mirror of https://github.com/scrapy/scrapy.git
42 lines
1.3 KiB
Python
42 lines
1.3 KiB
Python
from twisted.internet import reactor, error
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def listen_tcp(portrange, host, factory):
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"""Like reactor.listenTCP but tries different ports in a range."""
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assert len(portrange) <= 2, "invalid portrange: %s" % portrange
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if not hasattr(portrange, '__iter__'):
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return reactor.listenTCP(portrange, factory, interface=host)
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if not portrange:
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return reactor.listenTCP(0, factory, interface=host)
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if len(portrange) == 1:
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return reactor.listenTCP(portrange[0], factory, interface=host)
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for x in range(portrange[0], portrange[1]+1):
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try:
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return reactor.listenTCP(x, factory, interface=host)
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except error.CannotListenError:
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if x == portrange[1]:
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raise
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class CallLaterOnce(object):
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"""Schedule a function to be called in the next reactor loop, but only if
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it hasn't been already scheduled since the last time it run.
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"""
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def __init__(self, func, *a, **kw):
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self._func = func
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self._a = a
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self._kw = kw
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self._call = None
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def schedule(self, delay=0):
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if self._call is None:
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self._call = reactor.callLater(delay, self)
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def cancel(self):
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if self._call:
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self._call.cancel()
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def __call__(self):
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self._call = None
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return self._func(*self._a, **self._kw)
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