TcpServer.hpp

// SPDX-FileCopyrightText: 2025 Vincent Leroy
// SPDX-License-Identifier: MIT
//
// This file is part of dfx.
//
// Licensed under the MIT License. See the LICENSE file in the project root
// for full license information.
 
#pragma once
 
// Standard includes
#include <functional>
#include <mutex>
#include <unordered_map>
 
// Project includes
#include "TcpSession.hpp"
#include <dfx-fdwatch/PollerFd.hpp>
#include <dfx-fdwatch/Timer.hpp>
#include <dfx-utilities/CopyMoveControl.hpp>
 
namespace dfx::FdWatch
{
class Poller;
} // !namespace dfx::FdWatch
 
namespace dfx::Server
{
class TcpServer
{
public:
    using NewSessionCallback = std::move_only_function<void (TcpSessionPtr)>;
 
public:
    struct Options
    {
        std::string host;
        uint16_t port = 0;
        uint32_t backlog = 5;

        std::chrono::milliseconds inactivityTimeout{5000};

        std::chrono::milliseconds timeoutAccuracy{50};
    };
 
public:
    TcpServer(Options options, FdWatch::Poller & poller);

    DISABLE_COPY_AND_MOVE(TcpServer);

    virtual ~TcpServer();

    void setNewSessionCallback(NewSessionCallback cb) { _newSessionCb = std::move(cb); }

    void listen();

    void stop() noexcept;

    bool isListening() const noexcept { return _socket.isRegistered(); }
 
public:
    void terminateSession(TcpSessionPtr session);

    void forEachSession(std::move_only_function<void (TcpSessionPtr)> f);
 
protected:
    virtual TcpSessionPtr makeSession(std::string host, std::string serv,
                                      TcpServer & server, std::chrono::milliseconds initialTimeout) = 0;
 
private:
    void _onTimerTimeout();
    void _onServerSocketReadyRead(FdWatch::EventTriggers events);
 
private:
    FdWatch::Poller & _poller;
    Options _options;
    FdWatch::PollerFd _socket;
    FdWatch::Timer _timer;
 
private:
    std::recursive_mutex _sessionMutex;
    std::unordered_map<FdWatch::BorrowedFd, TcpSessionPtr> _sessions;
    NewSessionCallback _newSessionCb;
};
} // !namespace dfx::Server