From 7b27c125dc3025fe16b1f259695f7bbaa78ee9f0 Mon Sep 17 00:00:00 2001
From: Martin Hurton <hurtonm@gmail.com>
Date: Fri, 28 Jun 2013 11:24:14 +0200
Subject: [PATCH] Simplify ZMQ_STREAM socket implementation, part II

---
 src/stream.cpp | 57 ++++++++++++++++++--------------------------------
 src/stream.hpp |  3 ---
 2 files changed, 20 insertions(+), 40 deletions(-)

diff --git a/src/stream.cpp b/src/stream.cpp
index 68ab18d2..0cb7e272 100644
--- a/src/stream.cpp
+++ b/src/stream.cpp
@@ -28,7 +28,6 @@ zmq::stream_t::stream_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_),
     prefetched (false),
     identity_sent (false),
-    more_in (false),
     current_out (NULL),
     more_out (false),
     next_peer_id (generate_random ())
@@ -97,8 +96,6 @@ int zmq::stream_t::xsend (msg_t *msg_)
         //  TODO: The connections should be killed instead.
         if (msg_->flags () & msg_t::more) {
 
-            more_out = true;
-
             //  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 ());
@@ -109,18 +106,19 @@ int zmq::stream_t::xsend (msg_t *msg_)
                 if (!current_out->check_write ()) {
                     it->second.active = false;
                     current_out = NULL;
-                    more_out = false;
                     errno = EAGAIN;
                     return -1;
                 }
             }
             else {
-                more_out = false;
                 errno = EHOSTUNREACH;
                 return -1;
             }
         }
 
+        //  Expect one more message frame.
+        more_out = true;
+
         int rc = msg_->close ();
         errno_assert (rc == 0);
         rc = msg_->init ();
@@ -131,8 +129,8 @@ int zmq::stream_t::xsend (msg_t *msg_)
     //  Ignore the MORE flag
     msg_->reset_flags (msg_t::more);
 
-    //  Check whether this is the last part of the message.
-    more_out = msg_->flags () & msg_t::more ? true : false;
+    //  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) {
@@ -148,13 +146,9 @@ int zmq::stream_t::xsend (msg_t *msg_)
             return 0;
         }
         bool ok = current_out->write (msg_);
-        if (unlikely (!ok))
-            current_out = NULL;
-        else
-        if (!more_out) {
+        if (likely (ok))
             current_out->flush ();
-            current_out = NULL;
-        }
+        current_out = NULL;
     }
     else {
         int rc = msg_->close ();
@@ -181,46 +175,34 @@ int zmq::stream_t::xrecv (msg_t *msg_)
             errno_assert (rc == 0);
             prefetched = false;
         }
-        more_in = msg_->flags () & msg_t::more ? true : false;
         return 0;
     }
 
     pipe_t *pipe = NULL;
-    int rc = fq.recvpipe (msg_, &pipe);
+    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);
 
-    //  If we are in the middle of reading a message, just return the next part.
-    if (more_in)
-        more_in = msg_->flags () & msg_t::more ? true : false;
-    else {
-        //  We are at the beginning of a message.
-        //  Keep the message part we have in the prefetch buffer
-        //  and return the ID of the peer instead.
-        rc = prefetched_msg.move (*msg_);
-        errno_assert (rc == 0);
-        prefetched = true;
+    //  We have received a frame with TCP data.
+    //  Rather than sendig this frame, we keep it in prefetched
+    //  buffer and send a frame with peer's ID.
+    blob_t identity = pipe->get_identity ();
+    rc = msg_->init_size (identity.size ());
+    errno_assert (rc == 0);
+    memcpy (msg_->data (), identity.data (), identity.size ());
+    msg_->set_flags (msg_t::more);
 
-        blob_t identity = pipe->get_identity ();
-        rc = msg_->init_size (identity.size ());
-        errno_assert (rc == 0);
-        memcpy (msg_->data (), identity.data (), identity.size ());
-        msg_->set_flags (msg_t::more);
-        identity_sent = true;
-    }
+    prefetched = true;
+    identity_sent = true;
 
     return 0;
 }
 
 bool zmq::stream_t::xhas_in ()
 {
-    //  If we are in the middle of reading the messages, there are
-    //  definitely more parts available.
-    if (more_in)
-        return true;
-
     //  We may already have a message pre-fetched.
     if (prefetched)
         return true;
@@ -233,6 +215,7 @@ bool zmq::stream_t::xhas_in ()
         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 ());
diff --git a/src/stream.hpp b/src/stream.hpp
index 73e8ca21..7c8def8a 100644
--- a/src/stream.hpp
+++ b/src/stream.hpp
@@ -68,9 +68,6 @@ namespace zmq
         //  Holds the prefetched message.
         msg_t prefetched_msg;
 
-        //  If true, more incoming message parts are expected.
-        bool more_in;
-
         struct outpipe_t
         {
             zmq::pipe_t *pipe;