# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license # This is a nullcontext for both sync and async. 3.7 has a nullcontext, # but it is only for sync use. class NullContext: def __init__(self, enter_result=None): self.enter_result = enter_result def __enter__(self): return self.enter_result def __exit__(self, exc_type, exc_value, traceback): pass async def __aenter__(self): return self.enter_result async def __aexit__(self, exc_type, exc_value, traceback): pass # These are declared here so backends can import them without creating # circular dependencies with dns.asyncbackend. class Socket: # pragma: no cover async def close(self): pass async def getpeername(self): raise NotImplementedError async def getsockname(self): raise NotImplementedError async def getpeercert(self, timeout): raise NotImplementedError async def __aenter__(self): return self async def __aexit__(self, exc_type, exc_value, traceback): await self.close() class DatagramSocket(Socket): # pragma: no cover def __init__(self, family: int): self.family = family async def sendto(self, what, destination, timeout): raise NotImplementedError async def recvfrom(self, size, timeout): raise NotImplementedError class StreamSocket(Socket): # pragma: no cover async def sendall(self, what, timeout): raise NotImplementedError async def recv(self, size, timeout): raise NotImplementedError class NullTransport: async def connect_tcp(self, host, port, timeout, local_address): raise NotImplementedError class Backend: # pragma: no cover def name(self): return "unknown" async def make_socket( self, af, socktype, proto=0, source=None, destination=None, timeout=None, ssl_context=None, server_hostname=None, ): raise NotImplementedError def datagram_connection_required(self): return False async def sleep(self, interval): raise NotImplementedError def get_transport_class(self): raise NotImplementedError async def wait_for(self, awaitable, timeout): raise NotImplementedError