FM / dns

/usr/lib/python3.9/site-packages/dns

Name	Size	Mode	Actions
dnssecalgs/	-	0755	rm
quic/	-	0755	rm
rdtypes/	-	0755	rm
__pycache__/	-	0755	rm
asyncbackend.py	2796	0644	edit dl rm
asyncquery.py	26850	0644	edit dl rm
asyncresolver.py	17852	0644	edit dl rm
dnssec.py	40693	0644	edit dl rm
dnssectypes.py	1799	0644	edit dl rm
e164.py	3978	0644	edit dl rm
edns.py	15263	0644	edit dl rm
entropy.py	4242	0644	edit dl rm
enum.py	3691	0644	edit dl rm
exception.py	5957	0644	edit dl rm
flags.py	2750	0644	edit dl rm
grange.py	2148	0644	edit dl rm
immutable.py	2017	0644	edit dl rm
inet.py	5772	0644	edit dl rm
ipv4.py	2552	0644	edit dl rm
ipv6.py	6600	0644	edit dl rm
message.py	65993	0644	edit dl rm
name.py	42672	0644	edit dl rm
namedict.py	4000	0644	edit dl rm
nameserver.py	9909	0644	edit dl rm
node.py	12663	0644	edit dl rm
opcode.py	2730	0644	edit dl rm
query.py	54832	0644	edit dl rm
rcode.py	4156	0644	edit dl rm
rdata.py	29456	0644	edit dl rm
rdataclass.py	2984	0644	edit dl rm
rdataset.py	16756	0644	edit dl rm
rdatatype.py	7339	0644	edit dl rm
renderer.py	11254	0644	edit dl rm
resolver.py	73552	0644	edit dl rm
reversename.py	3828	0644	edit dl rm
rrset.py	9170	0644	edit dl rm
serial.py	3606	0644	edit dl rm
set.py	9088	0644	edit dl rm
tokenizer.py	23583	0644	edit dl rm
transaction.py	22636	0644	edit dl rm
tsig.py	11413	0644	edit dl rm
tsigkeyring.py	2633	0644	edit dl rm
ttl.py	2979	0644	edit dl rm
update.py	12243	0644	edit dl rm
version.py	1926	0644	edit dl rm
versioned.py	11765	0644	edit dl rm
win32util.py	9107	0644	edit dl rm
wire.py	2830	0644	edit dl rm
xfr.py	13273	0644	edit dl rm
zone.py	52086	0644	edit dl rm
zonefile.py	27929	0644	edit dl rm
zonetypes.py	690	0644	edit dl rm
_asyncbackend.py	2360	0644	edit dl rm
_asyncio_backend.py	8971	0644	edit dl rm
_ddr.py	5247	0644	edit dl rm
_features.py	2384	0644	edit dl rm
_immutable_ctx.py	2459	0644	edit dl rm
__init__.py	1663	0644	edit dl rm

Edit: /usr/lib/python3.9/site-packages/dns/asyncbackend.py (2796B)

# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license

from typing import Dict

import dns.exception

# pylint: disable=unused-import
from dns._asyncbackend import (  # noqa: F401  lgtm[py/unused-import]
    Backend,
    DatagramSocket,
    Socket,
    StreamSocket,
)

# pylint: enable=unused-import

_default_backend = None

_backends: Dict[str, Backend] = {}

# Allow sniffio import to be disabled for testing purposes
_no_sniffio = False

class AsyncLibraryNotFoundError(dns.exception.DNSException):
    pass

def get_backend(name: str) -> Backend:
    """Get the specified asynchronous backend.

*name*, a ``str``, the name of the backend.  Currently the "trio"
    and "asyncio" backends are available.

Raises NotImplementedError if an unknown backend name is specified.
    """
    # pylint: disable=import-outside-toplevel,redefined-outer-name
    backend = _backends.get(name)
    if backend:
        return backend
    if name == "trio":
        import dns._trio_backend

backend = dns._trio_backend.Backend()
    elif name == "asyncio":
        import dns._asyncio_backend

backend = dns._asyncio_backend.Backend()
    else:
        raise NotImplementedError(f"unimplemented async backend {name}")
    _backends[name] = backend
    return backend

def sniff() -> str:
    """Attempt to determine the in-use asynchronous I/O library by using
    the ``sniffio`` module if it is available.

Returns the name of the library, or raises AsyncLibraryNotFoundError
    if the library cannot be determined.
    """
    # pylint: disable=import-outside-toplevel
    try:
        if _no_sniffio:
            raise ImportError
        import sniffio

try:
            return sniffio.current_async_library()
        except sniffio.AsyncLibraryNotFoundError:
            raise AsyncLibraryNotFoundError("sniffio cannot determine async library")
    except ImportError:
        import asyncio

try:
            asyncio.get_running_loop()
            return "asyncio"
        except RuntimeError:
            raise AsyncLibraryNotFoundError("no async library detected")

def get_default_backend() -> Backend:
    """Get the default backend, initializing it if necessary."""
    if _default_backend:
        return _default_backend

return set_default_backend(sniff())

def set_default_backend(name: str) -> Backend:
    """Set the default backend.

It's not normally necessary to call this method, as
    ``get_default_backend()`` will initialize the backend
    appropriately in many cases.  If ``sniffio`` is not installed, or
    in testing situations, this function allows the backend to be set
    explicitly.
    """
    global _default_backend
    _default_backend = get_backend(name)
    return _default_backend

cmd: