mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-11 08:52:06 +00:00
85 lines
2.8 KiB
C++
85 lines
2.8 KiB
C++
#pragma once
|
|
|
|
#include <Interpreters/Context_fwd.h>
|
|
#include <Common/IFactoryWithAliases.h>
|
|
#include <Functions/IFunction.h>
|
|
#include <Functions/IFunctionAdaptors.h>
|
|
|
|
#include <functional>
|
|
#include <memory>
|
|
#include <string>
|
|
#include <unordered_map>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
/** Creates function by name.
|
|
* Function could use for initialization (take ownership of shared_ptr, for example)
|
|
* some dictionaries from Context.
|
|
*/
|
|
class FunctionFactory : private boost::noncopyable,
|
|
public IFactoryWithAliases<std::function<FunctionOverloadResolverPtr(ContextPtr)>>
|
|
{
|
|
public:
|
|
static FunctionFactory & instance();
|
|
|
|
template <typename Function>
|
|
void registerFunction(CaseSensitiveness case_sensitiveness = CaseSensitive)
|
|
{
|
|
registerFunction<Function>(Function::name, case_sensitiveness);
|
|
}
|
|
|
|
template <typename Function>
|
|
void registerFunction(const std::string & name, CaseSensitiveness case_sensitiveness = CaseSensitive)
|
|
{
|
|
|
|
if constexpr (std::is_base_of_v<IFunction, Function>)
|
|
registerFunction(name, &adaptFunctionToOverloadResolver<Function>, case_sensitiveness);
|
|
else
|
|
registerFunction(name, &Function::create, case_sensitiveness);
|
|
}
|
|
|
|
/// This function is used by YQL - internal Yandex product that depends on ClickHouse by source code.
|
|
std::vector<std::string> getAllNames() const;
|
|
|
|
bool has(const std::string & name) const;
|
|
|
|
/// Throws an exception if not found.
|
|
FunctionOverloadResolverPtr get(const std::string & name, ContextPtr context) const;
|
|
|
|
/// Returns nullptr if not found.
|
|
FunctionOverloadResolverPtr tryGet(const std::string & name, ContextPtr context) const;
|
|
|
|
/// The same methods to get developer interface implementation.
|
|
FunctionOverloadResolverPtr getImpl(const std::string & name, ContextPtr context) const;
|
|
FunctionOverloadResolverPtr tryGetImpl(const std::string & name, ContextPtr context) const;
|
|
|
|
/// Register a function by its name.
|
|
/// No locking, you must register all functions before usage of get.
|
|
void registerFunction(
|
|
const std::string & name,
|
|
Value creator,
|
|
CaseSensitiveness case_sensitiveness = CaseSensitive);
|
|
|
|
private:
|
|
using Functions = std::unordered_map<std::string, Value>;
|
|
|
|
Functions functions;
|
|
Functions case_insensitive_functions;
|
|
|
|
template <typename Function>
|
|
static FunctionOverloadResolverPtr adaptFunctionToOverloadResolver(ContextPtr context)
|
|
{
|
|
return std::make_unique<FunctionToOverloadResolverAdaptor>(Function::create(context));
|
|
}
|
|
|
|
const Functions & getMap() const override { return functions; }
|
|
|
|
const Functions & getCaseInsensitiveMap() const override { return case_insensitive_functions; }
|
|
|
|
String getFactoryName() const override { return "FunctionFactory"; }
|
|
};
|
|
|
|
}
|