Change XSUB -> XPUB multipart message processing.

Now only the first part in a multipart message will be treated as subscribe/unsubscribe.
The rest will be considered user messages regardless of the first byte.

src/xpub.cpp

@@ -41,7 +41,8 @@ zmq::xpub_t::xpub_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_),
     _verbose_subs (false),
     _verbose_unsubs (false),
-    _more (false),
+    _more_send (false),
+    _more_recv (false),
     _lossy (true),
     _manual (false),
     _send_last_pipe (false),
@@ -91,31 +92,40 @@ void zmq::xpub_t::xattach_pipe (pipe_t *pipe_,
 void zmq::xpub_t::xread_activated (pipe_t *pipe_)
 {
     //  There are some subscriptions waiting. Let's process them.
-    msg_t sub;
-    while (pipe_->read (&sub)) {
-        metadata_t *metadata = sub.metadata ();
-        unsigned char *msg_data = static_cast<unsigned char *> (sub.data ()),
+    msg_t msg;
+    while (pipe_->read (&msg)) {
+        metadata_t *metadata = msg.metadata ();
+        unsigned char *msg_data = static_cast<unsigned char *> (msg.data ()),
                       *data = NULL;
         size_t size = 0;
         bool subscribe = false;
+        bool is_subscribe_or_cancel = false;
 
-        //  Apply the subscription to the trie
-        if (sub.is_subscribe () || sub.is_cancel ()) {
-            data = static_cast<unsigned char *> (sub.command_body ());
-            size = sub.command_body_size ();
-            subscribe = sub.is_subscribe ();
-        } else if (sub.size () > 0 && (*msg_data == 0 || *msg_data == 1)) {
-            data = msg_data + 1;
-            size = sub.size () - 1;
-            subscribe = *msg_data == 1;
-        } else {
+        if (!_more_recv) {
+            //  Apply the subscription to the trie
+            if (msg.is_subscribe () || msg.is_cancel ()) {
+                data = static_cast<unsigned char *> (msg.command_body ());
+                size = msg.command_body_size ();
+                subscribe = msg.is_subscribe ();
+                is_subscribe_or_cancel = true;
+            } else if (msg.size () > 0 && (*msg_data == 0 || *msg_data == 1)) {
+                data = msg_data + 1;
+                size = msg.size () - 1;
+                subscribe = *msg_data == 1;
+                is_subscribe_or_cancel = true;
+            }
+        }
+
+        _more_recv = (msg.flags () & msg_t::more) != 0;
+
+        if (!is_subscribe_or_cancel) {
             //  Process user message coming upstream from xsub socket
-            _pending_data.push_back (blob_t (msg_data, sub.size ()));
+            _pending_data.push_back (blob_t (msg_data, msg.size ()));
             if (metadata)
                 metadata->add_ref ();
             _pending_metadata.push_back (metadata);
-            _pending_flags.push_back (sub.flags ());
-            sub.close ();
+            _pending_flags.push_back (msg.flags ());
+            msg.close ();
             continue;
         }
 
@@ -174,7 +184,7 @@ void zmq::xpub_t::xread_activated (pipe_t *pipe_)
                 _pending_flags.push_back (0);
             }
         }
-        sub.close ();
+        msg.close ();
     }
 }
 
@@ -278,7 +288,7 @@ int zmq::xpub_t::xsend (msg_t *msg_)
     bool msg_more = (msg_->flags () & msg_t::more) != 0;
 
     //  For the first part of multi-part message, find the matching pipes.
-    if (!_more) {
+    if (!_more_send) {
         if (unlikely (_manual && _last_pipe && _send_last_pipe)) {
             _subscriptions.match (static_cast<unsigned char *> (msg_->data ()),
                                   msg_->size (), mark_last_pipe_as_matching,
@@ -300,7 +310,7 @@ int zmq::xpub_t::xsend (msg_t *msg_)
             //  all the pipes as non-matching.
             if (!msg_more)
                 _dist.unmatch ();
-            _more = msg_more;
+            _more_send = msg_more;
             rc = 0; //  Yay, sent successfully
         }
     } else

src/xpub.hpp

@@ -91,7 +91,10 @@ class xpub_t : public socket_base_t
     bool _verbose_unsubs;
 
     //  True if we are in the middle of sending a multi-part message.
-    bool _more;
+    bool _more_send;
+
+    //  True if we are in the middle of receiving a multi-part message.
+    bool _more_recv;
 
     //  Drop messages if HWM reached, otherwise return with EAGAIN
     bool _lossy;

src/xsub.cpp

@@ -37,7 +37,8 @@
 zmq::xsub_t::xsub_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_),
     _has_message (false),
-    _more (false)
+    _more_send (false),
+    _more_recv (false)
 {
     options.type = ZMQ_XSUB;
 
@@ -99,6 +100,13 @@ int zmq::xsub_t::xsend (msg_t *msg_)
     size_t size = msg_->size ();
     unsigned char *data = static_cast<unsigned char *> (msg_->data ());
 
+    bool send_more = _more_send;
+    _more_send = (msg_->flags () & msg_t::more) != 0;
+
+    if (send_more)
+        //  User message sent upstream to XPUB socket
+        return _dist.send_to_all (msg_);
+
     if (msg_->is_subscribe () || (size > 0 && *data == 1)) {
         //  Process subscribe message
         //  This used to filter out duplicate subscriptions,
@@ -152,7 +160,7 @@ int zmq::xsub_t::xrecv (msg_t *msg_)
         int rc = msg_->move (_message);
         errno_assert (rc == 0);
         _has_message = false;
-        _more = (msg_->flags () & msg_t::more) != 0;
+        _more_recv = (msg_->flags () & msg_t::more) != 0;
         return 0;
     }
 
@@ -170,8 +178,8 @@ int zmq::xsub_t::xrecv (msg_t *msg_)
 
         //  Check whether the message matches at least one subscription.
         //  Non-initial parts of the message are passed
-        if (_more || !options.filter || match (msg_)) {
-            _more = (msg_->flags () & msg_t::more) != 0;
+        if (_more_recv || !options.filter || match (msg_)) {
+            _more_recv = (msg_->flags () & msg_t::more) != 0;
             return 0;
         }
 
@@ -187,7 +195,7 @@ int zmq::xsub_t::xrecv (msg_t *msg_)
 bool zmq::xsub_t::xhas_in ()
 {
     //  There are subsequent parts of the partly-read message available.
-    if (_more)
+    if (_more_recv)
         return true;
 
     //  If there's already a message prepared by a previous call to zmq_poll,

src/xsub.hpp

@@ -93,9 +93,13 @@ class xsub_t : public socket_base_t
     bool _has_message;
     msg_t _message;
 
+    //  If true, part of a multipart message was already sent, but
+    //  there are following parts still waiting.
+    bool _more_send;
+
     //  If true, part of a multipart message was already received, but
     //  there are following parts still waiting.
-    bool _more;
+    bool _more_recv;
 
     xsub_t (const xsub_t &);
     const xsub_t &operator= (const xsub_t &);

tests/test_xpub_manual.cpp

@@ -456,6 +456,58 @@ void test_user_message ()
     test_context_socket_close (sub);
 }
 
+void test_user_message_multi ()
+{
+    //  Create a publisher
+    void *pub = test_context_socket (ZMQ_XPUB);
+    TEST_ASSERT_SUCCESS_ERRNO (zmq_bind (pub, "inproc://soname"));
+
+    //  Create a subscriber
+    void *sub = test_context_socket (ZMQ_XSUB);
+    TEST_ASSERT_SUCCESS_ERRNO (zmq_connect (sub, "inproc://soname"));
+
+    //  Send some data that is neither sub nor unsub
+    const uint8_t msg_common[] = {'A', 'B', 'C'};
+    //  Message starts with 0 but should still treated as user
+    const uint8_t msg_0[] = {0, 'B', 'C'};
+    //  Message starts with 1 but should still treated as user
+    const uint8_t msg_1[] = {1, 'B', 'C'};
+
+    // Test second message starting with 0
+    send_array_expect_success (sub, msg_common, ZMQ_SNDMORE);
+    send_array_expect_success (sub, msg_0, 0);
+
+    // Receive messages from subscriber
+    recv_array_expect_success (pub, msg_common, 0);
+    recv_array_expect_success (pub, msg_0, 0);
+
+    // Test second message starting with 1
+    send_array_expect_success (sub, msg_common, ZMQ_SNDMORE);
+    send_array_expect_success (sub, msg_1, 0);
+
+    // Receive messages from subscriber
+    recv_array_expect_success (pub, msg_common, 0);
+    recv_array_expect_success (pub, msg_1, 0);
+
+    char buffer[255];
+    // Test first message starting with 0
+    send_array_expect_success (sub, msg_0, 0);
+
+    // wait
+    msleep (SETTLE_TIME);
+
+    int rc = zmq_recv (pub, buffer, sizeof (buffer), ZMQ_DONTWAIT);
+    TEST_ASSERT_EQUAL_INT (-1, rc);
+
+    // Test first message starting with 1
+    send_array_expect_success (sub, msg_1, 0);
+    recv_array_expect_success (pub, msg_1, 0);
+
+    //  Clean up.
+    test_context_socket_close (pub);
+    test_context_socket_close (sub);
+}
+
 int main ()
 {
     setup_test_environment ();
@@ -467,6 +519,7 @@ int main ()
     RUN_TEST (test_missing_subscriptions);
     RUN_TEST (test_unsubscribe_cleanup);
     RUN_TEST (test_user_message);
+    RUN_TEST (test_user_message_multi);
 
     return UNITY_END ();
 }