event_queue.hpp

// Copyright Take Vos 2021.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "wfree_fifo.hpp"
#include <concepts>
 
namespace tt {
namespace detail {
 
class event_queue_item_base {
public:
    virtual ~event_queue_item_base() = default;
    virtual void operator()() const noexcept = 0;
};
 
template<std::invocable Function>
class event_queue_item final : public event_queue_item_base {
public:
    constexpr event_queue_item(event_queue_item const &) noexcept = default;
    constexpr event_queue_item(event_queue_item &&) noexcept = default;
    constexpr event_queue_item &operator=(event_queue_item const &) noexcept = default;
    constexpr event_queue_item &operator=(event_queue_item &&) noexcept = default;
 
    constexpr event_queue_item(Function const &function) noexcept : function(function) {}
    constexpr event_queue_item(Function &&function) noexcept : function(std::move(function)) {}
 
    virtual void operator()() const noexcept
    {
        function();
    }
 
private:
    Function function;
};
} // namespace detail
 
class event_queue {
public:
    void emplace(std::invocable auto &&function) const noexcept
    {
        using function_type = std::remove_cvref_t<decltype(function)>;
 
        return fifo.emplace<detail::event_queue_item<function_type>>(std::forward<decltype(function)>(function));
    }
 
    bool take_one(std::invocable<detail::event_queue_item_base const &> auto &&operation) const noexcept
    {
        return fifo.take_one(std::forward<decltype(operation)>(operation));
    }
 
    void take_all(std::invocable<detail::event_queue_item_base const &> auto &&operation) const noexcept
    {
        return fifo.take_all(std::forward<decltype(operation)>(operation));
    }
 
private:
    mutable wfree_fifo<detail::event_queue_item_base, 128> fifo;
};
 
} // namespace tt