nats/aio/client.py
def drain(self, sid=None):
        """
        Drain will put a connection into a drain state. All subscriptions will
        immediately be put into a drain state. Upon completion, the publishers
        will be drained and can not publish any additional messages. Upon draining
        of the publishers, the connection will be closed. Use the `closed_cb'
        option to know when the connection has moved from draining to closed.

        If a sid is passed, just the subscription with that sid will be drained
        without closing the connection.
        """
        if self.is_draining:
            return
        if self.is_closed:
            raise ErrConnectionClosed
        if self.is_connecting or self.is_reconnecting:
            raise ErrConnectionReconnecting

        if sid is not None:
            return self._drain_sub(sid)

        # Start draining the subscriptions
        self._status = Client.DRAINING_SUBS

        drain_tasks = []
        for ssid, sub in self._subs.items():
            task = self._drain_sub(ssid)
            drain_tasks.append(task)

        drain_is_done = asyncio.gather(*drain_tasks)
        try:
            yield from asyncio.wait_for(drain_is_done, self.options["drain_timeout"])
        except asyncio.TimeoutError:
            drain_is_done.exception()
            drain_is_done.cancel()
            if self._error_cb is not None:
                yield from self._error_cb(ErrDrainTimeout)
        except asyncio.CancelledError:
            pass
        finally:
            self._status = Client.DRAINING_PUBS
            yield from self.flush()
            yield from self._close(Client.CLOSED)
def drain(self, sid=None):
        if self.is_draining:
            return
        if self.is_closed:
            raise ErrConnectionClosed
        if self.is_connecting or self.is_reconnecting:
            raise ErrConnectionReconnecting

        if sid is not None:
            return self._drain_sub(sid)

        # Start draining the subscriptions
        self._status = Client.DRAINING_SUBS

        drain_tasks = []
        for ssid, sub in self._subs.items():
            task = self._drain_sub(ssid)
            drain_tasks.append(task)

        drain_is_done = asyncio.gather(*drain_tasks)
        try:
            yield from asyncio.wait_for(drain_is_done, self.options["drain_timeout"])
        except asyncio.TimeoutError:
            drain_is_done.exception()
            drain_is_done.cancel()
            if self._error_cb is not None:
                yield from self._error_cb(ErrDrainTimeout)
        except asyncio.CancelledError:
            pass
        finally:
            self._status = Client.DRAINING_PUBS
            yield from self.flush()
            yield from self._close(Client.CLOSED)
def drain ( self , sid = None ) : if self . is_draining : return if self . is_closed : raise ErrConnectionClosed if self . is_connecting or self . is_reconnecting : raise ErrConnectionReconnecting if sid is not None : return self . _drain_sub ( sid ) # Start draining the subscriptions self . _status = Client . DRAINING_SUBS drain_tasks = [ ] for ssid , sub in self . _subs . items ( ) : task = self . _drain_sub ( ssid ) drain_tasks . append ( task ) drain_is_done = asyncio . gather ( * drain_tasks ) try : yield from asyncio . wait_for ( drain_is_done , self . options [ "drain_timeout" ] ) except asyncio . TimeoutError : drain_is_done . exception ( ) drain_is_done . cancel ( ) if self . _error_cb is not None : yield from self . _error_cb ( ErrDrainTimeout ) except asyncio . CancelledError : pass finally : self . _status = Client . DRAINING_PUBS yield from self . flush ( ) yield from self . _close ( Client . CLOSED )
Drain will put a connection into a drain state. All subscriptions will
        immediately be put into a drain state. Upon completion, the publishers
        will be drained and can not publish any additional messages. Upon draining
        of the publishers, the connection will be closed. Use the `closed_cb'
        option to know when the connection has moved from draining to closed.

        If a sid is passed, just the subscription with that sid will be drained
        without closing the connection.
Drain will put a connection into a drain state . All subscriptions will immediately be put into a drain state . Upon completion the publishers will be drained and can not publish any additional messages . Upon draining of the publishers the connection will be closed . Use the closed_cb option to know when the connection has moved from draining to closed .