Add support C++20 modules

.github/workflows/cpp20-modules.yml

@@ -0,0 +1,42 @@
+name: C++20
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  modules:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Checkout Drogon source code
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+          fetch-depth: 0
+
+      - name: Install dependencies
+        run: |
+          sudo apt update
+          sudo apt-get install -y cmake ninja-build clang
+          sudo apt-get install -y libjsoncpp-dev uuid-dev libssl-dev zlib1g-dev libsqlite3-dev
+          sudo apt-get install -y ninja-build libbrotli-dev
+          cmake --version
+          ninja --version
+          clang++ --version
+
+      - name: Clang Build Modules
+        run: |
+          mkdir build && cd build && pwd
+          CC=clang CXX=clang++ cmake ..     \
+          -DCMAKE_CXX_STANDARD=20           \
+          -GNinja                           \
+          -DDROGON_BUILD_MODULES=ON         \
+          -DDROGON_BUILD_MODULES_EXAMPLE=ON \
+          -DBUILD_TESTING=OFF
+          ninja -j 9

CMakeLists.txt

@@ -54,6 +54,60 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
 endif ()
 
 add_library(${PROJECT_NAME})
+
+option(DROGON_BUILD_MODULES "Build drogon library in C++20 Modules form" OFF)
+option(DROGON_BUILD_MODULES_EXAMPLE "Build drogon modules example" OFF)
+option(HAS_STD_MODULE "has c++ std module" OFF)
+
+if(${DROGON_BUILD_MODULES})
+    message("-- use c++20 module")
+
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.28)
+        cmake_policy(SET CMP0155 NEW)
+    elseif(CMAKE_VERSION VERSION_GREATER_EQUAL 3.27)
+        set(CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API "aa1f7df0-828a-4fcd-9afc-2dc80491aca7")
+    elseif(CMAKE_VERSION VERSION_GREATER_EQUAL 3.26)
+        set(CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API "2182bf5c-ef0d-489a-91da-49dbc3090d2a")
+        if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+            set(CMake_TEST_CXXModules_UUID "a246741c-d067-4019-a8fb-3d16b0c9d1d3")
+            set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
+            string(CONCAT CMAKE_EXPERIMENTAL_CXX_SCANDEP_SOURCE
+            "${CMAKE_CXX_COMPILER_CLANG_SCAN_DEPS}"
+            " -format=p1689"
+            " --"
+            " <CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS>"
+            " -x c++ <SOURCE> -c -o <OBJECT>"
+            " -MT <DYNDEP_FILE>"
+            " -MD -MF <DEP_FILE>"
+            " > <DYNDEP_FILE>")
+            set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FORMAT "clang")
+            set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FLAG "@<MODULE_MAP_FILE>")
+
+            set(CMAKE_CXX_EXTENSIONS OFF)
+        endif()
+        if (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
+            set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
+        endif()
+    endif()
+
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+    set(MODULES_SRCS "")
+    list(APPEND MODULES_SRCS ${PROJECT_SOURCE_DIR}/modules/drogon.cppm)
+    if (NOT ${HAS_STD_MODULE})
+      list(APPEND MODULES_SRCS ${PROJECT_SOURCE_DIR}/modules/std.mock.cppm)
+    endif()
+
+    message("${MODULES_SRCS}")
+
+    target_sources(${PROJECT_NAME} PUBLIC FILE_SET CXX_MODULES FILES ${MODULES_SRCS})
+    target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_20)
+    # build modules example
+    if(${DROGON_BUILD_MODULES_EXAMPLE})
+        add_subdirectory(examples/cpp20_modules_example)
+    endif()
+endif()
+
 if (BUILD_SHARED_LIBS)
     find_package(Threads)
     # set(BUILD_EXAMPLES FALSE)
@@ -678,12 +732,20 @@ if (BUILD_TESTING)
 endif (BUILD_TESTING)
 
 # Installation
-
+if(${DROGON_BUILD_MODULES})
+install(TARGETS ${PROJECT_NAME}
+    EXPORT DrogonTargets
+    RUNTIME DESTINATION "${INSTALL_BIN_DIR}" COMPONENT bin
+    ARCHIVE DESTINATION "${INSTALL_LIB_DIR}" COMPONENT lib
+    LIBRARY FILE_SET CXX_MODULES DESTINATION "${INSTALL_LIB_DIR}" COMPONENT lib)
+else()
 install(TARGETS ${PROJECT_NAME}
     EXPORT DrogonTargets
     RUNTIME DESTINATION "${INSTALL_BIN_DIR}" COMPONENT bin
     ARCHIVE DESTINATION "${INSTALL_LIB_DIR}" COMPONENT lib
     LIBRARY DESTINATION "${INSTALL_LIB_DIR}" COMPONENT lib)
+endif()
+
 
 install(FILES ${DROGON_HEADERS} DESTINATION ${INSTALL_INCLUDE_DIR}/drogon)
 

examples/cpp20_modules_example/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.28)
+
+project(modules_example)
+
+set(CMAKE_CXX_STANDARD 20)
+
+# Default to C++ extensions being off. Clang's modules support have trouble
+# with extensions right now.
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+find_package(jsoncpp REQUIRED)
+find_package(OpenSSL REQUIRED)
+# set(CMAKE_PREFIX_PATH /root/github/drogon/build/nqf/lib/cmake/Drogon;/root/github/drogon/build/nqf/lib/cmake/Trantor)
+# find_package(Drogon REQUIRED)
+
+add_executable(module_client module_client.cpp)
+target_link_libraries(module_client drogon OpenSSL::SSL OpenSSL::Crypto uuid pthread dl)
+
+add_executable(module_std module_std.cpp)
+target_link_libraries(module_std PUBLIC drogon OpenSSL::SSL OpenSSL::Crypto uuid pthread dl)
+
+add_executable(module_server module_server.cpp)
+target_link_libraries(module_server PUBLIC drogon OpenSSL::SSL OpenSSL::Crypto uuid pthread dl)

examples/cpp20_modules_example/module_client.cpp

@@ -0,0 +1,80 @@
+import drogon;
+import std;
+
+#include <trantor/utils/Logger.h>
+
+#ifdef __linux__
+#include <sys/socket.h>
+#include <netinet/tcp.h>
+#endif
+
+using namespace drogon;
+
+int nth_resp = 0;
+
+int main()
+{
+    trantor::Logger::setLogLevel(trantor::Logger::kTrace);
+    {
+        auto client = HttpClient::newHttpClient("http://www.baidu.com");
+        client->setSockOptCallback([](int fd) {
+            std::cout << "setSockOptCallback:" << fd << std::endl;
+#ifdef __linux__
+            int optval = 10;
+            ::setsockopt(fd,
+                         SOL_TCP,
+                         TCP_KEEPCNT,
+                         &optval,
+                         static_cast<socklen_t>(sizeof optval));
+            ::setsockopt(fd,
+                         SOL_TCP,
+                         TCP_KEEPIDLE,
+                         &optval,
+                         static_cast<socklen_t>(sizeof optval));
+            ::setsockopt(fd,
+                         SOL_TCP,
+                         TCP_KEEPINTVL,
+                         &optval,
+                         static_cast<socklen_t>(sizeof optval));
+#endif
+        });
+
+        auto req = HttpRequest::newHttpRequest();
+        req->setMethod(drogon::Get);
+        req->setPath("/s");
+        req->setParameter("wd", "wx");
+        req->setParameter("oq", "wx");
+
+        for (int i = 0; i < 10; ++i)
+        {
+            client->sendRequest(
+                req, [](ReqResult result, const HttpResponsePtr &response) {
+                    if (result != ReqResult::Ok)
+                    {
+                        std::cout
+                            << "error while sending request to server! result: "
+                            << result << std::endl;
+                        return;
+                    }
+
+                    std::cout << "receive response!" << std::endl;
+                    // auto headers=response.
+                    ++nth_resp;
+                    std::cout << response->getBody() << std::endl;
+                    auto cookies = response->cookies();
+                    for (auto const &cookie : cookies)
+                    {
+                        std::cout << cookie.first << "="
+                                  << cookie.second.value()
+                                  << ":domain=" << cookie.second.domain()
+                                  << std::endl;
+                    }
+                    std::cout << "count=" << nth_resp << std::endl;
+                });
+        }
+        std::cout << "requestsBufferSize:" << client->requestsBufferSize()
+                  << std::endl;
+    }
+
+    app().run();
+}

examples/cpp20_modules_example/module_server.cpp

@@ -0,0 +1,25 @@
+import drogon;
+import std;
+
+#include <trantor/utils/Logger.h>
+
+using namespace drogon;
+
+int main()
+{
+    trantor::Logger::setLogLevel(trantor::Logger::kTrace);
+    app().registerHandler(
+        "/",
+        [](const HttpRequestPtr &request,
+           std::function<void(const HttpResponsePtr &)> &&callback) {
+            LOG_INFO << "connected:"
+                     << (request->connected() ? "true" : "false");
+            auto resp = HttpResponse::newHttpResponse();
+            resp->setBody("Hello, World!");
+            callback(resp);
+        },
+        {Get});
+
+    LOG_INFO << "Server running on 127.0.0.1:8848";
+    app().addListener("127.0.0.1", 8848).run();
+}

examples/cpp20_modules_example/module_std.cpp

@@ -0,0 +1,30 @@
+import std;
+
+int main()
+{
+    std::cout << "hello world" << std::endl;
+
+    std::vector<std::string> vec;
+    vec.emplace_back("hello world");
+    std::cout << vec.size() << std::endl;
+
+    std::unordered_map<int, int> mp;
+    mp.emplace(1, 2);
+    std::cout << mp.size() << std::endl;
+
+    auto it =
+        std::ranges::find_if(vec, [](auto &&p) { return p == "hello world"; });
+    if (it != vec.end())
+    {
+        std::cout << "found" << std::endl;
+    }
+
+    std::unordered_set<int> s;
+    s.insert(100);
+    std::cout << s.size() << std::endl;
+
+    std::shared_ptr<std::string> ptr_1;
+    std::unique_ptr<std::string> ptr_2;
+
+    return 0;
+}