REQ socket implementation is layered on top of XREQ

1 files changed, 32 insertions, 211 deletions

diff --git a/src/req.cpp b/src/req.cpp
index b900961..74cce66 100644
--- a/src/req.cpp
+++ b/src/req.cpp
@@ -21,129 +21,16 @@
 
 #include "req.hpp"
 #include "err.hpp"
-#include "pipe.hpp"
 
 zmq::req_t::req_t (class ctx_t *parent_, uint32_t slot_) :
-    socket_base_t (parent_, slot_),
-    active (0),
-    current (0),
+    xreq_t (parent_, slot_),
     receiving_reply (false),
-    reply_pipe_active (false),
-    more (false),
-    reply_pipe (NULL)
+    message_begins (true)
 {
-    options.requires_in = true;
-    options.requires_out = true;
 }
 
 zmq::req_t::~req_t ()
 {
-    zmq_assert (in_pipes.empty ());
-    zmq_assert (out_pipes.empty ());
-}
-
-void zmq::req_t::xattach_pipes (reader_t *inpipe_, writer_t *outpipe_,
-    const blob_t &peer_identity_)
-{
-    zmq_assert (inpipe_ && outpipe_);
-    zmq_assert (in_pipes.size () == out_pipes.size ());
-
-    inpipe_->set_event_sink (this);
-    in_pipes.push_back (inpipe_);
-    in_pipes.swap (active, in_pipes.size () - 1);
-
-    outpipe_->set_event_sink (this);
-    out_pipes.push_back (outpipe_);
-    out_pipes.swap (active, out_pipes.size () - 1);
-
-    active++;
-}
-
-void zmq::req_t::xterm_pipes ()
-{
-    for (in_pipes_t::size_type i = 0; i != in_pipes.size (); i++)
-        in_pipes [i]->terminate ();
-    for (out_pipes_t::size_type i = 0; i != out_pipes.size (); i++)
-        out_pipes [i]->terminate ();
-}
-
-void zmq::req_t::terminated (reader_t *pipe_)
-{
-    zmq_assert (!receiving_reply || !more || reply_pipe != pipe_);
-
-    zmq_assert (pipe_);
-    zmq_assert (in_pipes.size () == out_pipes.size ());
-
-    //  TODO: The pipe we are awaiting the reply from is detached. What now?
-    if (receiving_reply && pipe_ == reply_pipe) {
-        zmq_assert (false);
-    }
-
-    in_pipes_t::size_type index = in_pipes.index (pipe_);
-
-    //  ???
-    if (!zombie) {
-        if (out_pipes [index])
-            out_pipes [index]->terminate ();
-        out_pipes.erase (index);
-    }
-
-    in_pipes.erase (index);
-
-    if (index < active) {
-        active--;
-        if (current == active)
-            current = 0;
-    }
-}
-
-void zmq::req_t::terminated (writer_t *pipe_)
-{
-    zmq_assert (receiving_reply || !more || out_pipes [current] != pipe_);
-
-    zmq_assert (pipe_);
-    zmq_assert (in_pipes.size () == out_pipes.size ());
-
-    out_pipes_t::size_type index = out_pipes.index (pipe_);
-
-    //  ???
-    if (!zombie) {
-        if (in_pipes [index])
-            in_pipes [index]->terminate ();
-        in_pipes.erase (index);
-    }
-
-    out_pipes.erase (index);
-    if (index < active) {
-        active--;
-        if (current == active)
-            current = 0;
-    }
-}
-
-bool zmq::req_t::xhas_pipes ()
-{
-    return !in_pipes.empty () || !out_pipes.empty ();
-}
-
-void zmq::req_t::activated (reader_t *pipe_)
-{
-    //  TODO: Actually, misbehaving peer can cause this kind of thing.
-    //  Handle it decently, presumably kill the offending connection.
-    zmq_assert (pipe_ == reply_pipe);
-    reply_pipe_active = true;
-}
-
-void zmq::req_t::activated (writer_t *pipe_)
-{
-    out_pipes_t::size_type index = out_pipes.index (pipe_);
-    zmq_assert (index >= active);
-
-    if (in_pipes [index] != NULL) {
-        in_pipes.swap (index, active);
-        out_pipes.swap (index, active);
-        active++;
-    }
 }
 
 int zmq::req_t::xsend (zmq_msg_t *msg_, int flags_)
@@ -155,99 +42,58 @@ int zmq::req_t::xsend (zmq_msg_t *msg_, int flags_)
         return -1;
     }
 
-    while (active > 0) {
-        if (out_pipes [current]->check_write ())
-            break;
-
-        zmq_assert (!more);
-        active--;
-        if (current < active) {
-            in_pipes.swap (current, active);
-            out_pipes.swap (current, active);
-        }
-        else
-            current = 0;
-    }
-
-    if (active == 0) {
-        errno = EAGAIN;
-        return -1;
-    }
-
-    //  If we are starting to send the request, generate a prefix.
-    if (!more) {
+    //  First part of the request is empty message part (stack bottom).
+    if (message_begins) {
         zmq_msg_t prefix;
         int rc = zmq_msg_init (&prefix);
         zmq_assert (rc == 0);
-        prefix.flags |= ZMQ_MSG_MORE;
-        bool written = out_pipes [current]->write (&prefix);
-        zmq_assert (written);
+        prefix.flags = ZMQ_MSG_MORE;
+        rc = xreq_t::xsend (&prefix, flags_);
+        if (rc != 0)
+            return rc;
+        message_begins = false;
     }
 
-    //  Push the message to the selected pipe.
-    bool written = out_pipes [current]->write (msg_);
-    zmq_assert (written);
-    more = msg_->flags & ZMQ_MSG_MORE;
-    if (!more) {
-        out_pipes [current]->flush ();
-        receiving_reply = true;
-        reply_pipe = in_pipes [current];
+    bool more = msg_->flags & ZMQ_MSG_MORE;
 
-        //  We can safely assume that the reply pipe is active as the last time
-        //  we've used it we've read the reply and haven't tried to read from it
-        //  anymore.
-        reply_pipe_active = true;
+    int rc = xreq_t::xsend (msg_, flags_);
+    if (rc != 0)
+        return rc;
 
-        //  Move to the next pipe (load-balancing).
-        current = (current + 1) % active;
+    //  If the request was fully sent, flip the FSM into reply-receiving state.
+    if (!more) {
+        receiving_reply = true;
+        message_begins = true;
     }
 
-    //  Detach the message from the data buffer.
-    int rc = zmq_msg_init (msg_);
-    zmq_assert (rc == 0);
-
     return 0;
 }
 
 int zmq::req_t::xrecv (zmq_msg_t *msg_, int flags_)
 {
-    //  Deallocate old content of the message.
-    int rc = zmq_msg_close (msg_);
-    zmq_assert (rc == 0);
-
     //  If request wasn't send, we can't wait for reply.
     if (!receiving_reply) {
-        zmq_msg_init (msg_);
         errno = EFSM;
         return -1;
     }
 
-    //  Get the reply from the reply pipe.
-    if (!reply_pipe_active || !reply_pipe->read (msg_)) {
-        reply_pipe_active = false;
-        zmq_msg_init (msg_);
-        errno = EAGAIN;
-        return -1;
-    }
-
-    //  If we are starting to receive new reply, check whether prefix
-    //  is well-formed and drop it.
-    if (!more) {
+    //  First part of the reply should be empty message part (stack bottom).
+    if (message_begins) {
+        int rc = xreq_t::xrecv (msg_, flags_);
+        if (rc != 0)
+            return rc;
         zmq_assert (msg_->flags & ZMQ_MSG_MORE);
         zmq_assert (zmq_msg_size (msg_) == 0);
-        rc = zmq_msg_close (msg_);
-        zmq_assert (rc == 0);
-
-        //  Get the actual reply.
-        bool recvd = reply_pipe->read (msg_);
-        zmq_assert (recvd);
     }
 
-    //  If this was last part of the reply, switch to request phase.
-    more = msg_->flags & ZMQ_MSG_MORE;
-    if (!more) {
+    int rc = xreq_t::xrecv (msg_, flags_);
+    if (rc != 0)
+        return rc;
+
+    //  If the reply is fully received, flip the FSM into request-sending state.
+    if (!(msg_->flags & ZMQ_MSG_MORE)) {
         receiving_reply = false;
-        reply_pipe = NULL;
+        message_begins = true;
     }
 
     return 0;
@@ -255,43 +101,18 @@ int zmq::req_t::xrecv (zmq_msg_t *msg_, int flags_)
 
 bool zmq::req_t::xhas_in ()
 {
-    if (receiving_reply && more)
-        return true;
-
-    if (!receiving_reply || !reply_pipe_active)
-        return false;
-
-    zmq_assert (reply_pipe);    
-    if (!reply_pipe->check_read ()) {
-        reply_pipe_active = false;
+    if (!receiving_reply)
         return false;
-    }
 
-    return true;
+    return xreq_t::xhas_in ();
 }
 
 bool zmq::req_t::xhas_out ()
 {
-    if (!receiving_reply && more)
-        return true;
-
     if (receiving_reply)
         return false;
 
-    while (active > 0) {
-        if (out_pipes [current]->check_write ())
-            return true;;
-
-        active--;
-        if (current < active) {
-            in_pipes.swap (current, active);
-            out_pipes.swap (current, active);
-        }
-        else
-            current = 0;
-    }
-
-    return false;
+    return xreq_t::xhas_out ();
 }