Refactor code so that messages go through engines

src/stream_engine.hpp

@@ -24,7 +24,6 @@
 
 #include "fd.hpp"
 #include "i_engine.hpp"
-#include "i_msg_sink.hpp"
 #include "io_object.hpp"
 #include "i_encoder.hpp"
 #include "i_decoder.hpp"
@@ -43,12 +42,13 @@ namespace zmq
     };
 
     class io_thread_t;
+    class msg_t;
     class session_base_t;
 
     //  This engine handles any socket with SOCK_STREAM semantics,
     //  e.g. TCP socket or an UNIX domain socket.
 
-    class stream_engine_t : public io_object_t, public i_engine, public i_msg_sink
+    class stream_engine_t : public io_object_t, public i_engine
     {
     public:
 
@@ -62,9 +62,6 @@ namespace zmq
         void activate_in ();
         void activate_out ();
 
-        //  i_msg_sink interface implementation.
-        virtual int push_msg (msg_t *msg_);
-
         //  i_poll_events interface implementation.
         void in_event ();
         void out_event ();
@@ -94,11 +91,14 @@ namespace zmq
         //  peer -1 is returned.
         int read (void *data_, size_t size_);
 
+        int read_msg (msg_t *msg_);
+
+        int write_msg (msg_t *msg_);
+
         //  Underlying socket.
         fd_t s;
 
-        //  True iff we are registered with an I/O poller.
-        bool io_enabled;
+        msg_t tx_msg;
 
         handle_t handle;
 
@@ -137,6 +137,29 @@ namespace zmq
         bool plugged;
         bool terminating;
 
+        bool io_error;
+
+        //  True iff the session could not accept more
+        //  messages due to flow control.
+        bool congested;
+
+        //  True iff the engine has received identity message.
+        bool identity_received;
+
+        //  True iff the engine has sent identity message.
+        bool identity_sent;
+
+        //  True iff the engine has received all ZMTP control messages.
+        bool rx_initialized;
+
+        //  True iff the engine has sent all ZMTP control messages.
+        bool tx_initialized;
+
+        //  Indicates whether the engine is to inject a phony
+        //  subscription message into the incomming stream.
+        //  Needed to support old peers.
+        bool subscription_required;
+
         // Socket
         zmq::socket_base_t *socket;