90 lines
3.2 KiB
Python
90 lines
3.2 KiB
Python
import asyncio
|
|
from contextlib import suppress
|
|
|
|
from twisted.internet import asyncioreactor, error
|
|
|
|
from scrapy.utils.misc import load_object
|
|
|
|
|
|
def listen_tcp(portrange, host, factory):
|
|
"""Like reactor.listenTCP but tries different ports in a range."""
|
|
from twisted.internet import reactor
|
|
if len(portrange) > 2:
|
|
raise ValueError(f"invalid portrange: {portrange}")
|
|
if not portrange:
|
|
return reactor.listenTCP(0, factory, interface=host)
|
|
if not hasattr(portrange, '__iter__'):
|
|
return reactor.listenTCP(portrange, factory, interface=host)
|
|
if len(portrange) == 1:
|
|
return reactor.listenTCP(portrange[0], factory, interface=host)
|
|
for x in range(portrange[0], portrange[1] + 1):
|
|
try:
|
|
return reactor.listenTCP(x, factory, interface=host)
|
|
except error.CannotListenError:
|
|
if x == portrange[1]:
|
|
raise
|
|
|
|
|
|
class CallLaterOnce:
|
|
"""Schedule a function to be called in the next reactor loop, but only if
|
|
it hasn't been already scheduled since the last time it ran.
|
|
"""
|
|
|
|
def __init__(self, func, *a, **kw):
|
|
self._func = func
|
|
self._a = a
|
|
self._kw = kw
|
|
self._call = None
|
|
|
|
def schedule(self, delay=0):
|
|
from twisted.internet import reactor
|
|
if self._call is None:
|
|
self._call = reactor.callLater(delay, self)
|
|
|
|
def cancel(self):
|
|
if self._call:
|
|
self._call.cancel()
|
|
|
|
def __call__(self):
|
|
self._call = None
|
|
return self._func(*self._a, **self._kw)
|
|
|
|
|
|
def install_reactor(reactor_path, event_loop_path=None):
|
|
"""Installs the :mod:`~twisted.internet.reactor` with the specified
|
|
import path. Also installs the asyncio event loop with the specified import
|
|
path if the asyncio reactor is enabled"""
|
|
reactor_class = load_object(reactor_path)
|
|
if reactor_class is asyncioreactor.AsyncioSelectorReactor:
|
|
with suppress(error.ReactorAlreadyInstalledError):
|
|
if event_loop_path is not None:
|
|
event_loop_class = load_object(event_loop_path)
|
|
event_loop = event_loop_class()
|
|
asyncio.set_event_loop(event_loop)
|
|
else:
|
|
event_loop = asyncio.get_event_loop()
|
|
asyncioreactor.install(eventloop=event_loop)
|
|
else:
|
|
*module, _ = reactor_path.split(".")
|
|
installer_path = module + ["install"]
|
|
installer = load_object(".".join(installer_path))
|
|
with suppress(error.ReactorAlreadyInstalledError):
|
|
installer()
|
|
|
|
|
|
def verify_installed_reactor(reactor_path):
|
|
"""Raises :exc:`Exception` if the installed
|
|
:mod:`~twisted.internet.reactor` does not match the specified import
|
|
path."""
|
|
from twisted.internet import reactor
|
|
reactor_class = load_object(reactor_path)
|
|
if not isinstance(reactor, reactor_class):
|
|
msg = ("The installed reactor "
|
|
f"({reactor.__module__}.{reactor.__class__.__name__}) does not "
|
|
f"match the requested one ({reactor_path})")
|
|
raise Exception(msg)
|
|
|
|
|
|
def is_asyncio_reactor_installed():
|
|
from twisted.internet import reactor
|
|
return isinstance(reactor, asyncioreactor.AsyncioSelectorReactor)
|