CppServer

Ultra fast and low latency asynchronous socket server & client C++ library with support TCP, SSL, UDP, HTTP, HTTPS, WebSocket protocols and 10K connections problem solution.

CppServer API reference

Contents

• Features
• Requirements
• How to build?
• Examples
  • Example: Asio service
  • Example: Asio timer
  • Example: TCP chat server
  • Example: TCP chat client
  • Example: SSL chat server
  • Example: SSL chat client
  • Example: UDP echo server
  • Example: UDP echo client
  • Example: UDP multicast server
  • Example: UDP multicast client
  • Example: HTTP server
  • Example: HTTP client
  • Example: HTTPS server
  • Example: HTTPS client
  • Example: WebSocket chat server
  • Example: WebSocket chat client
  • Example: WebSocket secure chat server
  • Example: WebSocket secure chat client
• Performance
  • Benchmark: Round-Trip
    • TCP echo server
    • SSL echo server
    • UDP echo server
    • WebSocket echo server
    • WebSocket secure echo server
  • Benchmark: Multicast
    • TCP multicast server
    • SSL multicast server
    • UDP multicast server
    • WebSocket multicast server
    • WebSocket secure multicast server
  • Benchmark: Web Server
    • HTTP Trace server
    • HTTPS Trace server
• OpenSSL certificates
  • Production
  • Development
  • Certificate Authority
  • SSL Server certificate
  • SSL Client certificate
  • Diffie-Hellman key exchange

Features

• Cross platform (Linux, OSX, Windows)
• Asynchronous communication
• Supported CPU scalability designs: IO service per thread, thread pool
• Supported transport protocols: TCP, SSL, UDP, UDP multicast
• Supported Web protocols: HTTP, HTTPS, WebSocket, WebSocket secure
• Supported Swagger OpenAPI iterative documentation

Requirements

• Linux (binutils-dev uuid-dev libssl-dev)
• OSX (openssl)
• Windows 10
• cmake
• gcc
• git
• gil
• python3

Optional:

• clang
• CLion
• MinGW
• Visual Studio

How to build?

Install gil (git links) tool

pip3 install gil

Setup repository

git clone https://github.com/chronoxor/CppServer.git
cd CppServer
gil update

Linux

cd build
./unix.sh

OSX

cd build
./unix.sh

Windows (MinGW)

cd build
mingw.bat

Windows (Visual Studio)

cd build
vs.bat

Examples

Example: Asio service

Asio service is used to host all clients/servers based on Asio C++ library. It is implemented based on Asio C++ Library and use a separate thread to perform all asynchronous IO operations and communications.

The common usecase is to instantiate one Asio service, start the service and attach TCP/UDP/WebSocket servers or/and clients to it. One Asio service can handle several servers and clients asynchronously at the same time in one I/O thread. If you want to scale your servers or clients it is possible to create and use more than one Asio services to handle your servers/clients in balance.

Also it is possible to dispatch or post your custom handler into I/O thread. Dispatch will execute the handler immediately if the current thread is I/O one. Otherwise the handler will be enqueued to the I/O queue. In opposite the post method will always enqueue the handler into the I/O queue.

Here comes an example of using custom Asio service with dispatch/post methods:

#include "server/asio/service.h"
#include "threads/thread.h"

#include <iostream>

int main(int argc, char** argv)
{
    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Dispatch
    std::cout << "1 - Dispatch from the main thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
    service->Dispatch([service]()
    {
        std::cout << "1.1 - Dispatched in thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;

        std::cout << "1.2 - Dispatch from thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        service->Dispatch([service]()
        {
            std::cout << "1.2.1 - Dispatched in thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        });

        std::cout << "1.3 - Post from thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        service->Post([service]()
        {
            std::cout << "1.3.1 - Posted in thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        });
    });

    // Post
    std::cout << "2 - Post from the main thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
    service->Post([service]()
    {
        std::cout << "2.1 - Posted in thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;

        std::cout << "2.2 - Dispatch from thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        service->Dispatch([service]()
        {
            std::cout << "2.2.1 - Dispatched in thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        });

        std::cout << "2.3 - Post from thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        service->Post([service]()
        {
            std::cout << "2.3.1 - Posted in thread with Id " << CppCommon::Thread::CurrentThreadId() << std::endl;
        });
    });

    // Wait for a while...
    CppCommon::Thread::Sleep(1000);

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Output of the above example is the following:

Asio service started!
1 - Dispatch from the main thread with Id 16744
2 - Post from the main thread with Id 16744
1.1 - Dispatched in thread with Id 19920
1.2 - Dispatch from thread with Id 19920
1.2.1 - Dispatched in thread with Id 19920
1.3 - Post from thread with Id 19920
2.1 - Posted in thread with Id 19920
2.2 - Dispatch from thread with Id 19920
2.2.1 - Dispatched in thread with Id 19920
2.3 - Post from thread with Id 19920
1.3.1 - Posted in thread with Id 19920
2.3.1 - Posted in thread with Id 19920
Asio service stopped!

Example: Asio timer

Here comes the example of Asio timer. It can be used to wait for some action in future with providing absolute time or relative time span. Asio timer can be used in synchronous or asynchronous modes.

#include "server/asio/timer.h"
#include "threads/thread.h"

#include <iostream>

class AsioTimer : public CppServer::Asio::Timer
{
public:
    using CppServer::Asio::Timer::Timer;

protected:
    void onTimer(bool canceled) override
    {
        std::cout << "Asio timer " << (canceled ? "canceled" : "expired") << std::endl;
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Asio timer caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new Asio timer
    auto timer = std::make_shared<AsioTimer>(service);

    // Setup and synchronously wait for the timer
    timer->Setup(CppCommon::UtcTime() + CppCommon::Timespan::seconds(1));
    timer->WaitSync();

    // Setup and asynchronously wait for the timer
    timer->Setup(CppCommon::Timespan::seconds(1));
    timer->WaitAsync();

    // Wait for a while...
    CppCommon::Thread::Sleep(2000);

    // Setup and asynchronously wait for the timer
    timer->Setup(CppCommon::Timespan::seconds(1));
    timer->WaitAsync();

    // Wait for a while...
    CppCommon::Thread::Sleep(500);

    // Cancel the timer
    timer->Cancel();

    // Wait for a while...
    CppCommon::Thread::Sleep(500);

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Output of the above example is the following:

Asio service starting...Done!
Timer was expired
Timer was canceled
Asio service stopping...Done!

Example: TCP chat server

Here comes the example of the TCP chat server. It handles multiple TCP client sessions and multicast received message from any session to all ones. Also it is possible to send admin message directly from the server.

#include "server/asio/tcp_server.h"
#include "threads/thread.h"

#include <iostream>

class ChatSession : public CppServer::Asio::TCPSession
{
public:
    using CppServer::Asio::TCPSession::TCPSession;

protected:
    void onConnected() override
    {
        std::cout << "Chat TCP session with Id " << id() << " connected!" << std::endl;

        // Send invite message
        std::string message("Hello from TCP chat! Please send a message or '!' to disconnect the client!");
        SendAsync(message);
    }

    void onDisconnected() override
    {
        std::cout << "Chat TCP session with Id " << id() << " disconnected!" << std::endl;
    }

    void onReceived(const void* buffer, size_t size) override
    {
        std::string message((const char*)buffer, size);
        std::cout << "Incoming: " << message << std::endl;

        // Multicast message to all connected sessions
        server()->Multicast(message);

        // If the buffer starts with '!' the disconnect the current session
        if (message == "!")
            DisconnectAsync();
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Chat TCP session caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

class ChatServer : public CppServer::Asio::TCPServer
{
public:
    using CppServer::Asio::TCPServer::TCPServer;

protected:
    std::shared_ptr<CppServer::Asio::TCPSession> CreateSession(std::shared_ptr<CppServer::Asio::TCPServer> server) override
    {
        return std::make_shared<ChatSession>(server);
    }

protected:
    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Chat TCP server caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // TCP server port
    int port = 1111;
    if (argc > 1)
        port = std::atoi(argv[1]);

    std::cout << "TCP server port: " << port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new TCP chat server
    auto server = std::make_shared<ChatServer>(service, port);

    // Start the server
    std::cout << "Server starting...";
    server->Start();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the server or '!' to restart the server..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Restart the server
        if (line == "!")
        {
            std::cout << "Server restarting...";
            server->Restart();
            std::cout << "Done!" << std::endl;
            continue;
        }

        // Multicast admin message to all sessions
        line = "(admin) " + line;
        server->Multicast(line);
    }

    // Stop the server
    std::cout << "Server stopping...";
    server->Stop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: TCP chat client

Here comes the example of the TCP chat client. It connects to the TCP chat server and allows to send message to it and receive new messages.

#include "server/asio/tcp_client.h"
#include "threads/thread.h"

#include <atomic>
#include <iostream>

class ChatClient : public CppServer::Asio::TCPClient
{
public:
    ChatClient(std::shared_ptr<CppServer::Asio::Service> service, const std::string& address, int port)
        : CppServer::Asio::TCPClient(service, address, port)
    {
        _stop = false;
    }

    void DisconnectAndStop()
    {
        _stop = true;
        DisconnectAsync();
        while (IsConnected())
            CppCommon::Thread::Yield();
    }

protected:
    void onConnected() override
    {
        std::cout << "Chat TCP client connected a new session with Id " << id() << std::endl;
    }

    void onDisconnected() override
    {
        std::cout << "Chat TCP client disconnected a session with Id " << id() << std::endl;

        // Wait for a while...
        CppCommon::Thread::Sleep(1000);

        // Try to connect again
        if (!_stop)
            ConnectAsync();
    }

    void onReceived(const void* buffer, size_t size) override
    {
        std::cout << "Incoming: " << std::string((const char*)buffer, size) << std::endl;
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Chat TCP client caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }

private:
    std::atomic<bool> _stop;
};

int main(int argc, char** argv)
{
    // TCP server address
    std::string address = "127.0.0.1";
    if (argc > 1)
        address = argv[1];

    // TCP server port
    int port = 1111;
    if (argc > 2)
        port = std::atoi(argv[2]);

    std::cout << "TCP server address: " << address << std::endl;
    std::cout << "TCP server port: " << port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new TCP chat client
    auto client = std::make_shared<ChatClient>(service, address, port);

    // Connect the client
    std::cout << "Client connecting...";
    client->ConnectAsync();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the client or '!' to reconnect the client..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Disconnect the client
        if (line == "!")
        {
            std::cout << "Client disconnecting...";
            client->DisconnectAsync();
            std::cout << "Done!" << std::endl;
            continue;
        }

        // Send the entered text to the chat server
        client->SendAsync(line);
    }

    // Disconnect the client
    std::cout << "Client disconnecting...";
    client->DisconnectAndStop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: SSL chat server

Here comes the example of the SSL chat server. It handles multiple SSL client sessions and multicast received message from any session to all ones. Also it is possible to send admin message directly from the server.

This example is very similar to the TCP one except the code that prepares SSL context and handshake handler.

#include "server/asio/ssl_server.h"
#include "threads/thread.h"

#include <iostream>

class ChatSession : public CppServer::Asio::SSLSession
{
public:
    using CppServer::Asio::SSLSession::SSLSession;

protected:
    void onConnected() override
    {
        std::cout << "Chat SSL session with Id " << id() << " connected!" << std::endl;
    }

    void onHandshaked() override
    {
        std::cout << "Chat SSL session with Id " << id() << " handshaked!" << std::endl;

        // Send invite message
        std::string message("Hello from SSL chat! Please send a message or '!' to disconnect the client!");
        SendAsync(message.data(), message.size());
    }

    void onDisconnected() override
    {
        std::cout << "Chat SSL session with Id " << id() << " disconnected!" << std::endl;
    }

    void onReceived(const void* buffer, size_t size) override
    {
        std::string message((const char*)buffer, size);
        std::cout << "Incoming: " << message << std::endl;

        // Multicast message to all connected sessions
        server()->Multicast(message);

        // If the buffer starts with '!' the disconnect the current session
        if (message == "!")
            DisconnectAsync();
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Chat SSL session caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

class ChatServer : public CppServer::Asio::SSLServer
{
public:
    using CppServer::Asio::SSLServer::SSLServer;

protected:
    std::shared_ptr<CppServer::Asio::SSLSession> CreateSession(std::shared_ptr<CppServer::Asio::SSLServer> server) override
    {
        return std::make_shared<ChatSession>(server);
    }

protected:
    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Chat TCP server caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // SSL server port
    int port = 2222;
    if (argc > 1)
        port = std::atoi(argv[1]);

    std::cout << "SSL server port: " << port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create and prepare a new SSL server context
    auto context = std::make_shared<CppServer::Asio::SSLContext>(asio::ssl::context::tlsv12);
    context->set_password_callback([](size_t max_length, asio::ssl::context::password_purpose purpose) -> std::string { return "qwerty"; });
    context->use_certificate_chain_file("../tools/certificates/server.pem");
    context->use_private_key_file("../tools/certificates/server.pem", asio::ssl::context::pem);
    context->use_tmp_dh_file("../tools/certificates/dh4096.pem");

    // Create a new SSL chat server
    auto server = std::make_shared<ChatServer>(service, context, port);

    // Start the server
    std::cout << "Server starting...";
    server->Start();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the server or '!' to restart the server..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Restart the server
        if (line == "!")
        {
            std::cout << "Server restarting...";
            server->Restart();
            std::cout << "Done!" << std::endl;
            continue;
        }

        // Multicast admin message to all sessions
        line = "(admin) " + line;
        server->Multicast(line);
    }

    // Stop the server
    std::cout << "Server stopping...";
    server->Stop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: SSL chat client

Here comes the example of the SSL chat client. It connects to the SSL chat server and allows to send message to it and receive new messages.

This example is very similar to the TCP one except the code that prepares SSL context and handshake handler.

#include "server/asio/ssl_client.h"
#include "threads/thread.h"

#include <atomic>
#include <iostream>

class ChatClient : public CppServer::Asio::SSLClient
{
public:
    ChatClient(std::shared_ptr<CppServer::Asio::Service> service, std::shared_ptr<CppServer::Asio::SSLContext> context, const std::string& address, int port)
        : CppServer::Asio::SSLClient(service, context, address, port)
    {
        _stop = false;
    }

    void DisconnectAndStop()
    {
        _stop = true;
        DisconnectAsync();
        while (IsConnected())
            CppCommon::Thread::Yield();
    }

protected:
    void onConnected() override
    {
        std::cout << "Chat SSL client connected a new session with Id " << id() << std::endl;
    }

    void onHandshaked() override
    {
        std::cout << "Chat SSL client handshaked a new session with Id " << id() << std::endl;
    }

    void onDisconnected() override
    {
        std::cout << "Chat SSL client disconnected a session with Id " << id() << std::endl;

        // Wait for a while...
        CppCommon::Thread::Sleep(1000);

        // Try to connect again
        if (!_stop)
            ConnectAsync();
    }

    void onReceived(const void* buffer, size_t size) override
    {
        std::cout << "Incoming: " << std::string((const char*)buffer, size) << std::endl;
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Chat SSL client caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }

private:
    std::atomic<bool> _stop;
};

int main(int argc, char** argv)
{
    // SSL server address
    std::string address = "127.0.0.1";
    if (argc > 1)
        address = argv[1];

    // SSL server port
    int port = 2222;
    if (argc > 2)
        port = std::atoi(argv[2]);

    std::cout << "SSL server address: " << address << std::endl;
    std::cout << "SSL server port: " << port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create and prepare a new SSL client context
    auto context = std::make_shared<CppServer::Asio::SSLContext>(asio::ssl::context::tlsv12);
    context->set_default_verify_paths();
    context->set_root_certs();
    context->set_verify_mode(asio::ssl::verify_peer | asio::ssl::verify_fail_if_no_peer_cert);
    context->load_verify_file("../tools/certificates/ca.pem");

    // Create a new SSL chat client
    auto client = std::make_shared<ChatClient>(service, context, address, port);

    // Connect the client
    std::cout << "Client connecting...";
    client->ConnectAsync();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the client or '!' to reconnect the client..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Disconnect the client
        if (line == "!")
        {
            std::cout << "Client disconnecting...";
            client->DisconnectAsync();
            std::cout << "Done!" << std::endl;
            continue;
        }

        // Send the entered text to the chat server
        client->SendAsync(line);
    }

    // Disconnect the client
    std::cout << "Client disconnecting...";
    client->DisconnectAndStop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: UDP echo server

Here comes the example of the UDP echo server. It receives a datagram mesage from any UDP client and resend it back without any changes.

#include "server/asio/udp_server.h"
#include "threads/thread.h"

#include <iostream>

class EchoServer : public CppServer::Asio::UDPServer
{
public:
    using CppServer::Asio::UDPServer::UDPServer;

protected:
    void onStarted() override
    {
        // Start receive datagrams
        ReceiveAsync();
    }

    void onReceived(const asio::ip::udp::endpoint& endpoint, const void* buffer, size_t size) override
    {
        std::string message((const char*)buffer, size);
        std::cout << "Incoming: " << message << std::endl;

        // Echo the message back to the sender
        SendAsync(endpoint, message);
    }

    void onSent(const asio::ip::udp::endpoint& endpoint, size_t sent) override
    {
        // Continue receive datagrams
        ReceiveAsync();
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Echo UDP server caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // UDP server port
    int port = 3333;
    if (argc > 1)
        port = std::atoi(argv[1]);

    std::cout << "UDP server port: " << port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new UDP echo server
    auto server = std::make_shared<EchoServer>(service, port);

    // Start the server
    std::cout << "Server starting...";
    server->Start();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the server or '!' to restart the server..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Restart the server
        if (line == "!")
        {
            std::cout << "Server restarting...";
            server->Restart();
            std::cout << "Done!" << std::endl;
            continue;
        }
    }

    // Stop the server
    std::cout << "Server stopping...";
    server->Stop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: UDP echo client

Here comes the example of the UDP echo client. It sends user datagram message to UDP server and listen for response.

#include "server/asio/udp_client.h"
#include "threads/thread.h"

#include <atomic>
#include <iostream>

class EchoClient : public CppServer::Asio::UDPClient
{
public:
    EchoClient(std::shared_ptr<CppServer::Asio::Service> service, const std::string& address, int port)
        : CppServer::Asio::UDPClient(service, address, port)
    {
        _stop = false;
    }

    void DisconnectAndStop()
    {
        _stop = true;
        DisconnectAsync();
        while (IsConnected())
            CppCommon::Thread::Yield();
    }

protected:
    void onConnected() override
    {
        std::cout << "Echo UDP client connected a new session with Id " << id() << std::endl;

        // Start receive datagrams
        ReceiveAsync();
    }

    void onDisconnected() override
    {
        std::cout << "Echo UDP client disconnected a session with Id " << id() << std::endl;

        // Wait for a while...
        CppCommon::Thread::Sleep(1000);

        // Try to connect again
        if (!_stop)
            ConnectAsync();
    }

    void onReceived(const asio::ip::udp::endpoint& endpoint, const void* buffer, size_t size) override
    {
        std::cout << "Incoming: " << std::string((const char*)buffer, size) << std::endl;

        // Continue receive datagrams
        ReceiveAsync();
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Echo UDP client caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }

private:
    std::atomic<bool> _stop;
};

int main(int argc, char** argv)
{
    // UDP server address
    std::string address = "127.0.0.1";
    if (argc > 1)
        address = argv[1];

    // UDP server port
    int port = 3333;
    if (argc > 2)
        port = std::atoi(argv[2]);

    std::cout << "UDP server address: " << address << std::endl;
    std::cout << "UDP server port: " << port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new UDP echo client
    auto client = std::make_shared<EchoClient>(service, address, port);

    // Connect the client
    std::cout << "Client connecting...";
    client->ConnectAsync();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the client or '!' to reconnect the client..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Disconnect the client
        if (line == "!")
        {
            std::cout << "Client disconnecting...";
            client->DisconnectAsync();
            std::cout << "Done!" << std::endl;
            continue;
        }

        // Send the entered text to the echo server
        client->SendSync(line);
    }

    // Disconnect the client
    std::cout << "Client disconnecting...";
    client->DisconnectAndStop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: UDP multicast server

Here comes the example of the UDP multicast server. It use multicast IP address to multicast datagram messages to all client that joined corresponding UDP multicast group.

#include "server/asio/udp_server.h"
#include "threads/thread.h"

#include <iostream>

class MulticastServer : public CppServer::Asio::UDPServer
{
public:
    using CppServer::Asio::UDPServer::UDPServer;

protected:
    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Multicast UDP server caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // UDP multicast address
    std::string multicast_address = "239.255.0.1";
    if (argc > 1)
        multicast_address = argv[1];

    // UDP multicast port
    int multicast_port = 3334;
    if (argc > 2)
        multicast_port = std::atoi(argv[2]);

    std::cout << "UDP multicast address: " << multicast_address << std::endl;
    std::cout << "UDP multicast port: " << multicast_port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new UDP multicast server
    auto server = std::make_shared<MulticastServer>(service, 0);

    // Start the multicast server
    std::cout << "Server starting...";
    server->Start(multicast_address, multicast_port);
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the server or '!' to restart the server..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Restart the server
        if (line == "!")
        {
            std::cout << "Server restarting...";
            server->Restart();
            std::cout << "Done!" << std::endl;
            continue;
        }

        // Multicast admin message to all sessions
        line = "(admin) " + line;
        server->MulticastSync(line);
    }

    // Stop the server
    std::cout << "Server stopping...";
    server->Stop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: UDP multicast client

Here comes the example of the UDP multicast client. It use multicast IP address and joins UDP multicast group in order to receive multicasted datagram messages from UDP server.

#include "server/asio/udp_client.h"
#include "threads/thread.h"

#include <atomic>
#include <iostream>

class MulticastClient : public CppServer::Asio::UDPClient
{
public:
    MulticastClient(std::shared_ptr<CppServer::Asio::Service> service, const std::string& address, const std::string& multicast, int port)
        : CppServer::Asio::UDPClient(service, address, port),
          _multicast(multicast)
    {
        _stop = false;
    }

    void DisconnectAndStop()
    {
        _stop = true;
        DisconnectAsync();
        while (IsConnected())
            CppCommon::Thread::Yield();
    }

protected:
    void onConnected() override
    {
        std::cout << "Multicast UDP client connected a new session with Id " << id() << std::endl;

        // Join UDP multicast group
        JoinMulticastGroupAsync(_multicast);

        // Start receive datagrams
        ReceiveAsync();
    }

    void onDisconnected() override
    {
        std::cout << "Multicast UDP client disconnected a session with Id " << id() << std::endl;

        // Wait for a while...
        CppCommon::Thread::Sleep(1000);

        // Try to connect again
        if (!_stop)
            ConnectAsync();
    }

    void onReceived(const asio::ip::udp::endpoint& endpoint, const void* buffer, size_t size) override
    {
        std::cout << "Incoming: " << std::string((const char*)buffer, size) << std::endl;

        // Continue receive datagrams
        ReceiveAsync();
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "Multicast UDP client caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }

private:
    std::atomic<bool> _stop;
    std::string _multicast;
};

int main(int argc, char** argv)
{
    // UDP listen address
    std::string listen_address = "0.0.0.0";
    if (argc > 1)
        listen_address = argv[1];

    // UDP multicast address
    std::string multicast_address = "239.255.0.1";
    if (argc > 2)
        multicast_address = argv[2];

    // UDP multicast port
    int multicast_port = 3334;
    if (argc > 3)
        multicast_port = std::atoi(argv[3]);

    std::cout << "UDP listen address: " << listen_address << std::endl;
    std::cout << "UDP multicast address: " << multicast_address << std::endl;
    std::cout << "UDP multicast port: " << multicast_port << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new UDP multicast client
    auto client = std::make_shared<MulticastClient>(service, listen_address, multicast_address, multicast_port);
    client->SetupMulticast(true);

    // Connect the client
    std::cout << "Client connecting...";
    client->ConnectAsync();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the client or '!' to reconnect the client..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Disconnect the client
        if (line == "!")
        {
            std::cout << "Client disconnecting...";
            client->DisconnectAsync();
            std::cout << "Done!" << std::endl;
            continue;
        }
    }

    // Disconnect the client
    std::cout << "Client disconnecting...";
    client->DisconnectAndStop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: HTTP server

Here comes the example of the HTTP cache server. It allows to manipulate cache data with HTTP methods (GET, POST, PUT and DELETE).

Use the following link to open Swagger OpenAPI iterative documentation: http://localhost:8080/api/index.html

#include "server/http/http_server.h"
#include "string/string_utils.h"
#include "utility/singleton.h"

#include <iostream>
#include <map>
#include <mutex>

class Cache : public CppCommon::Singleton<Cache>
{
   friend CppCommon::Singleton<Cache>;

public:
    std::string GetAllCache()
    {
        std::scoped_lock locker(_cache_lock);
        std::string result;
        result += "[\n";
        for (const auto& item : _cache)
        {
            result += "  {\n";
            result += "    \"key\": \"" + item.first + "\",\n";
            result += "    \"value\": \"" + item.second + "\",\n";
            result += "  },\n";
        }
        result += "]\n";
        return result;
    }

    bool GetCacheValue(std::string_view key, std::string& value)
    {
        std::scoped_lock locker(_cache_lock);
        auto it = _cache.find(key);
        if (it != _cache.end())
        {
            value = it->second;
            return true;
        }
        else
            return false;
    }

    void PutCacheValue(std::string_view key, std::string_view value)
    {
        std::scoped_lock locker(_cache_lock);
        auto it = _cache.emplace(key, value);
        if (!it.second)
            it.first->second = value;
    }

    bool DeleteCacheValue(std::string_view key, std::string& value)
    {
        std::scoped_lock locker(_cache_lock);
        auto it = _cache.find(key);
        if (it != _cache.end())
        {
            value = it->second;
            _cache.erase(it);
            return true;
        }
        else
            return false;
    }

private:
    std::mutex _cache_lock;
    std::map<std::string, std::string, std::less<>> _cache;
};

class HTTPCacheSession : public CppServer::HTTP::HTTPSession
{
public:
    using CppServer::HTTP::HTTPSession::HTTPSession;

protected:
    void onReceivedRequest(const CppServer::HTTP::HTTPRequest& request) override
    {
        // Show HTTP request content
        std::cout << std::endl << request;

        // Process HTTP request methods
        if (request.method() == "HEAD")
            SendResponseAsync(response().MakeHeadResponse());
        else if (request.method() == "GET")
        {
            std::string key(request.url());
            std::string value;

            // Decode the key value
            key = CppCommon::Encoding::URLDecode(key);
            CppCommon::StringUtils::ReplaceFirst(key, "/api/cache", "");
            CppCommon::StringUtils::ReplaceFirst(key, "?key=", "");

            if (key.empty())
            {
                // Response with all cache values
                SendResponseAsync(response().MakeGetResponse(Cache::GetInstance().GetAllCache(), "application/json; charset=UTF-8"));
            }
            // Get the cache value by the given key
            else if (Cache::GetInstance().GetCacheValue(key, value))
            {
                // Response with the cache value
                SendResponseAsync(response().MakeGetResponse(value));
            }
            else
                SendResponseAsync(response().MakeErrorResponse("Required cache value was not found for the key: " + key, 404));
        }
        else if ((request.method() == "POST") || (request.method() == "PUT"))
        {
            std::string key(request.url());
            std::string value(request.body());

            // Decode the key value
            key = CppCommon::Encoding::URLDecode(key);
            CppCommon::StringUtils::ReplaceFirst(key, "/api/cache", "");
            CppCommon::StringUtils::ReplaceFirst(key, "?key=", "");

            // Put the cache value
            Cache::GetInstance().PutCacheValue(key, value);

            // Response with the cache value
            SendResponseAsync(response().MakeOKResponse());
        }
        else if (request.method() == "DELETE")
        {
            std::string key(request.url());
            std::string value;

            // Decode the key value
            key = CppCommon::Encoding::URLDecode(key);
            CppCommon::StringUtils::ReplaceFirst(key, "/api/cache", "");
            CppCommon::StringUtils::ReplaceFirst(key, "?key=", "");

            // Delete the cache value
            if (Cache::GetInstance().DeleteCacheValue(key, value))
            {
                // Response with the cache value
                SendResponseAsync(response().MakeGetResponse(value));
            }
            else
                SendResponseAsync(response().MakeErrorResponse("Deleted cache value was not found for the key: " + key, 404));
        }
        else if (request.method() == "OPTIONS")
            SendResponseAsync(response().MakeOptionsResponse());
        else if (request.method() == "TRACE")
            SendResponseAsync(response().MakeTraceResponse(request.cache()));
        else
            SendResponseAsync(response().MakeErrorResponse("Unsupported HTTP method: " + std::string(request.method())));
    }

    void onReceivedRequestError(const CppServer::HTTP::HTTPRequest& request, const std::string& error) override
    {
        std::cout << "Request error: " << error << std::endl;
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "HTTP session caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

class HTTPCacheServer : public CppServer::HTTP::HTTPServer
{
public:
    using CppServer::HTTP::HTTPServer::HTTPServer;

protected:
    std::shared_ptr<CppServer::Asio::TCPSession> CreateSession(const std::shared_ptr<CppServer::Asio::TCPServer>& server) override
    {
        return std::make_shared<HTTPCacheSession>(std::dynamic_pointer_cast<CppServer::HTTP::HTTPServer>(server));
    }

protected:
    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "HTTP server caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // HTTP server port
    int port = 8080;
    if (argc > 1)
        port = std::atoi(argv[1]);
    // HTTP server content path
    std::string www = "../www/api";
    if (argc > 2)
        www = argv[2];

    std::cout << "HTTP server port: " << port << std::endl;
    std::cout << "HTTP server static content path: " << www << std::endl;
    std::cout << "HTTP server website: " << "http://localhost:" << port << "/api/index.html" << std::endl;

    std::cout << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new HTTP server
    auto server = std::make_shared<HTTPCacheServer>(service, port);
    server->AddStaticContent(www, "/api");

    // Start the server
    std::cout << "Server starting...";
    server->Start();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the server or '!' to restart the server..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Restart the server
        if (line == "!")
        {
            std::cout << "Server restarting...";
            server->Restart();
            std::cout << "Done!" << std::endl;
            continue;
        }
    }

    // Stop the server
    std::cout << "Server stopping...";
    server->Stop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: HTTP client

Here comes the example of the HTTP client. It allows to send HTTP requests (GET, POST, PUT and DELETE) and receive HTTP responses.

#include "server/http/http_client.h"
#include "string/string_utils.h"

#include <iostream>

int main(int argc, char** argv)
{
    // HTTP server address
    std::string address = "127.0.0.1";
    if (argc > 1)
        address = argv[1];

    std::cout << "HTTP server address: " << address << std::endl;

    std::cout << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create a new HTTP client
    auto client = std::make_shared<CppServer::HTTP::HTTPClientEx>(service, address, "http");

    std::cout << "Press Enter to stop the client or '!' to reconnect the client..." << std::endl;

    try
    {
        // Perform text input
        std::string line;
        while (getline(std::cin, line))
        {
            if (line.empty())
                break;

            // Reconnect the client
            if (line == "!")
            {
                std::cout << "Client reconnecting...";
                client->ReconnectAsync();
                std::cout << "Done!" << std::endl;
                continue;
            }

            auto commands = CppCommon::StringUtils::Split(line, ' ', true);
            if (commands.size() < 2)
            {
                std::cout << "HTTP method and URL must be entered!" << std::endl;
                continue;
            }

            if (CppCommon::StringUtils::ToUpper(commands[0]) == "HEAD")
            {
                auto response = client->SendHeadRequest(commands[1]).get();
                std::cout << response << std::endl;
            }
            else if (CppCommon::StringUtils::ToUpper(commands[0]) == "GET")
            {
                auto response = client->SendGetRequest(commands[1]).get();
                std::cout << response << std::endl;
            }
            else if (CppCommon::StringUtils::ToUpper(commands[0]) == "POST")
            {
                if (commands.size() < 3)
                {
                    std::cout << "HTTP method, URL and body must be entered!" << std::endl;
                    continue;
                }
                auto response = client->SendPostRequest(commands[1], commands[2]).get();
                std::cout << response << std::endl;
            }
            else if (CppCommon::StringUtils::ToUpper(commands[0]) == "PUT")
            {
                if (commands.size() < 3)
                {
                    std::cout << "HTTP method, URL and body must be entered!" << std::endl;
                    continue;
                }
                auto response = client->SendPutRequest(commands[1], commands[2]).get();
                std::cout << response << std::endl;
            }
            else if (CppCommon::StringUtils::ToUpper(commands[0]) == "DELETE")
            {
                auto response = client->SendDeleteRequest(commands[1]).get();
                std::cout << response << std::endl;
            }
            else if (CppCommon::StringUtils::ToUpper(commands[0]) == "OPTIONS")
            {
                auto response = client->SendOptionsRequest(commands[1]).get();
                std::cout << response << std::endl;
            }
            else if (CppCommon::StringUtils::ToUpper(commands[0]) == "TRACE")
            {
                auto response = client->SendTraceRequest(commands[1]).get();
                std::cout << response << std::endl;
            }
            else
                std::cout << "Unknown HTTP method: " << commands[0] << std::endl;
        }
    }
    catch (const std::exception& ex)
    {
        std::cerr << ex.what() << std::endl;
    }

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}

Example: HTTPS server

Here comes the example of the HTTPS cache server. It allows to manipulate cache data with HTTP methods (GET, POST, PUT and DELETE) with secured transport protocol.

Use the following link to open Swagger OpenAPI iterative documentation: https://localhost:8443/api/index.html

#include "server/http/https_server.h"
#include "string/string_utils.h"
#include "utility/singleton.h"

#include <iostream>
#include <map>
#include <mutex>

class Cache : public CppCommon::Singleton<Cache>
{
   friend CppCommon::Singleton<Cache>;

public:
    std::string GetAllCache()
    {
        std::scoped_lock locker(_cache_lock);
        std::string result;
        result += "[\n";
        for (const auto& item : _cache)
        {
            result += "  {\n";
            result += "    \"key\": \"" + item.first + "\",\n";
            result += "    \"value\": \"" + item.second + "\",\n";
            result += "  },\n";
        }
        result += "]\n";
        return result;
    }

    bool GetCacheValue(std::string_view key, std::string& value)
    {
        std::scoped_lock locker(_cache_lock);
        auto it = _cache.find(key);
        if (it != _cache.end())
        {
            value = it->second;
            return true;
        }
        else
            return false;
    }

    void PutCacheValue(std::string_view key, std::string_view value)
    {
        std::scoped_lock locker(_cache_lock);
        auto it = _cache.emplace(key, value);
        if (!it.second)
            it.first->second = value;
    }

    bool DeleteCacheValue(std::string_view key, std::string& value)
    {
        std::scoped_lock locker(_cache_lock);
        auto it = _cache.find(key);
        if (it != _cache.end())
        {
            value = it->second;
            _cache.erase(it);
            return true;
        }
        else
            return false;
    }

private:
    std::mutex _cache_lock;
    std::map<std::string, std::string, std::less<>> _cache;
};

class HTTPSCacheSession : public CppServer::HTTP::HTTPSSession
{
public:
    using CppServer::HTTP::HTTPSSession::HTTPSSession;

protected:
    void onReceivedRequest(const CppServer::HTTP::HTTPRequest& request) override
    {
        // Show HTTP request content
        std::cout << std::endl << request;

        // Process HTTP request methods
        if (request.method() == "HEAD")
            SendResponseAsync(response().MakeHeadResponse());
        else if (request.method() == "GET")
        {
            std::string key(request.url());
            std::string value;

            // Decode the key value
            key = CppCommon::Encoding::URLDecode(key);
            CppCommon::StringUtils::ReplaceFirst(key, "/api/cache", "");
            CppCommon::StringUtils::ReplaceFirst(key, "?key=", "");

            if (key.empty())
            {
                // Response with all cache values
                SendResponseAsync(response().MakeGetResponse(Cache::GetInstance().GetAllCache(), "application/json; charset=UTF-8"));
            }
            // Get the cache value by the given key
            else if (Cache::GetInstance().GetCacheValue(key, value))
            {
                // Response with the cache value
                SendResponseAsync(response().MakeGetResponse(value));
            }
            else
                SendResponseAsync(response().MakeErrorResponse("Required cache value was not found for the key: " + key, 404));
        }
        else if ((request.method() == "POST") || (request.method() == "PUT"))
        {
            std::string key(request.url());
            std::string value(request.body());

            // Decode the key value
            key = CppCommon::Encoding::URLDecode(key);
            CppCommon::StringUtils::ReplaceFirst(key, "/api/cache", "");
            CppCommon::StringUtils::ReplaceFirst(key, "?key=", "");

            // Put the cache value
            Cache::GetInstance().PutCacheValue(key, value);

            // Response with the cache value
            SendResponseAsync(response().MakeOKResponse());
        }
        else if (request.method() == "DELETE")
        {
            std::string key(request.url());
            std::string value;

            // Decode the key value
            key = CppCommon::Encoding::URLDecode(key);
            CppCommon::StringUtils::ReplaceFirst(key, "/api/cache", "");
            CppCommon::StringUtils::ReplaceFirst(key, "?key=", "");

            // Delete the cache value
            if (Cache::GetInstance().DeleteCacheValue(key, value))
            {
                // Response with the cache value
                SendResponseAsync(response().MakeGetResponse(value));
            }
            else
                SendResponseAsync(response().MakeErrorResponse("Deleted cache value was not found for the key: " + key, 404));
        }
        else if (request.method() == "OPTIONS")
            SendResponseAsync(response().MakeOptionsResponse());
        else if (request.method() == "TRACE")
            SendResponseAsync(response().MakeTraceResponse(request.cache()));
        else
            SendResponseAsync(response().MakeErrorResponse("Unsupported HTTP method: " + std::string(request.method())));
    }

    void onReceivedRequestError(const CppServer::HTTP::HTTPRequest& request, const std::string& error) override
    {
        std::cout << "Request error: " << error << std::endl;
    }

    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "HTTPS session caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

class HTTPSCacheServer : public CppServer::HTTP::HTTPSServer
{
public:
    using CppServer::HTTP::HTTPSServer::HTTPSServer;

protected:
    std::shared_ptr<CppServer::Asio::SSLSession> CreateSession(const std::shared_ptr<CppServer::Asio::SSLServer>& server) override
    {
        return std::make_shared<HTTPSCacheSession>(std::dynamic_pointer_cast<CppServer::HTTP::HTTPSServer>(server));
    }

protected:
    void onError(int error, const std::string& category, const std::string& message) override
    {
        std::cout << "HTTPS server caught an error with code " << error << " and category '" << category << "': " << message << std::endl;
    }
};

int main(int argc, char** argv)
{
    // HTTPS server port
    int port = 8443;
    if (argc > 1)
        port = std::atoi(argv[1]);
    // HTTPS server content path
    std::string www = "../www/api";
    if (argc > 2)
        www = argv[2];

    std::cout << "HTTPS server port: " << port << std::endl;
    std::cout << "HTTPS server static content path: " << www << std::endl;
    std::cout << "HTTPS server website: " << "https://localhost:" << port << "/api/index.html" << std::endl;

    std::cout << std::endl;

    // Create a new Asio service
    auto service = std::make_shared<CppServer::Asio::Service>();

    // Start the Asio service
    std::cout << "Asio service starting...";
    service->Start();
    std::cout << "Done!" << std::endl;

    // Create and prepare a new SSL server context
    auto context = std::make_shared<CppServer::Asio::SSLContext>(asio::ssl::context::tlsv12);
    context->set_password_callback([](size_t max_length, asio::ssl::context::password_purpose purpose) -> std::string { return "qwerty"; });
    context->use_certificate_chain_file("../tools/certificates/server.pem");
    context->use_private_key_file("../tools/certificates/server.pem", asio::ssl::context::pem);
    context->use_tmp_dh_file("../tools/certificates/dh4096.pem");

    // Create a new HTTPS server
    auto server = std::make_shared<HTTPSCacheServer>(service, context, port);
    server->AddStaticContent(www, "/api");

    // Start the server
    std::cout << "Server starting...";
    server->Start();
    std::cout << "Done!" << std::endl;

    std::cout << "Press Enter to stop the server or '!' to restart the server..." << std::endl;

    // Perform text input
    std::string line;
    while (getline(std::cin, line))
    {
        if (line.empty())
            break;

        // Restart the server
        if (line == "!")
        {
            std::cout << "Server restarting...";
            server->Restart();
            std::cout << "Done!" << std::endl;
            continue;
        }
    }

    // Stop the server
    std::cout << "Server stopping...";
    server->Stop();
    std::cout << "Done!" << std::endl;

    // Stop the Asio service
    std::cout << "Asio service stopping...";
    service->Stop();
    std::cout << "Done!" << std::endl;

    return 0;
}