slixmpp/sleekxmpp/xmlstream/handler/waiter.py
2012-02-18 11:44:05 -08:00

86 lines
2.6 KiB
Python

# -*- coding: utf-8 -*-
"""
sleekxmpp.xmlstream.handler.waiter
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Part of SleekXMPP: The Sleek XMPP Library
:copyright: (c) 2011 Nathanael C. Fritz
:license: MIT, see LICENSE for more details
"""
import logging
try:
import queue
except ImportError:
import Queue as queue
from sleekxmpp.xmlstream.handler.base import BaseHandler
log = logging.getLogger(__name__)
class Waiter(BaseHandler):
"""
The Waiter handler allows an event handler to block until a
particular stanza has been received. The handler will either be
given the matched stanza, or ``False`` if the waiter has timed out.
:param string name: The name of the handler.
:param matcher: A :class:`~sleekxmpp.xmlstream.matcher.base.MatcherBase`
derived object for matching stanza objects.
:param stream: The :class:`~sleekxmpp.xmlstream.xmlstream.XMLStream`
instance this handler should monitor.
"""
def __init__(self, name, matcher, stream=None):
BaseHandler.__init__(self, name, matcher, stream=stream)
self._payload = queue.Queue()
def prerun(self, payload):
"""Store the matched stanza when received during processing.
:param payload: The matched
:class:`~sleekxmpp.xmlstream.stanzabase.ElementBase` object.
"""
self._payload.put(payload)
def run(self, payload):
"""Do not process this handler during the main event loop."""
pass
def wait(self, timeout=None):
"""Block an event handler while waiting for a stanza to arrive.
Be aware that this will impact performance if called from a
non-threaded event handler.
Will return either the received stanza, or ``False`` if the
waiter timed out.
:param int timeout: The number of seconds to wait for the stanza
to arrive. Defaults to the the stream's
:class:`~sleekxmpp.xmlstream.xmlstream.XMLStream.response_timeout`
value.
"""
if timeout is None:
timeout = self.stream().response_timeout
elapsed_time = 0
stanza = False
while elapsed_time < timeout and not self.stream().stop.is_set():
try:
stanza = self._payload.get(True, 1)
break
except queue.Empty:
elapsed_time += 1
if elapsed_time >= timeout:
log.warning("Timed out waiting for %s", self.name)
self.stream().remove_handler(self.name)
return stanza
def check_delete(self):
"""Always remove waiters after use."""
return True