TrackableSignalMap.hpp

//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2024, the clio developers.
 
    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#pragma once
 
#include "feed/impl/TrackableSignal.hpp"
#include "util/Mutex.hpp"
 
#include <boost/signals2.hpp>
 
#include <concepts>
#include <cstddef>
#include <functional>
#include <memory>
#include <mutex>
#include <unordered_map>
 
namespace feed::impl {
 
template <typename T>
concept Hashable = requires(T a) {
    { std::hash<T>{}(a) } -> std::convertible_to<std::size_t>;
};
 
template <Hashable Key, typename Session, typename... Args>
class TrackableSignalMap {
    using ConnectionPtr = Session*;
    using ConnectionSharedPtr = std::shared_ptr<Session>;
 
    using SignalsMap = std::unordered_map<Key, TrackableSignal<Session, Args...>>;
    util::Mutex<SignalsMap> signalsMap_;
 
public:
    bool
    connectTrackableSlot(ConnectionSharedPtr const& trackable, Key const& key, std::function<void(Args...)> slot)
    {
        auto map = signalsMap_.template lock<std::scoped_lock>();
        return map->operator[](key).connectTrackableSlot(trackable, slot);
    }
 
    bool
    disconnect(ConnectionPtr trackablePtr, Key const& key)
    {
        auto map = signalsMap_.template lock<std::scoped_lock>();
        if (!map->contains(key))
            return false;
 
        auto const disconnected = map->operator[](key).disconnect(trackablePtr);
        // clean the map if there is no connection left.
        if (disconnected && map->operator[](key).count() == 0)
            map->erase(key);
 
        return disconnected;
    }
 
    void
    emit(Key const& key, Args const&... args)
    {
        auto map = signalsMap_.template lock<std::scoped_lock>();
        if (map->contains(key))
            map->operator[](key).emit(args...);
    }
};
}  // namespace feed::impl