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+/*
+ Copyright (c) 2007-2009 FastMQ Inc.
+
+ This file is part of 0MQ.
+
+ 0MQ is free software; you can redistribute it and/or modify it under
+ the terms of the Lesser GNU 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
+ Lesser GNU General Public License for more details.
+
+ You should have received a copy of the Lesser GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "../include/zs.h"
+
+#include "load_balancer.hpp"
+#include "pipe_writer.hpp"
+#include "err.hpp"
+#include "session.hpp"
+#include "msg.hpp"
+
+zs::load_balancer_t::load_balancer_t () :
+ session (NULL),
+ current (0)
+{
+}
+
+void zs::load_balancer_t::set_session (session_t *session_)
+{
+ zs_assert (!session);
+ session = session_;
+}
+
+void zs::load_balancer_t::shutdown ()
+{
+ // No need to deallocate pipes here. They'll be deallocated during the
+ // shutdown of the dispatcher.
+ delete this;
+}
+
+void zs::load_balancer_t::terminate ()
+{
+ // Pipe unregisters itself during the call to terminate, so the pipes
+ // list shinks by one in each iteration.
+ while (!pipes.empty ())
+ pipes [0]->terminate ();
+
+ delete this;
+}
+
+zs::load_balancer_t::~load_balancer_t ()
+{
+}
+
+void zs::load_balancer_t::attach_pipe (pipe_writer_t *pipe_)
+{
+ // Associate demux with a new pipe.
+ pipe_->set_demux (this);
+ pipe_->set_index (pipes.size ());
+ pipes.push_back (pipe_);
+}
+
+void zs::load_balancer_t::detach_pipe (pipe_writer_t *pipe_)
+{
+ // Release the reference to the pipe.
+ int index = pipe_->get_index ();
+ pipe_->set_index (-1);
+ pipes [index] = pipes.back ();
+ pipes [index]->set_index (index);
+ pipes.pop_back ();
+}
+
+bool zs::load_balancer_t::empty ()
+{
+ return pipes.empty ();
+}
+
+bool zs::load_balancer_t::send (zs_msg *msg_)
+{
+ // If there are no pipes, message cannot be sent.
+ if (pipes.size () == 0)
+ return false;
+
+ // Find the first pipe that is ready to accept the message.
+ bool found = false;
+ for (pipes_t::size_type i = 0; !found && i < pipes.size (); i++) {
+// if (pipes [current]->check_write (msg))
+ found = true;
+// else
+// current = (current + 1) % pipes.size ();
+ }
+
+ // Oops, no pipe is ready to accept the message.
+ if (!found)
+ return false;
+
+ // Send the message to the selected pipe.
+ write_to_pipe (pipes [current], msg_);
+ current = (current + 1) % pipes.size ();
+
+ // Detach the original message from the data buffer.
+ zs_msg_init (msg_);
+
+ return true;
+}
+
+void zs::load_balancer_t::flush ()
+{
+ // Flush all pipes. If there's large number of pipes, it can be pretty
+ // inefficient (especially if there's new message only in a single pipe).
+ // Can it be improved?
+ for (pipes_t::iterator it = pipes.begin (); it != pipes.end (); it ++)
+ (*it)->flush ();
+}
+
+void zs::load_balancer_t::write_to_pipe (class pipe_writer_t *pipe_,
+ struct zs_msg *msg_)
+{
+ if (!pipe_->write (msg_)) {
+ // TODO: Push gap notification to the pipe.
+ zs_assert (false);
+ }
+}
+