def __call__(self, environ, start_response):
"""
Hijack the main loop from the original thread and listen on events on the Redis
and the Websocket filedescriptors.
"""
websocket = None
subscriber = self.Subscriber(self._redis_connection)
try:
self.assure_protocol_requirements(environ)
request = WSGIRequest(environ)
if callable(private_settings.WS4REDIS_PROCESS_REQUEST):
private_settings.WS4REDIS_PROCESS_REQUEST(request)
else:
self.process_request(request)
channels, echo_message = self.process_subscriptions(request)
if callable(private_settings.WS4REDIS_ALLOWED_CHANNELS):
channels = list(private_settings.WS4REDIS_ALLOWED_CHANNELS(request, channels))
websocket = self.upgrade_websocket(environ, start_response)
logger.debug('Subscribed to channels: {0}'.format(', '.join(channels)))
subscriber.set_pubsub_channels(request, channels)
websocket_fd = websocket.get_file_descriptor()
listening_fds = [websocket_fd]
redis_fd = subscriber.get_file_descriptor()
if redis_fd:
listening_fds.append(redis_fd)
subscriber.send_persited_messages(websocket)
recvmsg = None
while websocket and not websocket.closed:
ready = self.select(listening_fds, [], [], 4.0)[0]
if not ready:
# flush empty socket
websocket.flush()
for fd in ready:
if fd == websocket_fd:
recvmsg = RedisMessage(websocket.receive())
if recvmsg:
subscriber.publish_message(recvmsg)
elif fd == redis_fd:
sendmsg = RedisMessage(subscriber.parse_response())
if sendmsg and (echo_message or sendmsg != recvmsg):
websocket.send(sendmsg)
else:
logger.error('Invalid file descriptor: {0}'.format(fd))
if private_settings.WS4REDIS_HEARTBEAT:
websocket.send(private_settings.WS4REDIS_HEARTBEAT)
except WebSocketError as excpt:
logger.warning('WebSocketError: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponse(status=1001, content='Websocket Closed')
except UpgradeRequiredError as excpt:
logger.info('Websocket upgrade required')
response = http.HttpResponseBadRequest(status=426, content=excpt)
except HandshakeError as excpt:
logger.warning('HandshakeError: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponseBadRequest(content=excpt)
except PermissionDenied as excpt:
logger.warning('PermissionDenied: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponseForbidden(content=excpt)
except Exception as excpt:
logger.error('Other Exception: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponseServerError(content=excpt)
else:
response = http.HttpResponse()
finally:
subscriber.release()
if websocket:
websocket.close(code=1001, message='Websocket Closed')
else:
logger.warning('Starting late response on websocket')
status_text = STATUS_CODE_TEXT.get(response.status_code, 'UNKNOWN STATUS CODE')
status = '{0} {1}'.format(response.status_code, status_text)
start_response(force_str(status), response._headers.values())
logger.info('Finish non-websocket response with status code: {}'.format(response.status_code))
return response
def __call__(self, environ, start_response):
"""
Hijack the main loop from the original thread and listen on events on the Redis
and the Websocket filedescriptors.
"""
websocket = None
subscriber = self.Subscriber(self._redis_connection)
try:
self.assure_protocol_requirements(environ)
request = WSGIRequest(environ)
if isinstance(private_settings.WS4REDIS_PROCESS_REQUEST, six.string_types):
import_string(private_settings.WS4REDIS_PROCESS_REQUEST)(request)
elif callable(private_settings.WS4REDIS_PROCESS_REQUEST):
private_settings.WS4REDIS_PROCESS_REQUEST(request)
else:
self.process_request(request)
channels, echo_message = self.process_subscriptions(request)
if callable(private_settings.WS4REDIS_ALLOWED_CHANNELS):
channels = list(private_settings.WS4REDIS_ALLOWED_CHANNELS(request, channels))
elif private_settings.WS4REDIS_ALLOWED_CHANNELS is not None:
try:
mod, callback = private_settings.WS4REDIS_ALLOWED_CHANNELS.rsplit('.', 1)
callback = getattr(import_module(mod), callback, None)
if callable(callback):
channels = list(callback(request, channels))
except AttributeError:
pass
websocket = self.upgrade_websocket(environ, start_response)
self._websockets.add(websocket)
logger.debug('Subscribed to channels: {0}'.format(', '.join(channels)))
subscriber.set_pubsub_channels(request, channels)
websocket_fd = websocket.get_file_descriptor()
listening_fds = [websocket_fd]
redis_fd = subscriber.get_file_descriptor()
if redis_fd:
listening_fds.append(redis_fd)
subscriber.send_persisted_messages(websocket)
recvmsg = None
while websocket and not websocket.closed:
ready = self.select(listening_fds, [], [], 4.0)[0]
if not ready:
# flush empty socket
websocket.flush()
for fd in ready:
if fd == websocket_fd:
recvmsg = RedisMessage(websocket.receive())
if recvmsg:
subscriber.publish_message(recvmsg)
elif fd == redis_fd:
while True:
parsed_msg = subscriber.parse_response()
if parsed_msg is None:
break
sendmsg = RedisMessage(parsed_msg)
if sendmsg and (echo_message or sendmsg != recvmsg):
websocket.send(sendmsg)
else:
logger.error('Invalid file descriptor: {0}'.format(fd))
# Check again that the websocket is closed before sending the heartbeat,
# because the websocket can closed previously in the loop.
if private_settings.WS4REDIS_HEARTBEAT and not websocket.closed:
websocket.send(private_settings.WS4REDIS_HEARTBEAT)
# Remove websocket from _websockets if closed
if websocket.closed:
self._websockets.remove(websocket)
except WebSocketError as excpt:
logger.warning('WebSocketError: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponse(status=1001, content='Websocket Closed')
except UpgradeRequiredError as excpt:
logger.info('Websocket upgrade required')
response = http.HttpResponseBadRequest(status=426, content=excpt)
except HandshakeError as excpt:
logger.warning('HandshakeError: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponseBadRequest(content=excpt)
except PermissionDenied as excpt:
logger.warning('PermissionDenied: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponseForbidden(content=excpt)
except Exception as excpt:
logger.error('Other Exception: {}'.format(excpt), exc_info=sys.exc_info())
response = http.HttpResponseServerError(content=excpt)
else:
response = http.HttpResponse()
finally:
subscriber.release()
if websocket:
websocket.close(code=1001, message='Websocket Closed')
else:
logger.warning('Starting late response on websocket')
status_text = http_client.responses.get(response.status_code, 'UNKNOWN STATUS CODE')
status = '{0} {1}'.format(response.status_code, status_text)
headers = response._headers.values()
if six.PY3:
headers = list(headers)
start_response(force_str(status), headers)
logger.info('Finish non-websocket response with status code: {}'.format(response.status_code))
return response