radio-dish join/leave are ZMTP commands

src/dish.cpp

@@ -90,13 +90,15 @@ void zmq::dish_t::xhiccuped (pipe_t *pipe_)
 
 int zmq::dish_t::xjoin (const char* group_)
 {
-    if (strlen (group_) > ZMQ_GROUP_MAX_LENGTH) {
+    std::string group = std::string (group_);
+
+    if (group.length () > ZMQ_GROUP_MAX_LENGTH) {
         errno = EINVAL;
         return -1;
     }
 
     subscriptions_t::iterator it =
-        std::find (subscriptions.begin (), subscriptions.end (), std::string(group_));
+        std::find (subscriptions.begin (), subscriptions.end (), group);
 
     //  User cannot join same group twice
     if (it != subscriptions.end ()) {
@@ -104,16 +106,14 @@ int zmq::dish_t::xjoin (const char* group_)
         return -1;
     }
 
-    subscriptions.push_back (std::string (group_));
+    subscriptions.push_back (group);
 
-    size_t len = strlen (group_);
     msg_t msg;
-    int rc = msg.init_size (len + 1);
+    int rc = msg.init_join ();
     errno_assert (rc == 0);
 
-    char *data = (char*) msg.data ();
-    data[0] = 'J';
-    memcpy (data + 1, group_, len);
+    rc = msg.set_group (group_);
+    errno_assert (rc == 0);
 
     int err = 0;
     rc = dist.send_to_all (&msg);
@@ -128,12 +128,14 @@ int zmq::dish_t::xjoin (const char* group_)
 
 int zmq::dish_t::xleave (const char* group_)
 {
-    if (strlen (group_) > ZMQ_GROUP_MAX_LENGTH) {
+    std::string group = std::string (group_);
+
+    if (group.length () > ZMQ_GROUP_MAX_LENGTH) {
         errno = EINVAL;
         return -1;
     }
 
-    subscriptions_t::iterator it =  std::find (subscriptions.begin (), subscriptions.end (), std::string (group_));
+    subscriptions_t::iterator it =  std::find (subscriptions.begin (), subscriptions.end (), group);
 
     if (it == subscriptions.end ()) {
         errno = EINVAL;
@@ -142,14 +144,12 @@ int zmq::dish_t::xleave (const char* group_)
 
     subscriptions.erase (it);
 
-    size_t len = strlen (group_);
     msg_t msg;
-    int rc = msg.init_size (len + 1);
+    int rc = msg.init_leave ();
     errno_assert (rc == 0);
 
-    char *data = (char*) msg.data ();
-    data[0] = 'L';
-    memcpy (data + 1, group_, len);
+    rc = msg.set_group (group_);
+    errno_assert (rc == 0);
 
     int err = 0;
     rc = dist.send_to_all (&msg);
@@ -226,20 +226,14 @@ void zmq::dish_t::send_subscriptions (pipe_t *pipe_)
 {
     for (subscriptions_t::iterator it = subscriptions.begin (); it != subscriptions.end (); ++it) {
         msg_t msg;
-        int rc = msg.init_size (it->length () + 1);
+        int rc = msg.init_join ();
+        errno_assert (rc == 0);
+
+        rc = msg.set_group (it->c_str());
         errno_assert (rc == 0);
-        char *data = (char*) msg.data ();
-        data [0] = 'J';
-        it->copy (data + 1, it->length ());
 
         //  Send it to the pipe.
-        bool sent = pipe_->write (&msg);
-
-        //  If we reached the SNDHWM, and thus cannot send the subscription, drop
-        //  the subscription message instead. This matches the behaviour of
-        //  zmq_setsockopt(ZMQ_SUBSCRIBE, ...), which also drops subscriptions
-        //  when the SNDHWM is reached.
-        if (!sent)
+        pipe_->write (&msg);
         msg.close ();
     }
 
@@ -303,6 +297,48 @@ int zmq::dish_session_t::push_msg (msg_t *msg_)
     }
 }
 
+int zmq::dish_session_t::pull_msg (msg_t *msg_)
+{
+    int rc = session_base_t::pull_msg (msg_);
+
+    if (rc != 0)
+        return rc;
+
+    if (!msg_->is_join () && !msg_->is_leave ())
+        return rc;
+    else {
+        int group_length = strlen (msg_->group ());
+
+        msg_t command;
+        int offset;
+
+        if (msg_->is_join ()) {
+            command.init_size (group_length + 5);
+            offset = 5;
+            memcpy (command.data (), "\4JOIN", 5);
+        }
+        else {
+            command.init_size (group_length + 6);
+            offset = 6;
+            memcpy (command.data (), "\5LEAVE", 6);
+        }
+
+        command.set_flags (msg_t::command);
+        char* command_data = (char*)command.data ();
+
+        //  Copy the group
+        memcpy (command_data + offset, msg_->group (), group_length);
+
+        //  Close the join message
+        int rc = msg_->close ();
+        errno_assert (rc == 0);
+
+        *msg_ = command;
+
+        return 0;
+    }
+}
+
 void zmq::dish_session_t::reset ()
 {
     session_base_t::reset ();

src/dish.hpp

@@ -104,6 +104,7 @@ namespace zmq
 
         //  Overrides of the functions from session_base_t.
         int push_msg (msg_t *msg_);
+        int pull_msg (msg_t *msg_);
         void reset ();
 
     private:

src/msg.cpp

@@ -200,6 +200,28 @@ int zmq::msg_t::init_delimiter ()
     return 0;
 }
 
+int zmq::msg_t::init_join ()
+{
+    u.base.metadata = NULL;
+    u.base.type = type_join;
+    u.base.flags = 0;
+    u.base.group[0] = '\0';
+    u.base.routing_id = 0;
+    u.base.fd = retired_fd;
+    return 0;
+}
+
+int zmq::msg_t::init_leave ()
+{
+    u.base.metadata = NULL;
+    u.base.type = type_leave;
+    u.base.flags = 0;
+    u.base.group[0] = '\0';
+    u.base.routing_id = 0;
+    u.base.fd = retired_fd;
+    return 0;
+}
+
 int zmq::msg_t::close ()
 {
     //  Check the validity of the message.
@@ -440,6 +462,16 @@ bool zmq::msg_t::is_zcmsg() const
     return u.base.type == type_zclmsg;
 }
 
+bool zmq::msg_t::is_join() const
+{
+    return u.base.type == type_join;
+}
+
+bool zmq::msg_t::is_leave() const
+{
+    return u.base.type == type_leave;
+}
+
 void zmq::msg_t::add_refs (int refs_)
 {
     zmq_assert (refs_ >= 0);

src/msg.hpp

@@ -95,6 +95,8 @@ namespace zmq
         int init_external_storage(content_t* content_, void *data_, size_t size_,
                                   msg_free_fn *ffn_, void *hint_);
         int init_delimiter ();
+        int init_join ();
+        int init_leave ();
         int close ();
         int move (msg_t &src_);
         int copy (msg_t &src_);
@@ -111,6 +113,8 @@ namespace zmq
         bool is_identity () const;
         bool is_credential () const;
         bool is_delimiter () const;
+        bool is_join () const;
+        bool is_leave () const;
         bool is_vsm () const;
         bool is_cmsg () const;
         bool is_zcmsg() const;
@@ -137,7 +141,6 @@ namespace zmq
                                             16 +
                                             sizeof (uint32_t) +
                                             sizeof (fd_t))};
-
     private:
         zmq::atomic_counter_t* refcnt();
 
@@ -157,7 +160,13 @@ namespace zmq
             // zero-copy LMSG message for v2_decoder
             type_zclmsg = 105,
 
-            type_max = 105
+            //  Join message for radio_dish
+            type_join = 106,
+
+            //  Leave message for radio_dish
+            type_leave = 107,
+
+            type_max = 107
         };
 
         //  Note that fields shared between different message types are not

src/radio.cpp

@@ -65,15 +65,13 @@ void zmq::radio_t::xattach_pipe (pipe_t *pipe_, bool subscribe_to_all_)
 void zmq::radio_t::xread_activated (pipe_t *pipe_)
 {
     //  There are some subscriptions waiting. Let's process them.
-    msg_t sub;
-    while (pipe_->read (&sub)) {
+    msg_t msg;
+    while (pipe_->read (&msg)) {
         //  Apply the subscription to the trie
-        const char * data = (char *) sub.data ();
-        const size_t size = sub.size ();
-        if (size > 0 && (*data == 'J' || *data == 'L')) {
-            std::string group = std::string (data + 1, sub. size() - 1);
+        if (msg.is_join () || msg.is_leave ()) {
+            std::string group = std::string (msg.group ());
 
-            if (*data == 'J')
+            if (msg.is_join ())
                 subscriptions.insert (subscriptions_t::value_type (group, pipe_));
             else {
                 std::pair<subscriptions_t::iterator, subscriptions_t::iterator> range =
@@ -87,7 +85,7 @@ void zmq::radio_t::xread_activated (pipe_t *pipe_)
                 }
             }
         }
-        sub.close ();
+        msg.close ();
     }
 }
 
@@ -157,6 +155,52 @@ zmq::radio_session_t::~radio_session_t ()
 {
 }
 
+int zmq::radio_session_t::push_msg (msg_t *msg_)
+{
+    if (msg_->flags() & msg_t::command) {
+        char *command_data =
+            static_cast <char *> (msg_->data ());
+        const size_t data_size = msg_->size ();
+
+        int group_length;
+        char * group;
+
+        msg_t join_leave_msg;
+        int rc;
+
+        //  Set the msg type to either JOIN or LEAVE
+        if (data_size >= 5 && memcmp (command_data, "\4JOIN", 5) == 0) {
+            group_length = data_size - 5;
+            group = command_data + 5;
+            rc = join_leave_msg.init_join ();
+        }
+        else if (data_size >= 6 && memcmp (command_data, "\5LEAVE", 6) == 0) {
+            group_length = data_size - 6;
+            group = command_data + 6;
+            rc = join_leave_msg.init_leave ();
+        }
+        //  If it is not a JOIN or LEAVE just push the message
+        else
+            return session_base_t::push_msg (msg_);
+
+        errno_assert (rc == 0);
+
+        //  Set the group
+        rc = join_leave_msg.set_group (group, group_length);
+        errno_assert (rc == 0);
+
+        //  Close the current command
+        rc = msg_->close ();
+        errno_assert (rc == 0);
+
+        //  Push the join or leave command
+        *msg_ = join_leave_msg;
+        return session_base_t::push_msg (msg_);
+    }
+    else
+        return session_base_t::push_msg (msg_);
+}
+
 int zmq::radio_session_t::pull_msg (msg_t *msg_)
 {
     if (state == group) {

src/radio.hpp

@@ -87,6 +87,7 @@ namespace zmq
         ~radio_session_t ();
 
         //  Overrides of the functions from session_base_t.
+        int push_msg (msg_t *msg_);
         int pull_msg (msg_t *msg_);
         void reset ();
     private: