C_subscription.hpp

/*
 * Copyright 2024 Guillaume Guillet
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#ifndef _FGE_C_SUBSCRIPTION_HPP_INCLUDED
#define _FGE_C_SUBSCRIPTION_HPP_INCLUDED
 
#include "FastEngine/fge_extern.hpp"
#include <cstdint>
#include <unordered_map>
#include <unordered_set>
 
namespace fge
{
 
class Subscriber;
 
class FGE_API Subscription
{
public:
    using SubscriberCount = unsigned int;
 
    Subscription() = default;
 
    Subscription([[maybe_unused]] fge::Subscription const& r) {};
    Subscription(fge::Subscription&& r) noexcept;
 
    virtual inline ~Subscription() { this->detachAll(); }
 
    fge::Subscription& operator=([[maybe_unused]] fge::Subscription const& r) { return *this; };
    fge::Subscription& operator=(fge::Subscription&& r) noexcept;
 
protected:
    virtual void onDetach(fge::Subscriber* subscriber) = 0;
 
    void detachAll();
 
    bool detach(fge::Subscriber* subscriber);
    fge::Subscription::SubscriberCount detachOnce(fge::Subscriber* subscriber);
 
    fge::Subscription::SubscriberCount attach(fge::Subscriber* subscriber);
 
    fge::Subscription::SubscriberCount getCount(fge::Subscriber* subscriber) const;
 
private:
    using SubscriptionDataType = std::unordered_map<fge::Subscriber*, fge::Subscription::SubscriberCount>;
 
    void detachSilent(fge::Subscriber* subscriber);
 
    fge::Subscription::SubscriptionDataType g_subData;
    friend class fge::Subscriber;
};
 
class FGE_API Subscriber
{
public:
    Subscriber() = default;
 
    Subscriber([[maybe_unused]] fge::Subscriber const& n) {};
    Subscriber(fge::Subscriber&& n) noexcept = delete;
 
    virtual inline ~Subscriber() { this->detachAll(); };
 
    fge::Subscriber& operator=([[maybe_unused]] fge::Subscriber const& n) { return *this; };
    fge::Subscriber& operator=(fge::Subscriber&& n) noexcept = delete;
 
    void detachAll();
    void detach(fge::Subscription* subscription);
 
protected:
    virtual void onDetach([[maybe_unused]] fge::Subscription* subscription) {}
 
private:
    using SubscriberDataType = std::unordered_set<fge::Subscription*>;
 
    void detachSilent(fge::Subscription* subscription);
    void attachSilent(fge::Subscription* subscription);
 
    fge::Subscriber::SubscriberDataType g_subData;
    friend class fge::Subscription;
};
 
} // namespace fge
 
#endif // _FGE_C_SUBSCRIPTION_HPP_INCLUDED