Files
scylladb/utils/class_registrator.hh
Botond Dénes b1082641f9 Make sure keyspace strategy class is stored in qualified form
Even when it's provided in unqualified (short) form.
Fixes #767

Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <4379f8864843e64c097d432fd06129ce4025f100.1499322476.git.bdenes@scylladb.com>
2017-07-06 14:50:00 +03:00

108 lines
3.9 KiB
C++

/*
* Copyright (C) 2015 ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <boost/range/algorithm/find_if.hpp>
class no_such_class : public std::runtime_error {
public:
using runtime_error::runtime_error;
};
// BaseType is a base type of a type hierarchy that this registry will hold
// Args... are parameters for object's constructor
template<typename BaseType, typename... Args>
class class_registry {
using creator_type = std::function<std::unique_ptr<BaseType>(Args...)>;
public:
static void register_class(sstring name, creator_type creator);
template<typename T>
static void register_class(sstring name);
static std::unique_ptr<BaseType> create(const sstring& name, Args&&...);
static std::unordered_map<sstring, creator_type>& classes() {
static std::unordered_map<sstring, creator_type> _classes;
return _classes;
}
static bool is_class_name_qualified(const sstring& class_name) {
return class_name.compare(0, 4, "org.") == 0;
}
static sstring to_qualified_class_name(sstring class_name);
};
template<typename BaseType, typename... Args>
void class_registry<BaseType, Args...>::register_class(sstring name, class_registry<BaseType, Args...>::creator_type creator) {
classes().emplace(name, std::move(creator));
}
template<typename BaseType, typename... Args>
template<typename T>
void class_registry<BaseType, Args...>::register_class(sstring name) {
register_class(name, [](Args&&... args) {
return std::make_unique<T>(std::forward<Args>(args)...);
});
}
template<typename BaseType, typename... Args>
sstring class_registry<BaseType, Args...>::to_qualified_class_name(sstring class_name) {
if (class_registry<BaseType, Args...>::is_class_name_qualified(class_name)) {
return class_name;
} else {
const auto& classes{class_registry<BaseType, Args...>::classes()};
const auto it = boost::find_if(classes, [&class_name](const auto& registered_class) {
// the fully qualified name contains the short name
return class_registry<BaseType, Args...>::is_class_name_qualified(registered_class.first) && registered_class.first.find(class_name) != sstring::npos;
});
return it == classes.end() ? class_name : it->first;
}
}
template<typename BaseType, typename T, typename... Args>
struct class_registrator {
class_registrator(const sstring& name) {
class_registry<BaseType, Args...>::template register_class<T>(name);
}
class_registrator(const sstring& name, std::function<std::unique_ptr<T>(Args...)> creator) {
class_registry<BaseType, Args...>::register_class(name, creator);
}
};
template<typename BaseType, typename... Args>
std::unique_ptr<BaseType> class_registry<BaseType, Args...>::create(const sstring& name, Args&&... args) {
auto it = classes().find(name);
if (it == classes().end()) {
throw no_such_class(sstring("unable to find class '") + name + sstring("'"));
}
return it->second(std::forward<Args>(args)...);
}
template<typename BaseType, typename... Args>
std::unique_ptr<BaseType> create_object(const sstring& name, Args&&... args) {
return class_registry<BaseType, Args...>::create(name, std::forward<Args>(args)...);
}