http-web-server/http_tcpServer.cpp at main · codeharris/http-web-server · GitHub

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#include "http_tcpServer.h"

#include <cerrno>
#include <cstring>
#include <iostream>
#include <sstream>
#include <stdexcept>
#include <thread>
#include <utility>
#include <unistd.h>

namespace
{
    constexpr int BUFFER_SIZE = 4096;
    constexpr int CONNECTION_BACKLOG = 20;

    void log(const std::string &message)
    {
        std::cout << message << std::endl;
    }

    std::runtime_error socketError(const std::string &message)
    {
        return std::runtime_error(message + ": " + std::strerror(errno));
    }
}

namespace http
{
    TcpServer::TcpServer(std::string ip_address, int port)
        : m_ip_address(std::move(ip_address)),
          m_port(port),
          m_socket(-1),
          m_sockAddress(),
          m_sockAddress_len(sizeof(m_sockAddress))
    {
        startServer();
    }

    TcpServer::~TcpServer()
    {
        closeServer();
    }

    int TcpServer::startServer()
    {
        m_socket = socket(AF_INET, SOCK_STREAM, 0);
        if (m_socket < 0)
        {
            throw socketError("Cannot create socket");
        }

        int reuseAddress = 1;
        if (setsockopt(m_socket, SOL_SOCKET, SO_REUSEADDR, &reuseAddress, sizeof(reuseAddress)) < 0)
        {
            throw socketError("Cannot set socket options");
        }

        m_sockAddress.sin_family = AF_INET;
        m_sockAddress.sin_port = htons(m_port);

        if (inet_pton(AF_INET, m_ip_address.c_str(), &m_sockAddress.sin_addr) <= 0)
        {
            throw std::runtime_error("Invalid IP address: " + m_ip_address);
        }

        if (bind(m_socket, reinterpret_cast<sockaddr *>(&m_sockAddress), m_sockAddress_len) < 0)
        {
            throw socketError("Cannot bind socket");
        }

        if (listen(m_socket, CONNECTION_BACKLOG) < 0)
        {
            throw socketError("Cannot listen on socket");
        }

        std::ostringstream serverAddress;
        serverAddress << "Listening on http://" << m_ip_address << ":" << m_port;
        log(serverAddress.str());

        return 0;
    }

    void TcpServer::startListen()
    {
        while (true)
        {
            sockaddr_in clientAddress{};
            socklen_t clientAddressLength = sizeof(clientAddress);

            const int clientSocket = accept(
                m_socket,
                reinterpret_cast<sockaddr *>(&clientAddress),
                &clientAddressLength);

            if (clientSocket < 0)
            {
                log("Failed to accept client connection: " + std::string(std::strerror(errno)));
                continue;
            }

            std::thread(&TcpServer::handleClient, this, clientSocket).detach();
        }
    }

    void TcpServer::handleClient(int clientSocket) const
    {
        char buffer[BUFFER_SIZE] = {};
        const ssize_t bytesReceived = recv(clientSocket, buffer, sizeof(buffer) - 1, 0);

        if (bytesReceived <= 0)
        {
            close(clientSocket);
            return;
        }

        const std::string request(buffer, static_cast<std::size_t>(bytesReceived));
        const std::string response = buildResponse(request);

        send(clientSocket, response.c_str(), response.size(), 0);
        close(clientSocket);
    }

    std::string TcpServer::buildResponse(const std::string &request) const
    {
        const bool isHealthCheck = request.rfind("GET /health ", 0) == 0;
        const bool isHomePage = request.rfind("GET / ", 0) == 0;

        const std::string body = isHealthCheck
            ? "OK\n"
            : isHomePage
                ? "<html><body><h1>Simple C++ Web Server</h1><p>Hello from a multithreaded TCP server.</p></body></html>\n"
                : "<html><body><h1>404 Not Found</h1></body></html>\n";

        const std::string status = (isHealthCheck || isHomePage)
            ? "HTTP/1.1 200 OK"
            : "HTTP/1.1 404 Not Found";

        std::ostringstream response;
        response << status << "\r\n"
                 << "Content-Length: " << body.size() << "\r\n"
                 << "Content-Type: " << (isHealthCheck ? "text/plain" : "text/html") << "\r\n"
                 << "Connection: close\r\n"
                 << "\r\n"
                 << body;

        return response.str();
    }

    void TcpServer::closeServer()
    {
        if (m_socket >= 0)
        {
            close(m_socket);
            m_socket = -1;
        }
    }
} // namespace http