38a54df863
People keep tripping over the old copyrights and copy-pasting them to new files. Search and replace "Cloudius Systems" with "ScyllaDB". Message-Id: <1460013664-25966-1-git-send-email-penberg@scylladb.com>
85 lines
2.9 KiB
C++
85 lines
2.9 KiB
C++
/*
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* Copyright (C) 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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class no_such_class : public std::runtime_error {
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public:
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using runtime_error::runtime_error;
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};
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// BaseType is a base type of a type hierarchy that this registry will hold
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// Args... are parameters for object's constructor
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template<typename BaseType, typename... Args>
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class class_registry {
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using creator_type = std::function<std::unique_ptr<BaseType>(Args...)>;
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public:
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static void register_class(sstring name, creator_type creator);
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template<typename T>
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static void register_class(sstring name);
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static std::unique_ptr<BaseType> create(const sstring& name, Args&&...);
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static std::unordered_map<sstring, creator_type>& classes() {
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static std::unordered_map<sstring, creator_type> _classes;
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return _classes;
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}
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};
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template<typename BaseType, typename... Args>
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void class_registry<BaseType, Args...>::register_class(sstring name, class_registry<BaseType, Args...>::creator_type creator) {
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classes().emplace(name, std::move(creator));
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}
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template<typename BaseType, typename... Args>
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template<typename T>
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void class_registry<BaseType, Args...>::register_class(sstring name) {
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register_class(name, [](Args&&... args) {
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return std::make_unique<T>(std::forward<Args>(args)...);
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});
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}
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template<typename BaseType, typename T, typename... Args>
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struct class_registrator {
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class_registrator(const sstring& name) {
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class_registry<BaseType, Args...>::template register_class<T>(name);
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}
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class_registrator(const sstring& name, std::function<std::unique_ptr<T>(Args...)> creator) {
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class_registry<BaseType, Args...>::register_class(name, creator);
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}
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};
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template<typename BaseType, typename... Args>
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std::unique_ptr<BaseType> class_registry<BaseType, Args...>::create(const sstring& name, Args&&... args) {
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auto it = classes().find(name);
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if (it == classes().end()) {
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throw no_such_class(sstring("unable to find class '") + name + sstring("'"));
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}
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return it->second(std::forward<Args>(args)...);
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}
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template<typename BaseType, typename... Args>
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std::unique_ptr<BaseType> create_object(const sstring& name, Args&&... args) {
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return class_registry<BaseType, Args...>::create(name, std::forward<Args>(args)...);
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}
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