Future<TransportSocketPtr> TransportSocketCache::socket(const ServiceInfo& servInfo, const std::string& protocol)
{
const std::string& machineId = servInfo.machineId();
ConnectionAttemptPtr couple = boost::make_shared<ConnectionAttempt>();
couple->relatedUrls = servInfo.endpoints();
bool local = machineId == os::getMachineId();
UrlVector connectionCandidates;
// If the connection is local, we're mainly interested in localhost endpoint
if (local)
connectionCandidates = localhost_only(servInfo.endpoints());
// If the connection isn't local or if the service doesn't expose local endpoints,
// try and connect to whatever is available.
if (connectionCandidates.size() == 0)
connectionCandidates = servInfo.endpoints();
couple->endpoint = TransportSocketPtr();
couple->state = State_Pending;
{
// If we already have a pending connection to one of the urls, we return the future in question
boost::mutex::scoped_lock lock(_socketMutex);
if (_dying)
return makeFutureError<TransportSocketPtr>("TransportSocketCache is closed.");
ConnectionMap::iterator machineIt = _connections.find(machineId);
if (machineIt != _connections.end())
{
// Check if any connection to the machine matches one of our urls
UrlVector& vurls = couple->relatedUrls;
for (std::map<Url, ConnectionAttemptPtr>::iterator b = machineIt->second.begin(), e = machineIt->second.end();
b != e;
b++)
{
UrlVector::iterator uIt = std::find(vurls.begin(), vurls.end(), b->first);
// We found a matching machineId and URL : return the connected endpoint.
if (uIt != vurls.end())
return b->second->promise.future();
}
}
// Otherwise, we keep track of all those URLs and assign them the same promise in our map.
// They will all track the same connection.
couple->attemptCount = connectionCandidates.size();
std::map<Url, ConnectionAttemptPtr>& urlMap = _connections[machineId];
for (UrlVector::iterator it = connectionCandidates.begin(), end = connectionCandidates.end(); it != end; ++it)
{
urlMap[*it] = couple;
TransportSocketPtr socket = makeTransportSocket(it->protocol());
_allPendingConnections.push_back(socket);
Future<void> sockFuture = socket->connect(*it);
qiLogDebug() << "Inserted [" << machineId << "][" << it->str() << "]";
sockFuture.connect(&TransportSocketCache::onSocketParallelConnectionAttempt, this, _1, socket, *it, servInfo);
}
}
return couple->promise.future();
}
static UrlVector localhost_only(const UrlVector& input)
{
UrlVector result;
result.reserve(input.size());
for (UrlVector::const_iterator it = input.begin(), end = input.end(); it != end; ++it)
{
const std::string& host = it->host();
if (boost::algorithm::starts_with(host, "127.") || host == "localhost")
result.push_back(*it);
}
return result;
}