Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/scrapy/utils/reactor.py

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+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)