1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
# slixmpp.xmlstream.handler.waiter
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Part of Slixmpp: The Slick XMPP Library
# :copyright: (c) 2011 Nathanael C. Fritz
# :license: MIT, see LICENSE for more details
from __future__ import annotations
import logging
from asyncio import Event, wait_for, TimeoutError
from typing import Optional, TYPE_CHECKING, Union
from xml.etree.ElementTree import Element
import slixmpp
from slixmpp.xmlstream.stanzabase import StanzaBase
from slixmpp.xmlstream.handler.base import BaseHandler
from slixmpp.xmlstream.matcher.base import MatcherBase
if TYPE_CHECKING:
from slixmpp.xmlstream.xmlstream import XMLStream
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:`~slixmpp.xmlstream.matcher.base.MatcherBase`
derived object for matching stanza objects.
:param stream: The :class:`~slixmpp.xmlstream.xmlstream.XMLStream`
instance this handler should monitor.
"""
_event: Event
def __init__(self, name: str, matcher: MatcherBase, stream: Optional[XMLStream] = None):
BaseHandler.__init__(self, name, matcher, stream=stream)
self._event = Event()
def prerun(self, payload: StanzaBase) -> None:
"""Store the matched stanza when received during processing.
:param payload: The matched
:class:`~slixmpp.xmlstream.stanzabase.StanzaBase` object.
"""
if not self._event.is_set():
self._event.set()
self._payload = payload
def run(self, payload: StanzaBase) -> None:
"""Do not process this handler during the main event loop."""
pass
async def wait(self, timeout: Optional[int] = None) -> Optional[StanzaBase]:
"""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:`~slixmpp.xmlstream.xmlstream.XMLStream.response_timeout`
value.
"""
stream_ref = self.stream
if stream_ref is None:
raise ValueError('wait() called without a stream')
stream = stream_ref()
if stream is None:
raise ValueError('wait() called without a stream')
if timeout is None:
timeout = slixmpp.xmlstream.RESPONSE_TIMEOUT
try:
await wait_for(
self._event.wait(), timeout, loop=stream.loop
)
except TimeoutError:
log.warning("Timed out waiting for %s", self.name)
stream.remove_handler(self.name)
return self._payload
def check_delete(self) -> bool:
"""Always remove waiters after use."""
return True
|
