return name;
|
|
}
|
|
|
|
bool isDeterministic() const override { return false; }
|
|
|
|
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
|
|
|
|
bool isDeterministicInScopeOfQuery() const override
|
|
{
|
|
return true;
|
|
}
|
|
|
|
/// getMacro may return different values on different shards/replicas, so it's not constant for distributed query
|
|
bool isSuitableForConstantFolding() const override { return !is_distributed; }
|
|
|
|
size_t getNumberOfArguments() const override
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
|
|
{
|
|
if (!isString(arguments[0]))
|
|
throw Exception("The argument of function " + getName() + " must have String type", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
|
|
return std::make_shared<DataTypeString>();
|
|
}
|
|
|
|
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
|
|
{
|
|
const IColumn * arg_column = arguments[0].column.get();
|
|
const ColumnString * arg_string = checkAndGetColumnConstData<ColumnString>(arg_column);
|
|
|
|
if (!arg_string)
|
|
throw Exception("The argument of function " + getName() + " must be constant String", ErrorCodes::ILLEGAL_COLUMN);
|
|
|
|
return result_type->createColumnConst(input_rows_count, macros->getValue(arg_string->getDataAt(0).toString()));
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
REGISTER_FUNCTION(GetMacro)
|
|
{
|
|
factory.registerFunction<FunctionGetMacro>();
|
|
}
|
|
|
|
}
|