Adapt to new draft header. Rebase dgram socket on pair socket

src/dgram.cpp

@@ -38,24 +38,18 @@
 
 zmq::dgram_t::dgram_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_),
+    pipe (NULL),
+    last_in (NULL),
     prefetched (false),
-    identity_sent (false),
-    current_out (NULL),
-    more_out (false),
-    next_rid (generate_random ())
+    more_out (false)
 {
     options.type = ZMQ_DGRAM;
     options.raw_socket = true;
-
-    prefetched_id.init ();
-    prefetched_msg.init ();
 }
 
 zmq::dgram_t::~dgram_t ()
 {
-    zmq_assert (outpipes.empty ());
-    prefetched_id.close ();
-    prefetched_msg.close ();
+    zmq_assert (!pipe);
 }
 
 void zmq::dgram_t::xattach_pipe (pipe_t *pipe_, bool subscribe_to_all_)
@@ -64,109 +58,84 @@ void zmq::dgram_t::xattach_pipe (pipe_t *pipe_, bool subscribe_to_all_)
 
     zmq_assert (pipe_);
 
-    identify_peer (pipe_);
-    fq.attach (pipe_);
+    //  ZMQ_DGRAM socket can only be connected to a single peer.
+    //  The socket rejects any further connection requests.
+    if (pipe == NULL)
+        pipe = pipe_;
+    else
+        pipe_->terminate (false);
 }
 
 void zmq::dgram_t::xpipe_terminated (pipe_t *pipe_)
 {
-    outpipes_t::iterator it = outpipes.find (pipe_->get_identity ());
-    zmq_assert (it != outpipes.end ());
-    outpipes.erase (it);
-    fq.pipe_terminated (pipe_);
-    if (pipe_ == current_out)
-        current_out = NULL;
+    if (pipe_ == pipe) {
+        if (last_in == pipe) {
+            saved_credential = last_in->get_credential ();
+            last_in = NULL;
+        }
+        pipe = NULL;
+    }
 }
 
-void zmq::dgram_t::xread_activated (pipe_t *pipe_)
+void zmq::dgram_t::xread_activated (pipe_t *)
 {
-    fq.activated (pipe_);
+    //  There's just one pipe. No lists of active and inactive pipes.
+    //  There's nothing to do here.
 }
 
-void zmq::dgram_t::xwrite_activated (pipe_t *pipe_)
+void zmq::dgram_t::xwrite_activated (pipe_t *)
 {
-    outpipes_t::iterator it;
-    for (it = outpipes.begin (); it != outpipes.end (); ++it)
-        if (it->second.pipe == pipe_)
-            break;
-
-    zmq_assert (it != outpipes.end ());
-    zmq_assert (!it->second.active);
-    it->second.active = true;
+    //  There's just one pipe. No lists of active and inactive pipes.
+    //  There's nothing to do here.
 }
 
 int zmq::dgram_t::xsend (msg_t *msg_)
 {
+    // If there's no out pipe, just drop it.
+    if (!pipe) {
+        int rc = msg_->close ();
+        errno_assert (rc == 0);
+        return -1;
+    }
+  
     //  If this is the first part of the message it's the ID of the
     //  peer to send the message to.
     if (!more_out) {
-        zmq_assert (!current_out);
-
-        //  If we have malformed message (prefix with no subsequent message)
-        //  then just silently ignore it.
-        //  TODO: The connections should be killed instead.
+        //  If we have malformed message (prefix with no subsequent message) then ignore it.
         if (msg_->flags () & msg_t::more) {
-
-            //  Find the pipe associated with the identity stored in the prefix.
-            //  If there's no such pipe return an error
-            blob_t identity ((unsigned char*) msg_->data (), msg_->size ());
-            outpipes_t::iterator it = outpipes.find (identity);
-
-            if (it != outpipes.end ()) {
-                current_out = it->second.pipe;
-                if (!current_out->check_write ()) {
-                    it->second.active = false;
-                    current_out = NULL;
-                    errno = EAGAIN;
-                    return -1;
-                }
-            }
-            else {
-                errno = EHOSTUNREACH;
-                return -1;
-            }
+            errno = EINVAL;
+            return -1;
         }
-
         //  Expect one more message frame.
         more_out = true;
-
-        int rc = msg_->close ();
-        errno_assert (rc == 0);
-        rc = msg_->init ();
-        errno_assert (rc == 0);
-        return 0;
+    }
+    else {
+        //  Ignore the MORE flag
+        msg_->reset_flags (msg_t::more);
+        //  This is the last part of the message.
+        more_out = false;
     }
 
-    //  Ignore the MORE flag
-    msg_->reset_flags (msg_t::more);
-
-    //  This is the last part of the message.
-    more_out = false;
-
-    //  Push the message into the pipe. If there's no out pipe, just drop it.
-    if (current_out) {
-
-        // Close the remote connection if user has asked to do so
-        // by sending zero length message.
-        // Pending messages in the pipe will be dropped (on receiving term- ack)
-        if (msg_->size () == 0) {
-            current_out->terminate (false);
-            int rc = msg_->close ();
-            errno_assert (rc == 0);
-            rc = msg_->init ();
-            errno_assert (rc == 0);
-            current_out = NULL;
-            return 0;
-        }
-        bool ok = current_out->write (msg_);
-        if (likely (ok))
-            current_out->flush ();
-        current_out = NULL;
+    // Close the remote connection if user has asked to do so
+    // by sending zero length message.
+    // Pending messages in the pipe will be dropped (on receiving term- ack)
+    if (msg_->size () == 0) {
+      pipe->terminate (false);
+      int rc = msg_->close ();
+      errno_assert (rc == 0);
+      rc = msg_->init ();
+      errno_assert (rc == 0);
+      pipe = NULL;
+      return 0;
     }
-    else {
-        int rc = msg_->close ();
-        errno_assert (rc == 0);
+    // Push the message into the pipe. 
+    if (!pipe->write (msg_)) {
+        errno = EAGAIN;
+        return -1;
     }
+      
+    if (!(msg_->flags () & msg_t::more))
+        pipe->flush ();
 
     //  Detach the message from the data buffer.
     int rc = msg_->init ();
@@ -175,78 +144,30 @@ int zmq::dgram_t::xsend (msg_t *msg_)
     return 0;
 }
 
-int zmq::dgram_t::xsetsockopt (int option_, const void *optval_,
-    size_t optvallen_)
+int zmq::dgram_t::xrecv (msg_t *msg_)
 {
-    bool is_int = (optvallen_ == sizeof (int));
-    int value = 0;
-    if (is_int) memcpy(&value, optval_, sizeof (int));
-
-    switch (option_) {
-        case ZMQ_CONNECT_RID:
-            if (optval_ && optvallen_) {
-                connect_rid.assign ((char*) optval_, optvallen_);
-                return 0;
-            }
-            break;
-
-        case ZMQ_STREAM_NOTIFY:
-            if (is_int && (value == 0 || value == 1)) {
-                options.raw_notify = (value != 0);
-                return 0;
-            }
-            break;
+    //  Deallocate old content of the message.
+    int rc = msg_->close ();
+    errno_assert (rc == 0);
+  
+    if (!pipe || !pipe->read (msg_)) {
+        //  Initialise the output parameter to be a 0-byte message.
+        rc = msg_->init ();
+        errno_assert (rc == 0);
 
-        default:
-            break;
+        errno = EAGAIN;
+        return -1;
     }
-    errno = EINVAL;
-    return -1;
-}
-
-int zmq::dgram_t::xrecv (msg_t *msg_)
-{
+    last_in = pipe;
+    
     if (prefetched) {
-        if (!identity_sent) {
-            int rc = msg_->move (prefetched_id);
-            errno_assert (rc == 0);
-            identity_sent = true;
-        }
-        else {
-            int rc = msg_->move (prefetched_msg);
-            errno_assert (rc == 0);
-            prefetched = false;
-        }
-        return 0;
+        msg_->reset_flags (msg_t::more);
+        prefetched = false;
+    }
+    else {
+        msg_->set_flags (msg_t::more);
+        prefetched = true;
     }
-
-    pipe_t *pipe = NULL;
-    int rc = fq.recvpipe (&prefetched_msg, &pipe);
-    if (rc != 0)
-        return -1;
-
-    zmq_assert (pipe != NULL);
-    zmq_assert ((prefetched_msg.flags () & msg_t::more) == 0);
-
-    //  We have received a frame with TCP data.
-    //  Rather than sending this frame, we keep it in prefetched
-    //  buffer and send a frame with peer's ID.
-    blob_t identity = pipe->get_identity ();
-    rc = msg_->close();
-    errno_assert (rc == 0);
-    rc = msg_->init_size (identity.size ());
-    errno_assert (rc == 0);
-
-    // forward metadata (if any)
-    metadata_t *metadata = prefetched_msg.metadata();
-    if (metadata)
-        msg_->set_metadata(metadata);
-
-    memcpy (msg_->data (), identity.data (), identity.size ());
-    msg_->set_flags (msg_t::more);
-
-    prefetched = true;
-    identity_sent = true;
 
     return 0;
 }
@@ -257,65 +178,24 @@ bool zmq::dgram_t::xhas_in ()
     if (prefetched)
         return true;
 
-    //  Try to read the next message.
-    //  The message, if read, is kept in the pre-fetch buffer.
-    pipe_t *pipe = NULL;
-    int rc = fq.recvpipe (&prefetched_msg, &pipe);
-    if (rc != 0)
+    if (!pipe)
         return false;
 
-    zmq_assert (pipe != NULL);
-    zmq_assert ((prefetched_msg.flags () & msg_t::more) == 0);
-
-    blob_t identity = pipe->get_identity ();
-    rc = prefetched_id.init_size (identity.size ());
-    errno_assert (rc == 0);
-
-    // forward metadata (if any)
-    metadata_t *metadata = prefetched_msg.metadata();
-    if (metadata)
-        prefetched_id.set_metadata(metadata);
-
-    memcpy (prefetched_id.data (), identity.data (), identity.size ());
-    prefetched_id.set_flags (msg_t::more);
-
-    prefetched = true;
-    identity_sent = false;
-
-    return true;
+    return pipe->check_read ();
 }
 
 bool zmq::dgram_t::xhas_out ()
 {
-    //  In theory, STREAM socket is always ready for writing. Whether actual
-    //  attempt to write succeeds depends on which pipe the message is going
-    //  to be routed to.
-    return true;
+    //if (more_out)
+    //    return false;
+  
+    if (!pipe)
+        return false;
+
+    return pipe->check_write ();
 }
 
-void zmq::dgram_t::identify_peer (pipe_t *pipe_)
+zmq::blob_t zmq::dgram_t::get_credential () const
 {
-    //  Always assign identity for raw-socket
-    unsigned char buffer [5];
-    buffer [0] = 0;
-    blob_t identity;
-    if (connect_rid.length ()) {
-        identity = blob_t ((unsigned char*) connect_rid.c_str(),
-            connect_rid.length ());
-        connect_rid.clear ();
-        outpipes_t::iterator it = outpipes.find (identity);
-        zmq_assert (it == outpipes.end ());
-    }
-    else {
-        put_uint32 (buffer + 1, next_rid++);
-        identity = blob_t (buffer, sizeof buffer);
-        memcpy (options.identity, identity.data (), identity.size ());
-        options.identity_size = (unsigned char) identity.size ();
-    }
-    pipe_->set_identity (identity);
-    //  Add the record into output pipes lookup table
-    outpipe_t outpipe = {pipe_, true};
-    const bool ok = outpipes.insert (
-        outpipes_t::value_type (identity, outpipe)).second;
-    zmq_assert (ok);
+    return last_in? last_in->get_credential (): saved_credential;
 }

src/dgram.hpp

@@ -30,15 +30,17 @@
 #ifndef __ZMQ_DGRAM_HPP_INCLUDED__
 #define __ZMQ_DGRAM_HPP_INCLUDED__
 
-#include <map>
-
-#include "router.hpp"
+#include "blob.hpp"
+#include "socket_base.hpp"
+#include "session_base.hpp"
 
 namespace zmq
 {
 
     class ctx_t;
+    class msg_t;
     class pipe_t;
+    class io_thread_t;
 
     class dgram_t :
         public socket_base_t
@@ -54,50 +56,25 @@ namespace zmq
         int xrecv (zmq::msg_t *msg_);
         bool xhas_in ();
         bool xhas_out ();
+        blob_t get_credential () const;
         void xread_activated (zmq::pipe_t *pipe_);
         void xwrite_activated (zmq::pipe_t *pipe_);
         void xpipe_terminated (zmq::pipe_t *pipe_);
-        int xsetsockopt (int option_, const void *optval_, size_t optvallen_);
+
     private:
-        //  Generate peer's id and update lookup map
-        void identify_peer (pipe_t *pipe_);
 
-        //  Fair queueing object for inbound pipes.
-        fq_t fq;
+        zmq::pipe_t *pipe;
+
+        zmq::pipe_t *last_in;
 
+        blob_t saved_credential;
+        
         //  True iff there is a message held in the pre-fetch buffer.
         bool prefetched;
 
-        //  If true, the receiver got the message part with
-        //  the peer's identity.
-        bool identity_sent;
-
-        //  Holds the prefetched identity.
-        msg_t prefetched_id;
-
-        //  Holds the prefetched message.
-        msg_t prefetched_msg;
-
-        struct outpipe_t
-        {
-            zmq::pipe_t *pipe;
-            bool active;
-        };
-
-        //  Outbound pipes indexed by the peer IDs.
-        typedef std::map <blob_t, outpipe_t> outpipes_t;
-        outpipes_t outpipes;
-
-        //  The pipe we are currently writing to.
-        zmq::pipe_t *current_out;
-
         //  If true, more outgoing message parts are expected.
         bool more_out;
 
-        //  Routing IDs are generated. It's a simple increment and wrap-over
-        //  algorithm. This value is the next ID to use (if not used already).
-        uint32_t next_rid;
-
         dgram_t (const dgram_t&);
         const dgram_t &operator = (const dgram_t&);
     };