def run(self):
"""
Manager's mainloop executed from within a thread.
Constantly poll for read events and, when available,
call related websockets' `once` method to
read and process the incoming data.
If the :meth:`once() <ambari_ws4py.websocket.WebSocket.once>`
method returns a `False` value, its :meth:`terminate() <ambari_ws4py.websocket.WebSocket.terminate>`
method is also applied to properly close
the websocket and its socket is unregistered from the poller.
Note that websocket shouldn't take long to process
their data or they will block the remaining
websockets with data to be handled. As for what long means,
it's up to your requirements.
"""
self.running = True
while self.running:
with self.lock:
polled = self.poller.poll()
if not self.running:
break
for fd in polled:
if not self.running:
break
ws = self.websockets.get(fd)
if ws and not ws.terminated:
# I don't know what kind of errors might spew out of here
# but they probably shouldn't crash the entire server.
try:
x = ws.once()
# Treat the error as if once() had returned None
except Exception as e:
x = None
logger.error(
"Terminating websocket %s due to exception: %s in once method"
% (format_addresses(ws), repr(e)))
if not x:
with self.lock:
self.websockets.pop(fd, None)
self.poller.unregister(fd)
if not ws.terminated:
logger.info("Terminating websocket %s" %
format_addresses(ws))
ws.terminate()
def remove(self, websocket):
"""
Remove the given ``websocket`` from the manager.
This does not call its :meth:`closed() <ambari_ws4py.websocket.WebSocket.closed>`
method as it's out-of-band by your application
or from within the manager's run loop.
"""
if websocket not in self:
return
logger.info("Removing websocket %s" % format_addresses(websocket))
with self.lock:
fd = websocket.sock.fileno()
self.websockets.pop(fd, None)
self.poller.unregister(fd)
def add(self, websocket):
"""
Manage a new websocket.
First calls its :meth:`opened() <ambari_ws4py.websocket.WebSocket.opened>`
method and register its socket against the poller
for reading events.
"""
if websocket in self:
return
logger.info("Managing websocket %s" % format_addresses(websocket))
websocket.opened()
with self.lock:
fd = websocket.sock.fileno()
self.websockets[fd] = websocket
self.poller.register(fd)
def track(self, websocket):
logger.info("Managing websocket %s" % format_addresses(websocket))
return self.spawn(websocket.run)