...

include/snipplib/network/snplib_network.h

@@ -1,7 +1,9 @@
 #pragma once
 
 #include <set>
+
 #include "../concepts/snplib_concepts.h"
+#include "../utils/snplib_logger.h"
 
 namespace snplib
 {
@@ -53,18 +55,26 @@ concept snplib_net_connection_c = requires(T t) {
 
 
 template <typename T>
-concept snplib_net_session_c = std::derived_from<T, std::enable_shared_from_this<T>> && requires(T t) {
-    // static constexpr member
-    std::formattable<decltype(T::id), char>;
-    []() { [[maybe_unused]] static constexpr auto val = T::id; }();
+concept snplib_net_session_c =
+    std::derived_from<T, std::enable_shared_from_this<T>> &&
+    requires(T t, const T t_const) {
+        typename T::ident_t;
+        typename T::context_t;
 
-    snplib_net_connection_c<typename T::connection_t>;
+        snplib_net_connection_c<typename T::connection_t>;
 
-    // { t.startSession(std::declval<typename T::connection_t>()) } -> snplib_async_retval_c;
-    t.startSession(std::declval<typename T::connection_t>());
+        { t_const.ident() } -> std::same_as<typename T::ident_t>;
 
-    t.stopSession();
-};
+        // { t.startSession(std::declval<typename T::connection_t>()) } -> snplib_async_retval_c;
+        t.startSession(std::declval<typename T::connection_t>());
+
+        t.stopSession();
+    } && (!std::is_void_v<typename T::context_t> || std::constructible_from<T, typename T::ident_t>) &&
+    (std::is_void_v<typename T::context_t> ||
+     (std::constructible_from<T, typename T::ident_t, typename T::context_t> ||
+      std::constructible_from<T, typename T::ident_t, typename T::context_t&>));  // can be constructible from value or
+                                                                                  // lvalue-reference or const
+                                                                                  // lvalue-reference of context_t-type
 
 
 template <typename T>
@@ -83,6 +93,45 @@ concept snplib_net_listener_c = requires(T t) {
 };
 
 
+// a type that defines at least two compile-time constants:
+//     ROLE_SERVER and ROLE_CLIENT
+template <typename T>
+concept snplib_net_initiator_role_c = requires {
+    []() {
+        [[maybe_unused]] static constexpr std::array arr{// server role (listener of connections)
+                                                         T::ROLE_SERVER,
+                                                         // cleant role (opener of connections)
+                                                         T::ROLE_CLIENT};
+    }();
+};
+
+// default library-wide type of network connection initiator role
+enum class snplib_net_initiator_role_e : int { ROLE_SERVER, ROLE_CLIENT };
+
+
+template <typename T>
+concept snplib_net_initiator_c =
+    requires(T t) {
+        // common part
+        requires snplib_net_initiator_role_c<decltype(T::ROLE)>;
+        []() { [[maybe_unused]] static constexpr auto val = T::ROLE; }();
+
+        snplib_net_connection_c<typename T::connection_t>;
+    } && ((T::ROLE != decltype(T::ROLE)::ROLE_SERVER) || requires(T t) {  // use of short-circuiting logic!!!
+        // server-role
+        { t.accept() } -> snplib_async_retval_c<typename T::connection_t>;
+
+        { t.startListen() } -> snplib_error_c;
+
+        t.stopListen();
+    }) && ((T::ROLE != decltype(T::ROLE)::ROLE_CLIENT) || requires(T t) {  // use of short-circuiting logic!!!
+        // client-role
+        { t.open() } -> snplib_async_retval_c<typename T::connection_t>;
+        t.close();
+    });
+
+
+
 template <typename T>
 concept snplib_netserver_c = requires(T t) {
     // static constexpr member
@@ -104,17 +153,118 @@ concept snplib_netserver_c = requires(T t) {
 };
 
 
+template <typename T, typename SessionT>
+concept snplib_session_manager_c =
+    requires(T t, SessionT::context_t cnx) {
+        requires snplib_net_session_c<SessionT>;
+
+        typename T::session_ptr_t;  // e.g. std::shared_ptr<SessionT>
+
+        // must be a non-blocking method!
+        t.startSession(std::declval<typename T::session_ptr_t>());
+
+        t.stopSession(std::declval<typename T::session_ptr_t>());
+
+        // must return number of stopped sessions
+        { t.stopSessions() } -> std::convertible_to<size_t>;
+
+        // true - if session exists
+        { t.isActive(std::declval<typename T::session_ptr_t>()) } -> std::convertible_to<bool>;
+    } && (!std::is_void_v<typename SessionT::context_t> || requires(T t) {
+        { t.createSession() } -> std::same_as<typename T::session_ptr_t>;
+    }) && (std::is_void_v<typename SessionT::context_t> || requires(T t, SessionT::context_t cnx) {
+        { t.createSession(cnx) } -> std::same_as<typename T::session_ptr_t>;
+    });
+;
+
 
 /*                          SINGLE-PROTO*/
 
-template <snplib_net_listener_c ListenerT, snplib_net_session_c SessionT>
+template <snplib_net_session_c SessionT>
+class snplib_session_manager_t
+{
+public:
+    typedef std::shared_ptr<SessionT> session_ptr_t;
+
+    session_ptr_t createSession(typename SessionT::context_t ctx)
+    {
+        std::lock_guard lock(_setMutex);
+
+        auto sptr = std::make_shared<SessionT>(ctx);
+        _sessions.insert(sptr);
+
+        return sptr;
+    }
+
+    //
+    // delegates an implementation to the derived class
+    //
+    template <std::derived_from<snplib_session_manager_t> SelfT>
+    auto startSession(this SelfT&& self, session_ptr_t ptr)
+    {
+        std::lock_guard lock(self._setMutex);
+
+        return std::forward<SelfT>(self)(std::move(ptr));
+    }
+
+    bool stopSession(session_ptr_t ptr)
+    {
+        std::lock_guard lock(_setMutex);
+
+        if (auto it = _sessions.find(ptr); it != _sessions.end()) {
+            if (auto sptr = it->lock()) {  // it is safe in multi-threaded environment!
+                sptr->stopSession();
+            }  // session pointer expired here
+        } else {
+            return false;
+        }
+
+        return true;
+    }
+
+    size_t stopSessions()
+    {
+        std::lock_guard lock(_setMutex);
+
+        size_t N = 0;
+        for (auto sess : _sessions) {
+            if (stopSession(sess)) {
+                ++N;
+            }
+        }
+
+        return N;
+    }
+
+protected:
+    std::unique_ptr<std::recursive_mutex> _setMutex{new std::recursive_mutex};
+    std::set<std::weak_ptr<SessionT>, std::owner_less<std::weak_ptr<SessionT>>> _sessions{};
+};
+
+
+
+template <snplib_net_listener_c ListenerT,
+          snplib_net_session_c SessionT,
+          snplib_session_manager_c<SessionT> SessManagerT,
+          snplib_logger_c LoggerT>
     requires std::same_as<typename ListenerT::connection_t, typename SessionT::connection_t>
-class snplib_generic_netserver_t
+class snplib_generic_netserver_t : protected SessManagerT, public LoggerT
 {
 public:
     // typedef std::error_code error_t;
 
-    snplib_generic_netserver_t(std::unique_ptr<ListenerT> listener) : _listener(std::move(listener)) {}
+    using LoggerT::logDebug;
+    using LoggerT::logError;
+    using LoggerT::logInfo;
+    using LoggerT::logTrace;
+    using LoggerT::logWarn;
+
+    template <typename... SessManagerCtorArgTs, typename... LoggerCtorArgTs>
+    snplib_generic_netserver_t(std::unique_ptr<ListenerT> listener) : _listener(std::move(listener))
+    {
+    }
+
+    virtual ~snplib_generic_netserver_t() = default;
 
     auto startServer()
     {