public static bool proxy(SocketBase frontend_,
SocketBase backend_, SocketBase capture_)
{
// The algorithm below assumes ratio of requests and replies processed
// under full load to be 1:1.
// TODO: The current implementation drops messages when
// any of the pipes becomes full.
bool success = true;
int rc;
long more;
Msg msg;
PollItem[] items = new PollItem[2];
items[0] = new PollItem (frontend_, ZMQ.ZmqPollin );
items[1] = new PollItem (backend_, ZMQ.ZmqPollin );
Selector selector;
try {
selector = Selector.open();
} catch (IOException e) {
throw new ZError.IOException(e);
}
try {
while (!Thread.currentThread().isInterrupted()) {
// Wait while there are either requests or replies to process.
rc = ZMQ.zmq_poll (selector, items, -1);
if (rc < 0)
return false;
// Process a request.
if (items [0].isReadable()) {
while (true) {
msg = frontend_.Recv (0);
if (msg == null) {
return false;
}
more = frontend_.getsockopt (ZMQ.ZMQ_RCVMORE);
if (more < 0)
return false;
// Copy message to capture socket if any
if (capture_ != null) {
Msg ctrl = new Msg (msg);
success = capture_.Send (ctrl, more > 0 ? ZMQ.ZMQ_SNDMORE: 0);
if (!success)
return false;
}
success = backend_.Send (msg, more > 0 ? ZMQ.ZMQ_SNDMORE: 0);
if (!success)
return false;
if (more == 0)
break;
}
}
// Process a reply.
if (items [1].isReadable()) {
while (true) {
msg = backend_.Recv (0);
if (msg == null) {
return false;
}
more = backend_.getsockopt (ZMQ.ZMQ_RCVMORE);
if (more < 0)
return false;
// Copy message to capture socket if any
if (capture_ != null) {
Msg ctrl = new Msg (msg);
success = capture_.Send (ctrl, more > 0 ? ZMQ.ZMQ_SNDMORE: 0);
if (!success)
return false;
}
success = frontend_.Send (msg, more > 0 ? ZMQ.ZMQ_SNDMORE: 0);
if (!success)
return false;
if (more == 0)
break;
}
}
}
} finally {
try {
selector.close();
} catch (Exception e) {
}
}
return true;
}