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/*
* Copyright (C) 2013 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 3 as
* published by the Free Software Foundation.
*
* This program 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/>.
*
* Authored by: Michi Henning <michi.henning@canonical.com>
*/
#include <unity/scopes/internal/zmq_middleware/ConnectionPool.h>
#include <unity/scopes/ScopeExceptions.h>
#include <cassert>
using namespace std;
namespace unity
{
namespace scopes
{
namespace internal
{
namespace zmq_middleware
{
ConnectionPool::ConnectionPool(zmqpp::context& context)
: context_(context)
{
}
ConnectionPool::~ConnectionPool()
{
pool_.clear();
}
zmqpp::socket& ConnectionPool::find(std::string const& endpoint)
{
assert(!endpoint.empty());
// Look for existing connection.
auto const& it = pool_.find(endpoint);
if (it != pool_.end())
{
return it->second;
}
// No existing connection yet, establish one.
auto s = create_connection(endpoint);
return pool_.emplace(make_pair(endpoint, move(s))).first->second;
}
zmqpp::socket ConnectionPool::create_connection(std::string const& endpoint)
{
zmqpp::socket s(context_, zmqpp::socket_type::push);
// Allow short linger time so messages written just before we shut down
// have some chance of being sent, and we don't block indefinitely if the
// peer has gone away.
s.set(zmqpp::socket_option::linger, 50);
// We set a reconnect interval of 20 ms, so we get to the peer quickly, in case
// the peer hasn't finished binding to its endpoint yet after the first query
// is sent. We back off exponentially to one second.
// TODO: This still doesn't entirely stop the reconnection attempts that are
// made by Zmq behind the scenes. We'll have to add a garbage collection
// thread that closes outgoing connections after some idle time.
s.set(zmqpp::socket_option::reconnect_interval, 20);
s.set(zmqpp::socket_option::reconnect_interval_max, 1000);
s.connect(endpoint);
return move(s);
}
void ConnectionPool::remove(std::string const& endpoint)
{
assert(!endpoint.empty());
auto const& it = pool_.find(endpoint);
if (it != pool_.end())
{
pool_.erase(it);
}
}
void ConnectionPool::register_socket(std::string const& endpoint, zmqpp::socket socket)
{
assert(!endpoint.empty());
pool_.emplace(endpoint, move(socket));
}
} // namespace zmq_middleware
} // namespace internal
} // namespace scopes
} // namespace unity
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