Problem: complexity of start_connecting

Solution: extract functions for each protocol

src/session_base.cpp

@@ -550,6 +550,51 @@ void zmq::session_base_t::reconnect ()
         _pipe->hiccup ();
 }
 
+zmq::session_base_t::connecter_factory_entry_t
+  zmq::session_base_t::_connecter_factories[] = {
+    std::make_pair (protocol_name::tcp,
+                    &zmq::session_base_t::create_connecter_tcp),
+#if !defined ZMQ_HAVE_WINDOWS && !defined ZMQ_HAVE_OPENVMS                     \
+  && !defined ZMQ_HAVE_VXWORKS
+    std::make_pair (protocol_name::ipc,
+                    &zmq::session_base_t::create_connecter_ipc),
+#endif
+#if defined ZMQ_HAVE_TIPC
+    std::make_pair (protocol_name::tipc,
+                    &zmq::session_base_t::create_connecter_tipc),
+#endif
+#if defined ZMQ_HAVE_VMCI
+    std::make_pair (protocol_name::vmci,
+                    &zmq::session_base_t::create_connecter_vmci),
+#endif
+};
+
+zmq::session_base_t::connecter_factory_map_t
+  zmq::session_base_t::_connecter_factories_map (
+    _connecter_factories,
+    _connecter_factories
+      + sizeof (_connecter_factories) / sizeof (_connecter_factories[0]));
+
+zmq::session_base_t::start_connecting_entry_t
+  zmq::session_base_t::_start_connecting_entries[] = {
+    std::make_pair (protocol_name::udp,
+                    &zmq::session_base_t::start_connecting_udp),
+#if defined ZMQ_HAVE_OPENPGM
+    std::make_pair ("pgm", &zmq::session_base_t::start_connecting_pgm),
+    std::make_pair ("epgm", &zmq::session_base_t::start_connecting_pgm),
+#endif
+#if defined ZMQ_HAVE_NORM
+    std::make_pair ("norm", &zmq::session_base_t::start_connecting_norm),
+#endif
+};
+
+zmq::session_base_t::start_connecting_map_t
+  zmq::session_base_t::_start_connecting_map (
+    _start_connecting_entries,
+    _start_connecting_entries
+      + sizeof (_start_connecting_entries)
+          / sizeof (_start_connecting_entries[0]));
+
 void zmq::session_base_t::start_connecting (bool wait_)
 {
     zmq_assert (_active);
@@ -560,78 +605,71 @@ void zmq::session_base_t::start_connecting (bool wait_)
     zmq_assert (io_thread);
 
     //  Create the connecter object.
-    own_t *connecter = NULL;
-    if (_addr->protocol == protocol_name::tcp) {
-        if (!options.socks_proxy_address.empty ()) {
-            address_t *proxy_address = new (std::nothrow)
-              address_t (protocol_name::tcp, options.socks_proxy_address,
-                         this->get_ctx ());
-            alloc_assert (proxy_address);
-            connecter = new (std::nothrow) socks_connecter_t (
-              io_thread, this, options, _addr, proxy_address, wait_);
-        } else {
-            connecter = new (std::nothrow)
-              tcp_connecter_t (io_thread, this, options, _addr, wait_);
-        }
-    }
-#if !defined ZMQ_HAVE_WINDOWS && !defined ZMQ_HAVE_OPENVMS                     \
-  && !defined ZMQ_HAVE_VXWORKS
-    else if (_addr->protocol == protocol_name::ipc) {
-        connecter = new (std::nothrow)
-          ipc_connecter_t (io_thread, this, options, _addr, wait_);
-    }
-#endif
-#if defined ZMQ_HAVE_TIPC
-    else if (_addr->protocol == protocol_name::tipc) {
-        connecter = new (std::nothrow)
-          tipc_connecter_t (io_thread, this, options, _addr, wait_);
-    }
-#endif
-#if defined ZMQ_HAVE_VMCI
-    else if (_addr->protocol == protocol_name::vmci) {
-        connecter = new (std::nothrow)
-          vmci_connecter_t (io_thread, this, options, _addr, wait_);
-    }
-#endif
-    if (connecter != NULL) {
+    const connecter_factory_map_t::const_iterator connecter_factories_it =
+      _connecter_factories_map.find (_addr->protocol);
+    if (connecter_factories_it != _connecter_factories_map.end ()) {
+        own_t *connecter =
+          (this->*connecter_factories_it->second) (io_thread, wait_);
+
         alloc_assert (connecter);
         launch_child (connecter);
         return;
     }
+    const start_connecting_map_t::const_iterator start_connecting_it =
+      _start_connecting_map.find (_addr->protocol);
+    if (start_connecting_it != _start_connecting_map.end ()) {
+        (this->*start_connecting_it->second) (io_thread);
+        return;
+    }
 
-    if (_addr->protocol == protocol_name::udp) {
-        zmq_assert (options.type == ZMQ_DISH || options.type == ZMQ_RADIO
-                    || options.type == ZMQ_DGRAM);
-
-        udp_engine_t *engine = new (std::nothrow) udp_engine_t (options);
-        alloc_assert (engine);
-
-        bool recv = false;
-        bool send = false;
+    zmq_assert (false);
+}
 
-        if (options.type == ZMQ_RADIO) {
-            send = true;
-            recv = false;
-        } else if (options.type == ZMQ_DISH) {
-            send = false;
-            recv = true;
-        } else if (options.type == ZMQ_DGRAM) {
-            send = true;
-            recv = true;
-        }
+#if defined ZMQ_HAVE_VMCI
+zmq::own_t *zmq::session_base_t::create_connecter_vmci (io_thread_t *io_thread_,
+                                                        bool wait_)
+{
+    return new (std::nothrow)
+      vmci_connecter_t (io_thread_, this, options, _addr, wait_);
+}
+#endif
 
-        int rc = engine->init (_addr, send, recv);
-        errno_assert (rc == 0);
+#if defined ZMQ_HAVE_TIPC
+zmq::own_t *zmq::session_base_t::create_connecter_tipc (io_thread_t *io_thread_,
+                                                        bool wait_)
+{
+    return new (std::nothrow)
+      tipc_connecter_t (io_thread_, this, options, _addr, wait_);
+}
+#endif
 
-        send_attach (this, engine);
+#if !defined ZMQ_HAVE_WINDOWS && !defined ZMQ_HAVE_OPENVMS                     \
+  && !defined ZMQ_HAVE_VXWORKS
+zmq::own_t *zmq::session_base_t::create_connecter_ipc (io_thread_t *io_thread_,
+                                                       bool wait_)
+{
+    return new (std::nothrow)
+      ipc_connecter_t (io_thread_, this, options, _addr, wait_);
+}
+#endif
 
-        return;
+zmq::own_t *zmq::session_base_t::create_connecter_tcp (io_thread_t *io_thread_,
+                                                       bool wait_)
+{
+    if (!options.socks_proxy_address.empty ()) {
+        address_t *proxy_address = new (std::nothrow) address_t (
+          protocol_name::tcp, options.socks_proxy_address, this->get_ctx ());
+        alloc_assert (proxy_address);
+        return new (std::nothrow) socks_connecter_t (
+          io_thread_, this, options, _addr, proxy_address, wait_);
     }
+    return new (std::nothrow)
+      tcp_connecter_t (io_thread_, this, options, _addr, wait_);
+}
 
 #ifdef ZMQ_HAVE_OPENPGM
-
-    //  Both PGM and EPGM transports are using the same infrastructure.
-    if (_addr->protocol == "pgm" || _addr->protocol == "epgm") {
+void zmq::session_base_t::start_connecting_pgm (io_thread_t *io_thread_)
+{
     zmq_assert (options.type == ZMQ_PUB || options.type == ZMQ_XPUB
                 || options.type == ZMQ_SUB || options.type == ZMQ_XSUB);
 
@@ -644,18 +682,17 @@ void zmq::session_base_t::start_connecting (bool wait_)
     if (options.type == ZMQ_PUB || options.type == ZMQ_XPUB) {
         //  PGM sender.
         pgm_sender_t *pgm_sender =
-              new (std::nothrow) pgm_sender_t (io_thread, options);
+          new (std::nothrow) pgm_sender_t (io_thread_, options);
         alloc_assert (pgm_sender);
 
-            int rc =
-              pgm_sender->init (udp_encapsulation, _addr->address.c_str ());
+        int rc = pgm_sender->init (udp_encapsulation, _addr->address.c_str ());
         errno_assert (rc == 0);
 
         send_attach (this, pgm_sender);
     } else {
         //  PGM receiver.
         pgm_receiver_t *pgm_receiver =
-              new (std::nothrow) pgm_receiver_t (io_thread, options);
+          new (std::nothrow) pgm_receiver_t (io_thread_, options);
         alloc_assert (pgm_receiver);
 
         int rc =
@@ -664,20 +701,19 @@ void zmq::session_base_t::start_connecting (bool wait_)
 
         send_attach (this, pgm_receiver);
     }
-
-        return;
-    }
+}
 #endif
 
 #ifdef ZMQ_HAVE_NORM
-    if (_addr->protocol == "norm") {
+void zmq::session_base_t::start_connecting_norm (io_thread_t *io_thread_)
+{
     //  At this point we'll create message pipes to the session straight
     //  away. There's no point in delaying it as no concept of 'connect'
     //  exists with NORM anyway.
     if (options.type == ZMQ_PUB || options.type == ZMQ_XPUB) {
         //  NORM sender.
         norm_engine_t *norm_sender =
-              new (std::nothrow) norm_engine_t (io_thread, options);
+          new (std::nothrow) norm_engine_t (io_thread_, options);
         alloc_assert (norm_sender);
 
         int rc = norm_sender->init (_addr->address.c_str (), true, false);
@@ -688,7 +724,7 @@ void zmq::session_base_t::start_connecting (bool wait_)
 
         //  NORM receiver.
         norm_engine_t *norm_receiver =
-              new (std::nothrow) norm_engine_t (io_thread, options);
+          new (std::nothrow) norm_engine_t (io_thread_, options);
         alloc_assert (norm_receiver);
 
         int rc = norm_receiver->init (_addr->address.c_str (), false, true);
@@ -696,9 +732,33 @@ void zmq::session_base_t::start_connecting (bool wait_)
 
         send_attach (this, norm_receiver);
     }
-        return;
+}
+#endif
+
+void zmq::session_base_t::start_connecting_udp (io_thread_t * /*io_thread_*/)
+{
+    zmq_assert (options.type == ZMQ_DISH || options.type == ZMQ_RADIO
+                || options.type == ZMQ_DGRAM);
+
+    udp_engine_t *engine = new (std::nothrow) udp_engine_t (options);
+    alloc_assert (engine);
+
+    bool recv = false;
+    bool send = false;
+
+    if (options.type == ZMQ_RADIO) {
+        send = true;
+        recv = false;
+    } else if (options.type == ZMQ_DISH) {
+        send = false;
+        recv = true;
+    } else if (options.type == ZMQ_DGRAM) {
+        send = true;
+        recv = true;
     }
-#endif // ZMQ_HAVE_NORM
 
-    zmq_assert (false);
+    const int rc = engine->init (_addr, send, recv);
+    errno_assert (rc == 0);
+
+    send_attach (this, engine);
 }

src/session_base.hpp

@@ -105,6 +105,33 @@ class session_base_t : public own_t, public io_object_t, public i_pipe_events
   private:
     void start_connecting (bool wait_);
 
+    typedef own_t *(session_base_t::*connecter_factory_fun_t) (
+      io_thread_t *io_thread, bool wait_);
+    typedef std::pair<std::string, connecter_factory_fun_t>
+      connecter_factory_entry_t;
+    static connecter_factory_entry_t _connecter_factories[];
+    typedef std::map<std::string, connecter_factory_fun_t>
+      connecter_factory_map_t;
+    static connecter_factory_map_t _connecter_factories_map;
+
+    own_t *create_connecter_vmci (io_thread_t *io_thread_, bool wait_);
+    own_t *create_connecter_tipc (io_thread_t *io_thread_, bool wait_);
+    own_t *create_connecter_ipc (io_thread_t *io_thread_, bool wait_);
+    own_t *create_connecter_tcp (io_thread_t *io_thread_, bool wait_);
+
+    typedef void (session_base_t::*start_connecting_fun_t) (
+      io_thread_t *io_thread);
+    typedef std::pair<std::string, start_connecting_fun_t>
+      start_connecting_entry_t;
+    static start_connecting_entry_t _start_connecting_entries[];
+    typedef std::map<std::string, start_connecting_fun_t>
+      start_connecting_map_t;
+    static start_connecting_map_t _start_connecting_map;
+
+    void start_connecting_pgm (io_thread_t *io_thread_);
+    void start_connecting_norm (io_thread_t *io_thread_);
+    void start_connecting_udp (io_thread_t *io_thread_);
+
     void reconnect ();
 
     //  Handlers for incoming commands.