a bit better way to treah handlers

CMakeLists.txt

@@ -46,6 +46,7 @@ target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
 target_compile_options(${PROJECT_NAME} PRIVATE ${COMPILE_OPTIONS})
 
 add_subdirectory(server)
+add_subdirectory(handler)
 add_subdirectory(request)
 add_subdirectory(response)
 add_subdirectory(stream)

handler/CMakeLists.txt

@@ -0,0 +1,13 @@
+set(HEADERS
+    handler.h
+    info.h
+    env.h
+)
+
+set(SOURCES
+    handler.cpp
+    info.cpp
+    env.cpp
+)
+
+target_sources(${PROJECT_NAME} PRIVATE ${SOURCES})

handler/env.cpp

@@ -0,0 +1,17 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "env.h"
+
+Handler::Env::Env():
+    Handler("env", Request::Method::get)
+{}
+
+void Handler::Env::handle(Request& request) {
+    nlohmann::json body = nlohmann::json::object();
+    request.printEnvironment(body);
+
+    Response res(request);
+    res.setBody(body);
+    res.send();
+}

handler/env.h

@@ -0,0 +1,16 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include "handler.h"
+
+namespace Handler {
+
+class Env : public Handler::Handler {
+public:
+    Env();
+    virtual void handle(Request& request);
+
+};
+}

handler/handler.cpp

@@ -0,0 +1,11 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "handler.h"
+
+Handler::Handler::Handler(const std::string& path, Request::Method method):
+    path(path),
+    method(method)
+{}
+
+Handler::Handler::~Handler() {}

handler/handler.h

@@ -0,0 +1,26 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <string>
+#include <memory>
+
+#include "request/request.h"
+#include "response/response.h"
+
+namespace Handler {
+
+class Handler {
+protected:
+    Handler(const std::string& path, Request::Method method);
+
+public:
+    virtual ~Handler();
+
+    virtual void handle(Request& request) = 0;
+
+    const std::string path;
+    const Request::Method method;
+};
+}

handler/info.cpp

@@ -0,0 +1,18 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "info.h"
+
+Handler::Info::Info():
+    Handler("info", Request::Method::get)
+{}
+
+void Handler::Info::handle(Request& request) {
+    Response res(request);
+    nlohmann::json body = nlohmann::json::object();
+    body["type"] = PROJECT_NAME;
+    body["version"] = PROJECT_VERSION;
+
+    res.setBody(body);
+    res.send();
+}

handler/info.h

@@ -0,0 +1,17 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include "handler.h"
+#include "config.h"
+
+namespace Handler {
+
+class Info : public Handler {
+public:
+    Info();
+    void handle(Request& request) override;
+};
+
+}

request/request.cpp

@@ -3,6 +3,8 @@
 
 #include "request.h"
 
+#include "response/response.h"
+
 constexpr static const char* GET("GET");
 
 constexpr static const char* REQUEST_METHOD("REQUEST_METHOD");
@@ -16,9 +18,18 @@ constexpr static const char* SERVER_NAME("SERVER_NAME");
 //
 // constexpr static const char* SCRIPT_NAME("SCRIPT_NAME");
 
+constexpr std::array<
+    std::pair<std::string_view, Request::Method>,
+    static_cast<uint8_t>(Request::Method::unknown)
+> methods = {{
+    {"GET", Request::Method::get},
+    {"POST", Request::Method::post}
+}};
+
 Request::Request ():
     state(State::initial),
-    raw()
+    raw(),
+    response(nullptr)
 {}
 
 Request::~Request() {
@@ -36,12 +47,17 @@ void Request::terminate() {
     }
 }
 
-bool Request::isGet() const {
-    if (state != State::accepted)
-        throw std::runtime_error("An attempt to read request type on a wrong request state");
+Request::Method Request::method() const {
+    if (state == State::initial)
+        throw std::runtime_error("An attempt to read request method on not accepted request");
 
     std::string_view method(FCGX_GetParam(REQUEST_METHOD, raw.envp));
-    return method == GET;
+    for (const auto& pair : methods) {
+        if (pair.first == method)
+            return pair.second;
+    }
+
+    return Request::Method::unknown;
 }
 
 bool Request::wait(int socketDescriptor) {
@@ -59,20 +75,61 @@ bool Request::wait(int socketDescriptor) {
     return result;
 }
 
-OStream Request::getOutputStream() {
-    if (state != State::accepted)
-        throw std::runtime_error("An attempt to request output stream on a wrong request state");
-
+OStream Request::getOutputStream(const Response* response) {
+    validateResponse(response);
     return OStream(raw.out);
 }
 
-OStream Request::getErrorStream() {
-    if (state != State::accepted)
-        throw std::runtime_error("An attempt to request error stream on a wrong request state");
-
+OStream Request::getErrorStream(const Response* response) {
+    validateResponse(response);
     return OStream(raw.err);
 }
 
+void Request::responseIsComplete(const Response* response) {
+    switch (state) {
+        case State::initial:
+            throw std::runtime_error("An attempt to mark the request as complete, but it wasn't even accepted yet");
+            break;
+        case State::accepted:
+            throw std::runtime_error("An attempt to mark the request as complete, but it wasn't responded");
+            break;
+        case State::responding:
+            if (Request::response != response)
+                throw std::runtime_error("An attempt to mark the request as complete by the different response who actually started responding");
+
+            Request::response = nullptr;
+            state = State::responded;
+            break;
+        case State::responded:
+            throw std::runtime_error("An attempt to mark the request as a complete for the second time");
+            break;
+    }
+}
+
+void Request::validateResponse(const Response* response) {
+    switch (state) {
+        case State::initial:
+            throw std::runtime_error("An attempt to request stream while the request wasn't even accepted yet");
+            break;
+        case State::accepted:
+            Request::response = response;
+            state = State::responding;
+            break;
+        case State::responding:
+            if (Request::response != response)
+                throw std::runtime_error("Error handling a request: first time one response started replying, then another continued");
+
+            break;
+        case State::responded:
+            throw std::runtime_error("An attempt to request stream on a request that was already done responding");
+            break;
+    }
+}
+
+Request::State Request::currentState() const {
+    return state;
+}
+
 std::string Request::getPath(const std::string& serverName) const {
     if (state != State::accepted)
         throw std::runtime_error("An attempt to request path on a wrong request state");

request/request.h

@@ -6,6 +6,8 @@
 #include <memory>
 #include <stdexcept>
 #include <string_view>
+#include <array>
+#include <map>
 
 #include <fcgiapp.h>
 
@@ -13,14 +15,22 @@
 
 #include "stream/ostream.h"
 
+class Response;
 class Request {
 public:
     enum class State {
         initial,
         accepted,
+        responding,
         responded
     };
 
+    enum class Method {
+        get,
+        post,
+        unknown
+    };
+
     Request();
     ~Request();
     Request(const Request& other) = delete;
@@ -30,17 +40,24 @@ public:
 
     bool wait(int socketDescriptor);
     void terminate();
-    bool isGet() const;
 
-    OStream getOutputStream();
-    OStream getErrorStream();
+    Method method() const;
+    State currentState() const;
+
+    OStream getOutputStream(const Response* response);
+    OStream getErrorStream(const Response* response);
+    void responseIsComplete(const Response* response);
 
     std::string getPath(const std::string& serverName) const;
     std::string getServerName() const;
     void printEnvironment(std::ostream& out);
     void printEnvironment(nlohmann::json& out);
 
+private:
+    void validateResponse(const Response* response);
+
 private:
     State state;
     FCGX_Request raw;
+    const Response* response;
 };

response/response.cpp

@@ -15,23 +15,25 @@ constexpr std::array<std::string_view, static_cast<uint8_t>(Response::ContentTyp
     "Content-type: application/json"
 };
 
-Response::Response():
+Response::Response(Request& request):
+    request(request),
     status(Status::ok),
     type(ContentType::text),
     body()
 {}
 
-Response::Response(Status status):
+Response::Response(Request& request, Status status):
+    request(request),
     status(status),
     type(ContentType::text),
     body()
 {}
 
-void Response::replyTo(Request& request) const {
+void Response::send() const {
     // OStream out = status == Status::ok ?
     //     request.getOutputStream() :
     //     request.getErrorStream();
-    OStream out = request.getOutputStream();
+    OStream out = request.getOutputStream(this);
 
     out << statusCodes[static_cast<uint8_t>(status)];
     if (!body.empty())
@@ -40,6 +42,8 @@ void Response::replyTo(Request& request) const {
         << '\n'
         << '\n'
         << body;
+
+    request.responseIsComplete(this);
 }
 
 void Response::setBody(const std::string& body) {

response/response.h

@@ -27,14 +27,15 @@ public:
         json,
         __size
     };
-    Response();
-    Response(Status status);
+    Response(Request& request);
+    Response(Request& request, Status status);
 
-    void replyTo(Request& request) const;
+    void send() const;
     void setBody(const std::string& body);
     void setBody(const nlohmann::json& body);
 
 private:
+    Request& request;
     Status status;
     ContentType type;
     std::string body;

server/router.cpp

@@ -4,41 +4,74 @@
 #include "router.h"
 
 Router::Router():
-    table()
-{
+    get(),
+    post()
+{}
 
+void Router::addRoute(Handler handler) {
+    std::pair<std::map<std::string, Handler>::const_iterator, bool> result;
+    switch (handler->method) {
+        case Request::Method::get:
+            result = get.emplace(handler->path, std::move(handler));
+            break;
+        case Request::Method::post:
+            result = post.emplace(handler->path, std::move(handler));
+            break;
+        default:
+            throw std::runtime_error("An attempt to register handler with unsupported method type: " + std::to_string((int)handler->method));
     }
 
-void Router::addRoute(const std::string& path, const Handler& handler) {
-    auto result = table.emplace(path, handler);
     if (!result.second)
-        std::cerr << "could'not add route " + path + " to the routing table";
+        throw std::runtime_error("could'not add route " + handler->path + " to the routing table");
 }
 
-void Router::route(const std::string& path, std::unique_ptr<Request> request, Server* server) {
-    auto itr = table.find(path);
-    if (itr == table.end())
+void Router::route(const std::string& path, std::unique_ptr<Request> request) {
+    std::map<std::string, Handler>::const_iterator itr, end;
+    switch (request->method()) {
+        case Request::Method::get:
+            itr = get.find(path);
+            end = get.end();
+            break;
+        case Request::Method::post:
+            itr = post.find(path);
+            end = post.end();
+            break;
+        default:
+            return handleMethodNotAllowed(path, std::move(request));
+    }
+
+    if (itr == end)
         return handleNotFound(path, std::move(request));
 
     try {
-        bool result = itr->second(request.get(), server);
-        if (!result)
-            handleInternalError(std::runtime_error("handler failed to handle the request"), std::move(request));
+        itr->second->handle(*request.get());
+
+        if (request->currentState() != Request::State::responded)
+            handleInternalError(path, std::runtime_error("handler failed to handle the request"), std::move(request));
+        else
+            std::cout << "Success:\t" << path << std::endl;
     } catch (const std::exception& e) {
-        handleInternalError(e, std::move(request));
+        handleInternalError(path, e, std::move(request));
     }
 }
 
 void Router::handleNotFound(const std::string& path, std::unique_ptr<Request> request) {
-    Response notFound(Response::Status::notFound);
+    Response notFound(*request.get(), Response::Status::notFound);
     notFound.setBody(std::string("Path \"") + path + "\" was not found");
-    notFound.replyTo(*request.get());
-    std::cerr << "Not found: " << path << std::endl;
+    notFound.send();
+    std::cerr << "Not found:\t" << path << std::endl;
 }
 
-void Router::handleInternalError(const std::exception& exception, std::unique_ptr<Request> request) {
-    Response error(Response::Status::internalError);
+void Router::handleInternalError(const std::string& path, const std::exception& exception, std::unique_ptr<Request> request) {
+    Response error(*request.get(), Response::Status::internalError);
     error.setBody(std::string(exception.what()));
-    error.replyTo(*request.get());
-    std::cerr << "Internal error: " << exception.what() << std::endl;
+    error.send();
+    std::cerr << "Internal error:\t" << path << "\n\t" << exception.what() << std::endl;
+}
+
+void Router::handleMethodNotAllowed(const std::string& path, std::unique_ptr<Request> request) {
+    Response error(*request.get(), Response::Status::methodNotAllowed);
+    error.setBody(std::string("Method not allowed"));
+    error.send();
+    std::cerr << "Method not allowed:\t" << path << std::endl;
 }

server/router.h

@@ -10,23 +10,25 @@
 
 #include "request/request.h"
 #include "response/response.h"
+#include "handler/handler.h"
 
 class Server;
 
 class Router {
+    using Handler = std::unique_ptr<Handler::Handler>;
 public:
-    using Handler = std::function<bool(Request*, Server*)>;
-
     Router();
 
-    void addRoute(const std::string& path, const Handler& handler);
-    void route(const std::string& path, std::unique_ptr<Request> request, Server* server);
+    void addRoute(Handler handler);
+    void route(const std::string& path, std::unique_ptr<Request> request);
 
 private:
     void handleNotFound(const std::string& path, std::unique_ptr<Request> request);
-    void handleInternalError(const std::exception& exception, std::unique_ptr<Request> request);
+    void handleInternalError(const std::string& path, const std::exception& exception, std::unique_ptr<Request> request);
+    void handleMethodNotAllowed(const std::string& path, std::unique_ptr<Request> request);
 
 private:
-    std::map<std::string, Handler> table;
+    std::map<std::string, Handler> get;
+    std::map<std::string, Handler> post;
 
 };

server/server.cpp

@@ -3,6 +3,9 @@
 
 #include "server.h"
 
+#include "handler/info.h"
+#include "handler/env.h"
+
 constexpr uint8_t currentDbVesion = 1;
 
 Server::Server():
@@ -23,8 +26,8 @@ Server::Server():
     db->connect("/run/mysqld/mysqld.sock");
     db->migrate(currentDbVesion);
 
-    router.addRoute("info", Server::info);
-    router.addRoute("env", Server::printEnvironment);
+    router.addRoute(std::make_unique<Handler::Info>());
+    router.addRoute(std::make_unique<Handler::Env>());
 }
 
 Server::~Server() {}
@@ -49,49 +52,12 @@ void Server::handleRequest(std::unique_ptr<Request> request) {
             std::cout << "received server name " << serverName.value() << std::endl;
         } catch (...) {
             std::cerr << "failed to read server name" << std::endl;
-            Response error(Response::Status::internalError);
-            error.replyTo(*request.get());
+            Response error(*request.get(), Response::Status::internalError);
+            error.send();
             return;
         }
     }
 
-    if (!request->isGet()) {
-        static const Response methodNotAllowed(Response::Status::methodNotAllowed);
-        methodNotAllowed.replyTo(*request.get());
-        return;
-    }
-
-    try {
     std::string path = request->getPath(serverName.value());
-        router.route(path.data(), std::move(request), this);
-    } catch (const std::exception& e) {
-        Response error(Response::Status::internalError);
-        error.setBody(std::string(e.what()));
-        error.replyTo(*request.get());
-    }
-}
-
-bool Server::printEnvironment(Request* request, Server* server) {
-    UNUSED(server);
-    nlohmann::json body = nlohmann::json::object();
-    request->printEnvironment(body);
-
-    Response res;
-    res.setBody(body);
-    res.replyTo(*request);
-
-    return true;
-}
-
-bool Server::info(Request* request, Server* server) {
-    UNUSED(server);
-    Response res;
-    nlohmann::json body = nlohmann::json::object();
-    body["type"] = PROJECT_NAME;
-    body["version"] = PROJECT_VERSION;
-
-    res.setBody(body);
-    res.replyTo(*request);
-
-    return true;
+    router.route(path.data(), std::move(request));
 }

server/server.h

@@ -34,9 +34,6 @@ public:
 private:
     void handleRequest(std::unique_ptr<Request> request);
 
-    static bool info(Request* request, Server* server);
-    static bool printEnvironment(Request* request, Server* server);
-
 private:
     bool terminating;
     uint64_t requestCount;