multi-part messages work with PUB/SUB

src/sub.cpp

@@ -26,7 +26,8 @@
 
 zmq::sub_t::sub_t (class app_thread_t *parent_) :
     socket_base_t (parent_),
-    has_message (false)
+    has_message (false),
+    tbc (false)
 {
     options.requires_in = true;
     options.requires_out = false;
@@ -105,6 +106,7 @@ int zmq::sub_t::xrecv (zmq_msg_t *msg_, int flags_)
     if (has_message) {
         zmq_msg_move (msg_, &message);
         has_message = false;
+        tbc = msg_->flags & ZMQ_MSG_TBC;
         return 0;
     }
 
@@ -122,13 +124,27 @@ int zmq::sub_t::xrecv (zmq_msg_t *msg_, int flags_)
             return -1;
 
         //  Check whether the message matches at least one subscription.
-        if (match (msg_))
+        //  Non-initial parts of the message are passed 
+        if (tbc || match (msg_)) {
+            tbc = msg_->flags & ZMQ_MSG_TBC;
             return 0;
+        }
+
+        //  Message doesn't match. Pop any remaining parts of the message
+        //  from the pipe.
+        while (msg_->flags & ZMQ_MSG_TBC) {
+            rc = fq.recv (msg_, ZMQ_NOBLOCK);
+            zmq_assert (rc == 0);
+        }
     }
 }
 
 bool zmq::sub_t::xhas_in ()
 {
+    //  There are subsequent parts of the partly-read message available.
+    if (tbc)
+        return true;
+
     //  If there's already a message prepared by a previous call to zmq_poll,
     //  return straight ahead.
     if (has_message)
@@ -153,6 +169,13 @@ bool zmq::sub_t::xhas_in ()
             has_message = true;
             return true;
         }
+
+        //  Message doesn't match. Pop any remaining parts of the message
+        //  from the pipe.
+        while (message.flags & ZMQ_MSG_TBC) {
+            rc = fq.recv (&message, ZMQ_NOBLOCK);
+            zmq_assert (rc == 0);
+        }
     }
 }