1 files changed, 141 insertions, 0 deletions
diff --git a/src/fq.cpp b/src/fq.cpp
new file mode 100644
index 0000000..1d846df
--- /dev/null
+++ b/src/fq.cpp
@@ -0,0 +1,141 @@
+/*
+    Copyright (c) 2009-2011 250bpm s.r.o.
+    Copyright (c) 2007-2009 iMatix Corporation
+    Copyright (c) 2011 VMware, Inc.
+    Copyright (c) 2007-2011 Other contributors as noted in the AUTHORS file
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "fq.hpp"
+#include "pipe.hpp"
+#include "err.hpp"
+#include "msg.hpp"
+
+zmq::fq_t::fq_t () :
+    active (0),
+    current (0),
+    more (false)
+{
+}
+
+zmq::fq_t::~fq_t ()
+{
+    zmq_assert (pipes.empty ());
+}
+
+void zmq::fq_t::attach (pipe_t *pipe_)
+{
+    pipes.push_back (pipe_);
+    pipes.swap (active, pipes.size () - 1);
+    active++;
+}
+
+void zmq::fq_t::terminated (pipe_t *pipe_)
+{
+    const pipes_t::size_type index = pipes.index (pipe_);
+
+    //  Remove the pipe from the list; adjust number of active pipes
+    //  accordingly.
+    if (index < active) {
+        active--;
+        pipes.swap (index, active);
+        if (current == active)
+            current = 0;
+    }
+    pipes.erase (pipe_);
+}
+
+void zmq::fq_t::activated (pipe_t *pipe_)
+{
+    //  Move the pipe to the list of active pipes.
+    pipes.swap (pipes.index (pipe_), active);
+    active++;
+}
+
+int zmq::fq_t::recv (msg_t *msg_)
+{
+    return recvpipe (msg_, NULL);
+}
+
+int zmq::fq_t::recvpipe (msg_t *msg_, pipe_t **pipe_)
+{
+    //  Deallocate old content of the message.
+    int rc = msg_->close ();
+    errno_assert (rc == 0);
+
+    //  Round-robin over the pipes to get the next message.
+    while (active > 0) {
+
+        //  Try to fetch new message. If we've already read part of the message
+        //  subsequent part should be immediately available.
+        bool fetched = pipes [current]->read (msg_);
+
+        //  Note that when message is not fetched, current pipe is deactivated
+        //  and replaced by another active pipe. Thus we don't have to increase
+        //  the 'current' pointer.
+        if (fetched) {
+            if (pipe_)
+                *pipe_ = pipes [current];
+            more = msg_->flags () & msg_t::more? true: false;
+            if (!more)
+                current = (current + 1) % active;
+            return 0;
+        }
+
+        //  Check the atomicity of the message.
+        //  If we've already received the first part of the message
+        //  we should get the remaining parts without blocking.
+        zmq_assert (!more);
+
+        active--;
+        pipes.swap (current, active);
+        if (current == active)
+            current = 0;
+    }
+
+    //  No message is available. Initialise the output parameter
+    //  to be a 0-byte message.
+    rc = msg_->init ();
+    errno_assert (rc == 0);
+    errno = EAGAIN;
+    return -1;
+}
+
+bool zmq::fq_t::has_in ()
+{
+    //  There are subsequent parts of the partly-read message available.
+    if (more)
+        return true;
+
+    //  Note that messing with current doesn't break the fairness of fair
+    //  queueing algorithm. If there are no messages available current will
+    //  get back to its original value. Otherwise it'll point to the first
+    //  pipe holding messages, skipping only pipes with no messages available.
+    while (active > 0) {
+        if (pipes [current]->check_read ())
+            return true;
+
+        //  Deactivate the pipe.
+        active--;
+        pipes.swap (current, active);
+        if (current == active)
+            current = 0;
+    }
+
+    return false;
+}
+