diff options
Diffstat (limited to 'sleekxmpp/plugins/xep_0198/stream_management.py')
| -rw-r--r-- | sleekxmpp/plugins/xep_0198/stream_management.py | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/sleekxmpp/plugins/xep_0198/stream_management.py b/sleekxmpp/plugins/xep_0198/stream_management.py new file mode 100644 index 00000000..6ed1ea26 --- /dev/null +++ b/sleekxmpp/plugins/xep_0198/stream_management.py @@ -0,0 +1,266 @@ +""" + SleekXMPP: The Sleek XMPP Library + Copyright (C) 2012 Nathanael C. Fritz, Lance J.T. Stout + This file is part of SleekXMPP. + + See the file LICENSE for copying permission. +""" + +import logging +import threading +import collections + +from sleekxmpp.stanza import Message, Presence, Iq, StreamFeatures +from sleekxmpp.xmlstream import register_stanza_plugin +from sleekxmpp.xmlstream.handler import Callback, Waiter +from sleekxmpp.xmlstream.matcher import MatchXPath, MatchMany +from sleekxmpp.plugins.base import BasePlugin +from sleekxmpp.plugins.xep_0198 import stanza + + +log = logging.getLogger(__name__) + + +MAX_SEQ = 2**32 + + +class XEP_0198(BasePlugin): + + """ + XEP-0198: Stream Management + """ + + name = 'xep_0198' + description = 'XEP-0198: Stream Management' + dependencies = set() + stanza = stanza + + def plugin_init(self): + """Start the XEP-0198 plugin.""" + + # Only enable stream management for non-components, + # since components do not yet perform feature negotiation. + if self.xmpp.is_component: + return + + #: The stream management ID for the stream. Knowing this value is + #: required in order to do stream resumption. + self.sm_id = self.config.get('sm_id', None) + + #: A counter of handled incoming stanzas, mod 2^32. + self.handled = self.config.get('handled', 0) + + #: A counter of unacked outgoing stanzas, mod 2^32. + self.seq = self.config.get('seq', 0) + + #: The last ack number received from the server. + self.last_ack = self.config.get('last_ack', 0) + + #: The number of stanzas to wait between sending ack requests to + #: the server. Setting this to ``1`` will send an ack request after + #: every sent stanza. Defaults to ``5``. + self.window = self.config.get('window', 5) + + #: Control whether or not the ability to resume the stream will be + #: requested when enabling stream management. Defaults to ``True``. + self.allow_resume = self.config.get('allow_resume', True) + + self.enabled = threading.Event() + self.unacked_queue = collections.deque() + + self.seq_lock = threading.Lock() + self.handled_lock = threading.Lock() + self.ack_lock = threading.Lock() + + register_stanza_plugin(StreamFeatures, stanza.StreamManagement) + self.xmpp.register_stanza(stanza.Enable) + self.xmpp.register_stanza(stanza.Enabled) + self.xmpp.register_stanza(stanza.Resume) + self.xmpp.register_stanza(stanza.Resumed) + self.xmpp.register_stanza(stanza.Ack) + self.xmpp.register_stanza(stanza.RequestAck) + + # Register the feature twice because it may be ordered two + # different ways: enabling after binding and resumption + # before binding. + self.xmpp.register_feature('sm', + self._handle_sm_feature, + restart=True, + order=self.config.get('order', 10100)) + self.xmpp.register_feature('sm', + self._handle_sm_feature, + restart=True, + order=self.config.get('resume_order', 9000)) + + self.xmpp.register_handler( + Callback('Stream Management Enabled', + MatchXPath(stanza.Enabled.tag_name()), + self._handle_enabled, + instream=True)) + + self.xmpp.register_handler( + Callback('Stream Management Resumed', + MatchXPath(stanza.Resumed.tag_name()), + self._handle_resumed, + instream=True)) + + self.xmpp.register_handler( + Callback('Stream Management Failed', + MatchXPath(stanza.Failed.tag_name()), + self._handle_failed, + instream=True)) + + self.xmpp.register_handler( + Callback('Stream Management Ack', + MatchXPath(stanza.Ack.tag_name()), + self._handle_ack, + instream=True)) + + self.xmpp.register_handler( + Callback('Stream Management Request Ack', + MatchXPath(stanza.RequestAck.tag_name()), + self._handle_request_ack, + instream=True)) + + self.xmpp.add_filter('in', self._handle_incoming) + self.xmpp.add_filter('out_sync', self._handle_outgoing) + + self.xmpp.add_event_handler('need_ack', self.request_ack) + + def send_ack(self): + """Send the current ack count to the server.""" + ack = stanza.Ack(self.xmpp) + with self.handled_lock: + ack['h'] = self.handled + ack.send() + + def request_ack(self, e=None): + """Request an ack from the server.""" + req = stanza.RequestAck(self.xmpp) + req.send() + + def _handle_sm_feature(self, features): + """ + Enable or resume stream management. + + If no SM-ID is stored, and resource binding has taken place, + stream management will be enabled. + + If an SM-ID is known, and the server allows resumption, the + previous stream will be resumed. + """ + if 'stream_management' in self.xmpp.features: + # We've already negotiated stream management, + # so no need to do it again. + return False + if not self.sm_id: + if 'bind' in self.xmpp.features: + self.enabled.set() + enable = stanza.Enable(self.xmpp) + enable['resume'] = self.allow_resume + enable.send() + self.handled = 0 + elif self.sm_id and self.allow_resume: + self.enabled.set() + resume = stanza.Resume(self.xmpp) + resume['h'] = self.handled + resume['previd'] = self.sm_id + resume.send(now=True) + + # Wait for a response before allowing stream feature processing + # to continue. The actual result processing will be done in the + # _handle_resumed() or _handle_failed() methods. + waiter = Waiter('resumed_or_failed', + MatchMany([ + MatchXPath(stanza.Resumed.tag_name()), + MatchXPath(stanza.Failed.tag_name())])) + self.xmpp.register_handler(waiter) + result = waiter.wait() + if result is not None and result.name == 'resumed': + return True + return False + + def _handle_enabled(self, stanza): + """Save the SM-ID, if provided. + + Raises an :term:`sm_enabled` event. + """ + self.xmpp.features.add('stream_management') + if stanza['id']: + self.sm_id = stanza['id'] + self.xmpp.event('sm_enabled', stanza) + + def _handle_resumed(self, stanza): + """Finish resuming a stream by resending unacked stanzas. + + Raises a :term:`session_resumed` event. + """ + self.xmpp.features.add('stream_management') + self._handle_ack(stanza) + for id, stanza in self.unacked_queue: + self.xmpp.send(stanza, now=True, use_filters=False) + self.xmpp.session_started_event.set() + self.xmpp.event('session_resumed', stanza) + + def _handle_failed(self, stanza): + """ + Disable and reset any features used since stream management was + requested (tracked stanzas may have been sent during the interval + between the enable request and the enabled response). + + Raises an :term:`sm_failed` event. + """ + self.enabled.clear() + self.unacked_queue.clear() + self.xmpp.event('sm_failed', stanza) + + def _handle_ack(self, ack): + """Process a server ack by freeing acked stanzas from the queue. + + Raises a :term:`stanza_acked` event for each acked stanza. + """ + if ack['h'] == self.last_ack: + return + + with self.ack_lock: + num_acked = (ack['h'] - self.last_ack) % MAX_SEQ + log.debug("Ack: %s, Last Ack: %s, Num Acked: %s, Unacked: %s", + ack['h'], + self.last_ack, + num_acked, + len(self.unacked_queue)) + for x in range(num_acked): + seq, stanza = self.unacked_queue.popleft() + self.xmpp.event('stanza_acked', stanza) + self.last_ack = ack['h'] + + def _handle_request_ack(self, req): + """Handle an ack request by sending an ack.""" + self.send_ack() + + def _handle_incoming(self, stanza): + """Increment the handled counter for each inbound stanza.""" + if not self.enabled.is_set(): + return stanza + + if isinstance(stanza, (Message, Presence, Iq)): + with self.handled_lock: + # Sequence numbers are mod 2^32 + self.handled = (self.handled + 1) % MAX_SEQ + return stanza + + def _handle_outgoing(self, stanza): + """Store outgoing stanzas in a queue to be acked.""" + if not self.enabled.is_set(): + return stanza + + if isinstance(stanza, (Message, Presence, Iq)): + seq = None + with self.seq_lock: + # Sequence numbers are mod 2^32 + self.seq = (self.seq + 1) % MAX_SEQ + seq = self.seq + self.unacked_queue.append((seq, stanza)) + if len(self.unacked_queue) > self.window: + self.xmpp.event('need_ack') + return stanza |